[oota-llvm.git] / lib / Target / X86 / X86ISelLowering.cpp

//===-- X86ISelLowering.cpp - X86 DAG Lowering Implementation -------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines the interfaces that X86 uses to lower LLVM code into a
// selection DAG.
//
//===----------------------------------------------------------------------===//

#include "X86ISelLowering.h"
#include "Utils/X86ShuffleDecode.h"
#include "X86CallingConv.h"
#include "X86FrameLowering.h"
#include "X86InstrBuilder.h"
#include "X86MachineFunctionInfo.h"
#include "X86TargetMachine.h"
#include "X86TargetObjectFile.h"
#include "llvm/ADT/SmallBitVector.h"
#include "llvm/ADT/SmallSet.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/StringSwitch.h"
#include "llvm/ADT/VariadicFunction.h"
#include "llvm/CodeGen/IntrinsicLowering.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineJumpTableInfo.h"
#include "llvm/CodeGen/MachineModuleInfo.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/IR/CallSite.h"
#include "llvm/IR/CallingConv.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/GlobalAlias.h"
#include "llvm/IR/GlobalVariable.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/Intrinsics.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Target/TargetOptions.h"
#include "X86IntrinsicsInfo.h"
#include <bitset>
#include <numeric>
#include <cctype>
using namespace llvm;

#define DEBUG_TYPE "x86-isel"

STATISTIC(NumTailCalls, "Number of tail calls");

static cl::opt<bool> ExperimentalVectorWideningLegalization(
    "x86-experimental-vector-widening-legalization", cl::init(false),
    cl::desc("Enable an experimental vector type legalization through widening "
             "rather than promotion."),
    cl::Hidden);

static cl::opt<bool> ExperimentalVectorShuffleLowering(
    "x86-experimental-vector-shuffle-lowering", cl::init(true),
    cl::desc("Enable an experimental vector shuffle lowering code path."),
    cl::Hidden);

static cl::opt<bool> ExperimentalVectorShuffleLegality(
    "x86-experimental-vector-shuffle-legality", cl::init(false),
    cl::desc("Enable experimental shuffle legality based on the experimental "
             "shuffle lowering. Should only be used with the experimental "
             "shuffle lowering."),
    cl::Hidden);

static cl::opt<int> ReciprocalEstimateRefinementSteps(
    "x86-recip-refinement-steps", cl::init(1),
    cl::desc("Specify the number of Newton-Raphson iterations applied to the "
             "result of the hardware reciprocal estimate instruction."),
    cl::NotHidden);

// Forward declarations.
static SDValue getMOVL(SelectionDAG &DAG, SDLoc dl, EVT VT, SDValue V1,
                       SDValue V2);

static SDValue ExtractSubVector(SDValue Vec, unsigned IdxVal,
                                SelectionDAG &DAG, SDLoc dl,
                                unsigned vectorWidth) {
  assert((vectorWidth == 128 || vectorWidth == 256) &&
         "Unsupported vector width");
  EVT VT = Vec.getValueType();
  EVT ElVT = VT.getVectorElementType();
  unsigned Factor = VT.getSizeInBits()/vectorWidth;
  EVT ResultVT = EVT::getVectorVT(*DAG.getContext(), ElVT,
                                  VT.getVectorNumElements()/Factor);

  // Extract from UNDEF is UNDEF.
  if (Vec.getOpcode() == ISD::UNDEF)
    return DAG.getUNDEF(ResultVT);

  // Extract the relevant vectorWidth bits.  Generate an EXTRACT_SUBVECTOR
  unsigned ElemsPerChunk = vectorWidth / ElVT.getSizeInBits();

  // This is the index of the first element of the vectorWidth-bit chunk
  // we want.
  unsigned NormalizedIdxVal = (((IdxVal * ElVT.getSizeInBits()) / vectorWidth)
                               * ElemsPerChunk);

  // If the input is a buildvector just emit a smaller one.
  if (Vec.getOpcode() == ISD::BUILD_VECTOR)
    return DAG.getNode(ISD::BUILD_VECTOR, dl, ResultVT,
                       makeArrayRef(Vec->op_begin() + NormalizedIdxVal,
                                    ElemsPerChunk));

  SDValue VecIdx = DAG.getIntPtrConstant(NormalizedIdxVal);
  return DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, ResultVT, Vec, VecIdx);
}

/// Generate a DAG to grab 128-bits from a vector > 128 bits.  This
/// sets things up to match to an AVX VEXTRACTF128 / VEXTRACTI128
/// or AVX-512 VEXTRACTF32x4 / VEXTRACTI32x4
/// instructions or a simple subregister reference. Idx is an index in the
/// 128 bits we want.  It need not be aligned to a 128-bit boundary.  That makes
/// lowering EXTRACT_VECTOR_ELT operations easier.
static SDValue Extract128BitVector(SDValue Vec, unsigned IdxVal,
                                   SelectionDAG &DAG, SDLoc dl) {
  assert((Vec.getValueType().is256BitVector() ||
          Vec.getValueType().is512BitVector()) && "Unexpected vector size!");
  return ExtractSubVector(Vec, IdxVal, DAG, dl, 128);
}

/// Generate a DAG to grab 256-bits from a 512-bit vector.
static SDValue Extract256BitVector(SDValue Vec, unsigned IdxVal,
                                   SelectionDAG &DAG, SDLoc dl) {
  assert(Vec.getValueType().is512BitVector() && "Unexpected vector size!");
  return ExtractSubVector(Vec, IdxVal, DAG, dl, 256);
}

static SDValue InsertSubVector(SDValue Result, SDValue Vec,
                               unsigned IdxVal, SelectionDAG &DAG,
                               SDLoc dl, unsigned vectorWidth) {
  assert((vectorWidth == 128 || vectorWidth == 256) &&
         "Unsupported vector width");
  // Inserting UNDEF is Result
  if (Vec.getOpcode() == ISD::UNDEF)
    return Result;
  EVT VT = Vec.getValueType();
  EVT ElVT = VT.getVectorElementType();
  EVT ResultVT = Result.getValueType();

  // Insert the relevant vectorWidth bits.
  unsigned ElemsPerChunk = vectorWidth/ElVT.getSizeInBits();

  // This is the index of the first element of the vectorWidth-bit chunk
  // we want.
  unsigned NormalizedIdxVal = (((IdxVal * ElVT.getSizeInBits())/vectorWidth)
                               * ElemsPerChunk);

  SDValue VecIdx = DAG.getIntPtrConstant(NormalizedIdxVal);
  return DAG.getNode(ISD::INSERT_SUBVECTOR, dl, ResultVT, Result, Vec, VecIdx);
}

/// Generate a DAG to put 128-bits into a vector > 128 bits.  This
/// sets things up to match to an AVX VINSERTF128/VINSERTI128 or
/// AVX-512 VINSERTF32x4/VINSERTI32x4 instructions or a
/// simple superregister reference.  Idx is an index in the 128 bits
/// we want.  It need not be aligned to a 128-bit boundary.  That makes
/// lowering INSERT_VECTOR_ELT operations easier.
static SDValue Insert128BitVector(SDValue Result, SDValue Vec, unsigned IdxVal,
                                  SelectionDAG &DAG,SDLoc dl) {
  assert(Vec.getValueType().is128BitVector() && "Unexpected vector size!");
  return InsertSubVector(Result, Vec, IdxVal, DAG, dl, 128);
}

static SDValue Insert256BitVector(SDValue Result, SDValue Vec, unsigned IdxVal,
                                  SelectionDAG &DAG, SDLoc dl) {
  assert(Vec.getValueType().is256BitVector() && "Unexpected vector size!");
  return InsertSubVector(Result, Vec, IdxVal, DAG, dl, 256);
}

/// Concat two 128-bit vectors into a 256 bit vector using VINSERTF128
/// instructions. This is used because creating CONCAT_VECTOR nodes of
/// BUILD_VECTORS returns a larger BUILD_VECTOR while we're trying to lower
/// large BUILD_VECTORS.
static SDValue Concat128BitVectors(SDValue V1, SDValue V2, EVT VT,
                                   unsigned NumElems, SelectionDAG &DAG,
                                   SDLoc dl) {
  SDValue V = Insert128BitVector(DAG.getUNDEF(VT), V1, 0, DAG, dl);
  return Insert128BitVector(V, V2, NumElems/2, DAG, dl);
}

static SDValue Concat256BitVectors(SDValue V1, SDValue V2, EVT VT,
                                   unsigned NumElems, SelectionDAG &DAG,
                                   SDLoc dl) {
  SDValue V = Insert256BitVector(DAG.getUNDEF(VT), V1, 0, DAG, dl);
  return Insert256BitVector(V, V2, NumElems/2, DAG, dl);
}

X86TargetLowering::X86TargetLowering(const X86TargetMachine &TM,
                                     const X86Subtarget &STI)
    : TargetLowering(TM), Subtarget(&STI) {
  X86ScalarSSEf64 = Subtarget->hasSSE2();
  X86ScalarSSEf32 = Subtarget->hasSSE1();
  TD = getDataLayout();

  // Set up the TargetLowering object.
  static const MVT IntVTs[] = { MVT::i8, MVT::i16, MVT::i32, MVT::i64 };

  // X86 is weird. It always uses i8 for shift amounts and setcc results.
  setBooleanContents(ZeroOrOneBooleanContent);
  // X86-SSE is even stranger. It uses -1 or 0 for vector masks.
  setBooleanVectorContents(ZeroOrNegativeOneBooleanContent);

  // For 64-bit, since we have so many registers, use the ILP scheduler.
  // For 32-bit, use the register pressure specific scheduling.
  // For Atom, always use ILP scheduling.
  if (Subtarget->isAtom())
    setSchedulingPreference(Sched::ILP);
  else if (Subtarget->is64Bit())
    setSchedulingPreference(Sched::ILP);
  else
    setSchedulingPreference(Sched::RegPressure);
  const X86RegisterInfo *RegInfo = Subtarget->getRegisterInfo();
  setStackPointerRegisterToSaveRestore(RegInfo->getStackRegister());

  // Bypass expensive divides on Atom when compiling with O2.
  if (TM.getOptLevel() >= CodeGenOpt::Default) {
    if (Subtarget->hasSlowDivide32())
      addBypassSlowDiv(32, 8);
    if (Subtarget->hasSlowDivide64() && Subtarget->is64Bit())
      addBypassSlowDiv(64, 16);
  }

  if (Subtarget->isTargetKnownWindowsMSVC()) {
    // Setup Windows compiler runtime calls.
    setLibcallName(RTLIB::SDIV_I64, "_alldiv");
    setLibcallName(RTLIB::UDIV_I64, "_aulldiv");
    setLibcallName(RTLIB::SREM_I64, "_allrem");
    setLibcallName(RTLIB::UREM_I64, "_aullrem");
    setLibcallName(RTLIB::MUL_I64, "_allmul");
    setLibcallCallingConv(RTLIB::SDIV_I64, CallingConv::X86_StdCall);
    setLibcallCallingConv(RTLIB::UDIV_I64, CallingConv::X86_StdCall);
    setLibcallCallingConv(RTLIB::SREM_I64, CallingConv::X86_StdCall);
    setLibcallCallingConv(RTLIB::UREM_I64, CallingConv::X86_StdCall);
    setLibcallCallingConv(RTLIB::MUL_I64, CallingConv::X86_StdCall);

    // The _ftol2 runtime function has an unusual calling conv, which
    // is modeled by a special pseudo-instruction.
    setLibcallName(RTLIB::FPTOUINT_F64_I64, nullptr);
    setLibcallName(RTLIB::FPTOUINT_F32_I64, nullptr);
    setLibcallName(RTLIB::FPTOUINT_F64_I32, nullptr);
    setLibcallName(RTLIB::FPTOUINT_F32_I32, nullptr);
  }

  if (Subtarget->isTargetDarwin()) {
    // Darwin should use _setjmp/_longjmp instead of setjmp/longjmp.
    setUseUnderscoreSetJmp(false);
    setUseUnderscoreLongJmp(false);
  } else if (Subtarget->isTargetWindowsGNU()) {
    // MS runtime is weird: it exports _setjmp, but longjmp!
    setUseUnderscoreSetJmp(true);
    setUseUnderscoreLongJmp(false);
  } else {
    setUseUnderscoreSetJmp(true);
    setUseUnderscoreLongJmp(true);
  }

  // Set up the register classes.
  addRegisterClass(MVT::i8, &X86::GR8RegClass);
  addRegisterClass(MVT::i16, &X86::GR16RegClass);
  addRegisterClass(MVT::i32, &X86::GR32RegClass);
  if (Subtarget->is64Bit())
    addRegisterClass(MVT::i64, &X86::GR64RegClass);

  for (MVT VT : MVT::integer_valuetypes())
    setLoadExtAction(ISD::SEXTLOAD, VT, MVT::i1, Promote);

  // We don't accept any truncstore of integer registers.
  setTruncStoreAction(MVT::i64, MVT::i32, Expand);
  setTruncStoreAction(MVT::i64, MVT::i16, Expand);
  setTruncStoreAction(MVT::i64, MVT::i8 , Expand);
  setTruncStoreAction(MVT::i32, MVT::i16, Expand);
  setTruncStoreAction(MVT::i32, MVT::i8 , Expand);
  setTruncStoreAction(MVT::i16, MVT::i8,  Expand);

  setTruncStoreAction(MVT::f64, MVT::f32, Expand);

  // SETOEQ and SETUNE require checking two conditions.
  setCondCodeAction(ISD::SETOEQ, MVT::f32, Expand);
  setCondCodeAction(ISD::SETOEQ, MVT::f64, Expand);
  setCondCodeAction(ISD::SETOEQ, MVT::f80, Expand);
  setCondCodeAction(ISD::SETUNE, MVT::f32, Expand);
  setCondCodeAction(ISD::SETUNE, MVT::f64, Expand);
  setCondCodeAction(ISD::SETUNE, MVT::f80, Expand);

  // Promote all UINT_TO_FP to larger SINT_TO_FP's, as X86 doesn't have this
  // operation.
  setOperationAction(ISD::UINT_TO_FP       , MVT::i1   , Promote);
  setOperationAction(ISD::UINT_TO_FP       , MVT::i8   , Promote);
  setOperationAction(ISD::UINT_TO_FP       , MVT::i16  , Promote);

  if (Subtarget->is64Bit()) {
    setOperationAction(ISD::UINT_TO_FP     , MVT::i32  , Promote);
    setOperationAction(ISD::UINT_TO_FP     , MVT::i64  , Custom);
  } else if (!TM.Options.UseSoftFloat) {
    // We have an algorithm for SSE2->double, and we turn this into a
    // 64-bit FILD followed by conditional FADD for other targets.
    setOperationAction(ISD::UINT_TO_FP     , MVT::i64  , Custom);
    // We have an algorithm for SSE2, and we turn this into a 64-bit
    // FILD for other targets.
    setOperationAction(ISD::UINT_TO_FP     , MVT::i32  , Custom);
  }

  // Promote i1/i8 SINT_TO_FP to larger SINT_TO_FP's, as X86 doesn't have
  // this operation.
  setOperationAction(ISD::SINT_TO_FP       , MVT::i1   , Promote);
  setOperationAction(ISD::SINT_TO_FP       , MVT::i8   , Promote);

  if (!TM.Options.UseSoftFloat) {
    // SSE has no i16 to fp conversion, only i32
    if (X86ScalarSSEf32) {
      setOperationAction(ISD::SINT_TO_FP     , MVT::i16  , Promote);
      // f32 and f64 cases are Legal, f80 case is not
      setOperationAction(ISD::SINT_TO_FP     , MVT::i32  , Custom);
    } else {
      setOperationAction(ISD::SINT_TO_FP     , MVT::i16  , Custom);
      setOperationAction(ISD::SINT_TO_FP     , MVT::i32  , Custom);
    }
  } else {
    setOperationAction(ISD::SINT_TO_FP     , MVT::i16  , Promote);
    setOperationAction(ISD::SINT_TO_FP     , MVT::i32  , Promote);
  }

  // In 32-bit mode these are custom lowered.  In 64-bit mode F32 and F64
  // are Legal, f80 is custom lowered.
  setOperationAction(ISD::FP_TO_SINT     , MVT::i64  , Custom);
  setOperationAction(ISD::SINT_TO_FP     , MVT::i64  , Custom);

  // Promote i1/i8 FP_TO_SINT to larger FP_TO_SINTS's, as X86 doesn't have
  // this operation.
  setOperationAction(ISD::FP_TO_SINT       , MVT::i1   , Promote);
  setOperationAction(ISD::FP_TO_SINT       , MVT::i8   , Promote);

  if (X86ScalarSSEf32) {
    setOperationAction(ISD::FP_TO_SINT     , MVT::i16  , Promote);
    // f32 and f64 cases are Legal, f80 case is not
    setOperationAction(ISD::FP_TO_SINT     , MVT::i32  , Custom);
  } else {
    setOperationAction(ISD::FP_TO_SINT     , MVT::i16  , Custom);
    setOperationAction(ISD::FP_TO_SINT     , MVT::i32  , Custom);
  }

  // Handle FP_TO_UINT by promoting the destination to a larger signed
  // conversion.
  setOperationAction(ISD::FP_TO_UINT       , MVT::i1   , Promote);
  setOperationAction(ISD::FP_TO_UINT       , MVT::i8   , Promote);
  setOperationAction(ISD::FP_TO_UINT       , MVT::i16  , Promote);

  if (Subtarget->is64Bit()) {
    setOperationAction(ISD::FP_TO_UINT     , MVT::i64  , Expand);
    setOperationAction(ISD::FP_TO_UINT     , MVT::i32  , Promote);
  } else if (!TM.Options.UseSoftFloat) {
    // Since AVX is a superset of SSE3, only check for SSE here.
    if (Subtarget->hasSSE1() && !Subtarget->hasSSE3())
      // Expand FP_TO_UINT into a select.
      // FIXME: We would like to use a Custom expander here eventually to do
      // the optimal thing for SSE vs. the default expansion in the legalizer.
      setOperationAction(ISD::FP_TO_UINT   , MVT::i32  , Expand);
    else
      // With SSE3 we can use fisttpll to convert to a signed i64; without
      // SSE, we're stuck with a fistpll.
      setOperationAction(ISD::FP_TO_UINT   , MVT::i32  , Custom);
  }

  if (isTargetFTOL()) {
    // Use the _ftol2 runtime function, which has a pseudo-instruction
    // to handle its weird calling convention.
    setOperationAction(ISD::FP_TO_UINT     , MVT::i64  , Custom);
  }

  // TODO: when we have SSE, these could be more efficient, by using movd/movq.
  if (!X86ScalarSSEf64) {
    setOperationAction(ISD::BITCAST        , MVT::f32  , Expand);
    setOperationAction(ISD::BITCAST        , MVT::i32  , Expand);
    if (Subtarget->is64Bit()) {
      setOperationAction(ISD::BITCAST      , MVT::f64  , Expand);
      // Without SSE, i64->f64 goes through memory.
      setOperationAction(ISD::BITCAST      , MVT::i64  , Expand);
    }
  }

  // Scalar integer divide and remainder are lowered to use operations that
  // produce two results, to match the available instructions. This exposes
  // the two-result form to trivial CSE, which is able to combine x/y and x%y
  // into a single instruction.
  //
  // Scalar integer multiply-high is also lowered to use two-result
  // operations, to match the available instructions. However, plain multiply
  // (low) operations are left as Legal, as there are single-result
  // instructions for this in x86. Using the two-result multiply instructions
  // when both high and low results are needed must be arranged by dagcombine.
  for (unsigned i = 0; i != array_lengthof(IntVTs); ++i) {
    MVT VT = IntVTs[i];
    setOperationAction(ISD::MULHS, VT, Expand);
    setOperationAction(ISD::MULHU, VT, Expand);
    setOperationAction(ISD::SDIV, VT, Expand);
    setOperationAction(ISD::UDIV, VT, Expand);
    setOperationAction(ISD::SREM, VT, Expand);
    setOperationAction(ISD::UREM, VT, Expand);

    // Add/Sub overflow ops with MVT::Glues are lowered to EFLAGS dependences.
    setOperationAction(ISD::ADDC, VT, Custom);
    setOperationAction(ISD::ADDE, VT, Custom);
    setOperationAction(ISD::SUBC, VT, Custom);
    setOperationAction(ISD::SUBE, VT, Custom);
  }

  setOperationAction(ISD::BR_JT            , MVT::Other, Expand);
  setOperationAction(ISD::BRCOND           , MVT::Other, Custom);
  setOperationAction(ISD::BR_CC            , MVT::f32,   Expand);
  setOperationAction(ISD::BR_CC            , MVT::f64,   Expand);
  setOperationAction(ISD::BR_CC            , MVT::f80,   Expand);
  setOperationAction(ISD::BR_CC            , MVT::i8,    Expand);
  setOperationAction(ISD::BR_CC            , MVT::i16,   Expand);
  setOperationAction(ISD::BR_CC            , MVT::i32,   Expand);
  setOperationAction(ISD::BR_CC            , MVT::i64,   Expand);
  setOperationAction(ISD::SELECT_CC        , MVT::f32,   Expand);
  setOperationAction(ISD::SELECT_CC        , MVT::f64,   Expand);
  setOperationAction(ISD::SELECT_CC        , MVT::f80,   Expand);
  setOperationAction(ISD::SELECT_CC        , MVT::i8,    Expand);
  setOperationAction(ISD::SELECT_CC        , MVT::i16,   Expand);
  setOperationAction(ISD::SELECT_CC        , MVT::i32,   Expand);
  setOperationAction(ISD::SELECT_CC        , MVT::i64,   Expand);
  if (Subtarget->is64Bit())
    setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i32, Legal);
  setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i16  , Legal);
  setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i8   , Legal);
  setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i1   , Expand);
  setOperationAction(ISD::FP_ROUND_INREG   , MVT::f32  , Expand);
  setOperationAction(ISD::FREM             , MVT::f32  , Expand);
  setOperationAction(ISD::FREM             , MVT::f64  , Expand);
  setOperationAction(ISD::FREM             , MVT::f80  , Expand);
  setOperationAction(ISD::FLT_ROUNDS_      , MVT::i32  , Custom);

  // Promote the i8 variants and force them on up to i32 which has a shorter
  // encoding.
  setOperationAction(ISD::CTTZ             , MVT::i8   , Promote);
  AddPromotedToType (ISD::CTTZ             , MVT::i8   , MVT::i32);
  setOperationAction(ISD::CTTZ_ZERO_UNDEF  , MVT::i8   , Promote);
  AddPromotedToType (ISD::CTTZ_ZERO_UNDEF  , MVT::i8   , MVT::i32);
  if (Subtarget->hasBMI()) {
    setOperationAction(ISD::CTTZ_ZERO_UNDEF, MVT::i16  , Expand);
    setOperationAction(ISD::CTTZ_ZERO_UNDEF, MVT::i32  , Expand);
    if (Subtarget->is64Bit())
      setOperationAction(ISD::CTTZ_ZERO_UNDEF, MVT::i64, Expand);
  } else {
    setOperationAction(ISD::CTTZ           , MVT::i16  , Custom);
    setOperationAction(ISD::CTTZ           , MVT::i32  , Custom);
    if (Subtarget->is64Bit())
      setOperationAction(ISD::CTTZ         , MVT::i64  , Custom);
  }

  if (Subtarget->hasLZCNT()) {
    // When promoting the i8 variants, force them to i32 for a shorter
    // encoding.
    setOperationAction(ISD::CTLZ           , MVT::i8   , Promote);
    AddPromotedToType (ISD::CTLZ           , MVT::i8   , MVT::i32);
    setOperationAction(ISD::CTLZ_ZERO_UNDEF, MVT::i8   , Promote);
    AddPromotedToType (ISD::CTLZ_ZERO_UNDEF, MVT::i8   , MVT::i32);
    setOperationAction(ISD::CTLZ_ZERO_UNDEF, MVT::i16  , Expand);
    setOperationAction(ISD::CTLZ_ZERO_UNDEF, MVT::i32  , Expand);
    if (Subtarget->is64Bit())
      setOperationAction(ISD::CTLZ_ZERO_UNDEF, MVT::i64, Expand);
  } else {
    setOperationAction(ISD::CTLZ           , MVT::i8   , Custom);
    setOperationAction(ISD::CTLZ           , MVT::i16  , Custom);
    setOperationAction(ISD::CTLZ           , MVT::i32  , Custom);
    setOperationAction(ISD::CTLZ_ZERO_UNDEF, MVT::i8   , Custom);
    setOperationAction(ISD::CTLZ_ZERO_UNDEF, MVT::i16  , Custom);
    setOperationAction(ISD::CTLZ_ZERO_UNDEF, MVT::i32  , Custom);
    if (Subtarget->is64Bit()) {
      setOperationAction(ISD::CTLZ         , MVT::i64  , Custom);
      setOperationAction(ISD::CTLZ_ZERO_UNDEF, MVT::i64, Custom);
    }
  }

  // Special handling for half-precision floating point conversions.
  // If we don't have F16C support, then lower half float conversions
  // into library calls.
  if (TM.Options.UseSoftFloat || !Subtarget->hasF16C()) {
    setOperationAction(ISD::FP16_TO_FP, MVT::f32, Expand);
    setOperationAction(ISD::FP_TO_FP16, MVT::f32, Expand);
  }

  // There's never any support for operations beyond MVT::f32.
  setOperationAction(ISD::FP16_TO_FP, MVT::f64, Expand);
  setOperationAction(ISD::FP16_TO_FP, MVT::f80, Expand);
  setOperationAction(ISD::FP_TO_FP16, MVT::f64, Expand);
  setOperationAction(ISD::FP_TO_FP16, MVT::f80, Expand);

  setLoadExtAction(ISD::EXTLOAD, MVT::f32, MVT::f16, Expand);
  setLoadExtAction(ISD::EXTLOAD, MVT::f64, MVT::f16, Expand);
  setLoadExtAction(ISD::EXTLOAD, MVT::f80, MVT::f16, Expand);
  setTruncStoreAction(MVT::f32, MVT::f16, Expand);
  setTruncStoreAction(MVT::f64, MVT::f16, Expand);
  setTruncStoreAction(MVT::f80, MVT::f16, Expand);

  if (Subtarget->hasPOPCNT()) {
    setOperationAction(ISD::CTPOP          , MVT::i8   , Promote);
  } else {
    setOperationAction(ISD::CTPOP          , MVT::i8   , Expand);
    setOperationAction(ISD::CTPOP          , MVT::i16  , Expand);
    setOperationAction(ISD::CTPOP          , MVT::i32  , Expand);
    if (Subtarget->is64Bit())
      setOperationAction(ISD::CTPOP        , MVT::i64  , Expand);
  }

  setOperationAction(ISD::READCYCLECOUNTER , MVT::i64  , Custom);

  if (!Subtarget->hasMOVBE())
    setOperationAction(ISD::BSWAP          , MVT::i16  , Expand);

  // These should be promoted to a larger select which is supported.
  setOperationAction(ISD::SELECT          , MVT::i1   , Promote);
  // X86 wants to expand cmov itself.
  setOperationAction(ISD::SELECT          , MVT::i8   , Custom);
  setOperationAction(ISD::SELECT          , MVT::i16  , Custom);
  setOperationAction(ISD::SELECT          , MVT::i32  , Custom);
  setOperationAction(ISD::SELECT          , MVT::f32  , Custom);
  setOperationAction(ISD::SELECT          , MVT::f64  , Custom);
  setOperationAction(ISD::SELECT          , MVT::f80  , Custom);
  setOperationAction(ISD::SETCC           , MVT::i8   , Custom);
  setOperationAction(ISD::SETCC           , MVT::i16  , Custom);
  setOperationAction(ISD::SETCC           , MVT::i32  , Custom);
  setOperationAction(ISD::SETCC           , MVT::f32  , Custom);
  setOperationAction(ISD::SETCC           , MVT::f64  , Custom);
  setOperationAction(ISD::SETCC           , MVT::f80  , Custom);
  if (Subtarget->is64Bit()) {
    setOperationAction(ISD::SELECT        , MVT::i64  , Custom);
    setOperationAction(ISD::SETCC         , MVT::i64  , Custom);
  }
  setOperationAction(ISD::EH_RETURN       , MVT::Other, Custom);
  // NOTE: EH_SJLJ_SETJMP/_LONGJMP supported here is NOT intended to support
  // SjLj exception handling but a light-weight setjmp/longjmp replacement to
  // support continuation, user-level threading, and etc.. As a result, no
  // other SjLj exception interfaces are implemented and please don't build
  // your own exception handling based on them.
  // LLVM/Clang supports zero-cost DWARF exception handling.
  setOperationAction(ISD::EH_SJLJ_SETJMP, MVT::i32, Custom);
  setOperationAction(ISD::EH_SJLJ_LONGJMP, MVT::Other, Custom);

  // Darwin ABI issue.
  setOperationAction(ISD::ConstantPool    , MVT::i32  , Custom);
  setOperationAction(ISD::JumpTable       , MVT::i32  , Custom);
  setOperationAction(ISD::GlobalAddress   , MVT::i32  , Custom);
  setOperationAction(ISD::GlobalTLSAddress, MVT::i32  , Custom);
  if (Subtarget->is64Bit())
    setOperationAction(ISD::GlobalTLSAddress, MVT::i64, Custom);
  setOperationAction(ISD::ExternalSymbol  , MVT::i32  , Custom);
  setOperationAction(ISD::BlockAddress    , MVT::i32  , Custom);
  if (Subtarget->is64Bit()) {
    setOperationAction(ISD::ConstantPool  , MVT::i64  , Custom);
    setOperationAction(ISD::JumpTable     , MVT::i64  , Custom);
    setOperationAction(ISD::GlobalAddress , MVT::i64  , Custom);
    setOperationAction(ISD::ExternalSymbol, MVT::i64  , Custom);
    setOperationAction(ISD::BlockAddress  , MVT::i64  , Custom);
  }
  // 64-bit addm sub, shl, sra, srl (iff 32-bit x86)
  setOperationAction(ISD::SHL_PARTS       , MVT::i32  , Custom);
  setOperationAction(ISD::SRA_PARTS       , MVT::i32  , Custom);
  setOperationAction(ISD::SRL_PARTS       , MVT::i32  , Custom);
  if (Subtarget->is64Bit()) {
    setOperationAction(ISD::SHL_PARTS     , MVT::i64  , Custom);
    setOperationAction(ISD::SRA_PARTS     , MVT::i64  , Custom);
    setOperationAction(ISD::SRL_PARTS     , MVT::i64  , Custom);
  }

  if (Subtarget->hasSSE1())
    setOperationAction(ISD::PREFETCH      , MVT::Other, Legal);

  setOperationAction(ISD::ATOMIC_FENCE  , MVT::Other, Custom);

  // Expand certain atomics
  for (unsigned i = 0; i != array_lengthof(IntVTs); ++i) {
    MVT VT = IntVTs[i];
    setOperationAction(ISD::ATOMIC_CMP_SWAP_WITH_SUCCESS, VT, Custom);
    setOperationAction(ISD::ATOMIC_LOAD_SUB, VT, Custom);
    setOperationAction(ISD::ATOMIC_STORE, VT, Custom);
  }

  if (Subtarget->hasCmpxchg16b()) {
    setOperationAction(ISD::ATOMIC_CMP_SWAP_WITH_SUCCESS, MVT::i128, Custom);
  }

  // FIXME - use subtarget debug flags
  if (!Subtarget->isTargetDarwin() && !Subtarget->isTargetELF() &&
      !Subtarget->isTargetCygMing() && !Subtarget->isTargetWin64()) {
    setOperationAction(ISD::EH_LABEL, MVT::Other, Expand);
  }

  if (Subtarget->is64Bit()) {
    setExceptionPointerRegister(X86::RAX);
    setExceptionSelectorRegister(X86::RDX);
  } else {
    setExceptionPointerRegister(X86::EAX);
    setExceptionSelectorRegister(X86::EDX);
  }
  setOperationAction(ISD::FRAME_TO_ARGS_OFFSET, MVT::i32, Custom);
  setOperationAction(ISD::FRAME_TO_ARGS_OFFSET, MVT::i64, Custom);

  setOperationAction(ISD::INIT_TRAMPOLINE, MVT::Other, Custom);
  setOperationAction(ISD::ADJUST_TRAMPOLINE, MVT::Other, Custom);

  setOperationAction(ISD::TRAP, MVT::Other, Legal);
  setOperationAction(ISD::DEBUGTRAP, MVT::Other, Legal);

  // VASTART needs to be custom lowered to use the VarArgsFrameIndex
  setOperationAction(ISD::VASTART           , MVT::Other, Custom);
  setOperationAction(ISD::VAEND             , MVT::Other, Expand);
  if (Subtarget->is64Bit() && !Subtarget->isTargetWin64()) {
    // TargetInfo::X86_64ABIBuiltinVaList
    setOperationAction(ISD::VAARG           , MVT::Other, Custom);
    setOperationAction(ISD::VACOPY          , MVT::Other, Custom);
  } else {
    // TargetInfo::CharPtrBuiltinVaList
    setOperationAction(ISD::VAARG           , MVT::Other, Expand);
    setOperationAction(ISD::VACOPY          , MVT::Other, Expand);
  }

  setOperationAction(ISD::STACKSAVE,          MVT::Other, Expand);
  setOperationAction(ISD::STACKRESTORE,       MVT::Other, Expand);

  setOperationAction(ISD::DYNAMIC_STACKALLOC, getPointerTy(), Custom);

  if (!TM.Options.UseSoftFloat && X86ScalarSSEf64) {
    // f32 and f64 use SSE.
    // Set up the FP register classes.
    addRegisterClass(MVT::f32, &X86::FR32RegClass);
    addRegisterClass(MVT::f64, &X86::FR64RegClass);

    // Use ANDPD to simulate FABS.
    setOperationAction(ISD::FABS , MVT::f64, Custom);
    setOperationAction(ISD::FABS , MVT::f32, Custom);

    // Use XORP to simulate FNEG.
    setOperationAction(ISD::FNEG , MVT::f64, Custom);
    setOperationAction(ISD::FNEG , MVT::f32, Custom);

    // Use ANDPD and ORPD to simulate FCOPYSIGN.
    setOperationAction(ISD::FCOPYSIGN, MVT::f64, Custom);
    setOperationAction(ISD::FCOPYSIGN, MVT::f32, Custom);

    // Lower this to FGETSIGNx86 plus an AND.
    setOperationAction(ISD::FGETSIGN, MVT::i64, Custom);
    setOperationAction(ISD::FGETSIGN, MVT::i32, Custom);

    // We don't support sin/cos/fmod
    setOperationAction(ISD::FSIN   , MVT::f64, Expand);
    setOperationAction(ISD::FCOS   , MVT::f64, Expand);
    setOperationAction(ISD::FSINCOS, MVT::f64, Expand);
    setOperationAction(ISD::FSIN   , MVT::f32, Expand);
    setOperationAction(ISD::FCOS   , MVT::f32, Expand);
    setOperationAction(ISD::FSINCOS, MVT::f32, Expand);

    // Expand FP immediates into loads from the stack, except for the special
    // cases we handle.
    addLegalFPImmediate(APFloat(+0.0)); // xorpd
    addLegalFPImmediate(APFloat(+0.0f)); // xorps
  } else if (!TM.Options.UseSoftFloat && X86ScalarSSEf32) {
    // Use SSE for f32, x87 for f64.
    // Set up the FP register classes.
    addRegisterClass(MVT::f32, &X86::FR32RegClass);
    addRegisterClass(MVT::f64, &X86::RFP64RegClass);

    // Use ANDPS to simulate FABS.
    setOperationAction(ISD::FABS , MVT::f32, Custom);

    // Use XORP to simulate FNEG.
    setOperationAction(ISD::FNEG , MVT::f32, Custom);

    setOperationAction(ISD::UNDEF,     MVT::f64, Expand);

    // Use ANDPS and ORPS to simulate FCOPYSIGN.
    setOperationAction(ISD::FCOPYSIGN, MVT::f64, Expand);
    setOperationAction(ISD::FCOPYSIGN, MVT::f32, Custom);

    // We don't support sin/cos/fmod
    setOperationAction(ISD::FSIN   , MVT::f32, Expand);
    setOperationAction(ISD::FCOS   , MVT::f32, Expand);
    setOperationAction(ISD::FSINCOS, MVT::f32, Expand);

    // Special cases we handle for FP constants.
    addLegalFPImmediate(APFloat(+0.0f)); // xorps
    addLegalFPImmediate(APFloat(+0.0)); // FLD0
    addLegalFPImmediate(APFloat(+1.0)); // FLD1
    addLegalFPImmediate(APFloat(-0.0)); // FLD0/FCHS
    addLegalFPImmediate(APFloat(-1.0)); // FLD1/FCHS

    if (!TM.Options.UnsafeFPMath) {
      setOperationAction(ISD::FSIN   , MVT::f64, Expand);
      setOperationAction(ISD::FCOS   , MVT::f64, Expand);
      setOperationAction(ISD::FSINCOS, MVT::f64, Expand);
    }
  } else if (!TM.Options.UseSoftFloat) {
    // f32 and f64 in x87.
    // Set up the FP register classes.
    addRegisterClass(MVT::f64, &X86::RFP64RegClass);
    addRegisterClass(MVT::f32, &X86::RFP32RegClass);

    setOperationAction(ISD::UNDEF,     MVT::f64, Expand);
    setOperationAction(ISD::UNDEF,     MVT::f32, Expand);
    setOperationAction(ISD::FCOPYSIGN, MVT::f64, Expand);
    setOperationAction(ISD::FCOPYSIGN, MVT::f32, Expand);

    if (!TM.Options.UnsafeFPMath) {
      setOperationAction(ISD::FSIN   , MVT::f64, Expand);
      setOperationAction(ISD::FSIN   , MVT::f32, Expand);
      setOperationAction(ISD::FCOS   , MVT::f64, Expand);
      setOperationAction(ISD::FCOS   , MVT::f32, Expand);
      setOperationAction(ISD::FSINCOS, MVT::f64, Expand);
      setOperationAction(ISD::FSINCOS, MVT::f32, Expand);
    }
    addLegalFPImmediate(APFloat(+0.0)); // FLD0
    addLegalFPImmediate(APFloat(+1.0)); // FLD1
    addLegalFPImmediate(APFloat(-0.0)); // FLD0/FCHS
    addLegalFPImmediate(APFloat(-1.0)); // FLD1/FCHS
    addLegalFPImmediate(APFloat(+0.0f)); // FLD0
    addLegalFPImmediate(APFloat(+1.0f)); // FLD1
    addLegalFPImmediate(APFloat(-0.0f)); // FLD0/FCHS
    addLegalFPImmediate(APFloat(-1.0f)); // FLD1/FCHS
  }

  // We don't support FMA.
  setOperationAction(ISD::FMA, MVT::f64, Expand);
  setOperationAction(ISD::FMA, MVT::f32, Expand);

  // Long double always uses X87.
  if (!TM.Options.UseSoftFloat) {
    addRegisterClass(MVT::f80, &X86::RFP80RegClass);
    setOperationAction(ISD::UNDEF,     MVT::f80, Expand);
    setOperationAction(ISD::FCOPYSIGN, MVT::f80, Expand);
    {
      APFloat TmpFlt = APFloat::getZero(APFloat::x87DoubleExtended);
      addLegalFPImmediate(TmpFlt);  // FLD0
      TmpFlt.changeSign();
      addLegalFPImmediate(TmpFlt);  // FLD0/FCHS

      bool ignored;
      APFloat TmpFlt2(+1.0);
      TmpFlt2.convert(APFloat::x87DoubleExtended, APFloat::rmNearestTiesToEven,
                      &ignored);
      addLegalFPImmediate(TmpFlt2);  // FLD1
      TmpFlt2.changeSign();
      addLegalFPImmediate(TmpFlt2);  // FLD1/FCHS
    }

    if (!TM.Options.UnsafeFPMath) {
      setOperationAction(ISD::FSIN   , MVT::f80, Expand);
      setOperationAction(ISD::FCOS   , MVT::f80, Expand);
      setOperationAction(ISD::FSINCOS, MVT::f80, Expand);
    }

    setOperationAction(ISD::FFLOOR, MVT::f80, Expand);
    setOperationAction(ISD::FCEIL,  MVT::f80, Expand);
    setOperationAction(ISD::FTRUNC, MVT::f80, Expand);
    setOperationAction(ISD::FRINT,  MVT::f80, Expand);
    setOperationAction(ISD::FNEARBYINT, MVT::f80, Expand);
    setOperationAction(ISD::FMA, MVT::f80, Expand);
  }

  // Always use a library call for pow.
  setOperationAction(ISD::FPOW             , MVT::f32  , Expand);
  setOperationAction(ISD::FPOW             , MVT::f64  , Expand);
  setOperationAction(ISD::FPOW             , MVT::f80  , Expand);

  setOperationAction(ISD::FLOG, MVT::f80, Expand);
  setOperationAction(ISD::FLOG2, MVT::f80, Expand);
  setOperationAction(ISD::FLOG10, MVT::f80, Expand);
  setOperationAction(ISD::FEXP, MVT::f80, Expand);
  setOperationAction(ISD::FEXP2, MVT::f80, Expand);
  setOperationAction(ISD::FMINNUM, MVT::f80, Expand);
  setOperationAction(ISD::FMAXNUM, MVT::f80, Expand);

  // First set operation action for all vector types to either promote
  // (for widening) or expand (for scalarization). Then we will selectively
  // turn on ones that can be effectively codegen'd.
  for (MVT VT : MVT::vector_valuetypes()) {
    setOperationAction(ISD::ADD , VT, Expand);
    setOperationAction(ISD::SUB , VT, Expand);
    setOperationAction(ISD::FADD, VT, Expand);
    setOperationAction(ISD::FNEG, VT, Expand);
    setOperationAction(ISD::FSUB, VT, Expand);
    setOperationAction(ISD::MUL , VT, Expand);
    setOperationAction(ISD::FMUL, VT, Expand);
    setOperationAction(ISD::SDIV, VT, Expand);
    setOperationAction(ISD::UDIV, VT, Expand);
    setOperationAction(ISD::FDIV, VT, Expand);
    setOperationAction(ISD::SREM, VT, Expand);
    setOperationAction(ISD::UREM, VT, Expand);
    setOperationAction(ISD::LOAD, VT, Expand);
    setOperationAction(ISD::VECTOR_SHUFFLE, VT, Expand);
    setOperationAction(ISD::EXTRACT_VECTOR_ELT, VT,Expand);
    setOperationAction(ISD::INSERT_VECTOR_ELT, VT, Expand);
    setOperationAction(ISD::EXTRACT_SUBVECTOR, VT,Expand);
    setOperationAction(ISD::INSERT_SUBVECTOR, VT,Expand);
    setOperationAction(ISD::FABS, VT, Expand);
    setOperationAction(ISD::FSIN, VT, Expand);
    setOperationAction(ISD::FSINCOS, VT, Expand);
    setOperationAction(ISD::FCOS, VT, Expand);
    setOperationAction(ISD::FSINCOS, VT, Expand);
    setOperationAction(ISD::FREM, VT, Expand);
    setOperationAction(ISD::FMA,  VT, Expand);
    setOperationAction(ISD::FPOWI, VT, Expand);
    setOperationAction(ISD::FSQRT, VT, Expand);
    setOperationAction(ISD::FCOPYSIGN, VT, Expand);
    setOperationAction(ISD::FFLOOR, VT, Expand);
    setOperationAction(ISD::FCEIL, VT, Expand);
    setOperationAction(ISD::FTRUNC, VT, Expand);
    setOperationAction(ISD::FRINT, VT, Expand);
    setOperationAction(ISD::FNEARBYINT, VT, Expand);
    setOperationAction(ISD::SMUL_LOHI, VT, Expand);
    setOperationAction(ISD::MULHS, VT, Expand);
    setOperationAction(ISD::UMUL_LOHI, VT, Expand);
    setOperationAction(ISD::MULHU, VT, Expand);
    setOperationAction(ISD::SDIVREM, VT, Expand);
    setOperationAction(ISD::UDIVREM, VT, Expand);
    setOperationAction(ISD::FPOW, VT, Expand);
    setOperationAction(ISD::CTPOP, VT, Expand);
    setOperationAction(ISD::CTTZ, VT, Expand);
    setOperationAction(ISD::CTTZ_ZERO_UNDEF, VT, Expand);
    setOperationAction(ISD::CTLZ, VT, Expand);
    setOperationAction(ISD::CTLZ_ZERO_UNDEF, VT, Expand);
    setOperationAction(ISD::SHL, VT, Expand);
    setOperationAction(ISD::SRA, VT, Expand);
    setOperationAction(ISD::SRL, VT, Expand);
    setOperationAction(ISD::ROTL, VT, Expand);
    setOperationAction(ISD::ROTR, VT, Expand);
    setOperationAction(ISD::BSWAP, VT, Expand);
    setOperationAction(ISD::SETCC, VT, Expand);
    setOperationAction(ISD::FLOG, VT, Expand);
    setOperationAction(ISD::FLOG2, VT, Expand);
    setOperationAction(ISD::FLOG10, VT, Expand);
    setOperationAction(ISD::FEXP, VT, Expand);
    setOperationAction(ISD::FEXP2, VT, Expand);
    setOperationAction(ISD::FP_TO_UINT, VT, Expand);
    setOperationAction(ISD::FP_TO_SINT, VT, Expand);
    setOperationAction(ISD::UINT_TO_FP, VT, Expand);
    setOperationAction(ISD::SINT_TO_FP, VT, Expand);
    setOperationAction(ISD::SIGN_EXTEND_INREG, VT,Expand);
    setOperationAction(ISD::TRUNCATE, VT, Expand);
    setOperationAction(ISD::SIGN_EXTEND, VT, Expand);
    setOperationAction(ISD::ZERO_EXTEND, VT, Expand);
    setOperationAction(ISD::ANY_EXTEND, VT, Expand);
    setOperationAction(ISD::VSELECT, VT, Expand);
    setOperationAction(ISD::SELECT_CC, VT, Expand);
    for (MVT InnerVT : MVT::vector_valuetypes()) {
      setTruncStoreAction(InnerVT, VT, Expand);

      setLoadExtAction(ISD::SEXTLOAD, InnerVT, VT, Expand);
      setLoadExtAction(ISD::ZEXTLOAD, InnerVT, VT, Expand);

      // N.b. ISD::EXTLOAD legality is basically ignored except for i1-like
      // types, we have to deal with them whether we ask for Expansion or not.
      // Setting Expand causes its own optimisation problems though, so leave
      // them legal.
      if (VT.getVectorElementType() == MVT::i1)
        setLoadExtAction(ISD::EXTLOAD, InnerVT, VT, Expand);
    }
  }

  // FIXME: In order to prevent SSE instructions being expanded to MMX ones
  // with -msoft-float, disable use of MMX as well.
  if (!TM.Options.UseSoftFloat && Subtarget->hasMMX()) {
    addRegisterClass(MVT::x86mmx, &X86::VR64RegClass);
    // No operations on x86mmx supported, everything uses intrinsics.
  }

  // MMX-sized vectors (other than x86mmx) are expected to be expanded
  // into smaller operations.
  setOperationAction(ISD::MULHS,              MVT::v8i8,  Expand);
  setOperationAction(ISD::MULHS,              MVT::v4i16, Expand);
  setOperationAction(ISD::MULHS,              MVT::v2i32, Expand);
  setOperationAction(ISD::MULHS,              MVT::v1i64, Expand);
  setOperationAction(ISD::AND,                MVT::v8i8,  Expand);
  setOperationAction(ISD::AND,                MVT::v4i16, Expand);
  setOperationAction(ISD::AND,                MVT::v2i32, Expand);
  setOperationAction(ISD::AND,                MVT::v1i64, Expand);
  setOperationAction(ISD::OR,                 MVT::v8i8,  Expand);
  setOperationAction(ISD::OR,                 MVT::v4i16, Expand);
  setOperationAction(ISD::OR,                 MVT::v2i32, Expand);
  setOperationAction(ISD::OR,                 MVT::v1i64, Expand);
  setOperationAction(ISD::XOR,                MVT::v8i8,  Expand);
  setOperationAction(ISD::XOR,                MVT::v4i16, Expand);
  setOperationAction(ISD::XOR,                MVT::v2i32, Expand);
  setOperationAction(ISD::XOR,                MVT::v1i64, Expand);
  setOperationAction(ISD::SCALAR_TO_VECTOR,   MVT::v8i8,  Expand);
  setOperationAction(ISD::SCALAR_TO_VECTOR,   MVT::v4i16, Expand);
  setOperationAction(ISD::SCALAR_TO_VECTOR,   MVT::v2i32, Expand);
  setOperationAction(ISD::SCALAR_TO_VECTOR,   MVT::v1i64, Expand);
  setOperationAction(ISD::INSERT_VECTOR_ELT,  MVT::v1i64, Expand);
  setOperationAction(ISD::SELECT,             MVT::v8i8,  Expand);
  setOperationAction(ISD::SELECT,             MVT::v4i16, Expand);
  setOperationAction(ISD::SELECT,             MVT::v2i32, Expand);
  setOperationAction(ISD::SELECT,             MVT::v1i64, Expand);
  setOperationAction(ISD::BITCAST,            MVT::v8i8,  Expand);
  setOperationAction(ISD::BITCAST,            MVT::v4i16, Expand);
  setOperationAction(ISD::BITCAST,            MVT::v2i32, Expand);
  setOperationAction(ISD::BITCAST,            MVT::v1i64, Expand);

  if (!TM.Options.UseSoftFloat && Subtarget->hasSSE1()) {
    addRegisterClass(MVT::v4f32, &X86::VR128RegClass);

    setOperationAction(ISD::FADD,               MVT::v4f32, Legal);
    setOperationAction(ISD::FSUB,               MVT::v4f32, Legal);
    setOperationAction(ISD::FMUL,               MVT::v4f32, Legal);
    setOperationAction(ISD::FDIV,               MVT::v4f32, Legal);
    setOperationAction(ISD::FSQRT,              MVT::v4f32, Legal);
    setOperationAction(ISD::FNEG,               MVT::v4f32, Custom);
    setOperationAction(ISD::FABS,               MVT::v4f32, Custom);
    setOperationAction(ISD::LOAD,               MVT::v4f32, Legal);
    setOperationAction(ISD::BUILD_VECTOR,       MVT::v4f32, Custom);
    setOperationAction(ISD::VECTOR_SHUFFLE,     MVT::v4f32, Custom);
    setOperationAction(ISD::VSELECT,            MVT::v4f32, Custom);
    setOperationAction(ISD::EXTRACT_VECTOR_ELT, MVT::v4f32, Custom);
    setOperationAction(ISD::SELECT,             MVT::v4f32, Custom);
    setOperationAction(ISD::UINT_TO_FP,         MVT::v4i32, Custom);
  }

  if (!TM.Options.UseSoftFloat && Subtarget->hasSSE2()) {
    addRegisterClass(MVT::v2f64, &X86::VR128RegClass);

    // FIXME: Unfortunately, -soft-float and -no-implicit-float mean XMM
    // registers cannot be used even for integer operations.
    addRegisterClass(MVT::v16i8, &X86::VR128RegClass);
    addRegisterClass(MVT::v8i16, &X86::VR128RegClass);
    addRegisterClass(MVT::v4i32, &X86::VR128RegClass);
    addRegisterClass(MVT::v2i64, &X86::VR128RegClass);

    setOperationAction(ISD::ADD,                MVT::v16i8, Legal);
    setOperationAction(ISD::ADD,                MVT::v8i16, Legal);
    setOperationAction(ISD::ADD,                MVT::v4i32, Legal);
    setOperationAction(ISD::ADD,                MVT::v2i64, Legal);
    setOperationAction(ISD::MUL,                MVT::v4i32, Custom);
    setOperationAction(ISD::MUL,                MVT::v2i64, Custom);
    setOperationAction(ISD::UMUL_LOHI,          MVT::v4i32, Custom);
    setOperationAction(ISD::SMUL_LOHI,          MVT::v4i32, Custom);
    setOperationAction(ISD::MULHU,              MVT::v8i16, Legal);
    setOperationAction(ISD::MULHS,              MVT::v8i16, Legal);
    setOperationAction(ISD::SUB,                MVT::v16i8, Legal);
    setOperationAction(ISD::SUB,                MVT::v8i16, Legal);
    setOperationAction(ISD::SUB,                MVT::v4i32, Legal);
    setOperationAction(ISD::SUB,                MVT::v2i64, Legal);
    setOperationAction(ISD::MUL,                MVT::v8i16, Legal);
    setOperationAction(ISD::FADD,               MVT::v2f64, Legal);
    setOperationAction(ISD::FSUB,               MVT::v2f64, Legal);
    setOperationAction(ISD::FMUL,               MVT::v2f64, Legal);
    setOperationAction(ISD::FDIV,               MVT::v2f64, Legal);
    setOperationAction(ISD::FSQRT,              MVT::v2f64, Legal);
    setOperationAction(ISD::FNEG,               MVT::v2f64, Custom);
    setOperationAction(ISD::FABS,               MVT::v2f64, Custom);

    setOperationAction(ISD::SETCC,              MVT::v2i64, Custom);
    setOperationAction(ISD::SETCC,              MVT::v16i8, Custom);
    setOperationAction(ISD::SETCC,              MVT::v8i16, Custom);
    setOperationAction(ISD::SETCC,              MVT::v4i32, Custom);

    setOperationAction(ISD::SCALAR_TO_VECTOR,   MVT::v16i8, Custom);
    setOperationAction(ISD::SCALAR_TO_VECTOR,   MVT::v8i16, Custom);
    setOperationAction(ISD::INSERT_VECTOR_ELT,  MVT::v8i16, Custom);
    setOperationAction(ISD::INSERT_VECTOR_ELT,  MVT::v4i32, Custom);
    setOperationAction(ISD::INSERT_VECTOR_ELT,  MVT::v4f32, Custom);

    // Only provide customized ctpop vector bit twiddling for vector types we
    // know to perform better than using the popcnt instructions on each vector
    // element. If popcnt isn't supported, always provide the custom version.
    if (!Subtarget->hasPOPCNT()) {
      setOperationAction(ISD::CTPOP,            MVT::v4i32, Custom);
      setOperationAction(ISD::CTPOP,            MVT::v2i64, Custom);
    }

    // Custom lower build_vector, vector_shuffle, and extract_vector_elt.
    for (int i = MVT::v16i8; i != MVT::v2i64; ++i) {
      MVT VT = (MVT::SimpleValueType)i;
      // Do not attempt to custom lower non-power-of-2 vectors
      if (!isPowerOf2_32(VT.getVectorNumElements()))
        continue;
      // Do not attempt to custom lower non-128-bit vectors
      if (!VT.is128BitVector())
        continue;
      setOperationAction(ISD::BUILD_VECTOR,       VT, Custom);
      setOperationAction(ISD::VECTOR_SHUFFLE,     VT, Custom);
      setOperationAction(ISD::VSELECT,            VT, Custom);
      setOperationAction(ISD::EXTRACT_VECTOR_ELT, VT, Custom);
    }

    // We support custom legalizing of sext and anyext loads for specific
    // memory vector types which we can load as a scalar (or sequence of
    // scalars) and extend in-register to a legal 128-bit vector type. For sext
    // loads these must work with a single scalar load.
    for (MVT VT : MVT::integer_vector_valuetypes()) {
      setLoadExtAction(ISD::SEXTLOAD, VT, MVT::v4i8, Custom);
      setLoadExtAction(ISD::SEXTLOAD, VT, MVT::v4i16, Custom);
      setLoadExtAction(ISD::SEXTLOAD, VT, MVT::v8i8, Custom);
      setLoadExtAction(ISD::EXTLOAD, VT, MVT::v2i8, Custom);
      setLoadExtAction(ISD::EXTLOAD, VT, MVT::v2i16, Custom);
      setLoadExtAction(ISD::EXTLOAD, VT, MVT::v2i32, Custom);
      setLoadExtAction(ISD::EXTLOAD, VT, MVT::v4i8, Custom);
      setLoadExtAction(ISD::EXTLOAD, VT, MVT::v4i16, Custom);
      setLoadExtAction(ISD::EXTLOAD, VT, MVT::v8i8, Custom);
    }

    setOperationAction(ISD::BUILD_VECTOR,       MVT::v2f64, Custom);
    setOperationAction(ISD::BUILD_VECTOR,       MVT::v2i64, Custom);
    setOperationAction(ISD::VECTOR_SHUFFLE,     MVT::v2f64, Custom);
    setOperationAction(ISD::VECTOR_SHUFFLE,     MVT::v2i64, Custom);
    setOperationAction(ISD::VSELECT,            MVT::v2f64, Custom);
    setOperationAction(ISD::VSELECT,            MVT::v2i64, Custom);
    setOperationAction(ISD::INSERT_VECTOR_ELT,  MVT::v2f64, Custom);
    setOperationAction(ISD::EXTRACT_VECTOR_ELT, MVT::v2f64, Custom);

    if (Subtarget->is64Bit()) {
      setOperationAction(ISD::INSERT_VECTOR_ELT,  MVT::v2i64, Custom);
      setOperationAction(ISD::EXTRACT_VECTOR_ELT, MVT::v2i64, Custom);
    }

    // Promote v16i8, v8i16, v4i32 load, select, and, or, xor to v2i64.
    for (int i = MVT::v16i8; i != MVT::v2i64; ++i) {
      MVT VT = (MVT::SimpleValueType)i;

      // Do not attempt to promote non-128-bit vectors
      if (!VT.is128BitVector())
        continue;

      setOperationAction(ISD::AND,    VT, Promote);
      AddPromotedToType (ISD::AND,    VT, MVT::v2i64);
      setOperationAction(ISD::OR,     VT, Promote);
      AddPromotedToType (ISD::OR,     VT, MVT::v2i64);
      setOperationAction(ISD::XOR,    VT, Promote);
      AddPromotedToType (ISD::XOR,    VT, MVT::v2i64);
      setOperationAction(ISD::LOAD,   VT, Promote);
      AddPromotedToType (ISD::LOAD,   VT, MVT::v2i64);
      setOperationAction(ISD::SELECT, VT, Promote);
      AddPromotedToType (ISD::SELECT, VT, MVT::v2i64);
    }

    // Custom lower v2i64 and v2f64 selects.
    setOperationAction(ISD::LOAD,               MVT::v2f64, Legal);
    setOperationAction(ISD::LOAD,               MVT::v2i64, Legal);
    setOperationAction(ISD::SELECT,             MVT::v2f64, Custom);
    setOperationAction(ISD::SELECT,             MVT::v2i64, Custom);

    setOperationAction(ISD::FP_TO_SINT,         MVT::v4i32, Legal);
    setOperationAction(ISD::SINT_TO_FP,         MVT::v4i32, Legal);

    setOperationAction(ISD::UINT_TO_FP,         MVT::v4i8,  Custom);
    setOperationAction(ISD::UINT_TO_FP,         MVT::v4i16, Custom);
    // As there is no 64-bit GPR available, we need build a special custom
    // sequence to convert from v2i32 to v2f32.
    if (!Subtarget->is64Bit())
      setOperationAction(ISD::UINT_TO_FP,       MVT::v2f32, Custom);

    setOperationAction(ISD::FP_EXTEND,          MVT::v2f32, Custom);
    setOperationAction(ISD::FP_ROUND,           MVT::v2f32, Custom);

    for (MVT VT : MVT::fp_vector_valuetypes())
      setLoadExtAction(ISD::EXTLOAD, VT, MVT::v2f32, Legal);

    setOperationAction(ISD::BITCAST,            MVT::v2i32, Custom);
    setOperationAction(ISD::BITCAST,            MVT::v4i16, Custom);
    setOperationAction(ISD::BITCAST,            MVT::v8i8,  Custom);
  }

  if (!TM.Options.UseSoftFloat && Subtarget->hasSSE41()) {
    setOperationAction(ISD::FFLOOR,             MVT::f32,   Legal);
    setOperationAction(ISD::FCEIL,              MVT::f32,   Legal);
    setOperationAction(ISD::FTRUNC,             MVT::f32,   Legal);
    setOperationAction(ISD::FRINT,              MVT::f32,   Legal);
    setOperationAction(ISD::FNEARBYINT,         MVT::f32,   Legal);
    setOperationAction(ISD::FFLOOR,             MVT::f64,   Legal);
    setOperationAction(ISD::FCEIL,              MVT::f64,   Legal);
    setOperationAction(ISD::FTRUNC,             MVT::f64,   Legal);
    setOperationAction(ISD::FRINT,              MVT::f64,   Legal);
    setOperationAction(ISD::FNEARBYINT,         MVT::f64,   Legal);

    setOperationAction(ISD::FFLOOR,             MVT::v4f32, Legal);
    setOperationAction(ISD::FCEIL,              MVT::v4f32, Legal);
    setOperationAction(ISD::FTRUNC,             MVT::v4f32, Legal);
    setOperationAction(ISD::FRINT,              MVT::v4f32, Legal);
    setOperationAction(ISD::FNEARBYINT,         MVT::v4f32, Legal);
    setOperationAction(ISD::FFLOOR,             MVT::v2f64, Legal);
    setOperationAction(ISD::FCEIL,              MVT::v2f64, Legal);
    setOperationAction(ISD::FTRUNC,             MVT::v2f64, Legal);
    setOperationAction(ISD::FRINT,              MVT::v2f64, Legal);
    setOperationAction(ISD::FNEARBYINT,         MVT::v2f64, Legal);

    // FIXME: Do we need to handle scalar-to-vector here?
    setOperationAction(ISD::MUL,                MVT::v4i32, Legal);

    // We directly match byte blends in the backend as they match the VSELECT
    // condition form.
    setOperationAction(ISD::VSELECT,            MVT::v16i8, Legal);

    // SSE41 brings specific instructions for doing vector sign extend even in
    // cases where we don't have SRA.
    for (MVT VT : MVT::integer_vector_valuetypes()) {
      setLoadExtAction(ISD::SEXTLOAD, VT, MVT::v2i8, Custom);
      setLoadExtAction(ISD::SEXTLOAD, VT, MVT::v2i16, Custom);
      setLoadExtAction(ISD::SEXTLOAD, VT, MVT::v2i32, Custom);
    }

    // SSE41 also has vector sign/zero extending loads, PMOV[SZ]X
    setLoadExtAction(ISD::SEXTLOAD, MVT::v8i16, MVT::v8i8,  Legal);
    setLoadExtAction(ISD::SEXTLOAD, MVT::v4i32, MVT::v4i8,  Legal);
    setLoadExtAction(ISD::SEXTLOAD, MVT::v2i64, MVT::v2i8,  Legal);
    setLoadExtAction(ISD::SEXTLOAD, MVT::v4i32, MVT::v4i16, Legal);
    setLoadExtAction(ISD::SEXTLOAD, MVT::v2i64, MVT::v2i16, Legal);
    setLoadExtAction(ISD::SEXTLOAD, MVT::v2i64, MVT::v2i32, Legal);

    setLoadExtAction(ISD::ZEXTLOAD, MVT::v8i16, MVT::v8i8,  Legal);
    setLoadExtAction(ISD::ZEXTLOAD, MVT::v4i32, MVT::v4i8,  Legal);
    setLoadExtAction(ISD::ZEXTLOAD, MVT::v2i64, MVT::v2i8,  Legal);
    setLoadExtAction(ISD::ZEXTLOAD, MVT::v4i32, MVT::v4i16, Legal);
    setLoadExtAction(ISD::ZEXTLOAD, MVT::v2i64, MVT::v2i16, Legal);
    setLoadExtAction(ISD::ZEXTLOAD, MVT::v2i64, MVT::v2i32, Legal);

    // i8 and i16 vectors are custom because the source register and source
    // source memory operand types are not the same width.  f32 vectors are
    // custom since the immediate controlling the insert encodes additional
    // information.
    setOperationAction(ISD::INSERT_VECTOR_ELT,  MVT::v16i8, Custom);
    setOperationAction(ISD::INSERT_VECTOR_ELT,  MVT::v8i16, Custom);
    setOperationAction(ISD::INSERT_VECTOR_ELT,  MVT::v4i32, Custom);
    setOperationAction(ISD::INSERT_VECTOR_ELT,  MVT::v4f32, Custom);

    setOperationAction(ISD::EXTRACT_VECTOR_ELT, MVT::v16i8, Custom);
    setOperationAction(ISD::EXTRACT_VECTOR_ELT, MVT::v8i16, Custom);
    setOperationAction(ISD::EXTRACT_VECTOR_ELT, MVT::v4i32, Custom);
    setOperationAction(ISD::EXTRACT_VECTOR_ELT, MVT::v4f32, Custom);

    // FIXME: these should be Legal, but that's only for the case where
    // the index is constant.  For now custom expand to deal with that.
    if (Subtarget->is64Bit()) {
      setOperationAction(ISD::INSERT_VECTOR_ELT,  MVT::v2i64, Custom);
      setOperationAction(ISD::EXTRACT_VECTOR_ELT, MVT::v2i64, Custom);
    }
  }

  if (Subtarget->hasSSE2()) {
    setOperationAction(ISD::SRL,               MVT::v8i16, Custom);
    setOperationAction(ISD::SRL,               MVT::v16i8, Custom);

    setOperationAction(ISD::SHL,               MVT::v8i16, Custom);
    setOperationAction(ISD::SHL,               MVT::v16i8, Custom);

    setOperationAction(ISD::SRA,               MVT::v8i16, Custom);
    setOperationAction(ISD::SRA,               MVT::v16i8, Custom);

    // In the customized shift lowering, the legal cases in AVX2 will be
    // recognized.
    setOperationAction(ISD::SRL,               MVT::v2i64, Custom);
    setOperationAction(ISD::SRL,               MVT::v4i32, Custom);

    setOperationAction(ISD::SHL,               MVT::v2i64, Custom);
    setOperationAction(ISD::SHL,               MVT::v4i32, Custom);

    setOperationAction(ISD::SRA,               MVT::v4i32, Custom);
  }

  if (!TM.Options.UseSoftFloat && Subtarget->hasFp256()) {
    addRegisterClass(MVT::v32i8,  &X86::VR256RegClass);
    addRegisterClass(MVT::v16i16, &X86::VR256RegClass);
    addRegisterClass(MVT::v8i32,  &X86::VR256RegClass);
    addRegisterClass(MVT::v8f32,  &X86::VR256RegClass);
    addRegisterClass(MVT::v4i64,  &X86::VR256RegClass);
    addRegisterClass(MVT::v4f64,  &X86::VR256RegClass);

    setOperationAction(ISD::LOAD,               MVT::v8f32, Legal);
    setOperationAction(ISD::LOAD,               MVT::v4f64, Legal);
    setOperationAction(ISD::LOAD,               MVT::v4i64, Legal);

    setOperationAction(ISD::FADD,               MVT::v8f32, Legal);
    setOperationAction(ISD::FSUB,               MVT::v8f32, Legal);
    setOperationAction(ISD::FMUL,               MVT::v8f32, Legal);
    setOperationAction(ISD::FDIV,               MVT::v8f32, Legal);
    setOperationAction(ISD::FSQRT,              MVT::v8f32, Legal);
    setOperationAction(ISD::FFLOOR,             MVT::v8f32, Legal);
    setOperationAction(ISD::FCEIL,              MVT::v8f32, Legal);
    setOperationAction(ISD::FTRUNC,             MVT::v8f32, Legal);
    setOperationAction(ISD::FRINT,              MVT::v8f32, Legal);
    setOperationAction(ISD::FNEARBYINT,         MVT::v8f32, Legal);
    setOperationAction(ISD::FNEG,               MVT::v8f32, Custom);
    setOperationAction(ISD::FABS,               MVT::v8f32, Custom);

    setOperationAction(ISD::FADD,               MVT::v4f64, Legal);
    setOperationAction(ISD::FSUB,               MVT::v4f64, Legal);
    setOperationAction(ISD::FMUL,               MVT::v4f64, Legal);
    setOperationAction(ISD::FDIV,               MVT::v4f64, Legal);
    setOperationAction(ISD::FSQRT,              MVT::v4f64, Legal);
    setOperationAction(ISD::FFLOOR,             MVT::v4f64, Legal);
    setOperationAction(ISD::FCEIL,              MVT::v4f64, Legal);
    setOperationAction(ISD::FTRUNC,             MVT::v4f64, Legal);
    setOperationAction(ISD::FRINT,              MVT::v4f64, Legal);
    setOperationAction(ISD::FNEARBYINT,         MVT::v4f64, Legal);
    setOperationAction(ISD::FNEG,               MVT::v4f64, Custom);
    setOperationAction(ISD::FABS,               MVT::v4f64, Custom);

    // (fp_to_int:v8i16 (v8f32 ..)) requires the result type to be promoted
    // even though v8i16 is a legal type.
    setOperationAction(ISD::FP_TO_SINT,         MVT::v8i16, Promote);
    setOperationAction(ISD::FP_TO_UINT,         MVT::v8i16, Promote);
    setOperationAction(ISD::FP_TO_SINT,         MVT::v8i32, Legal);

    setOperationAction(ISD::SINT_TO_FP,         MVT::v8i16, Promote);
    setOperationAction(ISD::SINT_TO_FP,         MVT::v8i32, Legal);
    setOperationAction(ISD::FP_ROUND,           MVT::v4f32, Legal);

    setOperationAction(ISD::UINT_TO_FP,         MVT::v8i8,  Custom);
    setOperationAction(ISD::UINT_TO_FP,         MVT::v8i16, Custom);

    for (MVT VT : MVT::fp_vector_valuetypes())
      setLoadExtAction(ISD::EXTLOAD, VT, MVT::v4f32, Legal);

    setOperationAction(ISD::SRL,               MVT::v16i16, Custom);
    setOperationAction(ISD::SRL,               MVT::v32i8, Custom);

    setOperationAction(ISD::SHL,               MVT::v16i16, Custom);
    setOperationAction(ISD::SHL,               MVT::v32i8, Custom);

    setOperationAction(ISD::SRA,               MVT::v16i16, Custom);
    setOperationAction(ISD::SRA,               MVT::v32i8, Custom);

    setOperationAction(ISD::SETCC,             MVT::v32i8, Custom);
    setOperationAction(ISD::SETCC,             MVT::v16i16, Custom);
    setOperationAction(ISD::SETCC,             MVT::v8i32, Custom);
    setOperationAction(ISD::SETCC,             MVT::v4i64, Custom);

    setOperationAction(ISD::SELECT,            MVT::v4f64, Custom);
    setOperationAction(ISD::SELECT,            MVT::v4i64, Custom);
    setOperationAction(ISD::SELECT,            MVT::v8f32, Custom);

    setOperationAction(ISD::SIGN_EXTEND,       MVT::v4i64, Custom);
    setOperationAction(ISD::SIGN_EXTEND,       MVT::v8i32, Custom);
    setOperationAction(ISD::SIGN_EXTEND,       MVT::v16i16, Custom);
    setOperationAction(ISD::ZERO_EXTEND,       MVT::v4i64, Custom);
    setOperationAction(ISD::ZERO_EXTEND,       MVT::v8i32, Custom);
    setOperationAction(ISD::ZERO_EXTEND,       MVT::v16i16, Custom);
    setOperationAction(ISD::ANY_EXTEND,        MVT::v4i64, Custom);
    setOperationAction(ISD::ANY_EXTEND,        MVT::v8i32, Custom);
    setOperationAction(ISD::ANY_EXTEND,        MVT::v16i16, Custom);
    setOperationAction(ISD::TRUNCATE,          MVT::v16i8, Custom);
    setOperationAction(ISD::TRUNCATE,          MVT::v8i16, Custom);
    setOperationAction(ISD::TRUNCATE,          MVT::v4i32, Custom);

    if (Subtarget->hasFMA() || Subtarget->hasFMA4()) {
      setOperationAction(ISD::FMA,             MVT::v8f32, Legal);
      setOperationAction(ISD::FMA,             MVT::v4f64, Legal);
      setOperationAction(ISD::FMA,             MVT::v4f32, Legal);
      setOperationAction(ISD::FMA,             MVT::v2f64, Legal);
      setOperationAction(ISD::FMA,             MVT::f32, Legal);
      setOperationAction(ISD::FMA,             MVT::f64, Legal);
    }

    if (Subtarget->hasInt256()) {
      setOperationAction(ISD::ADD,             MVT::v4i64, Legal);
      setOperationAction(ISD::ADD,             MVT::v8i32, Legal);
      setOperationAction(ISD::ADD,             MVT::v16i16, Legal);
      setOperationAction(ISD::ADD,             MVT::v32i8, Legal);

      setOperationAction(ISD::SUB,             MVT::v4i64, Legal);
      setOperationAction(ISD::SUB,             MVT::v8i32, Legal);
      setOperationAction(ISD::SUB,             MVT::v16i16, Legal);
      setOperationAction(ISD::SUB,             MVT::v32i8, Legal);

      setOperationAction(ISD::MUL,             MVT::v4i64, Custom);
      setOperationAction(ISD::MUL,             MVT::v8i32, Legal);
      setOperationAction(ISD::MUL,             MVT::v16i16, Legal);
      // Don't lower v32i8 because there is no 128-bit byte mul

      setOperationAction(ISD::UMUL_LOHI,       MVT::v8i32, Custom);
      setOperationAction(ISD::SMUL_LOHI,       MVT::v8i32, Custom);
      setOperationAction(ISD::MULHU,           MVT::v16i16, Legal);
      setOperationAction(ISD::MULHS,           MVT::v16i16, Legal);

      // The custom lowering for UINT_TO_FP for v8i32 becomes interesting
      // when we have a 256bit-wide blend with immediate.
      setOperationAction(ISD::UINT_TO_FP, MVT::v8i32, Custom);

      // Only provide customized ctpop vector bit twiddling for vector types we
      // know to perform better than using the popcnt instructions on each
      // vector element. If popcnt isn't supported, always provide the custom
      // version.
      if (!Subtarget->hasPOPCNT())
        setOperationAction(ISD::CTPOP,           MVT::v4i64, Custom);

      // Custom CTPOP always performs better on natively supported v8i32
      setOperationAction(ISD::CTPOP,             MVT::v8i32, Custom);

      // AVX2 also has wider vector sign/zero extending loads, VPMOV[SZ]X
      setLoadExtAction(ISD::SEXTLOAD, MVT::v16i16, MVT::v16i8, Legal);
      setLoadExtAction(ISD::SEXTLOAD, MVT::v8i32,  MVT::v8i8,  Legal);
      setLoadExtAction(ISD::SEXTLOAD, MVT::v4i64,  MVT::v4i8,  Legal);
      setLoadExtAction(ISD::SEXTLOAD, MVT::v8i32,  MVT::v8i16, Legal);
      setLoadExtAction(ISD::SEXTLOAD, MVT::v4i64,  MVT::v4i16, Legal);
      setLoadExtAction(ISD::SEXTLOAD, MVT::v4i64,  MVT::v4i32, Legal);

      setLoadExtAction(ISD::ZEXTLOAD, MVT::v16i16, MVT::v16i8, Legal);
      setLoadExtAction(ISD::ZEXTLOAD, MVT::v8i32,  MVT::v8i8,  Legal);
      setLoadExtAction(ISD::ZEXTLOAD, MVT::v4i64,  MVT::v4i8,  Legal);
      setLoadExtAction(ISD::ZEXTLOAD, MVT::v8i32,  MVT::v8i16, Legal);
      setLoadExtAction(ISD::ZEXTLOAD, MVT::v4i64,  MVT::v4i16, Legal);
      setLoadExtAction(ISD::ZEXTLOAD, MVT::v4i64,  MVT::v4i32, Legal);
    } else {
      setOperationAction(ISD::ADD,             MVT::v4i64, Custom);
      setOperationAction(ISD::ADD,             MVT::v8i32, Custom);
      setOperationAction(ISD::ADD,             MVT::v16i16, Custom);
      setOperationAction(ISD::ADD,             MVT::v32i8, Custom);

      setOperationAction(ISD::SUB,             MVT::v4i64, Custom);
      setOperationAction(ISD::SUB,             MVT::v8i32, Custom);
      setOperationAction(ISD::SUB,             MVT::v16i16, Custom);
      setOperationAction(ISD::SUB,             MVT::v32i8, Custom);

      setOperationAction(ISD::MUL,             MVT::v4i64, Custom);
      setOperationAction(ISD::MUL,             MVT::v8i32, Custom);
      setOperationAction(ISD::MUL,             MVT::v16i16, Custom);
      // Don't lower v32i8 because there is no 128-bit byte mul
    }

    // In the customized shift lowering, the legal cases in AVX2 will be
    // recognized.
    setOperationAction(ISD::SRL,               MVT::v4i64, Custom);
    setOperationAction(ISD::SRL,               MVT::v8i32, Custom);

    setOperationAction(ISD::SHL,               MVT::v4i64, Custom);
    setOperationAction(ISD::SHL,               MVT::v8i32, Custom);

    setOperationAction(ISD::SRA,               MVT::v8i32, Custom);

    // Custom lower several nodes for 256-bit types.
    for (MVT VT : MVT::vector_valuetypes()) {
      if (VT.getScalarSizeInBits() >= 32) {
        setOperationAction(ISD::MLOAD,  VT, Legal);
        setOperationAction(ISD::MSTORE, VT, Legal);
      }
      // Extract subvector is special because the value type
      // (result) is 128-bit but the source is 256-bit wide.
      if (VT.is128BitVector()) {
        setOperationAction(ISD::EXTRACT_SUBVECTOR, VT, Custom);
      }
      // Do not attempt to custom lower other non-256-bit vectors
      if (!VT.is256BitVector())
        continue;

      setOperationAction(ISD::BUILD_VECTOR,       VT, Custom);
      setOperationAction(ISD::VECTOR_SHUFFLE,     VT, Custom);
      setOperationAction(ISD::VSELECT,            VT, Custom);
      setOperationAction(ISD::INSERT_VECTOR_ELT,  VT, Custom);
      setOperationAction(ISD::EXTRACT_VECTOR_ELT, VT, Custom);
      setOperationAction(ISD::SCALAR_TO_VECTOR,   VT, Custom);
      setOperationAction(ISD::INSERT_SUBVECTOR,   VT, Custom);
      setOperationAction(ISD::CONCAT_VECTORS,     VT, Custom);
    }

    if (Subtarget->hasInt256())
      setOperationAction(ISD::VSELECT,         MVT::v32i8, Legal);


    // Promote v32i8, v16i16, v8i32 select, and, or, xor to v4i64.
    for (int i = MVT::v32i8; i != MVT::v4i64; ++i) {
      MVT VT = (MVT::SimpleValueType)i;

      // Do not attempt to promote non-256-bit vectors
      if (!VT.is256BitVector())
        continue;

      setOperationAction(ISD::AND,    VT, Promote);
      AddPromotedToType (ISD::AND,    VT, MVT::v4i64);
      setOperationAction(ISD::OR,     VT, Promote);
      AddPromotedToType (ISD::OR,     VT, MVT::v4i64);
      setOperationAction(ISD::XOR,    VT, Promote);
      AddPromotedToType (ISD::XOR,    VT, MVT::v4i64);
      setOperationAction(ISD::LOAD,   VT, Promote);
      AddPromotedToType (ISD::LOAD,   VT, MVT::v4i64);
      setOperationAction(ISD::SELECT, VT, Promote);
      AddPromotedToType (ISD::SELECT, VT, MVT::v4i64);
    }
  }

  if (!TM.Options.UseSoftFloat && Subtarget->hasAVX512()) {
    addRegisterClass(MVT::v16i32, &X86::VR512RegClass);
    addRegisterClass(MVT::v16f32, &X86::VR512RegClass);
    addRegisterClass(MVT::v8i64,  &X86::VR512RegClass);
    addRegisterClass(MVT::v8f64,  &X86::VR512RegClass);

    addRegisterClass(MVT::i1,     &X86::VK1RegClass);
    addRegisterClass(MVT::v8i1,   &X86::VK8RegClass);
    addRegisterClass(MVT::v16i1,  &X86::VK16RegClass);

    for (MVT VT : MVT::fp_vector_valuetypes())
      setLoadExtAction(ISD::EXTLOAD, VT, MVT::v8f32, Legal);

    setOperationAction(ISD::BR_CC,              MVT::i1,    Expand);
    setOperationAction(ISD::SETCC,              MVT::i1,    Custom);
    setOperationAction(ISD::XOR,                MVT::i1,    Legal);
    setOperationAction(ISD::OR,                 MVT::i1,    Legal);
    setOperationAction(ISD::AND,                MVT::i1,    Legal);
    setOperationAction(ISD::LOAD,               MVT::v16f32, Legal);
    setOperationAction(ISD::LOAD,               MVT::v8f64, Legal);
    setOperationAction(ISD::LOAD,               MVT::v8i64, Legal);
    setOperationAction(ISD::LOAD,               MVT::v16i32, Legal);
    setOperationAction(ISD::LOAD,               MVT::v16i1, Legal);

    setOperationAction(ISD::FADD,               MVT::v16f32, Legal);
    setOperationAction(ISD::FSUB,               MVT::v16f32, Legal);
    setOperationAction(ISD::FMUL,               MVT::v16f32, Legal);
    setOperationAction(ISD::FDIV,               MVT::v16f32, Legal);
    setOperationAction(ISD::FSQRT,              MVT::v16f32, Legal);
    setOperationAction(ISD::FNEG,               MVT::v16f32, Custom);

    setOperationAction(ISD::FADD,               MVT::v8f64, Legal);
    setOperationAction(ISD::FSUB,               MVT::v8f64, Legal);
    setOperationAction(ISD::FMUL,               MVT::v8f64, Legal);
    setOperationAction(ISD::FDIV,               MVT::v8f64, Legal);
    setOperationAction(ISD::FSQRT,              MVT::v8f64, Legal);
    setOperationAction(ISD::FNEG,               MVT::v8f64, Custom);
    setOperationAction(ISD::FMA,                MVT::v8f64, Legal);
    setOperationAction(ISD::FMA,                MVT::v16f32, Legal);

    setOperationAction(ISD::FP_TO_SINT,         MVT::i32, Legal);
    setOperationAction(ISD::FP_TO_UINT,         MVT::i32, Legal);
    setOperationAction(ISD::SINT_TO_FP,         MVT::i32, Legal);
    setOperationAction(ISD::UINT_TO_FP,         MVT::i32, Legal);
    if (Subtarget->is64Bit()) {
      setOperationAction(ISD::FP_TO_UINT,       MVT::i64, Legal);
      setOperationAction(ISD::FP_TO_SINT,       MVT::i64, Legal);
      setOperationAction(ISD::SINT_TO_FP,       MVT::i64, Legal);
      setOperationAction(ISD::UINT_TO_FP,       MVT::i64, Legal);
    }
    setOperationAction(ISD::FP_TO_SINT,         MVT::v16i32, Legal);
    setOperationAction(ISD::FP_TO_UINT,         MVT::v16i32, Legal);
    setOperationAction(ISD::FP_TO_UINT,         MVT::v8i32, Legal);
    setOperationAction(ISD::FP_TO_UINT,         MVT::v4i32, Legal);
    setOperationAction(ISD::SINT_TO_FP,         MVT::v16i32, Legal);
    setOperationAction(ISD::SINT_TO_FP,         MVT::v8i1,   Custom);
    setOperationAction(ISD::SINT_TO_FP,         MVT::v16i1,  Custom);
    setOperationAction(ISD::SINT_TO_FP,         MVT::v16i8,  Promote);
    setOperationAction(ISD::SINT_TO_FP,         MVT::v16i16, Promote);
    setOperationAction(ISD::UINT_TO_FP,         MVT::v16i32, Legal);
    setOperationAction(ISD::UINT_TO_FP,         MVT::v8i32, Legal);
    setOperationAction(ISD::UINT_TO_FP,         MVT::v4i32, Legal);
    setOperationAction(ISD::FP_ROUND,           MVT::v8f32, Legal);
    setOperationAction(ISD::FP_EXTEND,          MVT::v8f32, Legal);

    setOperationAction(ISD::TRUNCATE,           MVT::i1, Custom);
    setOperationAction(ISD::TRUNCATE,           MVT::v16i8, Custom);
    setOperationAction(ISD::TRUNCATE,           MVT::v8i32, Custom);
    setOperationAction(ISD::TRUNCATE,           MVT::v8i1, Custom);
    setOperationAction(ISD::TRUNCATE,           MVT::v16i1, Custom);
    setOperationAction(ISD::TRUNCATE,           MVT::v16i16, Custom);
    setOperationAction(ISD::ZERO_EXTEND,        MVT::v16i32, Custom);
    setOperationAction(ISD::ZERO_EXTEND,        MVT::v8i64, Custom);
    setOperationAction(ISD::SIGN_EXTEND,        MVT::v16i32, Custom);
    setOperationAction(ISD::SIGN_EXTEND,        MVT::v8i64, Custom);
    setOperationAction(ISD::SIGN_EXTEND,        MVT::v16i8, Custom);
    setOperationAction(ISD::SIGN_EXTEND,        MVT::v8i16, Custom);
    setOperationAction(ISD::SIGN_EXTEND,        MVT::v16i16, Custom);

    setOperationAction(ISD::FFLOOR,             MVT::v16f32, Legal);
    setOperationAction(ISD::FFLOOR,             MVT::v8f64, Legal);
    setOperationAction(ISD::FCEIL,              MVT::v16f32, Legal);
    setOperationAction(ISD::FCEIL,              MVT::v8f64, Legal);
    setOperationAction(ISD::FTRUNC,             MVT::v16f32, Legal);
    setOperationAction(ISD::FTRUNC,             MVT::v8f64, Legal);
    setOperationAction(ISD::FRINT,              MVT::v16f32, Legal);
    setOperationAction(ISD::FRINT,              MVT::v8f64, Legal);
    setOperationAction(ISD::FNEARBYINT,         MVT::v16f32, Legal);
    setOperationAction(ISD::FNEARBYINT,         MVT::v8f64, Legal);

    setOperationAction(ISD::CONCAT_VECTORS,     MVT::v8f64,  Custom);
    setOperationAction(ISD::CONCAT_VECTORS,     MVT::v8i64,  Custom);
    setOperationAction(ISD::CONCAT_VECTORS,     MVT::v16f32,  Custom);
    setOperationAction(ISD::CONCAT_VECTORS,     MVT::v16i32,  Custom);
    setOperationAction(ISD::CONCAT_VECTORS,     MVT::v8i1,    Custom);
    setOperationAction(ISD::CONCAT_VECTORS,     MVT::v16i1, Legal);

    setOperationAction(ISD::SETCC,              MVT::v16i1, Custom);
    setOperationAction(ISD::SETCC,              MVT::v8i1, Custom);

    setOperationAction(ISD::MUL,              MVT::v8i64, Custom);

    setOperationAction(ISD::EXTRACT_VECTOR_ELT, MVT::v8i1,  Custom);
    setOperationAction(ISD::EXTRACT_VECTOR_ELT, MVT::v16i1, Custom);
    setOperationAction(ISD::INSERT_VECTOR_ELT,  MVT::v16i1, Custom);
    setOperationAction(ISD::INSERT_VECTOR_ELT,  MVT::v8i1, Custom);
    setOperationAction(ISD::BUILD_VECTOR,       MVT::v8i1, Custom);
    setOperationAction(ISD::BUILD_VECTOR,       MVT::v16i1, Custom);
    setOperationAction(ISD::SELECT,             MVT::v8f64, Custom);
    setOperationAction(ISD::SELECT,             MVT::v8i64, Custom);
    setOperationAction(ISD::SELECT,             MVT::v16f32, Custom);

    setOperationAction(ISD::ADD,                MVT::v8i64, Legal);
    setOperationAction(ISD::ADD,                MVT::v16i32, Legal);

    setOperationAction(ISD::SUB,                MVT::v8i64, Legal);
    setOperationAction(ISD::SUB,                MVT::v16i32, Legal);

    setOperationAction(ISD::MUL,                MVT::v16i32, Legal);

    setOperationAction(ISD::SRL,                MVT::v8i64, Custom);
    setOperationAction(ISD::SRL,                MVT::v16i32, Custom);

    setOperationAction(ISD::SHL,                MVT::v8i64, Custom);
    setOperationAction(ISD::SHL,                MVT::v16i32, Custom);

    setOperationAction(ISD::SRA,                MVT::v8i64, Custom);
    setOperationAction(ISD::SRA,                MVT::v16i32, Custom);

    setOperationAction(ISD::AND,                MVT::v8i64, Legal);
    setOperationAction(ISD::OR,                 MVT::v8i64, Legal);
    setOperationAction(ISD::XOR,                MVT::v8i64, Legal);
    setOperationAction(ISD::AND,                MVT::v16i32, Legal);
    setOperationAction(ISD::OR,                 MVT::v16i32, Legal);
    setOperationAction(ISD::XOR,                MVT::v16i32, Legal);

    if (Subtarget->hasCDI()) {
      setOperationAction(ISD::CTLZ,             MVT::v8i64, Legal);
      setOperationAction(ISD::CTLZ,             MVT::v16i32, Legal);
    }

    // Custom lower several nodes.
    for (MVT VT : MVT::vector_valuetypes()) {
      unsigned EltSize = VT.getVectorElementType().getSizeInBits();
      // Extract subvector is special because the value type
      // (result) is 256/128-bit but the source is 512-bit wide.
      if (VT.is128BitVector() || VT.is256BitVector()) {
        setOperationAction(ISD::EXTRACT_SUBVECTOR, VT, Custom);
      }
      if (VT.getVectorElementType() == MVT::i1)
        setOperationAction(ISD::EXTRACT_SUBVECTOR, VT, Legal);

      // Do not attempt to custom lower other non-512-bit vectors
      if (!VT.is512BitVector())
        continue;

      if ( EltSize >= 32) {
        setOperationAction(ISD::VECTOR_SHUFFLE,      VT, Custom);
        setOperationAction(ISD::INSERT_VECTOR_ELT,   VT, Custom);
        setOperationAction(ISD::BUILD_VECTOR,        VT, Custom);
        setOperationAction(ISD::VSELECT,             VT, Legal);
        setOperationAction(ISD::EXTRACT_VECTOR_ELT,  VT, Custom);
        setOperationAction(ISD::SCALAR_TO_VECTOR,    VT, Custom);
        setOperationAction(ISD::INSERT_SUBVECTOR,    VT, Custom);
        setOperationAction(ISD::MLOAD,               VT, Legal);
        setOperationAction(ISD::MSTORE,              VT, Legal);
      }
    }
    for (int i = MVT::v32i8; i != MVT::v8i64; ++i) {
      MVT VT = (MVT::SimpleValueType)i;

      // Do not attempt to promote non-512-bit vectors.
      if (!VT.is512BitVector())
        continue;

      setOperationAction(ISD::SELECT, VT, Promote);
      AddPromotedToType (ISD::SELECT, VT, MVT::v8i64);
    }
  }// has  AVX-512

  if (!TM.Options.UseSoftFloat && Subtarget->hasBWI()) {
    addRegisterClass(MVT::v32i16, &X86::VR512RegClass);
    addRegisterClass(MVT::v64i8,  &X86::VR512RegClass);

    addRegisterClass(MVT::v32i1,  &X86::VK32RegClass);
    addRegisterClass(MVT::v64i1,  &X86::VK64RegClass);

    setOperationAction(ISD::LOAD,               MVT::v32i16, Legal);
    setOperationAction(ISD::LOAD,               MVT::v64i8, Legal);
    setOperationAction(ISD::SETCC,              MVT::v32i1, Custom);
    setOperationAction(ISD::SETCC,              MVT::v64i1, Custom);
    setOperationAction(ISD::ADD,                MVT::v32i16, Legal);
    setOperationAction(ISD::ADD,                MVT::v64i8, Legal);
    setOperationAction(ISD::SUB,                MVT::v32i16, Legal);
    setOperationAction(ISD::SUB,                MVT::v64i8, Legal);
    setOperationAction(ISD::MUL,                MVT::v32i16, Legal);

    for (int i = MVT::v32i8; i != MVT::v8i64; ++i) {
      const MVT VT = (MVT::SimpleValueType)i;

      const unsigned EltSize = VT.getVectorElementType().getSizeInBits();

      // Do not attempt to promote non-512-bit vectors.
      if (!VT.is512BitVector())
        continue;

      if (EltSize < 32) {
        setOperationAction(ISD::BUILD_VECTOR,        VT, Custom);
        setOperationAction(ISD::VSELECT,             VT, Legal);
      }
    }
  }

  if (!TM.Options.UseSoftFloat && Subtarget->hasVLX()) {
    addRegisterClass(MVT::v4i1,   &X86::VK4RegClass);
    addRegisterClass(MVT::v2i1,   &X86::VK2RegClass);

    setOperationAction(ISD::SETCC,              MVT::v4i1, Custom);
    setOperationAction(ISD::SETCC,              MVT::v2i1, Custom);
    setOperationAction(ISD::INSERT_SUBVECTOR,   MVT::v8i1, Legal);

    setOperationAction(ISD::AND,                MVT::v8i32, Legal);
    setOperationAction(ISD::OR,                 MVT::v8i32, Legal);
    setOperationAction(ISD::XOR,                MVT::v8i32, Legal);
    setOperationAction(ISD::AND,                MVT::v4i32, Legal);
    setOperationAction(ISD::OR,                 MVT::v4i32, Legal);
    setOperationAction(ISD::XOR,                MVT::v4i32, Legal);
  }

  // SIGN_EXTEND_INREGs are evaluated by the extend type. Handle the expansion
  // of this type with custom code.
  for (MVT VT : MVT::vector_valuetypes())
    setOperationAction(ISD::SIGN_EXTEND_INREG, VT, Custom);

  // We want to custom lower some of our intrinsics.
  setOperationAction(ISD::INTRINSIC_WO_CHAIN, MVT::Other, Custom);
  setOperationAction(ISD::INTRINSIC_W_CHAIN, MVT::Other, Custom);
  setOperationAction(ISD::INTRINSIC_VOID, MVT::Other, Custom);
  if (!Subtarget->is64Bit())
    setOperationAction(ISD::INTRINSIC_W_CHAIN, MVT::i64, Custom);

  // Only custom-lower 64-bit SADDO and friends on 64-bit because we don't
  // handle type legalization for these operations here.
  //
  // FIXME: We really should do custom legalization for addition and
  // subtraction on x86-32 once PR3203 is fixed.  We really can't do much better
  // than generic legalization for 64-bit multiplication-with-overflow, though.
  for (unsigned i = 0, e = 3+Subtarget->is64Bit(); i != e; ++i) {
    // Add/Sub/Mul with overflow operations are custom lowered.
    MVT VT = IntVTs[i];
    setOperationAction(ISD::SADDO, VT, Custom);
    setOperationAction(ISD::UADDO, VT, Custom);
    setOperationAction(ISD::SSUBO, VT, Custom);
    setOperationAction(ISD::USUBO, VT, Custom);
    setOperationAction(ISD::SMULO, VT, Custom);
    setOperationAction(ISD::UMULO, VT, Custom);
  }


  if (!Subtarget->is64Bit()) {
    // These libcalls are not available in 32-bit.
    setLibcallName(RTLIB::SHL_I128, nullptr);
    setLibcallName(RTLIB::SRL_I128, nullptr);
    setLibcallName(RTLIB::SRA_I128, nullptr);
  }

  // Combine sin / cos into one node or libcall if possible.
  if (Subtarget->hasSinCos()) {
    setLibcallName(RTLIB::SINCOS_F32, "sincosf");
    setLibcallName(RTLIB::SINCOS_F64, "sincos");
    if (Subtarget->isTargetDarwin()) {
      // For MacOSX, we don't want the normal expansion of a libcall to sincos.
      // We want to issue a libcall to __sincos_stret to avoid memory traffic.
      setOperationAction(ISD::FSINCOS, MVT::f64, Custom);
      setOperationAction(ISD::FSINCOS, MVT::f32, Custom);
    }
  }

  if (Subtarget->isTargetWin64()) {
    setOperationAction(ISD::SDIV, MVT::i128, Custom);
    setOperationAction(ISD::UDIV, MVT::i128, Custom);
    setOperationAction(ISD::SREM, MVT::i128, Custom);
    setOperationAction(ISD::UREM, MVT::i128, Custom);
    setOperationAction(ISD::SDIVREM, MVT::i128, Custom);
    setOperationAction(ISD::UDIVREM, MVT::i128, Custom);
  }

  // We have target-specific dag combine patterns for the following nodes:
  setTargetDAGCombine(ISD::VECTOR_SHUFFLE);
  setTargetDAGCombine(ISD::EXTRACT_VECTOR_ELT);
  setTargetDAGCombine(ISD::BITCAST);
  setTargetDAGCombine(ISD::VSELECT);
  setTargetDAGCombine(ISD::SELECT);
  setTargetDAGCombine(ISD::SHL);
  setTargetDAGCombine(ISD::SRA);
  setTargetDAGCombine(ISD::SRL);
  setTargetDAGCombine(ISD::OR);
  setTargetDAGCombine(ISD::AND);
  setTargetDAGCombine(ISD::ADD);
  setTargetDAGCombine(ISD::FADD);
  setTargetDAGCombine(ISD::FSUB);
  setTargetDAGCombine(ISD::FMA);
  setTargetDAGCombine(ISD::SUB);
  setTargetDAGCombine(ISD::LOAD);
  setTargetDAGCombine(ISD::MLOAD);
  setTargetDAGCombine(ISD::STORE);
  setTargetDAGCombine(ISD::MSTORE);
  setTargetDAGCombine(ISD::ZERO_EXTEND);
  setTargetDAGCombine(ISD::ANY_EXTEND);
  setTargetDAGCombine(ISD::SIGN_EXTEND);
  setTargetDAGCombine(ISD::SIGN_EXTEND_INREG);
  setTargetDAGCombine(ISD::TRUNCATE);
  setTargetDAGCombine(ISD::SINT_TO_FP);
  setTargetDAGCombine(ISD::SETCC);
  setTargetDAGCombine(ISD::INTRINSIC_WO_CHAIN);
  setTargetDAGCombine(ISD::BUILD_VECTOR);
  setTargetDAGCombine(ISD::MUL);
  setTargetDAGCombine(ISD::XOR);

  computeRegisterProperties();

  // On Darwin, -Os means optimize for size without hurting performance,
  // do not reduce the limit.
  MaxStoresPerMemset = 16; // For @llvm.memset -> sequence of stores
  MaxStoresPerMemsetOptSize = Subtarget->isTargetDarwin() ? 16 : 8;
  MaxStoresPerMemcpy = 8; // For @llvm.memcpy -> sequence of stores
  MaxStoresPerMemcpyOptSize = Subtarget->isTargetDarwin() ? 8 : 4;
  MaxStoresPerMemmove = 8; // For @llvm.memmove -> sequence of stores
  MaxStoresPerMemmoveOptSize = Subtarget->isTargetDarwin() ? 8 : 4;
  setPrefLoopAlignment(4); // 2^4 bytes.

  // Predictable cmov don't hurt on atom because it's in-order.
  PredictableSelectIsExpensive = !Subtarget->isAtom();
  EnableExtLdPromotion = true;
  setPrefFunctionAlignment(4); // 2^4 bytes.

  verifyIntrinsicTables();
}

// This has so far only been implemented for 64-bit MachO.
bool X86TargetLowering::useLoadStackGuardNode() const {
  return Subtarget->isTargetMachO() && Subtarget->is64Bit();
}

TargetLoweringBase::LegalizeTypeAction
X86TargetLowering::getPreferredVectorAction(EVT VT) const {
  if (ExperimentalVectorWideningLegalization &&
      VT.getVectorNumElements() != 1 &&
      VT.getVectorElementType().getSimpleVT() != MVT::i1)
    return TypeWidenVector;

  return TargetLoweringBase::getPreferredVectorAction(VT);
}

EVT X86TargetLowering::getSetCCResultType(LLVMContext &, EVT VT) const {
  if (!VT.isVector())
    return Subtarget->hasAVX512() ? MVT::i1: MVT::i8;

  const unsigned NumElts = VT.getVectorNumElements();
  const EVT EltVT = VT.getVectorElementType();
  if (VT.is512BitVector()) {
    if (Subtarget->hasAVX512())
      if (EltVT == MVT::i32 || EltVT == MVT::i64 ||
          EltVT == MVT::f32 || EltVT == MVT::f64)
        switch(NumElts) {
        case  8: return MVT::v8i1;
        case 16: return MVT::v16i1;
      }
    if (Subtarget->hasBWI())
      if (EltVT == MVT::i8 || EltVT == MVT::i16)
        switch(NumElts) {
        case 32: return MVT::v32i1;
        case 64: return MVT::v64i1;
      }
  }

  if (VT.is256BitVector() || VT.is128BitVector()) {
    if (Subtarget->hasVLX())
      if (EltVT == MVT::i32 || EltVT == MVT::i64 ||
          EltVT == MVT::f32 || EltVT == MVT::f64)
        switch(NumElts) {
        case 2: return MVT::v2i1;
        case 4: return MVT::v4i1;
        case 8: return MVT::v8i1;
      }
    if (Subtarget->hasBWI() && Subtarget->hasVLX())
      if (EltVT == MVT::i8 || EltVT == MVT::i16)
        switch(NumElts) {
        case  8: return MVT::v8i1;
        case 16: return MVT::v16i1;
        case 32: return MVT::v32i1;
      }
  }

  return VT.changeVectorElementTypeToInteger();
}

/// Helper for getByValTypeAlignment to determine
/// the desired ByVal argument alignment.
static void getMaxByValAlign(Type *Ty, unsigned &MaxAlign) {
  if (MaxAlign == 16)
    return;
  if (VectorType *VTy = dyn_cast<VectorType>(Ty)) {
    if (VTy->getBitWidth() == 128)
      MaxAlign = 16;
  } else if (ArrayType *ATy = dyn_cast<ArrayType>(Ty)) {
    unsigned EltAlign = 0;
    getMaxByValAlign(ATy->getElementType(), EltAlign);
    if (EltAlign > MaxAlign)
      MaxAlign = EltAlign;
  } else if (StructType *STy = dyn_cast<StructType>(Ty)) {
    for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) {
      unsigned EltAlign = 0;
      getMaxByValAlign(STy->getElementType(i), EltAlign);
      if (EltAlign > MaxAlign)
        MaxAlign = EltAlign;
      if (MaxAlign == 16)
        break;
    }
  }
}

/// Return the desired alignment for ByVal aggregate
/// function arguments in the caller parameter area. For X86, aggregates
/// that contain SSE vectors are placed at 16-byte boundaries while the rest
/// are at 4-byte boundaries.
unsigned X86TargetLowering::getByValTypeAlignment(Type *Ty) const {
  if (Subtarget->is64Bit()) {
    // Max of 8 and alignment of type.
    unsigned TyAlign = TD->getABITypeAlignment(Ty);
    if (TyAlign > 8)
      return TyAlign;
    return 8;
  }

  unsigned Align = 4;
  if (Subtarget->hasSSE1())
    getMaxByValAlign(Ty, Align);
  return Align;
}

/// Returns the target specific optimal type for load
/// and store operations as a result of memset, memcpy, and memmove
/// lowering. If DstAlign is zero that means it's safe to destination
/// alignment can satisfy any constraint. Similarly if SrcAlign is zero it
/// means there isn't a need to check it against alignment requirement,
/// probably because the source does not need to be loaded. If 'IsMemset' is
/// true, that means it's expanding a memset. If 'ZeroMemset' is true, that
/// means it's a memset of zero. 'MemcpyStrSrc' indicates whether the memcpy
/// source is constant so it does not need to be loaded.
/// It returns EVT::Other if the type should be determined using generic
/// target-independent logic.
EVT
X86TargetLowering::getOptimalMemOpType(uint64_t Size,
                                       unsigned DstAlign, unsigned SrcAlign,
                                       bool IsMemset, bool ZeroMemset,
                                       bool MemcpyStrSrc,
                                       MachineFunction &MF) const {
  const Function *F = MF.getFunction();
  if ((!IsMemset || ZeroMemset) &&
      !F->hasFnAttribute(Attribute::NoImplicitFloat)) {
    if (Size >= 16 &&
        (Subtarget->isUnalignedMemAccessFast() ||
         ((DstAlign == 0 || DstAlign >= 16) &&
          (SrcAlign == 0 || SrcAlign >= 16)))) {
      if (Size >= 32) {
        if (Subtarget->hasInt256())
          return MVT::v8i32;
        if (Subtarget->hasFp256())
          return MVT::v8f32;
      }
      if (Subtarget->hasSSE2())
        return MVT::v4i32;
      if (Subtarget->hasSSE1())
        return MVT::v4f32;
    } else if (!MemcpyStrSrc && Size >= 8 &&
               !Subtarget->is64Bit() &&
               Subtarget->hasSSE2()) {
      // Do not use f64 to lower memcpy if source is string constant. It's
      // better to use i32 to avoid the loads.
      return MVT::f64;
    }
  }
  if (Subtarget->is64Bit() && Size >= 8)
    return MVT::i64;
  return MVT::i32;
}

bool X86TargetLowering::isSafeMemOpType(MVT VT) const {
  if (VT == MVT::f32)
    return X86ScalarSSEf32;
  else if (VT == MVT::f64)
    return X86ScalarSSEf64;
  return true;
}

bool
X86TargetLowering::allowsMisalignedMemoryAccesses(EVT VT,
                                                  unsigned,
                                                  unsigned,
                                                  bool *Fast) const {
  if (Fast)
    *Fast = Subtarget->isUnalignedMemAccessFast();
  return true;
}

/// Return the entry encoding for a jump table in the
/// current function.  The returned value is a member of the
/// MachineJumpTableInfo::JTEntryKind enum.
unsigned X86TargetLowering::getJumpTableEncoding() const {
  // In GOT pic mode, each entry in the jump table is emitted as a @GOTOFF
  // symbol.
  if (getTargetMachine().getRelocationModel() == Reloc::PIC_ &&
      Subtarget->isPICStyleGOT())
    return MachineJumpTableInfo::EK_Custom32;

  // Otherwise, use the normal jump table encoding heuristics.
  return TargetLowering::getJumpTableEncoding();
}

const MCExpr *
X86TargetLowering::LowerCustomJumpTableEntry(const MachineJumpTableInfo *MJTI,
                                             const MachineBasicBlock *MBB,
                                             unsigned uid,MCContext &Ctx) const{
  assert(MBB->getParent()->getTarget().getRelocationModel() == Reloc::PIC_ &&
         Subtarget->isPICStyleGOT());
  // In 32-bit ELF systems, our jump table entries are formed with @GOTOFF
  // entries.
  return MCSymbolRefExpr::Create(MBB->getSymbol(),
                                 MCSymbolRefExpr::VK_GOTOFF, Ctx);
}

/// Returns relocation base for the given PIC jumptable.
SDValue X86TargetLowering::getPICJumpTableRelocBase(SDValue Table,
                                                    SelectionDAG &DAG) const {
  if (!Subtarget->is64Bit())
    // This doesn't have SDLoc associated with it, but is not really the
    // same as a Register.
    return DAG.getNode(X86ISD::GlobalBaseReg, SDLoc(), getPointerTy());
  return Table;
}

/// This returns the relocation base for the given PIC jumptable,
/// the same as getPICJumpTableRelocBase, but as an MCExpr.
const MCExpr *X86TargetLowering::
getPICJumpTableRelocBaseExpr(const MachineFunction *MF, unsigned JTI,
                             MCContext &Ctx) const {
  // X86-64 uses RIP relative addressing based on the jump table label.
  if (Subtarget->isPICStyleRIPRel())
    return TargetLowering::getPICJumpTableRelocBaseExpr(MF, JTI, Ctx);

  // Otherwise, the reference is relative to the PIC base.
  return MCSymbolRefExpr::Create(MF->getPICBaseSymbol(), Ctx);
}

// FIXME: Why this routine is here? Move to RegInfo!
std::pair<const TargetRegisterClass*, uint8_t>
X86TargetLowering::findRepresentativeClass(MVT VT) const{
  const TargetRegisterClass *RRC = nullptr;
  uint8_t Cost = 1;
  switch (VT.SimpleTy) {
  default:
    return TargetLowering::findRepresentativeClass(VT);
  case MVT::i8: case MVT::i16: case MVT::i32: case MVT::i64:
    RRC = Subtarget->is64Bit() ? &X86::GR64RegClass : &X86::GR32RegClass;
    break;
  case MVT::x86mmx:
    RRC = &X86::VR64RegClass;
    break;
  case MVT::f32: case MVT::f64:
  case MVT::v16i8: case MVT::v8i16: case MVT::v4i32: case MVT::v2i64:
  case MVT::v4f32: case MVT::v2f64:
  case MVT::v32i8: case MVT::v8i32: case MVT::v4i64: case MVT::v8f32:
  case MVT::v4f64:
    RRC = &X86::VR128RegClass;
    break;
  }
  return std::make_pair(RRC, Cost);
}

bool X86TargetLowering::getStackCookieLocation(unsigned &AddressSpace,
                                               unsigned &Offset) const {
  if (!Subtarget->isTargetLinux())
    return false;

  if (Subtarget->is64Bit()) {
    // %fs:0x28, unless we're using a Kernel code model, in which case it's %gs:
    Offset = 0x28;
    if (getTargetMachine().getCodeModel() == CodeModel::Kernel)
      AddressSpace = 256;
    else
      AddressSpace = 257;
  } else {
    // %gs:0x14 on i386
    Offset = 0x14;
    AddressSpace = 256;
  }
  return true;
}

bool X86TargetLowering::isNoopAddrSpaceCast(unsigned SrcAS,
                                            unsigned DestAS) const {
  assert(SrcAS != DestAS && "Expected different address spaces!");

  return SrcAS < 256 && DestAS < 256;
}

//===----------------------------------------------------------------------===//
//               Return Value Calling Convention Implementation
//===----------------------------------------------------------------------===//

#include "X86GenCallingConv.inc"

bool
X86TargetLowering::CanLowerReturn(CallingConv::ID CallConv,
                                  MachineFunction &MF, bool isVarArg,
                        const SmallVectorImpl<ISD::OutputArg> &Outs,
                        LLVMContext &Context) const {
  SmallVector<CCValAssign, 16> RVLocs;
  CCState CCInfo(CallConv, isVarArg, MF, RVLocs, Context);
  return CCInfo.CheckReturn(Outs, RetCC_X86);
}

const MCPhysReg *X86TargetLowering::getScratchRegisters(CallingConv::ID) const {
  static const MCPhysReg ScratchRegs[] = { X86::R11, 0 };
  return ScratchRegs;
}

SDValue
X86TargetLowering::LowerReturn(SDValue Chain,
                               CallingConv::ID CallConv, bool isVarArg,
                               const SmallVectorImpl<ISD::OutputArg> &Outs,
                               const SmallVectorImpl<SDValue> &OutVals,
                               SDLoc dl, SelectionDAG &DAG) const {
  MachineFunction &MF = DAG.getMachineFunction();
  X86MachineFunctionInfo *FuncInfo = MF.getInfo<X86MachineFunctionInfo>();

  SmallVector<CCValAssign, 16> RVLocs;
  CCState CCInfo(CallConv, isVarArg, MF, RVLocs, *DAG.getContext());
  CCInfo.AnalyzeReturn(Outs, RetCC_X86);

  SDValue Flag;
  SmallVector<SDValue, 6> RetOps;
  RetOps.push_back(Chain); // Operand #0 = Chain (updated below)
  // Operand #1 = Bytes To Pop
  RetOps.push_back(DAG.getTargetConstant(FuncInfo->getBytesToPopOnReturn(),
                   MVT::i16));

  // Copy the result values into the output registers.
  for (unsigned i = 0; i != RVLocs.size(); ++i) {
    CCValAssign &VA = RVLocs[i];
    assert(VA.isRegLoc() && "Can only return in registers!");
    SDValue ValToCopy = OutVals[i];
    EVT ValVT = ValToCopy.getValueType();

    // Promote values to the appropriate types.
    if (VA.getLocInfo() == CCValAssign::SExt)
      ValToCopy = DAG.getNode(ISD::SIGN_EXTEND, dl, VA.getLocVT(), ValToCopy);
    else if (VA.getLocInfo() == CCValAssign::ZExt)
      ValToCopy = DAG.getNode(ISD::ZERO_EXTEND, dl, VA.getLocVT(), ValToCopy);
    else if (VA.getLocInfo() == CCValAssign::AExt)
      ValToCopy = DAG.getNode(ISD::ANY_EXTEND, dl, VA.getLocVT(), ValToCopy);
    else if (VA.getLocInfo() == CCValAssign::BCvt)
      ValToCopy = DAG.getNode(ISD::BITCAST, dl, VA.getLocVT(), ValToCopy);

    assert(VA.getLocInfo() != CCValAssign::FPExt &&
           "Unexpected FP-extend for return value.");

    // If this is x86-64, and we disabled SSE, we can't return FP values,
    // or SSE or MMX vectors.
    if ((ValVT == MVT::f32 || ValVT == MVT::f64 ||
         VA.getLocReg() == X86::XMM0 || VA.getLocReg() == X86::XMM1) &&
          (Subtarget->is64Bit() && !Subtarget->hasSSE1())) {
      report_fatal_error("SSE register return with SSE disabled");
    }
    // Likewise we can't return F64 values with SSE1 only.  gcc does so, but
    // llvm-gcc has never done it right and no one has noticed, so this
    // should be OK for now.
    if (ValVT == MVT::f64 &&
        (Subtarget->is64Bit() && !Subtarget->hasSSE2()))
      report_fatal_error("SSE2 register return with SSE2 disabled");

    // Returns in ST0/ST1 are handled specially: these are pushed as operands to
    // the RET instruction and handled by the FP Stackifier.
    if (VA.getLocReg() == X86::FP0 ||
        VA.getLocReg() == X86::FP1) {
      // If this is a copy from an xmm register to ST(0), use an FPExtend to
      // change the value to the FP stack register class.
      if (isScalarFPTypeInSSEReg(VA.getValVT()))
        ValToCopy = DAG.getNode(ISD::FP_EXTEND, dl, MVT::f80, ValToCopy);
      RetOps.push_back(ValToCopy);
      // Don't emit a copytoreg.
      continue;
    }

    // 64-bit vector (MMX) values are returned in XMM0 / XMM1 except for v1i64
    // which is returned in RAX / RDX.
    if (Subtarget->is64Bit()) {
      if (ValVT == MVT::x86mmx) {
        if (VA.getLocReg() == X86::XMM0 || VA.getLocReg() == X86::XMM1) {
          ValToCopy = DAG.getNode(ISD::BITCAST, dl, MVT::i64, ValToCopy);
          ValToCopy = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, MVT::v2i64,
                                  ValToCopy);
          // If we don't have SSE2 available, convert to v4f32 so the generated
          // register is legal.
          if (!Subtarget->hasSSE2())
            ValToCopy = DAG.getNode(ISD::BITCAST, dl, MVT::v4f32,ValToCopy);
        }
      }
    }

    Chain = DAG.getCopyToReg(Chain, dl, VA.getLocReg(), ValToCopy, Flag);
    Flag = Chain.getValue(1);
    RetOps.push_back(DAG.getRegister(VA.getLocReg(), VA.getLocVT()));
  }

  // The x86-64 ABIs require that for returning structs by value we copy
  // the sret argument into %rax/%eax (depending on ABI) for the return.
  // Win32 requires us to put the sret argument to %eax as well.
  // We saved the argument into a virtual register in the entry block,
  // so now we copy the value out and into %rax/%eax.
  //
  // Checking Function.hasStructRetAttr() here is insufficient because the IR
  // may not have an explicit sret argument. If FuncInfo.CanLowerReturn is
  // false, then an sret argument may be implicitly inserted in the SelDAG. In
  // either case FuncInfo->setSRetReturnReg() will have been called.
  if (unsigned SRetReg = FuncInfo->getSRetReturnReg()) {
    assert((Subtarget->is64Bit() || Subtarget->isTargetKnownWindowsMSVC()) &&
           "No need for an sret register");
    SDValue Val = DAG.getCopyFromReg(Chain, dl, SRetReg, getPointerTy());

    unsigned RetValReg
        = (Subtarget->is64Bit() && !Subtarget->isTarget64BitILP32()) ?
          X86::RAX : X86::EAX;
    Chain = DAG.getCopyToReg(Chain, dl, RetValReg, Val, Flag);
    Flag = Chain.getValue(1);

    // RAX/EAX now acts like a return value.
    RetOps.push_back(DAG.getRegister(RetValReg, getPointerTy()));
  }

  RetOps[0] = Chain;  // Update chain.

  // Add the flag if we have it.
  if (Flag.getNode())
    RetOps.push_back(Flag);

  return DAG.getNode(X86ISD::RET_FLAG, dl, MVT::Other, RetOps);
}

bool X86TargetLowering::isUsedByReturnOnly(SDNode *N, SDValue &Chain) const {
  if (N->getNumValues() != 1)
    return false;
  if (!N->hasNUsesOfValue(1, 0))
    return false;

  SDValue TCChain = Chain;
  SDNode *Copy = *N->use_begin();
  if (Copy->getOpcode() == ISD::CopyToReg) {
    // If the copy has a glue operand, we conservatively assume it isn't safe to
    // perform a tail call.
    if (Copy->getOperand(Copy->getNumOperands()-1).getValueType() == MVT::Glue)
      return false;
    TCChain = Copy->getOperand(0);
  } else if (Copy->getOpcode() != ISD::FP_EXTEND)
    return false;

  bool HasRet = false;
  for (SDNode::use_iterator UI = Copy->use_begin(), UE = Copy->use_end();
       UI != UE; ++UI) {
    if (UI->getOpcode() != X86ISD::RET_FLAG)
      return false;
    // If we are returning more than one value, we can definitely
    // not make a tail call see PR19530
    if (UI->getNumOperands() > 4)
      return false;
    if (UI->getNumOperands() == 4 &&
        UI->getOperand(UI->getNumOperands()-1).getValueType() != MVT::Glue)
      return false;
    HasRet = true;
  }

  if (!HasRet)
    return false;

  Chain = TCChain;
  return true;
}

EVT
X86TargetLowering::getTypeForExtArgOrReturn(LLVMContext &Context, EVT VT,
                                            ISD::NodeType ExtendKind) const {
  MVT ReturnMVT;
  // TODO: Is this also valid on 32-bit?
  if (Subtarget->is64Bit() && VT == MVT::i1 && ExtendKind == ISD::ZERO_EXTEND)
    ReturnMVT = MVT::i8;
  else
    ReturnMVT = MVT::i32;

  EVT MinVT = getRegisterType(Context, ReturnMVT);
  return VT.bitsLT(MinVT) ? MinVT : VT;
}

/// Lower the result values of a call into the
/// appropriate copies out of appropriate physical registers.
///
SDValue
X86TargetLowering::LowerCallResult(SDValue Chain, SDValue InFlag,
                                   CallingConv::ID CallConv, bool isVarArg,
                                   const SmallVectorImpl<ISD::InputArg> &Ins,
                                   SDLoc dl, SelectionDAG &DAG,
                                   SmallVectorImpl<SDValue> &InVals) const {

  // Assign locations to each value returned by this call.
  SmallVector<CCValAssign, 16> RVLocs;
  bool Is64Bit = Subtarget->is64Bit();
  CCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(), RVLocs,
                 *DAG.getContext());
  CCInfo.AnalyzeCallResult(Ins, RetCC_X86);

  // Copy all of the result registers out of their specified physreg.
  for (unsigned i = 0, e = RVLocs.size(); i != e; ++i) {
    CCValAssign &VA = RVLocs[i];
    EVT CopyVT = VA.getValVT();

    // If this is x86-64, and we disabled SSE, we can't return FP values
    if ((CopyVT == MVT::f32 || CopyVT == MVT::f64) &&
        ((Is64Bit || Ins[i].Flags.isInReg()) && !Subtarget->hasSSE1())) {
      report_fatal_error("SSE register return with SSE disabled");
    }

    // If we prefer to use the value in xmm registers, copy it out as f80 and
    // use a truncate to move it from fp stack reg to xmm reg.
    if ((VA.getLocReg() == X86::FP0 || VA.getLocReg() == X86::FP1) &&
        isScalarFPTypeInSSEReg(VA.getValVT()))
      CopyVT = MVT::f80;

    Chain = DAG.getCopyFromReg(Chain, dl, VA.getLocReg(),
                               CopyVT, InFlag).getValue(1);
    SDValue Val = Chain.getValue(0);

    if (CopyVT != VA.getValVT())
      Val = DAG.getNode(ISD::FP_ROUND, dl, VA.getValVT(), Val,
                        // This truncation won't change the value.
                        DAG.getIntPtrConstant(1));

    InFlag = Chain.getValue(2);
    InVals.push_back(Val);
  }

  return Chain;
}

//===----------------------------------------------------------------------===//
//                C & StdCall & Fast Calling Convention implementation
//===----------------------------------------------------------------------===//
//  StdCall calling convention seems to be standard for many Windows' API
//  routines and around. It differs from C calling convention just a little:
//  callee should clean up the stack, not caller. Symbols should be also
//  decorated in some fancy way :) It doesn't support any vector arguments.
//  For info on fast calling convention see Fast Calling Convention (tail call)
//  implementation LowerX86_32FastCCCallTo.

/// CallIsStructReturn - Determines whether a call uses struct return
/// semantics.
enum StructReturnType {
  NotStructReturn,
  RegStructReturn,
  StackStructReturn
};
static StructReturnType
callIsStructReturn(const SmallVectorImpl<ISD::OutputArg> &Outs) {
  if (Outs.empty())
    return NotStructReturn;

  const ISD::ArgFlagsTy &Flags = Outs[0].Flags;
  if (!Flags.isSRet())
    return NotStructReturn;
  if (Flags.isInReg())
    return RegStructReturn;
  return StackStructReturn;
}

/// Determines whether a function uses struct return semantics.
static StructReturnType
argsAreStructReturn(const SmallVectorImpl<ISD::InputArg> &Ins) {
  if (Ins.empty())
    return NotStructReturn;

  const ISD::ArgFlagsTy &Flags = Ins[0].Flags;
  if (!Flags.isSRet())
    return NotStructReturn;
  if (Flags.isInReg())
    return RegStructReturn;
  return StackStructReturn;
}

/// Make a copy of an aggregate at address specified by "Src" to address
/// "Dst" with size and alignment information specified by the specific
/// parameter attribute. The copy will be passed as a byval function parameter.
static SDValue
CreateCopyOfByValArgument(SDValue Src, SDValue Dst, SDValue Chain,
                          ISD::ArgFlagsTy Flags, SelectionDAG &DAG,
                          SDLoc dl) {
  SDValue SizeNode = DAG.getConstant(Flags.getByValSize(), MVT::i32);

  return DAG.getMemcpy(Chain, dl, Dst, Src, SizeNode, Flags.getByValAlign(),
                       /*isVolatile*/false, /*AlwaysInline=*/true,
                       MachinePointerInfo(), MachinePointerInfo());
}

/// Return true if the calling convention is one that
/// supports tail call optimization.
static bool IsTailCallConvention(CallingConv::ID CC) {
  return (CC == CallingConv::Fast || CC == CallingConv::GHC ||
          CC == CallingConv::HiPE);
}

/// \brief Return true if the calling convention is a C calling convention.
static bool IsCCallConvention(CallingConv::ID CC) {
  return (CC == CallingConv::C || CC == CallingConv::X86_64_Win64 ||
          CC == CallingConv::X86_64_SysV);
}

bool X86TargetLowering::mayBeEmittedAsTailCall(CallInst *CI) const {
  if (!CI->isTailCall() || getTargetMachine().Options.DisableTailCalls)
    return false;

  CallSite CS(CI);
  CallingConv::ID CalleeCC = CS.getCallingConv();
  if (!IsTailCallConvention(CalleeCC) && !IsCCallConvention(CalleeCC))
    return false;

  return true;
}

/// Return true if the function is being made into
/// a tailcall target by changing its ABI.
static bool FuncIsMadeTailCallSafe(CallingConv::ID CC,
                                   bool GuaranteedTailCallOpt) {
  return GuaranteedTailCallOpt && IsTailCallConvention(CC);
}

SDValue
X86TargetLowering::LowerMemArgument(SDValue Chain,
                                    CallingConv::ID CallConv,
                                    const SmallVectorImpl<ISD::InputArg> &Ins,
                                    SDLoc dl, SelectionDAG &DAG,
                                    const CCValAssign &VA,
                                    MachineFrameInfo *MFI,
                                    unsigned i) const {
  // Create the nodes corresponding to a load from this parameter slot.
  ISD::ArgFlagsTy Flags = Ins[i].Flags;
  bool AlwaysUseMutable = FuncIsMadeTailCallSafe(
      CallConv, DAG.getTarget().Options.GuaranteedTailCallOpt);
  bool isImmutable = !AlwaysUseMutable && !Flags.isByVal();
  EVT ValVT;

  // If value is passed by pointer we have address passed instead of the value
  // itself.
  if (VA.getLocInfo() == CCValAssign::Indirect)
    ValVT = VA.getLocVT();
  else
    ValVT = VA.getValVT();

  // FIXME: For now, all byval parameter objects are marked mutable. This can be
  // changed with more analysis.
  // In case of tail call optimization mark all arguments mutable. Since they
  // could be overwritten by lowering of arguments in case of a tail call.
  if (Flags.isByVal()) {
    unsigned Bytes = Flags.getByValSize();
    if (Bytes == 0) Bytes = 1; // Don't create zero-sized stack objects.
    int FI = MFI->CreateFixedObject(Bytes, VA.getLocMemOffset(), isImmutable);
    return DAG.getFrameIndex(FI, getPointerTy());
  } else {
    int FI = MFI->CreateFixedObject(ValVT.getSizeInBits()/8,
                                    VA.getLocMemOffset(), isImmutable);
    SDValue FIN = DAG.getFrameIndex(FI, getPointerTy());
    return DAG.getLoad(ValVT, dl, Chain, FIN,
                       MachinePointerInfo::getFixedStack(FI),
                       false, false, false, 0);
  }
}

// FIXME: Get this from tablegen.
static ArrayRef<MCPhysReg> get64BitArgumentGPRs(CallingConv::ID CallConv,
                                                const X86Subtarget *Subtarget) {
  assert(Subtarget->is64Bit());

  if (Subtarget->isCallingConvWin64(CallConv)) {
    static const MCPhysReg GPR64ArgRegsWin64[] = {
      X86::RCX, X86::RDX, X86::R8,  X86::R9
    };
    return makeArrayRef(std::begin(GPR64ArgRegsWin64), std::end(GPR64ArgRegsWin64));
  }

  static const MCPhysReg GPR64ArgRegs64Bit[] = {
    X86::RDI, X86::RSI, X86::RDX, X86::RCX, X86::R8, X86::R9
  };
  return makeArrayRef(std::begin(GPR64ArgRegs64Bit), std::end(GPR64ArgRegs64Bit));
}

// FIXME: Get this from tablegen.
static ArrayRef<MCPhysReg> get64BitArgumentXMMs(MachineFunction &MF,
                                                CallingConv::ID CallConv,
                                                const X86Subtarget *Subtarget) {
  assert(Subtarget->is64Bit());
  if (Subtarget->isCallingConvWin64(CallConv)) {
    // The XMM registers which might contain var arg parameters are shadowed
    // in their paired GPR.  So we only need to save the GPR to their home
    // slots.
    // TODO: __vectorcall will change this.
    return None;
  }

  const Function *Fn = MF.getFunction();
  bool NoImplicitFloatOps = Fn->hasFnAttribute(Attribute::NoImplicitFloat);
  assert(!(MF.getTarget().Options.UseSoftFloat && NoImplicitFloatOps) &&
         "SSE register cannot be used when SSE is disabled!");
  if (MF.getTarget().Options.UseSoftFloat || NoImplicitFloatOps ||
      !Subtarget->hasSSE1())
    // Kernel mode asks for SSE to be disabled, so there are no XMM argument
    // registers.
    return None;

  static const MCPhysReg XMMArgRegs64Bit[] = {
    X86::XMM0, X86::XMM1, X86::XMM2, X86::XMM3,
    X86::XMM4, X86::XMM5, X86::XMM6, X86::XMM7
  };
  return makeArrayRef(std::begin(XMMArgRegs64Bit), std::end(XMMArgRegs64Bit));
}

SDValue
X86TargetLowering::LowerFormalArguments(SDValue Chain,
                                        CallingConv::ID CallConv,
                                        bool isVarArg,
                                      const SmallVectorImpl<ISD::InputArg> &Ins,
                                        SDLoc dl,
                                        SelectionDAG &DAG,
                                        SmallVectorImpl<SDValue> &InVals)
                                          const {
  MachineFunction &MF = DAG.getMachineFunction();
  X86MachineFunctionInfo *FuncInfo = MF.getInfo<X86MachineFunctionInfo>();

  const Function* Fn = MF.getFunction();
  if (Fn->hasExternalLinkage() &&
      Subtarget->isTargetCygMing() &&
      Fn->getName() == "main")
    FuncInfo->setForceFramePointer(true);

  MachineFrameInfo *MFI = MF.getFrameInfo();
  bool Is64Bit = Subtarget->is64Bit();
  bool IsWin64 = Subtarget->isCallingConvWin64(CallConv);

  assert(!(isVarArg && IsTailCallConvention(CallConv)) &&
         "Var args not supported with calling convention fastcc, ghc or hipe");

  // Assign locations to all of the incoming arguments.
  SmallVector<CCValAssign, 16> ArgLocs;
  CCState CCInfo(CallConv, isVarArg, MF, ArgLocs, *DAG.getContext());

  // Allocate shadow area for Win64
  if (IsWin64)
    CCInfo.AllocateStack(32, 8);

  CCInfo.AnalyzeFormalArguments(Ins, CC_X86);

  unsigned LastVal = ~0U;
  SDValue ArgValue;
  for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
    CCValAssign &VA = ArgLocs[i];
    // TODO: If an arg is passed in two places (e.g. reg and stack), skip later
    // places.
    assert(VA.getValNo() != LastVal &&
           "Don't support value assigned to multiple locs yet");
    (void)LastVal;
    LastVal = VA.getValNo();

    if (VA.isRegLoc()) {
      EVT RegVT = VA.getLocVT();
      const TargetRegisterClass *RC;
      if (RegVT == MVT::i32)
        RC = &X86::GR32RegClass;
      else if (Is64Bit && RegVT == MVT::i64)
        RC = &X86::GR64RegClass;
      else if (RegVT == MVT::f32)
        RC = &X86::FR32RegClass;
      else if (RegVT == MVT::f64)
        RC = &X86::FR64RegClass;
      else if (RegVT.is512BitVector())
        RC = &X86::VR512RegClass;
      else if (RegVT.is256BitVector())
        RC = &X86::VR256RegClass;
      else if (RegVT.is128BitVector())
        RC = &X86::VR128RegClass;
      else if (RegVT == MVT::x86mmx)
        RC = &X86::VR64RegClass;
      else if (RegVT == MVT::i1)
        RC = &X86::VK1RegClass;
      else if (RegVT == MVT::v8i1)
        RC = &X86::VK8RegClass;
      else if (RegVT == MVT::v16i1)
        RC = &X86::VK16RegClass;
      else if (RegVT == MVT::v32i1)
        RC = &X86::VK32RegClass;
      else if (RegVT == MVT::v64i1)
        RC = &X86::VK64RegClass;
      else
        llvm_unreachable("Unknown argument type!");

      unsigned Reg = MF.addLiveIn(VA.getLocReg(), RC);
      ArgValue = DAG.getCopyFromReg(Chain, dl, Reg, RegVT);

      // If this is an 8 or 16-bit value, it is really passed promoted to 32
      // bits.  Insert an assert[sz]ext to capture this, then truncate to the
      // right size.
      if (VA.getLocInfo() == CCValAssign::SExt)
        ArgValue = DAG.getNode(ISD::AssertSext, dl, RegVT, ArgValue,
                               DAG.getValueType(VA.getValVT()));
      else if (VA.getLocInfo() == CCValAssign::ZExt)
        ArgValue = DAG.getNode(ISD::AssertZext, dl, RegVT, ArgValue,
                               DAG.getValueType(VA.getValVT()));
      else if (VA.getLocInfo() == CCValAssign::BCvt)
        ArgValue = DAG.getNode(ISD::BITCAST, dl, VA.getValVT(), ArgValue);

      if (VA.isExtInLoc()) {
        // Handle MMX values passed in XMM regs.
        if (RegVT.isVector())
          ArgValue = DAG.getNode(X86ISD::MOVDQ2Q, dl, VA.getValVT(), ArgValue);
        else
          ArgValue = DAG.getNode(ISD::TRUNCATE, dl, VA.getValVT(), ArgValue);
      }
    } else {
      assert(VA.isMemLoc());
      ArgValue = LowerMemArgument(Chain, CallConv, Ins, dl, DAG, VA, MFI, i);
    }

    // If value is passed via pointer - do a load.
    if (VA.getLocInfo() == CCValAssign::Indirect)
      ArgValue = DAG.getLoad(VA.getValVT(), dl, Chain, ArgValue,
                             MachinePointerInfo(), false, false, false, 0);

    InVals.push_back(ArgValue);
  }

  if (Subtarget->is64Bit() || Subtarget->isTargetKnownWindowsMSVC()) {
    for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
      // The x86-64 ABIs require that for returning structs by value we copy
      // the sret argument into %rax/%eax (depending on ABI) for the return.
      // Win32 requires us to put the sret argument to %eax as well.
      // Save the argument into a virtual register so that we can access it
      // from the return points.
      if (Ins[i].Flags.isSRet()) {
        unsigned Reg = FuncInfo->getSRetReturnReg();
        if (!Reg) {
          MVT PtrTy = getPointerTy();
          Reg = MF.getRegInfo().createVirtualRegister(getRegClassFor(PtrTy));
          FuncInfo->setSRetReturnReg(Reg);
        }
        SDValue Copy = DAG.getCopyToReg(DAG.getEntryNode(), dl, Reg, InVals[i]);
        Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Copy, Chain);
        break;
      }
    }
  }

  unsigned StackSize = CCInfo.getNextStackOffset();
  // Align stack specially for tail calls.
  if (FuncIsMadeTailCallSafe(CallConv,
                             MF.getTarget().Options.GuaranteedTailCallOpt))
    StackSize = GetAlignedArgumentStackSize(StackSize, DAG);

  // If the function takes variable number of arguments, make a frame index for
  // the start of the first vararg value... for expansion of llvm.va_start. We
  // can skip this if there are no va_start calls.
  if (MFI->hasVAStart() &&
      (Is64Bit || (CallConv != CallingConv::X86_FastCall &&
                   CallConv != CallingConv::X86_ThisCall))) {
    FuncInfo->setVarArgsFrameIndex(
        MFI->CreateFixedObject(1, StackSize, true));
  }

  // Figure out if XMM registers are in use.
  assert(!(MF.getTarget().Options.UseSoftFloat &&
           Fn->hasFnAttribute(Attribute::NoImplicitFloat)) &&
         "SSE register cannot be used when SSE is disabled!");

  // 64-bit calling conventions support varargs and register parameters, so we
  // have to do extra work to spill them in the prologue.
  if (Is64Bit && isVarArg && MFI->hasVAStart()) {
    // Find the first unallocated argument registers.
    ArrayRef<MCPhysReg> ArgGPRs = get64BitArgumentGPRs(CallConv, Subtarget);
    ArrayRef<MCPhysReg> ArgXMMs = get64BitArgumentXMMs(MF, CallConv, Subtarget);
    unsigned NumIntRegs =
        CCInfo.getFirstUnallocated(ArgGPRs.data(), ArgGPRs.size());
    unsigned NumXMMRegs =
        CCInfo.getFirstUnallocated(ArgXMMs.data(), ArgXMMs.size());
    assert(!(NumXMMRegs && !Subtarget->hasSSE1()) &&
           "SSE register cannot be used when SSE is disabled!");

    // Gather all the live in physical registers.
    SmallVector<SDValue, 6> LiveGPRs;
    SmallVector<SDValue, 8> LiveXMMRegs;
    SDValue ALVal;
    for (MCPhysReg Reg : ArgGPRs.slice(NumIntRegs)) {
      unsigned GPR = MF.addLiveIn(Reg, &X86::GR64RegClass);
      LiveGPRs.push_back(
          DAG.getCopyFromReg(Chain, dl, GPR, MVT::i64));
    }
    if (!ArgXMMs.empty()) {
      unsigned AL = MF.addLiveIn(X86::AL, &X86::GR8RegClass);
      ALVal = DAG.getCopyFromReg(Chain, dl, AL, MVT::i8);
      for (MCPhysReg Reg : ArgXMMs.slice(NumXMMRegs)) {
        unsigned XMMReg = MF.addLiveIn(Reg, &X86::VR128RegClass);
        LiveXMMRegs.push_back(
            DAG.getCopyFromReg(Chain, dl, XMMReg, MVT::v4f32));
      }
    }

    if (IsWin64) {
      const TargetFrameLowering &TFI = *Subtarget->getFrameLowering();
      // Get to the caller-allocated home save location.  Add 8 to account
      // for the return address.
      int HomeOffset = TFI.getOffsetOfLocalArea() + 8;
      FuncInfo->setRegSaveFrameIndex(
          MFI->CreateFixedObject(1, NumIntRegs * 8 + HomeOffset, false));
      // Fixup to set vararg frame on shadow area (4 x i64).
      if (NumIntRegs < 4)
        FuncInfo->setVarArgsFrameIndex(FuncInfo->getRegSaveFrameIndex());
    } else {
      // For X86-64, if there are vararg parameters that are passed via
      // registers, then we must store them to their spots on the stack so
      // they may be loaded by deferencing the result of va_next.
      FuncInfo->setVarArgsGPOffset(NumIntRegs * 8);
      FuncInfo->setVarArgsFPOffset(ArgGPRs.size() * 8 + NumXMMRegs * 16);
      FuncInfo->setRegSaveFrameIndex(MFI->CreateStackObject(
          ArgGPRs.size() * 8 + ArgXMMs.size() * 16, 16, false));
    }

    // Store the integer parameter registers.
    SmallVector<SDValue, 8> MemOps;
    SDValue RSFIN = DAG.getFrameIndex(FuncInfo->getRegSaveFrameIndex(),
                                      getPointerTy());
    unsigned Offset = FuncInfo->getVarArgsGPOffset();
    for (SDValue Val : LiveGPRs) {
      SDValue FIN = DAG.getNode(ISD::ADD, dl, getPointerTy(), RSFIN,
                                DAG.getIntPtrConstant(Offset));
      SDValue Store =
        DAG.getStore(Val.getValue(1), dl, Val, FIN,
                     MachinePointerInfo::getFixedStack(
                       FuncInfo->getRegSaveFrameIndex(), Offset),
                     false, false, 0);
      MemOps.push_back(Store);
      Offset += 8;
    }

    if (!ArgXMMs.empty() && NumXMMRegs != ArgXMMs.size()) {
      // Now store the XMM (fp + vector) parameter registers.
      SmallVector<SDValue, 12> SaveXMMOps;
      SaveXMMOps.push_back(Chain);
      SaveXMMOps.push_back(ALVal);
      SaveXMMOps.push_back(DAG.getIntPtrConstant(
                             FuncInfo->getRegSaveFrameIndex()));
      SaveXMMOps.push_back(DAG.getIntPtrConstant(
                             FuncInfo->getVarArgsFPOffset()));
      SaveXMMOps.insert(SaveXMMOps.end(), LiveXMMRegs.begin(),
                        LiveXMMRegs.end());
      MemOps.push_back(DAG.getNode(X86ISD::VASTART_SAVE_XMM_REGS, dl,
                                   MVT::Other, SaveXMMOps));
    }

    if (!MemOps.empty())
      Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, MemOps);
  }

  if (isVarArg && MFI->hasMustTailInVarArgFunc()) {
    // Find the largest legal vector type.
    MVT VecVT = MVT::Other;
    // FIXME: Only some x86_32 calling conventions support AVX512.
    if (Subtarget->hasAVX512() &&
        (Is64Bit || (CallConv == CallingConv::X86_VectorCall ||
                     CallConv == CallingConv::Intel_OCL_BI)))
      VecVT = MVT::v16f32;
    else if (Subtarget->hasAVX())
      VecVT = MVT::v8f32;
    else if (Subtarget->hasSSE2())
      VecVT = MVT::v4f32;

    // We forward some GPRs and some vector types.
    SmallVector<MVT, 2> RegParmTypes;
    MVT IntVT = Is64Bit ? MVT::i64 : MVT::i32;
    RegParmTypes.push_back(IntVT);
    if (VecVT != MVT::Other)
      RegParmTypes.push_back(VecVT);

    // Compute the set of forwarded registers. The rest are scratch.
    SmallVectorImpl<ForwardedRegister> &Forwards =
        FuncInfo->getForwardedMustTailRegParms();
    CCInfo.analyzeMustTailForwardedRegisters(Forwards, RegParmTypes, CC_X86);

    // Conservatively forward AL on x86_64, since it might be used for varargs.
    if (Is64Bit && !CCInfo.isAllocated(X86::AL)) {
      unsigned ALVReg = MF.addLiveIn(X86::AL, &X86::GR8RegClass);
      Forwards.push_back(ForwardedRegister(ALVReg, X86::AL, MVT::i8));
    }

    // Copy all forwards from physical to virtual registers.
    for (ForwardedRegister &F : Forwards) {
      // FIXME: Can we use a less constrained schedule?
      SDValue RegVal = DAG.getCopyFromReg(Chain, dl, F.VReg, F.VT);
      F.VReg = MF.getRegInfo().createVirtualRegister(getRegClassFor(F.VT));
      Chain = DAG.getCopyToReg(Chain, dl, F.VReg, RegVal);
    }
  }

  // Some CCs need callee pop.
  if (X86::isCalleePop(CallConv, Is64Bit, isVarArg,
                       MF.getTarget().Options.GuaranteedTailCallOpt)) {
    FuncInfo->setBytesToPopOnReturn(StackSize); // Callee pops everything.
  } else {
    FuncInfo->setBytesToPopOnReturn(0); // Callee pops nothing.
    // If this is an sret function, the return should pop the hidden pointer.
    if (!Is64Bit && !IsTailCallConvention(CallConv) &&
        !Subtarget->getTargetTriple().isOSMSVCRT() &&
        argsAreStructReturn(Ins) == StackStructReturn)
      FuncInfo->setBytesToPopOnReturn(4);
  }

  if (!Is64Bit) {
    // RegSaveFrameIndex is X86-64 only.
    FuncInfo->setRegSaveFrameIndex(0xAAAAAAA);
    if (CallConv == CallingConv::X86_FastCall ||
        CallConv == CallingConv::X86_ThisCall)
      // fastcc functions can't have varargs.
      FuncInfo->setVarArgsFrameIndex(0xAAAAAAA);
  }

  FuncInfo->setArgumentStackSize(StackSize);

  return Chain;
}

SDValue
X86TargetLowering::LowerMemOpCallTo(SDValue Chain,
                                    SDValue StackPtr, SDValue Arg,
                                    SDLoc dl, SelectionDAG &DAG,
                                    const CCValAssign &VA,
                                    ISD::ArgFlagsTy Flags) const {
  unsigned LocMemOffset = VA.getLocMemOffset();
  SDValue PtrOff = DAG.getIntPtrConstant(LocMemOffset);
  PtrOff = DAG.getNode(ISD::ADD, dl, getPointerTy(), StackPtr, PtrOff);
  if (Flags.isByVal())
    return CreateCopyOfByValArgument(Arg, PtrOff, Chain, Flags, DAG, dl);

  return DAG.getStore(Chain, dl, Arg, PtrOff,
                      MachinePointerInfo::getStack(LocMemOffset),
                      false, false, 0);
}

/// Emit a load of return address if tail call
/// optimization is performed and it is required.
SDValue
X86TargetLowering::EmitTailCallLoadRetAddr(SelectionDAG &DAG,
                                           SDValue &OutRetAddr, SDValue Chain,
                                           bool IsTailCall, bool Is64Bit,
                                           int FPDiff, SDLoc dl) const {
  // Adjust the Return address stack slot.
  EVT VT = getPointerTy();
  OutRetAddr = getReturnAddressFrameIndex(DAG);

  // Load the "old" Return address.
  OutRetAddr = DAG.getLoad(VT, dl, Chain, OutRetAddr, MachinePointerInfo(),
                           false, false, false, 0);
  return SDValue(OutRetAddr.getNode(), 1);
}

/// Emit a store of the return address if tail call
/// optimization is performed and it is required (FPDiff!=0).
static SDValue EmitTailCallStoreRetAddr(SelectionDAG &DAG, MachineFunction &MF,
                                        SDValue Chain, SDValue RetAddrFrIdx,
                                        EVT PtrVT, unsigned SlotSize,
                                        int FPDiff, SDLoc dl) {
  // Store the return address to the appropriate stack slot.
  if (!FPDiff) return Chain;
  // Calculate the new stack slot for the return address.
  int NewReturnAddrFI =
    MF.getFrameInfo()->CreateFixedObject(SlotSize, (int64_t)FPDiff - SlotSize,
                                         false);
  SDValue NewRetAddrFrIdx = DAG.getFrameIndex(NewReturnAddrFI, PtrVT);
  Chain = DAG.getStore(Chain, dl, RetAddrFrIdx, NewRetAddrFrIdx,
                       MachinePointerInfo::getFixedStack(NewReturnAddrFI),
                       false, false, 0);
  return Chain;
}

SDValue
X86TargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI,
                             SmallVectorImpl<SDValue> &InVals) const {
  SelectionDAG &DAG                     = CLI.DAG;
  SDLoc &dl                             = CLI.DL;
  SmallVectorImpl<ISD::OutputArg> &Outs = CLI.Outs;
  SmallVectorImpl<SDValue> &OutVals     = CLI.OutVals;
  SmallVectorImpl<ISD::InputArg> &Ins   = CLI.Ins;
  SDValue Chain                         = CLI.Chain;
  SDValue Callee                        = CLI.Callee;
  CallingConv::ID CallConv              = CLI.CallConv;
  bool &isTailCall                      = CLI.IsTailCall;
  bool isVarArg                         = CLI.IsVarArg;

  MachineFunction &MF = DAG.getMachineFunction();
  bool Is64Bit        = Subtarget->is64Bit();
  bool IsWin64        = Subtarget->isCallingConvWin64(CallConv);
  StructReturnType SR = callIsStructReturn(Outs);
  bool IsSibcall      = false;
  X86MachineFunctionInfo *X86Info = MF.getInfo<X86MachineFunctionInfo>();

  if (MF.getTarget().Options.DisableTailCalls)
    isTailCall = false;

  bool IsMustTail = CLI.CS && CLI.CS->isMustTailCall();
  if (IsMustTail) {
    // Force this to be a tail call.  The verifier rules are enough to ensure
    // that we can lower this successfully without moving the return address
    // around.
    isTailCall = true;
  } else if (isTailCall) {
    // Check if it's really possible to do a tail call.
    isTailCall = IsEligibleForTailCallOptimization(Callee, CallConv,
                    isVarArg, SR != NotStructReturn,
                    MF.getFunction()->hasStructRetAttr(), CLI.RetTy,
                    Outs, OutVals, Ins, DAG);

    // Sibcalls are automatically detected tailcalls which do not require
    // ABI changes.
    if (!MF.getTarget().Options.GuaranteedTailCallOpt && isTailCall)
      IsSibcall = true;

    if (isTailCall)
      ++NumTailCalls;
  }

  assert(!(isVarArg && IsTailCallConvention(CallConv)) &&
         "Var args not supported with calling convention fastcc, ghc or hipe");

  // Analyze operands of the call, assigning locations to each operand.
  SmallVector<CCValAssign, 16> ArgLocs;
  CCState CCInfo(CallConv, isVarArg, MF, ArgLocs, *DAG.getContext());

  // Allocate shadow area for Win64
  if (IsWin64)
    CCInfo.AllocateStack(32, 8);

  CCInfo.AnalyzeCallOperands(Outs, CC_X86);

  // Get a count of how many bytes are to be pushed on the stack.
  unsigned NumBytes = CCInfo.getNextStackOffset();
  if (IsSibcall)
    // This is a sibcall. The memory operands are available in caller's
    // own caller's stack.
    NumBytes = 0;
  else if (MF.getTarget().Options.GuaranteedTailCallOpt &&
           IsTailCallConvention(CallConv))
    NumBytes = GetAlignedArgumentStackSize(NumBytes, DAG);

  int FPDiff = 0;
  if (isTailCall && !IsSibcall && !IsMustTail) {
    // Lower arguments at fp - stackoffset + fpdiff.
    unsigned NumBytesCallerPushed = X86Info->getBytesToPopOnReturn();

    FPDiff = NumBytesCallerPushed - NumBytes;

    // Set the delta of movement of the returnaddr stackslot.
    // But only set if delta is greater than previous delta.
    if (FPDiff < X86Info->getTCReturnAddrDelta())
      X86Info->setTCReturnAddrDelta(FPDiff);
  }

  unsigned NumBytesToPush = NumBytes;
  unsigned NumBytesToPop = NumBytes;

  // If we have an inalloca argument, all stack space has already been allocated
  // for us and be right at the top of the stack.  We don't support multiple
  // arguments passed in memory when using inalloca.
  if (!Outs.empty() && Outs.back().Flags.isInAlloca()) {
    NumBytesToPush = 0;
    if (!ArgLocs.back().isMemLoc())
      report_fatal_error("cannot use inalloca attribute on a register "
                         "parameter");
    if (ArgLocs.back().getLocMemOffset() != 0)
      report_fatal_error("any parameter with the inalloca attribute must be "
                         "the only memory argument");
  }

  if (!IsSibcall)
    Chain = DAG.getCALLSEQ_START(
        Chain, DAG.getIntPtrConstant(NumBytesToPush, true), dl);

  SDValue RetAddrFrIdx;
  // Load return address for tail calls.
  if (isTailCall && FPDiff)
    Chain = EmitTailCallLoadRetAddr(DAG, RetAddrFrIdx, Chain, isTailCall,
                                    Is64Bit, FPDiff, dl);

  SmallVector<std::pair<unsigned, SDValue>, 8> RegsToPass;
  SmallVector<SDValue, 8> MemOpChains;
  SDValue StackPtr;

  // Walk the register/memloc assignments, inserting copies/loads.  In the case
  // of tail call optimization arguments are handle later.
  const X86RegisterInfo *RegInfo = Subtarget->getRegisterInfo();
  for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
    // Skip inalloca arguments, they have already been written.
    ISD::ArgFlagsTy Flags = Outs[i].Flags;
    if (Flags.isInAlloca())
      continue;

    CCValAssign &VA = ArgLocs[i];
    EVT RegVT = VA.getLocVT();
    SDValue Arg = OutVals[i];
    bool isByVal = Flags.isByVal();

    // Promote the value if needed.
    switch (VA.getLocInfo()) {
    default: llvm_unreachable("Unknown loc info!");
    case CCValAssign::Full: break;
    case CCValAssign::SExt:
      Arg = DAG.getNode(ISD::SIGN_EXTEND, dl, RegVT, Arg);
      break;
    case CCValAssign::ZExt:
      Arg = DAG.getNode(ISD::ZERO_EXTEND, dl, RegVT, Arg);
      break;
    case CCValAssign::AExt:
      if (RegVT.is128BitVector()) {
        // Special case: passing MMX values in XMM registers.
        Arg = DAG.getNode(ISD::BITCAST, dl, MVT::i64, Arg);
        Arg = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, MVT::v2i64, Arg);
        Arg = getMOVL(DAG, dl, MVT::v2i64, DAG.getUNDEF(MVT::v2i64), Arg);
      } else
        Arg = DAG.getNode(ISD::ANY_EXTEND, dl, RegVT, Arg);
      break;
    case CCValAssign::BCvt:
      Arg = DAG.getNode(ISD::BITCAST, dl, RegVT, Arg);
      break;
    case CCValAssign::Indirect: {
      // Store the argument.
      SDValue SpillSlot = DAG.CreateStackTemporary(VA.getValVT());
      int FI = cast<FrameIndexSDNode>(SpillSlot)->getIndex();
      Chain = DAG.getStore(Chain, dl, Arg, SpillSlot,
                           MachinePointerInfo::getFixedStack(FI),
                           false, false, 0);
      Arg = SpillSlot;
      break;
    }
    }

    if (VA.isRegLoc()) {
      RegsToPass.push_back(std::make_pair(VA.getLocReg(), Arg));
      if (isVarArg && IsWin64) {
        // Win64 ABI requires argument XMM reg to be copied to the corresponding
        // shadow reg if callee is a varargs function.
        unsigned ShadowReg = 0;
        switch (VA.getLocReg()) {
        case X86::XMM0: ShadowReg = X86::RCX; break;
        case X86::XMM1: ShadowReg = X86::RDX; break;
        case X86::XMM2: ShadowReg = X86::R8; break;
        case X86::XMM3: ShadowReg = X86::R9; break;
        }
        if (ShadowReg)
          RegsToPass.push_back(std::make_pair(ShadowReg, Arg));
      }
    } else if (!IsSibcall && (!isTailCall || isByVal)) {
      assert(VA.isMemLoc());
      if (!StackPtr.getNode())
        StackPtr = DAG.getCopyFromReg(Chain, dl, RegInfo->getStackRegister(),
                                      getPointerTy());
      MemOpChains.push_back(LowerMemOpCallTo(Chain, StackPtr, Arg,
                                             dl, DAG, VA, Flags));
    }
  }

  if (!MemOpChains.empty())
    Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, MemOpChains);

  if (Subtarget->isPICStyleGOT()) {
    // ELF / PIC requires GOT in the EBX register before function calls via PLT
    // GOT pointer.
    if (!isTailCall) {
      RegsToPass.push_back(std::make_pair(unsigned(X86::EBX),
               DAG.getNode(X86ISD::GlobalBaseReg, SDLoc(), getPointerTy())));
    } else {
      // If we are tail calling and generating PIC/GOT style code load the
      // address of the callee into ECX. The value in ecx is used as target of
      // the tail jump. This is done to circumvent the ebx/callee-saved problem
      // for tail calls on PIC/GOT architectures. Normally we would just put the
      // address of GOT into ebx and then call target@PLT. But for tail calls
      // ebx would be restored (since ebx is callee saved) before jumping to the
      // target@PLT.

      // Note: The actual moving to ECX is done further down.
      GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee);
      if (G && !G->getGlobal()->hasHiddenVisibility() &&
          !G->getGlobal()->hasProtectedVisibility())
        Callee = LowerGlobalAddress(Callee, DAG);
      else if (isa<ExternalSymbolSDNode>(Callee))
        Callee = LowerExternalSymbol(Callee, DAG);
    }
  }

  if (Is64Bit && isVarArg && !IsWin64 && !IsMustTail) {
    // From AMD64 ABI document:
    // For calls that may call functions that use varargs or stdargs
    // (prototype-less calls or calls to functions containing ellipsis (...) in
    // the declaration) %al is used as hidden argument to specify the number
    // of SSE registers used. The contents of %al do not need to match exactly
    // the number of registers, but must be an ubound on the number of SSE
    // registers used and is in the range 0 - 8 inclusive.

    // Count the number of XMM registers allocated.
    static const MCPhysReg XMMArgRegs[] = {
      X86::XMM0, X86::XMM1, X86::XMM2, X86::XMM3,
      X86::XMM4, X86::XMM5, X86::XMM6, X86::XMM7
    };
    unsigned NumXMMRegs = CCInfo.getFirstUnallocated(XMMArgRegs, 8);
    assert((Subtarget->hasSSE1() || !NumXMMRegs)
           && "SSE registers cannot be used when SSE is disabled");

    RegsToPass.push_back(std::make_pair(unsigned(X86::AL),
                                        DAG.getConstant(NumXMMRegs, MVT::i8)));
  }

  if (isVarArg && IsMustTail) {
    const auto &Forwards = X86Info->getForwardedMustTailRegParms();
    for (const auto &F : Forwards) {
      SDValue Val = DAG.getCopyFromReg(Chain, dl, F.VReg, F.VT);
      RegsToPass.push_back(std::make_pair(unsigned(F.PReg), Val));
    }
  }

  // For tail calls lower the arguments to the 'real' stack slots.  Sibcalls
  // don't need this because the eligibility check rejects calls that require
  // shuffling arguments passed in memory.
  if (!IsSibcall && isTailCall) {
    // Force all the incoming stack arguments to be loaded from the stack
    // before any new outgoing arguments are stored to the stack, because the
    // outgoing stack slots may alias the incoming argument stack slots, and
    // the alias isn't otherwise explicit. This is slightly more conservative
    // than necessary, because it means that each store effectively depends
    // on every argument instead of just those arguments it would clobber.
    SDValue ArgChain = DAG.getStackArgumentTokenFactor(Chain);

    SmallVector<SDValue, 8> MemOpChains2;
    SDValue FIN;
    int FI = 0;
    for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
      CCValAssign &VA = ArgLocs[i];
      if (VA.isRegLoc())
        continue;
      assert(VA.isMemLoc());
      SDValue Arg = OutVals[i];
      ISD::ArgFlagsTy Flags = Outs[i].Flags;
      // Skip inalloca arguments.  They don't require any work.
      if (Flags.isInAlloca())
        continue;
      // Create frame index.
      int32_t Offset = VA.getLocMemOffset()+FPDiff;
      uint32_t OpSize = (VA.getLocVT().getSizeInBits()+7)/8;
      FI = MF.getFrameInfo()->CreateFixedObject(OpSize, Offset, true);
      FIN = DAG.getFrameIndex(FI, getPointerTy());

      if (Flags.isByVal()) {
        // Copy relative to framepointer.
        SDValue Source = DAG.getIntPtrConstant(VA.getLocMemOffset());
        if (!StackPtr.getNode())
          StackPtr = DAG.getCopyFromReg(Chain, dl,
                                        RegInfo->getStackRegister(),
                                        getPointerTy());
        Source = DAG.getNode(ISD::ADD, dl, getPointerTy(), StackPtr, Source);

        MemOpChains2.push_back(CreateCopyOfByValArgument(Source, FIN,
                                                         ArgChain,
                                                         Flags, DAG, dl));
      } else {
        // Store relative to framepointer.
        MemOpChains2.push_back(
          DAG.getStore(ArgChain, dl, Arg, FIN,
                       MachinePointerInfo::getFixedStack(FI),
                       false, false, 0));
      }
    }

    if (!MemOpChains2.empty())
      Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, MemOpChains2);

    // Store the return address to the appropriate stack slot.
    Chain = EmitTailCallStoreRetAddr(DAG, MF, Chain, RetAddrFrIdx,
                                     getPointerTy(), RegInfo->getSlotSize(),
                                     FPDiff, dl);
  }

  // Build a sequence of copy-to-reg nodes chained together with token chain
  // and flag operands which copy the outgoing args into registers.
  SDValue InFlag;
  for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) {
    Chain = DAG.getCopyToReg(Chain, dl, RegsToPass[i].first,
                             RegsToPass[i].second, InFlag);
    InFlag = Chain.getValue(1);
  }

  if (DAG.getTarget().getCodeModel() == CodeModel::Large) {
    assert(Is64Bit && "Large code model is only legal in 64-bit mode.");
    // In the 64-bit large code model, we have to make all calls
    // through a register, since the call instruction's 32-bit
    // pc-relative offset may not be large enough to hold the whole
    // address.
  } else if (Callee->getOpcode() == ISD::GlobalAddress) {
    // If the callee is a GlobalAddress node (quite common, every direct call
    // is) turn it into a TargetGlobalAddress node so that legalize doesn't hack
    // it.
    GlobalAddressSDNode* G = cast<GlobalAddressSDNode>(Callee);

    // We should use extra load for direct calls to dllimported functions in
    // non-JIT mode.
    const GlobalValue *GV = G->getGlobal();
    if (!GV->hasDLLImportStorageClass()) {
      unsigned char OpFlags = 0;
      bool ExtraLoad = false;
      unsigned WrapperKind = ISD::DELETED_NODE;

      // On ELF targets, in both X86-64 and X86-32 mode, direct calls to
      // external symbols most go through the PLT in PIC mode.  If the symbol
      // has hidden or protected visibility, or if it is static or local, then
      // we don't need to use the PLT - we can directly call it.
      if (Subtarget->isTargetELF() &&
          DAG.getTarget().getRelocationModel() == Reloc::PIC_ &&
          GV->hasDefaultVisibility() && !GV->hasLocalLinkage()) {
        OpFlags = X86II::MO_PLT;
      } else if (Subtarget->isPICStyleStubAny() &&
                 (GV->isDeclaration() || GV->isWeakForLinker()) &&
                 (!Subtarget->getTargetTriple().isMacOSX() ||
                  Subtarget->getTargetTriple().isMacOSXVersionLT(10, 5))) {
        // PC-relative references to external symbols should go through $stub,
        // unless we're building with the leopard linker or later, which
        // automatically synthesizes these stubs.
        OpFlags = X86II::MO_DARWIN_STUB;
      } else if (Subtarget->isPICStyleRIPRel() && isa<Function>(GV) &&
                 cast<Function>(GV)->hasFnAttribute(Attribute::NonLazyBind)) {
        // If the function is marked as non-lazy, generate an indirect call
        // which loads from the GOT directly. This avoids runtime overhead
        // at the cost of eager binding (and one extra byte of encoding).
        OpFlags = X86II::MO_GOTPCREL;
        WrapperKind = X86ISD::WrapperRIP;
        ExtraLoad = true;
      }

      Callee = DAG.getTargetGlobalAddress(GV, dl, getPointerTy(),
                                          G->getOffset(), OpFlags);

      // Add a wrapper if needed.
      if (WrapperKind != ISD::DELETED_NODE)
        Callee = DAG.getNode(X86ISD::WrapperRIP, dl, getPointerTy(), Callee);
      // Add extra indirection if needed.
      if (ExtraLoad)
        Callee = DAG.getLoad(getPointerTy(), dl, DAG.getEntryNode(), Callee,
                             MachinePointerInfo::getGOT(),
                             false, false, false, 0);
    }
  } else if (ExternalSymbolSDNode *S = dyn_cast<ExternalSymbolSDNode>(Callee)) {
    unsigned char OpFlags = 0;

    // On ELF targets, in either X86-64 or X86-32 mode, direct calls to
    // external symbols should go through the PLT.
    if (Subtarget->isTargetELF() &&
        DAG.getTarget().getRelocationModel() == Reloc::PIC_) {
      OpFlags = X86II::MO_PLT;
    } else if (Subtarget->isPICStyleStubAny() &&
               (!Subtarget->getTargetTriple().isMacOSX() ||
                Subtarget->getTargetTriple().isMacOSXVersionLT(10, 5))) {
      // PC-relative references to external symbols should go through $stub,
      // unless we're building with the leopard linker or later, which
      // automatically synthesizes these stubs.
      OpFlags = X86II::MO_DARWIN_STUB;
    }

    Callee = DAG.getTargetExternalSymbol(S->getSymbol(), getPointerTy(),
                                         OpFlags);
  } else if (Subtarget->isTarget64BitILP32() &&
             Callee->getValueType(0) == MVT::i32) {
    // Zero-extend the 32-bit Callee address into a 64-bit according to x32 ABI
    Callee = DAG.getNode(ISD::ZERO_EXTEND, dl, MVT::i64, Callee);
  }

  // Returns a chain & a flag for retval copy to use.
  SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue);
  SmallVector<SDValue, 8> Ops;

  if (!IsSibcall && isTailCall) {
    Chain = DAG.getCALLSEQ_END(Chain,
                               DAG.getIntPtrConstant(NumBytesToPop, true),
                               DAG.getIntPtrConstant(0, true), InFlag, dl);
    InFlag = Chain.getValue(1);
  }

  Ops.push_back(Chain);
  Ops.push_back(Callee);

  if (isTailCall)
    Ops.push_back(DAG.getConstant(FPDiff, MVT::i32));

  // Add argument registers to the end of the list so that they are known live
  // into the call.
  for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i)
    Ops.push_back(DAG.getRegister(RegsToPass[i].first,
                                  RegsToPass[i].second.getValueType()));

  // Add a register mask operand representing the call-preserved registers.
  const TargetRegisterInfo *TRI = Subtarget->getRegisterInfo();
  const uint32_t *Mask = TRI->getCallPreservedMask(CallConv);
  assert(Mask && "Missing call preserved mask for calling convention");
  Ops.push_back(DAG.getRegisterMask(Mask));

  if (InFlag.getNode())
    Ops.push_back(InFlag);

  if (isTailCall) {
    // We used to do:
    //// If this is the first return lowered for this function, add the regs
    //// to the liveout set for the function.
    // This isn't right, although it's probably harmless on x86; liveouts
    // should be computed from returns not tail calls.  Consider a void
    // function making a tail call to a function returning int.
    return DAG.getNode(X86ISD::TC_RETURN, dl, NodeTys, Ops);
  }

  Chain = DAG.getNode(X86ISD::CALL, dl, NodeTys, Ops);
  InFlag = Chain.getValue(1);

  // Create the CALLSEQ_END node.
  unsigned NumBytesForCalleeToPop;
  if (X86::isCalleePop(CallConv, Is64Bit, isVarArg,
                       DAG.getTarget().Options.GuaranteedTailCallOpt))
    NumBytesForCalleeToPop = NumBytes;    // Callee pops everything
  else if (!Is64Bit && !IsTailCallConvention(CallConv) &&
           !Subtarget->getTargetTriple().isOSMSVCRT() &&
           SR == StackStructReturn)
    // If this is a call to a struct-return function, the callee
    // pops the hidden struct pointer, so we have to push it back.
    // This is common for Darwin/X86, Linux & Mingw32 targets.
    // For MSVC Win32 targets, the caller pops the hidden struct pointer.
    NumBytesForCalleeToPop = 4;
  else
    NumBytesForCalleeToPop = 0;  // Callee pops nothing.

  // Returns a flag for retval copy to use.
  if (!IsSibcall) {
    Chain = DAG.getCALLSEQ_END(Chain,
                               DAG.getIntPtrConstant(NumBytesToPop, true),
                               DAG.getIntPtrConstant(NumBytesForCalleeToPop,
                                                     true),
                               InFlag, dl);
    InFlag = Chain.getValue(1);
  }

  // Handle result values, copying them out of physregs into vregs that we
  // return.
  return LowerCallResult(Chain, InFlag, CallConv, isVarArg,
                         Ins, dl, DAG, InVals);
}

//===----------------------------------------------------------------------===//
//                Fast Calling Convention (tail call) implementation
//===----------------------------------------------------------------------===//

//  Like std call, callee cleans arguments, convention except that ECX is
//  reserved for storing the tail called function address. Only 2 registers are
//  free for argument passing (inreg). Tail call optimization is performed
//  provided:
//                * tailcallopt is enabled
//                * caller/callee are fastcc
//  On X86_64 architecture with GOT-style position independent code only local
//  (within module) calls are supported at the moment.
//  To keep the stack aligned according to platform abi the function
//  GetAlignedArgumentStackSize ensures that argument delta is always multiples
//  of stack alignment. (Dynamic linkers need this - darwin's dyld for example)
//  If a tail called function callee has more arguments than the caller the
//  caller needs to make sure that there is room to move the RETADDR to. This is
//  achieved by reserving an area the size of the argument delta right after the
//  original RETADDR, but before the saved framepointer or the spilled registers
//  e.g. caller(arg1, arg2) calls callee(arg1, arg2,arg3,arg4)
//  stack layout:
//    arg1
//    arg2
//    RETADDR
//    [ new RETADDR
//      move area ]
//    (possible EBP)
//    ESI
//    EDI
//    local1 ..

/// GetAlignedArgumentStackSize - Make the stack size align e.g 16n + 12 aligned
/// for a 16 byte align requirement.
unsigned
X86TargetLowering::GetAlignedArgumentStackSize(unsigned StackSize,
                                               SelectionDAG& DAG) const {
  const X86RegisterInfo *RegInfo = Subtarget->getRegisterInfo();
  const TargetFrameLowering &TFI = *Subtarget->getFrameLowering();
  unsigned StackAlignment = TFI.getStackAlignment();
  uint64_t AlignMask = StackAlignment - 1;
  int64_t Offset = StackSize;
  unsigned SlotSize = RegInfo->getSlotSize();
  if ( (Offset & AlignMask) <= (StackAlignment - SlotSize) ) {
    // Number smaller than 12 so just add the difference.
    Offset += ((StackAlignment - SlotSize) - (Offset & AlignMask));
  } else {
    // Mask out lower bits, add stackalignment once plus the 12 bytes.
    Offset = ((~AlignMask) & Offset) + StackAlignment +
      (StackAlignment-SlotSize);
  }
  return Offset;
}

/// MatchingStackOffset - Return true if the given stack call argument is
/// already available in the same position (relatively) of the caller's
/// incoming argument stack.
static
bool MatchingStackOffset(SDValue Arg, unsigned Offset, ISD::ArgFlagsTy Flags,
                         MachineFrameInfo *MFI, const MachineRegisterInfo *MRI,
                         const X86InstrInfo *TII) {
  unsigned Bytes = Arg.getValueType().getSizeInBits() / 8;
  int FI = INT_MAX;
  if (Arg.getOpcode() == ISD::CopyFromReg) {
    unsigned VR = cast<RegisterSDNode>(Arg.getOperand(1))->getReg();
    if (!TargetRegisterInfo::isVirtualRegister(VR))
      return false;
    MachineInstr *Def = MRI->getVRegDef(VR);
    if (!Def)
      return false;
    if (!Flags.isByVal()) {
      if (!TII->isLoadFromStackSlot(Def, FI))
        return false;
    } else {
      unsigned Opcode = Def->getOpcode();
      if ((Opcode == X86::LEA32r || Opcode == X86::LEA64r ||
           Opcode == X86::LEA64_32r) &&
          Def->getOperand(1).isFI()) {
        FI = Def->getOperand(1).getIndex();
        Bytes = Flags.getByValSize();
      } else
        return false;
    }
  } else if (LoadSDNode *Ld = dyn_cast<LoadSDNode>(Arg)) {
    if (Flags.isByVal())
      // ByVal argument is passed in as a pointer but it's now being
      // dereferenced. e.g.
      // define @foo(%struct.X* %A) {
      //   tail call @bar(%struct.X* byval %A)
      // }
      return false;
    SDValue Ptr = Ld->getBasePtr();
    FrameIndexSDNode *FINode = dyn_cast<FrameIndexSDNode>(Ptr);
    if (!FINode)
      return false;
    FI = FINode->getIndex();
  } else if (Arg.getOpcode() == ISD::FrameIndex && Flags.isByVal()) {
    FrameIndexSDNode *FINode = cast<FrameIndexSDNode>(Arg);
    FI = FINode->getIndex();
    Bytes = Flags.getByValSize();
  } else
    return false;

  assert(FI != INT_MAX);
  if (!MFI->isFixedObjectIndex(FI))
    return false;
  return Offset == MFI->getObjectOffset(FI) && Bytes == MFI->getObjectSize(FI);
}

/// IsEligibleForTailCallOptimization - Check whether the call is eligible
/// for tail call optimization. Targets which want to do tail call
/// optimization should implement this function.
bool
X86TargetLowering::IsEligibleForTailCallOptimization(SDValue Callee,
                                                     CallingConv::ID CalleeCC,
                                                     bool isVarArg,
                                                     bool isCalleeStructRet,
                                                     bool isCallerStructRet,
                                                     Type *RetTy,
                                    const SmallVectorImpl<ISD::OutputArg> &Outs,
                                    const SmallVectorImpl<SDValue> &OutVals,
                                    const SmallVectorImpl<ISD::InputArg> &Ins,
                                                     SelectionDAG &DAG) const {
  if (!IsTailCallConvention(CalleeCC) && !IsCCallConvention(CalleeCC))
    return false;

  // If -tailcallopt is specified, make fastcc functions tail-callable.
  const MachineFunction &MF = DAG.getMachineFunction();
  const Function *CallerF = MF.getFunction();

  // If the function return type is x86_fp80 and the callee return type is not,
  // then the FP_EXTEND of the call result is not a nop. It's not safe to
  // perform a tailcall optimization here.
  if (CallerF->getReturnType()->isX86_FP80Ty() && !RetTy->isX86_FP80Ty())
    return false;

  CallingConv::ID CallerCC = CallerF->getCallingConv();
  bool CCMatch = CallerCC == CalleeCC;
  bool IsCalleeWin64 = Subtarget->isCallingConvWin64(CalleeCC);
  bool IsCallerWin64 = Subtarget->isCallingConvWin64(CallerCC);

  if (DAG.getTarget().Options.GuaranteedTailCallOpt) {
    if (IsTailCallConvention(CalleeCC) && CCMatch)
      return true;
    return false;
  }

  // Look for obvious safe cases to perform tail call optimization that do not
  // require ABI changes. This is what gcc calls sibcall.

  // Can't do sibcall if stack needs to be dynamically re-aligned. PEI needs to
  // emit a special epilogue.
  const X86RegisterInfo *RegInfo = Subtarget->getRegisterInfo();
  if (RegInfo->needsStackRealignment(MF))
    return false;

  // Also avoid sibcall optimization if either caller or callee uses struct
  // return semantics.
  if (isCalleeStructRet || isCallerStructRet)
    return false;

  // An stdcall/thiscall caller is expected to clean up its arguments; the
  // callee isn't going to do that.
  // FIXME: this is more restrictive than needed. We could produce a tailcall
  // when the stack adjustment matches. For example, with a thiscall that takes
  // only one argument.
  if (!CCMatch && (CallerCC == CallingConv::X86_StdCall ||
                   CallerCC == CallingConv::X86_ThisCall))
    return false;

  // Do not sibcall optimize vararg calls unless all arguments are passed via
  // registers.
  if (isVarArg && !Outs.empty()) {

    // Optimizing for varargs on Win64 is unlikely to be safe without
    // additional testing.
    if (IsCalleeWin64 || IsCallerWin64)
      return false;

    SmallVector<CCValAssign, 16> ArgLocs;
    CCState CCInfo(CalleeCC, isVarArg, DAG.getMachineFunction(), ArgLocs,
                   *DAG.getContext());

    CCInfo.AnalyzeCallOperands(Outs, CC_X86);
    for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i)
      if (!ArgLocs[i].isRegLoc())
        return false;
  }

  // If the call result is in ST0 / ST1, it needs to be popped off the x87
  // stack.  Therefore, if it's not used by the call it is not safe to optimize
  // this into a sibcall.
  bool Unused = false;
  for (unsigned i = 0, e = Ins.size(); i != e; ++i) {
    if (!Ins[i].Used) {
      Unused = true;
      break;
    }
  }
  if (Unused) {
    SmallVector<CCValAssign, 16> RVLocs;
    CCState CCInfo(CalleeCC, false, DAG.getMachineFunction(), RVLocs,
                   *DAG.getContext());
    CCInfo.AnalyzeCallResult(Ins, RetCC_X86);
    for (unsigned i = 0, e = RVLocs.size(); i != e; ++i) {
      CCValAssign &VA = RVLocs[i];
      if (VA.getLocReg() == X86::FP0 || VA.getLocReg() == X86::FP1)
        return false;
    }
  }

  // If the calling conventions do not match, then we'd better make sure the
  // results are returned in the same way as what the caller expects.
  if (!CCMatch) {
    SmallVector<CCValAssign, 16> RVLocs1;
    CCState CCInfo1(CalleeCC, false, DAG.getMachineFunction(), RVLocs1,
                    *DAG.getContext());
    CCInfo1.AnalyzeCallResult(Ins, RetCC_X86);

    SmallVector<CCValAssign, 16> RVLocs2;
    CCState CCInfo2(CallerCC, false, DAG.getMachineFunction(), RVLocs2,
                    *DAG.getContext());
    CCInfo2.AnalyzeCallResult(Ins, RetCC_X86);

    if (RVLocs1.size() != RVLocs2.size())
      return false;
    for (unsigned i = 0, e = RVLocs1.size(); i != e; ++i) {
      if (RVLocs1[i].isRegLoc() != RVLocs2[i].isRegLoc())
        return false;
      if (RVLocs1[i].getLocInfo() != RVLocs2[i].getLocInfo())
        return false;
      if (RVLocs1[i].isRegLoc()) {
        if (RVLocs1[i].getLocReg() != RVLocs2[i].getLocReg())
          return false;
      } else {
        if (RVLocs1[i].getLocMemOffset() != RVLocs2[i].getLocMemOffset())
          return false;
      }
    }
  }

  // If the callee takes no arguments then go on to check the results of the
  // call.
  if (!Outs.empty()) {
    // Check if stack adjustment is needed. For now, do not do this if any
    // argument is passed on the stack.
    SmallVector<CCValAssign, 16> ArgLocs;
    CCState CCInfo(CalleeCC, isVarArg, DAG.getMachineFunction(), ArgLocs,
                   *DAG.getContext());

    // Allocate shadow area for Win64
    if (IsCalleeWin64)
      CCInfo.AllocateStack(32, 8);

    CCInfo.AnalyzeCallOperands(Outs, CC_X86);
    if (CCInfo.getNextStackOffset()) {
      MachineFunction &MF = DAG.getMachineFunction();
      if (MF.getInfo<X86MachineFunctionInfo>()->getBytesToPopOnReturn())
        return false;

      // Check if the arguments are already laid out in the right way as
      // the caller's fixed stack objects.
      MachineFrameInfo *MFI = MF.getFrameInfo();
      const MachineRegisterInfo *MRI = &MF.getRegInfo();
      const X86InstrInfo *TII = Subtarget->getInstrInfo();
      for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
        CCValAssign &VA = ArgLocs[i];
        SDValue Arg = OutVals[i];
        ISD::ArgFlagsTy Flags = Outs[i].Flags;
        if (VA.getLocInfo() == CCValAssign::Indirect)
          return false;
        if (!VA.isRegLoc()) {
          if (!MatchingStackOffset(Arg, VA.getLocMemOffset(), Flags,
                                   MFI, MRI, TII))
            return false;
        }
      }
    }

    // If the tailcall address may be in a register, then make sure it's
    // possible to register allocate for it. In 32-bit, the call address can
    // only target EAX, EDX, or ECX since the tail call must be scheduled after
    // callee-saved registers are restored. These happen to be the same
    // registers used to pass 'inreg' arguments so watch out for those.
    if (!Subtarget->is64Bit() &&
        ((!isa<GlobalAddressSDNode>(Callee) &&
          !isa<ExternalSymbolSDNode>(Callee)) ||
         DAG.getTarget().getRelocationModel() == Reloc::PIC_)) {
      unsigned NumInRegs = 0;
      // In PIC we need an extra register to formulate the address computation
      // for the callee.
      unsigned MaxInRegs =
        (DAG.getTarget().getRelocationModel() == Reloc::PIC_) ? 2 : 3;

      for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
        CCValAssign &VA = ArgLocs[i];
        if (!VA.isRegLoc())
          continue;
        unsigned Reg = VA.getLocReg();
        switch (Reg) {
        default: break;
        case X86::EAX: case X86::EDX: case X86::ECX:
          if (++NumInRegs == MaxInRegs)
            return false;
          break;
        }
      }
    }
  }

  return true;
}

FastISel *
X86TargetLowering::createFastISel(FunctionLoweringInfo &funcInfo,
                                  const TargetLibraryInfo *libInfo) const {
  return X86::createFastISel(funcInfo, libInfo);
}

//===----------------------------------------------------------------------===//
//                           Other Lowering Hooks
//===----------------------------------------------------------------------===//

static bool MayFoldLoad(SDValue Op) {
  return Op.hasOneUse() && ISD::isNormalLoad(Op.getNode());
}

static bool MayFoldIntoStore(SDValue Op) {
  return Op.hasOneUse() && ISD::isNormalStore(*Op.getNode()->use_begin());
}

static bool isTargetShuffle(unsigned Opcode) {
  switch(Opcode) {
  default: return false;
  case X86ISD::BLENDI:
  case X86ISD::PSHUFB:
  case X86ISD::PSHUFD:
  case X86ISD::PSHUFHW:
  case X86ISD::PSHUFLW:
  case X86ISD::SHUFP:
  case X86ISD::PALIGNR:
  case X86ISD::MOVLHPS:
  case X86ISD::MOVLHPD:
  case X86ISD::MOVHLPS:
  case X86ISD::MOVLPS:
  case X86ISD::MOVLPD:
  case X86ISD::MOVSHDUP:
  case X86ISD::MOVSLDUP:
  case X86ISD::MOVDDUP:
  case X86ISD::MOVSS:
  case X86ISD::MOVSD:
  case X86ISD::UNPCKL:
  case X86ISD::UNPCKH:
  case X86ISD::VPERMILPI:
  case X86ISD::VPERM2X128:
  case X86ISD::VPERMI:
    return true;
  }
}

static SDValue getTargetShuffleNode(unsigned Opc, SDLoc dl, EVT VT,
                                    SDValue V1, SelectionDAG &DAG) {
  switch(Opc) {
  default: llvm_unreachable("Unknown x86 shuffle node");
  case X86ISD::MOVSHDUP:
  case X86ISD::MOVSLDUP:
  case X86ISD::MOVDDUP:
    return DAG.getNode(Opc, dl, VT, V1);
  }
}

static SDValue getTargetShuffleNode(unsigned Opc, SDLoc dl, EVT VT,
                                    SDValue V1, unsigned TargetMask,
                                    SelectionDAG &DAG) {
  switch(Opc) {
  default: llvm_unreachable("Unknown x86 shuffle node");
  case X86ISD::PSHUFD:
  case X86ISD::PSHUFHW:
  case X86ISD::PSHUFLW:
  case X86ISD::VPERMILPI:
  case X86ISD::VPERMI:
    return DAG.getNode(Opc, dl, VT, V1, DAG.getConstant(TargetMask, MVT::i8));
  }
}

static SDValue getTargetShuffleNode(unsigned Opc, SDLoc dl, EVT VT,
                                    SDValue V1, SDValue V2, unsigned TargetMask,
                                    SelectionDAG &DAG) {
  switch(Opc) {
  default: llvm_unreachable("Unknown x86 shuffle node");
  case X86ISD::PALIGNR:
  case X86ISD::VALIGN:
  case X86ISD::SHUFP:
  case X86ISD::VPERM2X128:
    return DAG.getNode(Opc, dl, VT, V1, V2,
                       DAG.getConstant(TargetMask, MVT::i8));
  }
}

static SDValue getTargetShuffleNode(unsigned Opc, SDLoc dl, EVT VT,
                                    SDValue V1, SDValue V2, SelectionDAG &DAG) {
  switch(Opc) {
  default: llvm_unreachable("Unknown x86 shuffle node");
  case X86ISD::MOVLHPS:
  case X86ISD::MOVLHPD:
  case X86ISD::MOVHLPS:
  case X86ISD::MOVLPS:
  case X86ISD::MOVLPD:
  case X86ISD::MOVSS:
  case X86ISD::MOVSD:
  case X86ISD::UNPCKL:
  case X86ISD::UNPCKH:
    return DAG.getNode(Opc, dl, VT, V1, V2);
  }
}

SDValue X86TargetLowering::getReturnAddressFrameIndex(SelectionDAG &DAG) const {
  MachineFunction &MF = DAG.getMachineFunction();
  const X86RegisterInfo *RegInfo = Subtarget->getRegisterInfo();
  X86MachineFunctionInfo *FuncInfo = MF.getInfo<X86MachineFunctionInfo>();
  int ReturnAddrIndex = FuncInfo->getRAIndex();

  if (ReturnAddrIndex == 0) {
    // Set up a frame object for the return address.
    unsigned SlotSize = RegInfo->getSlotSize();
    ReturnAddrIndex = MF.getFrameInfo()->CreateFixedObject(SlotSize,
                                                           -(int64_t)SlotSize,
                                                           false);
    FuncInfo->setRAIndex(ReturnAddrIndex);
  }

  return DAG.getFrameIndex(ReturnAddrIndex, getPointerTy());
}

bool X86::isOffsetSuitableForCodeModel(int64_t Offset, CodeModel::Model M,
                                       bool hasSymbolicDisplacement) {
  // Offset should fit into 32 bit immediate field.
  if (!isInt<32>(Offset))
    return false;

  // If we don't have a symbolic displacement - we don't have any extra
  // restrictions.
  if (!hasSymbolicDisplacement)
    return true;

  // FIXME: Some tweaks might be needed for medium code model.
  if (M != CodeModel::Small && M != CodeModel::Kernel)
    return false;

  // For small code model we assume that latest object is 16MB before end of 31
  // bits boundary. We may also accept pretty large negative constants knowing
  // that all objects are in the positive half of address space.
  if (M == CodeModel::Small && Offset < 16*1024*1024)
    return true;

  // For kernel code model we know that all object resist in the negative half
  // of 32bits address space. We may not accept negative offsets, since they may
  // be just off and we may accept pretty large positive ones.
  if (M == CodeModel::Kernel && Offset >= 0)
    return true;

  return false;
}

/// isCalleePop - Determines whether the callee is required to pop its
/// own arguments. Callee pop is necessary to support tail calls.
bool X86::isCalleePop(CallingConv::ID CallingConv,
                      bool is64Bit, bool IsVarArg, bool TailCallOpt) {
  switch (CallingConv) {
  default:
    return false;
  case CallingConv::X86_StdCall:
  case CallingConv::X86_FastCall:
  case CallingConv::X86_ThisCall:
    return !is64Bit;
  case CallingConv::Fast:
  case CallingConv::GHC:
  case CallingConv::HiPE:
    if (IsVarArg)
      return false;
    return TailCallOpt;
  }
}

/// \brief Return true if the condition is an unsigned comparison operation.
static bool isX86CCUnsigned(unsigned X86CC) {
  switch (X86CC) {
  default: llvm_unreachable("Invalid integer condition!");
  case X86::COND_E:     return true;
  case X86::COND_G:     return false;
  case X86::COND_GE:    return false;
  case X86::COND_L:     return false;
  case X86::COND_LE:    return false;
  case X86::COND_NE:    return true;
  case X86::COND_B:     return true;
  case X86::COND_A:     return true;
  case X86::COND_BE:    return true;
  case X86::COND_AE:    return true;
  }
  llvm_unreachable("covered switch fell through?!");
}

/// TranslateX86CC - do a one to one translation of a ISD::CondCode to the X86
/// specific condition code, returning the condition code and the LHS/RHS of the
/// comparison to make.
static unsigned TranslateX86CC(ISD::CondCode SetCCOpcode, bool isFP,
                               SDValue &LHS, SDValue &RHS, SelectionDAG &DAG) {
  if (!isFP) {
    if (ConstantSDNode *RHSC = dyn_cast<ConstantSDNode>(RHS)) {
      if (SetCCOpcode == ISD::SETGT && RHSC->isAllOnesValue()) {
        // X > -1   -> X == 0, jump !sign.
        RHS = DAG.getConstant(0, RHS.getValueType());
        return X86::COND_NS;
      }
      if (SetCCOpcode == ISD::SETLT && RHSC->isNullValue()) {
        // X < 0   -> X == 0, jump on sign.
        return X86::COND_S;
      }
      if (SetCCOpcode == ISD::SETLT && RHSC->getZExtValue() == 1) {
        // X < 1   -> X <= 0
        RHS = DAG.getConstant(0, RHS.getValueType());
        return X86::COND_LE;
      }
    }

    switch (SetCCOpcode) {
    default: llvm_unreachable("Invalid integer condition!");
    case ISD::SETEQ:  return X86::COND_E;
    case ISD::SETGT:  return X86::COND_G;
    case ISD::SETGE:  return X86::COND_GE;
    case ISD::SETLT:  return X86::COND_L;
    case ISD::SETLE:  return X86::COND_LE;
    case ISD::SETNE:  return X86::COND_NE;
    case ISD::SETULT: return X86::COND_B;
    case ISD::SETUGT: return X86::COND_A;
    case ISD::SETULE: return X86::COND_BE;
    case ISD::SETUGE: return X86::COND_AE;
    }
  }

  // First determine if it is required or is profitable to flip the operands.

  // If LHS is a foldable load, but RHS is not, flip the condition.
  if (ISD::isNON_EXTLoad(LHS.getNode()) &&
      !ISD::isNON_EXTLoad(RHS.getNode())) {
    SetCCOpcode = getSetCCSwappedOperands(SetCCOpcode);
    std::swap(LHS, RHS);
  }

  switch (SetCCOpcode) {
  default: break;
  case ISD::SETOLT:
  case ISD::SETOLE:
  case ISD::SETUGT:
  case ISD::SETUGE:
    std::swap(LHS, RHS);
    break;
  }

  // On a floating point condition, the flags are set as follows:
  // ZF  PF  CF   op
  //  0 | 0 | 0 | X > Y
  //  0 | 0 | 1 | X < Y
  //  1 | 0 | 0 | X == Y
  //  1 | 1 | 1 | unordered
  switch (SetCCOpcode) {
  default: llvm_unreachable("Condcode should be pre-legalized away");
  case ISD::SETUEQ:
  case ISD::SETEQ:   return X86::COND_E;
  case ISD::SETOLT:              // flipped
  case ISD::SETOGT:
  case ISD::SETGT:   return X86::COND_A;
  case ISD::SETOLE:              // flipped
  case ISD::SETOGE:
  case ISD::SETGE:   return X86::COND_AE;
  case ISD::SETUGT:              // flipped
  case ISD::SETULT:
  case ISD::SETLT:   return X86::COND_B;
  case ISD::SETUGE:              // flipped
  case ISD::SETULE:
  case ISD::SETLE:   return X86::COND_BE;
  case ISD::SETONE:
  case ISD::SETNE:   return X86::COND_NE;
  case ISD::SETUO:   return X86::COND_P;
  case ISD::SETO:    return X86::COND_NP;
  case ISD::SETOEQ:
  case ISD::SETUNE:  return X86::COND_INVALID;
  }
}

/// hasFPCMov - is there a floating point cmov for the specific X86 condition
/// code. Current x86 isa includes the following FP cmov instructions:
/// fcmovb, fcomvbe, fcomve, fcmovu, fcmovae, fcmova, fcmovne, fcmovnu.
static bool hasFPCMov(unsigned X86CC) {
  switch (X86CC) {
  default:
    return false;
  case X86::COND_B:
  case X86::COND_BE:
  case X86::COND_E:
  case X86::COND_P:
  case X86::COND_A:
  case X86::COND_AE:
  case X86::COND_NE:
  case X86::COND_NP:
    return true;
  }
}

/// isFPImmLegal - Returns true if the target can instruction select the
/// specified FP immediate natively. If false, the legalizer will
/// materialize the FP immediate as a load from a constant pool.
bool X86TargetLowering::isFPImmLegal(const APFloat &Imm, EVT VT) const {
  for (unsigned i = 0, e = LegalFPImmediates.size(); i != e; ++i) {
    if (Imm.bitwiseIsEqual(LegalFPImmediates[i]))
      return true;
  }
  return false;
}

bool X86TargetLowering::shouldReduceLoadWidth(SDNode *Load,
                                              ISD::LoadExtType ExtTy,
                                              EVT NewVT) const {
  // "ELF Handling for Thread-Local Storage" specifies that R_X86_64_GOTTPOFF
  // relocation target a movq or addq instruction: don't let the load shrink.
  SDValue BasePtr = cast<LoadSDNode>(Load)->getBasePtr();
  if (BasePtr.getOpcode() == X86ISD::WrapperRIP)
    if (const auto *GA = dyn_cast<GlobalAddressSDNode>(BasePtr.getOperand(0)))
      return GA->getTargetFlags() != X86II::MO_GOTTPOFF;
  return true;
}

/// \brief Returns true if it is beneficial to convert a load of a constant
/// to just the constant itself.
bool X86TargetLowering::shouldConvertConstantLoadToIntImm(const APInt &Imm,
                                                          Type *Ty) const {
  assert(Ty->isIntegerTy());

  unsigned BitSize = Ty->getPrimitiveSizeInBits();
  if (BitSize == 0 || BitSize > 64)
    return false;
  return true;
}

bool X86TargetLowering::isExtractSubvectorCheap(EVT ResVT,
                                                unsigned Index) const {
  if (!isOperationLegalOrCustom(ISD::EXTRACT_SUBVECTOR, ResVT))
    return false;

  return (Index == 0 || Index == ResVT.getVectorNumElements());
}

bool X86TargetLowering::isCheapToSpeculateCttz() const {
  // Speculate cttz only if we can directly use TZCNT.
  return Subtarget->hasBMI();
}

bool X86TargetLowering::isCheapToSpeculateCtlz() const {
  // Speculate ctlz only if we can directly use LZCNT.
  return Subtarget->hasLZCNT();
}

/// isUndefOrInRange - Return true if Val is undef or if its value falls within
/// the specified range (L, H].
static bool isUndefOrInRange(int Val, int Low, int Hi) {
  return (Val < 0) || (Val >= Low && Val < Hi);
}

/// isUndefOrEqual - Val is either less than zero (undef) or equal to the
/// specified value.
static bool isUndefOrEqual(int Val, int CmpVal) {
  return (Val < 0 || Val == CmpVal);
}

/// isSequentialOrUndefInRange - Return true if every element in Mask, beginning
/// from position Pos and ending in Pos+Size, falls within the specified
/// sequential range (Low, Low+Size]. or is undef.
static bool isSequentialOrUndefInRange(ArrayRef<int> Mask,
                                       unsigned Pos, unsigned Size, int Low) {
  for (unsigned i = Pos, e = Pos+Size; i != e; ++i, ++Low)
    if (!isUndefOrEqual(Mask[i], Low))
      return false;
  return true;
}

/// isPSHUFDMask - Return true if the node specifies a shuffle of elements that
/// is suitable for input to PSHUFD. That is, it doesn't reference the other
/// operand - by default will match for first operand.
static bool isPSHUFDMask(ArrayRef<int> Mask, MVT VT,
                         bool TestSecondOperand = false) {
  if (VT != MVT::v4f32 && VT != MVT::v4i32 &&
      VT != MVT::v2f64 && VT != MVT::v2i64)
    return false;

  unsigned NumElems = VT.getVectorNumElements();
  unsigned Lo = TestSecondOperand ? NumElems : 0;
  unsigned Hi = Lo + NumElems;

  for (unsigned i = 0; i < NumElems; ++i)
    if (!isUndefOrInRange(Mask[i], (int)Lo, (int)Hi))
      return false;

  return true;
}

/// isPSHUFHWMask - Return true if the node specifies a shuffle of elements that
/// is suitable for input to PSHUFHW.
static bool isPSHUFHWMask(ArrayRef<int> Mask, MVT VT, bool HasInt256) {
  if (VT != MVT::v8i16 && (!HasInt256 || VT != MVT::v16i16))
    return false;

  // Lower quadword copied in order or undef.
  if (!isSequentialOrUndefInRange(Mask, 0, 4, 0))
    return false;

  // Upper quadword shuffled.
  for (unsigned i = 4; i != 8; ++i)
    if (!isUndefOrInRange(Mask[i], 4, 8))
      return false;

  if (VT == MVT::v16i16) {
    // Lower quadword copied in order or undef.
    if (!isSequentialOrUndefInRange(Mask, 8, 4, 8))
      return false;

    // Upper quadword shuffled.
    for (unsigned i = 12; i != 16; ++i)
      if (!isUndefOrInRange(Mask[i], 12, 16))
        return false;
  }

  return true;
}

/// isPSHUFLWMask - Return true if the node specifies a shuffle of elements that
/// is suitable for input to PSHUFLW.
static bool isPSHUFLWMask(ArrayRef<int> Mask, MVT VT, bool HasInt256) {
  if (VT != MVT::v8i16 && (!HasInt256 || VT != MVT::v16i16))
    return false;

  // Upper quadword copied in order.
  if (!isSequentialOrUndefInRange(Mask, 4, 4, 4))
    return false;

  // Lower quadword shuffled.
  for (unsigned i = 0; i != 4; ++i)
    if (!isUndefOrInRange(Mask[i], 0, 4))
      return false;

  if (VT == MVT::v16i16) {
    // Upper quadword copied in order.
    if (!isSequentialOrUndefInRange(Mask, 12, 4, 12))
      return false;

    // Lower quadword shuffled.
    for (unsigned i = 8; i != 12; ++i)
      if (!isUndefOrInRange(Mask[i], 8, 12))
        return false;
  }

  return true;
}

/// \brief Return true if the mask specifies a shuffle of elements that is
/// suitable for input to intralane (palignr) or interlane (valign) vector
/// right-shift.
static bool isAlignrMask(ArrayRef<int> Mask, MVT VT, bool InterLane) {
  unsigned NumElts = VT.getVectorNumElements();
  unsigned NumLanes = InterLane ? 1: VT.getSizeInBits()/128;
  unsigned NumLaneElts = NumElts/NumLanes;

  // Do not handle 64-bit element shuffles with palignr.
  if (NumLaneElts == 2)
    return false;

  for (unsigned l = 0; l != NumElts; l+=NumLaneElts) {
    unsigned i;
    for (i = 0; i != NumLaneElts; ++i) {
      if (Mask[i+l] >= 0)
        break;
    }

    // Lane is all undef, go to next lane
    if (i == NumLaneElts)
      continue;

    int Start = Mask[i+l];

    // Make sure its in this lane in one of the sources
    if (!isUndefOrInRange(Start, l, l+NumLaneElts) &&
        !isUndefOrInRange(Start, l+NumElts, l+NumElts+NumLaneElts))
      return false;

    // If not lane 0, then we must match lane 0
    if (l != 0 && Mask[i] >= 0 && !isUndefOrEqual(Start, Mask[i]+l))
      return false;

    // Correct second source to be contiguous with first source
    if (Start >= (int)NumElts)
      Start -= NumElts - NumLaneElts;

    // Make sure we're shifting in the right direction.
    if (Start <= (int)(i+l))
      return false;

    Start -= i;

    // Check the rest of the elements to see if they are consecutive.
    for (++i; i != NumLaneElts; ++i) {
      int Idx = Mask[i+l];

      // Make sure its in this lane
      if (!isUndefOrInRange(Idx, l, l+NumLaneElts) &&
          !isUndefOrInRange(Idx, l+NumElts, l+NumElts+NumLaneElts))
        return false;

      // If not lane 0, then we must match lane 0
      if (l != 0 && Mask[i] >= 0 && !isUndefOrEqual(Idx, Mask[i]+l))
        return false;

      if (Idx >= (int)NumElts)
        Idx -= NumElts - NumLaneElts;

      if (!isUndefOrEqual(Idx, Start+i))
        return false;

    }
  }

  return true;
}

/// \brief Return true if the node specifies a shuffle of elements that is
/// suitable for input to PALIGNR.
static bool isPALIGNRMask(ArrayRef<int> Mask, MVT VT,
                          const X86Subtarget *Subtarget) {
  if ((VT.is128BitVector() && !Subtarget->hasSSSE3()) ||
      (VT.is256BitVector() && !Subtarget->hasInt256()) ||
      VT.is512BitVector())
    // FIXME: Add AVX512BW.
    return false;

  return isAlignrMask(Mask, VT, false);
}

/// \brief Return true if the node specifies a shuffle of elements that is
/// suitable for input to VALIGN.
static bool isVALIGNMask(ArrayRef<int> Mask, MVT VT,
                          const X86Subtarget *Subtarget) {
  // FIXME: Add AVX512VL.
  if (!VT.is512BitVector() || !Subtarget->hasAVX512())
    return false;
  return isAlignrMask(Mask, VT, true);
}

/// CommuteVectorShuffleMask - Change values in a shuffle permute mask assuming
/// the two vector operands have swapped position.
static void CommuteVectorShuffleMask(SmallVectorImpl<int> &Mask,
                                     unsigned NumElems) {
  for (unsigned i = 0; i != NumElems; ++i) {
    int idx = Mask[i];
    if (idx < 0)
      continue;
    else if (idx < (int)NumElems)
      Mask[i] = idx + NumElems;
    else
      Mask[i] = idx - NumElems;
  }
}

/// isSHUFPMask - Return true if the specified VECTOR_SHUFFLE operand
/// specifies a shuffle of elements that is suitable for input to 128/256-bit
/// SHUFPS and SHUFPD. If Commuted is true, then it checks for sources to be
/// reverse of what x86 shuffles want.
static bool isSHUFPMask(ArrayRef<int> Mask, MVT VT, bool Commuted = false) {

  unsigned NumElems = VT.getVectorNumElements();
  unsigned NumLanes = VT.getSizeInBits()/128;
  unsigned NumLaneElems = NumElems/NumLanes;

  if (NumLaneElems != 2 && NumLaneElems != 4)
    return false;

  unsigned EltSize = VT.getVectorElementType().getSizeInBits();
  bool symmetricMaskRequired =
    (VT.getSizeInBits() >= 256) && (EltSize == 32);

  // VSHUFPSY divides the resulting vector into 4 chunks.
  // The sources are also splitted into 4 chunks, and each destination
  // chunk must come from a different source chunk.
  //
  //  SRC1 =>   X7    X6    X5    X4    X3    X2    X1    X0
  //  SRC2 =>   Y7    Y6    Y5    Y4    Y3    Y2    Y1    Y9
  //
  //  DST  =>  Y7..Y4,   Y7..Y4,   X7..X4,   X7..X4,
  //           Y3..Y0,   Y3..Y0,   X3..X0,   X3..X0
  //
  // VSHUFPDY divides the resulting vector into 4 chunks.
  // The sources are also splitted into 4 chunks, and each destination
  // chunk must come from a different source chunk.
  //
  //  SRC1 =>      X3       X2       X1       X0
  //  SRC2 =>      Y3       Y2       Y1       Y0
  //
  //  DST  =>  Y3..Y2,  X3..X2,  Y1..Y0,  X1..X0
  //
  SmallVector<int, 4> MaskVal(NumLaneElems, -1);
  unsigned HalfLaneElems = NumLaneElems/2;
  for (unsigned l = 0; l != NumElems; l += NumLaneElems) {
    for (unsigned i = 0; i != NumLaneElems; ++i) {
      int Idx = Mask[i+l];
      unsigned RngStart = l + ((Commuted == (i<HalfLaneElems)) ? NumElems : 0);
      if (!isUndefOrInRange(Idx, RngStart, RngStart+NumLaneElems))
        return false;
      // For VSHUFPSY, the mask of the second half must be the same as the
      // first but with the appropriate offsets. This works in the same way as
      // VPERMILPS works with masks.
      if (!symmetricMaskRequired || Idx < 0)
        continue;
      if (MaskVal[i] < 0) {
        MaskVal[i] = Idx - l;
        continue;
      }
      if ((signed)(Idx - l) != MaskVal[i])
        return false;
    }
  }

  return true;
}

/// isMOVHLPSMask - Return true if the specified VECTOR_SHUFFLE operand
/// specifies a shuffle of elements that is suitable for input to MOVHLPS.
static bool isMOVHLPSMask(ArrayRef<int> Mask, MVT VT) {
  if (!VT.is128BitVector())
    return false;

  unsigned NumElems = VT.getVectorNumElements();

  if (NumElems != 4)
    return false;

  // Expect bit0 == 6, bit1 == 7, bit2 == 2, bit3 == 3
  return isUndefOrEqual(Mask[0], 6) &&
         isUndefOrEqual(Mask[1], 7) &&
         isUndefOrEqual(Mask[2], 2) &&
         isUndefOrEqual(Mask[3], 3);
}

/// isMOVHLPS_v_undef_Mask - Special case of isMOVHLPSMask for canonical form
/// of vector_shuffle v, v, <2, 3, 2, 3>, i.e. vector_shuffle v, undef,
/// <2, 3, 2, 3>
static bool isMOVHLPS_v_undef_Mask(ArrayRef<int> Mask, MVT VT) {
  if (!VT.is128BitVector())
    return false;

  unsigned NumElems = VT.getVectorNumElements();

  if (NumElems != 4)
    return false;

  return isUndefOrEqual(Mask[0], 2) &&
         isUndefOrEqual(Mask[1], 3) &&
         isUndefOrEqual(Mask[2], 2) &&
         isUndefOrEqual(Mask[3], 3);
}

/// isMOVLPMask - Return true if the specified VECTOR_SHUFFLE operand
/// specifies a shuffle of elements that is suitable for input to MOVLP{S|D}.
static bool isMOVLPMask(ArrayRef<int> Mask, MVT VT) {
  if (!VT.is128BitVector())
    return false;

  unsigned NumElems = VT.getVectorNumElements();

  if (NumElems != 2 && NumElems != 4)
    return false;

  for (unsigned i = 0, e = NumElems/2; i != e; ++i)
    if (!isUndefOrEqual(Mask[i], i + NumElems))
      return false;

  for (unsigned i = NumElems/2, e = NumElems; i != e; ++i)
    if (!isUndefOrEqual(Mask[i], i))
      return false;

  return true;
}

/// isMOVLHPSMask - Return true if the specified VECTOR_SHUFFLE operand
/// specifies a shuffle of elements that is suitable for input to MOVLHPS.
static bool isMOVLHPSMask(ArrayRef<int> Mask, MVT VT) {
  if (!VT.is128BitVector())
    return false;

  unsigned NumElems = VT.getVectorNumElements();

  if (NumElems != 2 && NumElems != 4)
    return false;

  for (unsigned i = 0, e = NumElems/2; i != e; ++i)
    if (!isUndefOrEqual(Mask[i], i))
      return false;

  for (unsigned i = 0, e = NumElems/2; i != e; ++i)
    if (!isUndefOrEqual(Mask[i + e], i + NumElems))
      return false;

  return true;
}

/// isINSERTPSMask - Return true if the specified VECTOR_SHUFFLE operand
/// specifies a shuffle of elements that is suitable for input to INSERTPS.
/// i. e: If all but one element come from the same vector.
static bool isINSERTPSMask(ArrayRef<int> Mask, MVT VT) {
  // TODO: Deal with AVX's VINSERTPS
  if (!VT.is128BitVector() || (VT != MVT::v4f32 && VT != MVT::v4i32))
    return false;

  unsigned CorrectPosV1 = 0;
  unsigned CorrectPosV2 = 0;
  for (int i = 0, e = (int)VT.getVectorNumElements(); i != e; ++i) {
    if (Mask[i] == -1) {
      ++CorrectPosV1;
      ++CorrectPosV2;
      continue;
    }

    if (Mask[i] == i)
      ++CorrectPosV1;
    else if (Mask[i] == i + 4)
      ++CorrectPosV2;
  }

  if (CorrectPosV1 == 3 || CorrectPosV2 == 3)
    // We have 3 elements (undefs count as elements from any vector) from one
    // vector, and one from another.
    return true;

  return false;
}

//
// Some special combinations that can be optimized.
//
static
SDValue Compact8x32ShuffleNode(ShuffleVectorSDNode *SVOp,
                               SelectionDAG &DAG) {
  MVT VT = SVOp->getSimpleValueType(0);
  SDLoc dl(SVOp);

  if (VT != MVT::v8i32 && VT != MVT::v8f32)
    return SDValue();

  ArrayRef<int> Mask = SVOp->getMask();

  // These are the special masks that may be optimized.
  static const int MaskToOptimizeEven[] = {0, 8, 2, 10, 4, 12, 6, 14};
  static const int MaskToOptimizeOdd[]  = {1, 9, 3, 11, 5, 13, 7, 15};
  bool MatchEvenMask = true;
  bool MatchOddMask  = true;
  for (int i=0; i<8; ++i) {
    if (!isUndefOrEqual(Mask[i], MaskToOptimizeEven[i]))
      MatchEvenMask = false;
    if (!isUndefOrEqual(Mask[i], MaskToOptimizeOdd[i]))
      MatchOddMask = false;
  }

  if (!MatchEvenMask && !MatchOddMask)
    return SDValue();

  SDValue UndefNode = DAG.getNode(ISD::UNDEF, dl, VT);

  SDValue Op0 = SVOp->getOperand(0);
  SDValue Op1 = SVOp->getOperand(1);

  if (MatchEvenMask) {
    // Shift the second operand right to 32 bits.
    static const int ShiftRightMask[] = {-1, 0, -1, 2, -1, 4, -1, 6 };
    Op1 = DAG.getVectorShuffle(VT, dl, Op1, UndefNode, ShiftRightMask);
  } else {
    // Shift the first operand left to 32 bits.
    static const int ShiftLeftMask[] = {1, -1, 3, -1, 5, -1, 7, -1 };
    Op0 = DAG.getVectorShuffle(VT, dl, Op0, UndefNode, ShiftLeftMask);
  }
  static const int BlendMask[] = {0, 9, 2, 11, 4, 13, 6, 15};
  return DAG.getVectorShuffle(VT, dl, Op0, Op1, BlendMask);
}

/// isUNPCKLMask - Return true if the specified VECTOR_SHUFFLE operand
/// specifies a shuffle of elements that is suitable for input to UNPCKL.
static bool isUNPCKLMask(ArrayRef<int> Mask, MVT VT,
                         bool HasInt256, bool V2IsSplat = false) {

  assert(VT.getSizeInBits() >= 128 &&
         "Unsupported vector type for unpckl");

  unsigned NumElts = VT.getVectorNumElements();
  if (VT.is256BitVector() && NumElts != 4 && NumElts != 8 &&
      (!HasInt256 || (NumElts != 16 && NumElts != 32)))
    return false;

  assert((!VT.is512BitVector() || VT.getScalarType().getSizeInBits() >= 32) &&
         "Unsupported vector type for unpckh");

  // AVX defines UNPCK* to operate independently on 128-bit lanes.
  unsigned NumLanes = VT.getSizeInBits()/128;
  unsigned NumLaneElts = NumElts/NumLanes;

  for (unsigned l = 0; l != NumElts; l += NumLaneElts) {
    for (unsigned i = 0, j = l; i != NumLaneElts; i += 2, ++j) {
      int BitI  = Mask[l+i];
      int BitI1 = Mask[l+i+1];
      if (!isUndefOrEqual(BitI, j))
        return false;
      if (V2IsSplat) {
        if (!isUndefOrEqual(BitI1, NumElts))
          return false;
      } else {
        if (!isUndefOrEqual(BitI1, j + NumElts))
          return false;
      }
    }
  }

  return true;
}

/// isUNPCKHMask - Return true if the specified VECTOR_SHUFFLE operand
/// specifies a shuffle of elements that is suitable for input to UNPCKH.
static bool isUNPCKHMask(ArrayRef<int> Mask, MVT VT,
                         bool HasInt256, bool V2IsSplat = false) {
  assert(VT.getSizeInBits() >= 128 &&
         "Unsupported vector type for unpckh");

  unsigned NumElts = VT.getVectorNumElements();
  if (VT.is256BitVector() && NumElts != 4 && NumElts != 8 &&
      (!HasInt256 || (NumElts != 16 && NumElts != 32)))
    return false;

  assert((!VT.is512BitVector() || VT.getScalarType().getSizeInBits() >= 32) &&
         "Unsupported vector type for unpckh");

  // AVX defines UNPCK* to operate independently on 128-bit lanes.
  unsigned NumLanes = VT.getSizeInBits()/128;
  unsigned NumLaneElts = NumElts/NumLanes;

  for (unsigned l = 0; l != NumElts; l += NumLaneElts) {
    for (unsigned i = 0, j = l+NumLaneElts/2; i != NumLaneElts; i += 2, ++j) {
      int BitI  = Mask[l+i];
      int BitI1 = Mask[l+i+1];
      if (!isUndefOrEqual(BitI, j))
        return false;
      if (V2IsSplat) {
        if (isUndefOrEqual(BitI1, NumElts))
          return false;
      } else {
        if (!isUndefOrEqual(BitI1, j+NumElts))
          return false;
      }
    }
  }
  return true;
}

/// isUNPCKL_v_undef_Mask - Special case of isUNPCKLMask for canonical form
/// of vector_shuffle v, v, <0, 4, 1, 5>, i.e. vector_shuffle v, undef,
/// <0, 0, 1, 1>
static bool isUNPCKL_v_undef_Mask(ArrayRef<int> Mask, MVT VT, bool HasInt256) {
  unsigned NumElts = VT.getVectorNumElements();
  bool Is256BitVec = VT.is256BitVector();

  if (VT.is512BitVector())
    return false;
  assert((VT.is128BitVector() || VT.is256BitVector()) &&
         "Unsupported vector type for unpckh");

  if (Is256BitVec && NumElts != 4 && NumElts != 8 &&
      (!HasInt256 || (NumElts != 16 && NumElts != 32)))
    return false;

  // For 256-bit i64/f64, use MOVDDUPY instead, so reject the matching pattern
  // FIXME: Need a better way to get rid of this, there's no latency difference
  // between UNPCKLPD and MOVDDUP, the later should always be checked first and
  // the former later. We should also remove the "_undef" special mask.
  if (NumElts == 4 && Is256BitVec)
    return false;

  // Handle 128 and 256-bit vector lengths. AVX defines UNPCK* to operate
  // independently on 128-bit lanes.
  unsigned NumLanes = VT.getSizeInBits()/128;
  unsigned NumLaneElts = NumElts/NumLanes;

  for (unsigned l = 0; l != NumElts; l += NumLaneElts) {
    for (unsigned i = 0, j = l; i != NumLaneElts; i += 2, ++j) {
      int BitI  = Mask[l+i];
      int BitI1 = Mask[l+i+1];

      if (!isUndefOrEqual(BitI, j))
        return false;
      if (!isUndefOrEqual(BitI1, j))
        return false;
    }
  }

  return true;
}

/// isUNPCKH_v_undef_Mask - Special case of isUNPCKHMask for canonical form
/// of vector_shuffle v, v, <2, 6, 3, 7>, i.e. vector_shuffle v, undef,
/// <2, 2, 3, 3>
static bool isUNPCKH_v_undef_Mask(ArrayRef<int> Mask, MVT VT, bool HasInt256) {
  unsigned NumElts = VT.getVectorNumElements();

  if (VT.is512BitVector())
    return false;

  assert((VT.is128BitVector() || VT.is256BitVector()) &&
         "Unsupported vector type for unpckh");

  if (VT.is256BitVector() && NumElts != 4 && NumElts != 8 &&
      (!HasInt256 || (NumElts != 16 && NumElts != 32)))
    return false;

  // Handle 128 and 256-bit vector lengths. AVX defines UNPCK* to operate
  // independently on 128-bit lanes.
  unsigned NumLanes = VT.getSizeInBits()/128;
  unsigned NumLaneElts = NumElts/NumLanes;

  for (unsigned l = 0; l != NumElts; l += NumLaneElts) {
    for (unsigned i = 0, j = l+NumLaneElts/2; i != NumLaneElts; i += 2, ++j) {
      int BitI  = Mask[l+i];
      int BitI1 = Mask[l+i+1];
      if (!isUndefOrEqual(BitI, j))
        return false;
      if (!isUndefOrEqual(BitI1, j))
        return false;
    }
  }
  return true;
}

// Match for INSERTI64x4 INSERTF64x4 instructions (src0[0], src1[0]) or
// (src1[0], src0[1]), manipulation with 256-bit sub-vectors
static bool isINSERT64x4Mask(ArrayRef<int> Mask, MVT VT, unsigned int *Imm) {
  if (!VT.is512BitVector())
    return false;

  unsigned NumElts = VT.getVectorNumElements();
  unsigned HalfSize = NumElts/2;
  if (isSequentialOrUndefInRange(Mask, 0, HalfSize, 0)) {
    if (isSequentialOrUndefInRange(Mask, HalfSize, HalfSize, NumElts)) {
      *Imm = 1;
      return true;
    }
  }
  if (isSequentialOrUndefInRange(Mask, 0, HalfSize, NumElts)) {
    if (isSequentialOrUndefInRange(Mask, HalfSize, HalfSize, HalfSize)) {
      *Imm = 0;
      return true;
    }
  }
  return false;
}

/// isMOVLMask - Return true if the specified VECTOR_SHUFFLE operand
/// specifies a shuffle of elements that is suitable for input to MOVSS,
/// MOVSD, and MOVD, i.e. setting the lowest element.
static bool isMOVLMask(ArrayRef<int> Mask, EVT VT) {
  if (VT.getVectorElementType().getSizeInBits() < 32)
    return false;
  if (!VT.is128BitVector())
    return false;

  unsigned NumElts = VT.getVectorNumElements();

  if (!isUndefOrEqual(Mask[0], NumElts))
    return false;

  for (unsigned i = 1; i != NumElts; ++i)
    if (!isUndefOrEqual(Mask[i], i))
      return false;

  return true;
}

/// isVPERM2X128Mask - Match 256-bit shuffles where the elements are considered
/// as permutations between 128-bit chunks or halves. As an example: this
/// shuffle bellow:
///   vector_shuffle <4, 5, 6, 7, 12, 13, 14, 15>
/// The first half comes from the second half of V1 and the second half from the
/// the second half of V2.
static bool isVPERM2X128Mask(ArrayRef<int> Mask, MVT VT, bool HasFp256) {
  if (!HasFp256 || !VT.is256BitVector())
    return false;

  // The shuffle result is divided into half A and half B. In total the two
  // sources have 4 halves, namely: C, D, E, F. The final values of A and
  // B must come from C, D, E or F.
  unsigned HalfSize = VT.getVectorNumElements()/2;
  bool MatchA = false, MatchB = false;

  // Check if A comes from one of C, D, E, F.
  for (unsigned Half = 0; Half != 4; ++Half) {
    if (isSequentialOrUndefInRange(Mask, 0, HalfSize, Half*HalfSize)) {
      MatchA = true;
      break;
    }
  }

  // Check if B comes from one of C, D, E, F.
  for (unsigned Half = 0; Half != 4; ++Half) {
    if (isSequentialOrUndefInRange(Mask, HalfSize, HalfSize, Half*HalfSize)) {
      MatchB = true;
      break;
    }
  }

  return MatchA && MatchB;
}

/// getShuffleVPERM2X128Immediate - Return the appropriate immediate to shuffle
/// the specified VECTOR_MASK mask with VPERM2F128/VPERM2I128 instructions.
static unsigned getShuffleVPERM2X128Immediate(ShuffleVectorSDNode *SVOp) {
  MVT VT = SVOp->getSimpleValueType(0);

  unsigned HalfSize = VT.getVectorNumElements()/2;

  unsigned FstHalf = 0, SndHalf = 0;
  for (unsigned i = 0; i < HalfSize; ++i) {
    if (SVOp->getMaskElt(i) > 0) {
      FstHalf = SVOp->getMaskElt(i)/HalfSize;
      break;
    }
  }
  for (unsigned i = HalfSize; i < HalfSize*2; ++i) {
    if (SVOp->getMaskElt(i) > 0) {
      SndHalf = SVOp->getMaskElt(i)/HalfSize;
      break;
    }
  }

  return (FstHalf | (SndHalf << 4));
}

// Symmetric in-lane mask. Each lane has 4 elements (for imm8)
static bool isPermImmMask(ArrayRef<int> Mask, MVT VT, unsigned& Imm8) {
  unsigned EltSize = VT.getVectorElementType().getSizeInBits();
  if (EltSize < 32)
    return false;

  unsigned NumElts = VT.getVectorNumElements();
  Imm8 = 0;
  if (VT.is128BitVector() || (VT.is256BitVector() && EltSize == 64)) {
    for (unsigned i = 0; i != NumElts; ++i) {
      if (Mask[i] < 0)
        continue;
      Imm8 |= Mask[i] << (i*2);
    }
    return true;
  }

  unsigned LaneSize = 4;
  SmallVector<int, 4> MaskVal(LaneSize, -1);

  for (unsigned l = 0; l != NumElts; l += LaneSize) {
    for (unsigned i = 0; i != LaneSize; ++i) {
      if (!isUndefOrInRange(Mask[i+l], l, l+LaneSize))
        return false;
      if (Mask[i+l] < 0)
        continue;
      if (MaskVal[i] < 0) {
        MaskVal[i] = Mask[i+l] - l;
        Imm8 |= MaskVal[i] << (i*2);
        continue;
      }
      if (Mask[i+l] != (signed)(MaskVal[i]+l))
        return false;
    }
  }
  return true;
}

/// isVPERMILPMask - Return true if the specified VECTOR_SHUFFLE operand
/// specifies a shuffle of elements that is suitable for input to VPERMILPD*.
/// Note that VPERMIL mask matching is different depending whether theunderlying
/// type is 32 or 64. In the VPERMILPS the high half of the mask should point
/// to the same elements of the low, but to the higher half of the source.
/// In VPERMILPD the two lanes could be shuffled independently of each other
/// with the same restriction that lanes can't be crossed. Also handles PSHUFDY.
static bool isVPERMILPMask(ArrayRef<int> Mask, MVT VT) {
  unsigned EltSize = VT.getVectorElementType().getSizeInBits();
  if (VT.getSizeInBits() < 256 || EltSize < 32)
    return false;
  bool symmetricMaskRequired = (EltSize == 32);
  unsigned NumElts = VT.getVectorNumElements();

  unsigned NumLanes = VT.getSizeInBits()/128;
  unsigned LaneSize = NumElts/NumLanes;
  // 2 or 4 elements in one lane

  SmallVector<int, 4> ExpectedMaskVal(LaneSize, -1);
  for (unsigned l = 0; l != NumElts; l += LaneSize) {
    for (unsigned i = 0; i != LaneSize; ++i) {
      if (!isUndefOrInRange(Mask[i+l], l, l+LaneSize))
        return false;
      if (symmetricMaskRequired) {
        if (ExpectedMaskVal[i] < 0 && Mask[i+l] >= 0) {
          ExpectedMaskVal[i] = Mask[i+l] - l;
          continue;
        }
        if (!isUndefOrEqual(Mask[i+l], ExpectedMaskVal[i]+l))
          return false;
      }
    }
  }
  return true;
}

/// isCommutedMOVLMask - Returns true if the shuffle mask is except the reverse
/// of what x86 movss want. X86 movs requires the lowest  element to be lowest
/// element of vector 2 and the other elements to come from vector 1 in order.
static bool isCommutedMOVLMask(ArrayRef<int> Mask, MVT VT,
                               bool V2IsSplat = false, bool V2IsUndef = false) {
  if (!VT.is128BitVector())
    return false;

  unsigned NumOps = VT.getVectorNumElements();
  if (NumOps != 2 && NumOps != 4 && NumOps != 8 && NumOps != 16)
    return false;

  if (!isUndefOrEqual(Mask[0], 0))
    return false;

  for (unsigned i = 1; i != NumOps; ++i)
    if (!(isUndefOrEqual(Mask[i], i+NumOps) ||
          (V2IsUndef && isUndefOrInRange(Mask[i], NumOps, NumOps*2)) ||
          (V2IsSplat && isUndefOrEqual(Mask[i], NumOps))))
      return false;

  return true;
}

/// isMOVSHDUPMask - Return true if the specified VECTOR_SHUFFLE operand
/// specifies a shuffle of elements that is suitable for input to MOVSHDUP.
/// Masks to match: <1, 1, 3, 3> or <1, 1, 3, 3, 5, 5, 7, 7>
static bool isMOVSHDUPMask(ArrayRef<int> Mask, MVT VT,
                           const X86Subtarget *Subtarget) {
  if (!Subtarget->hasSSE3())
    return false;

  unsigned NumElems = VT.getVectorNumElements();

  if ((VT.is128BitVector() && NumElems != 4) ||
      (VT.is256BitVector() && NumElems != 8) ||
      (VT.is512BitVector() && NumElems != 16))
    return false;

  // "i+1" is the value the indexed mask element must have
  for (unsigned i = 0; i != NumElems; i += 2)
    if (!isUndefOrEqual(Mask[i], i+1) ||
        !isUndefOrEqual(Mask[i+1], i+1))
      return false;

  return true;
}

/// isMOVSLDUPMask - Return true if the specified VECTOR_SHUFFLE operand
/// specifies a shuffle of elements that is suitable for input to MOVSLDUP.
/// Masks to match: <0, 0, 2, 2> or <0, 0, 2, 2, 4, 4, 6, 6>
static bool isMOVSLDUPMask(ArrayRef<int> Mask, MVT VT,
                           const X86Subtarget *Subtarget) {
  if (!Subtarget->hasSSE3())
    return false;

  unsigned NumElems = VT.getVectorNumElements();

  if ((VT.is128BitVector() && NumElems != 4) ||
      (VT.is256BitVector() && NumElems != 8) ||
      (VT.is512BitVector() && NumElems != 16))
    return false;

  // "i" is the value the indexed mask element must have
  for (unsigned i = 0; i != NumElems; i += 2)
    if (!isUndefOrEqual(Mask[i], i) ||
        !isUndefOrEqual(Mask[i+1], i))
      return false;

  return true;
}

/// isMOVDDUPYMask - Return true if the specified VECTOR_SHUFFLE operand
/// specifies a shuffle of elements that is suitable for input to 256-bit
/// version of MOVDDUP.
static bool isMOVDDUPYMask(ArrayRef<int> Mask, MVT VT, bool HasFp256) {
  if (!HasFp256 || !VT.is256BitVector())
    return false;

  unsigned NumElts = VT.getVectorNumElements();
  if (NumElts != 4)
    return false;

  for (unsigned i = 0; i != NumElts/2; ++i)
    if (!isUndefOrEqual(Mask[i], 0))
      return false;
  for (unsigned i = NumElts/2; i != NumElts; ++i)
    if (!isUndefOrEqual(Mask[i], NumElts/2))
      return false;
  return true;
}

/// isMOVDDUPMask - Return true if the specified VECTOR_SHUFFLE operand
/// specifies a shuffle of elements that is suitable for input to 128-bit
/// version of MOVDDUP.
static bool isMOVDDUPMask(ArrayRef<int> Mask, MVT VT) {
  if (!VT.is128BitVector())
    return false;

  unsigned e = VT.getVectorNumElements() / 2;
  for (unsigned i = 0; i != e; ++i)
    if (!isUndefOrEqual(Mask[i], i))
      return false;
  for (unsigned i = 0; i != e; ++i)
    if (!isUndefOrEqual(Mask[e+i], i))
      return false;
  return true;
}

/// isVEXTRACTIndex - Return true if the specified
/// EXTRACT_SUBVECTOR operand specifies a vector extract that is
/// suitable for instruction that extract 128 or 256 bit vectors
static bool isVEXTRACTIndex(SDNode *N, unsigned vecWidth) {
  assert((vecWidth == 128 || vecWidth == 256) && "Unexpected vector width");
  if (!isa<ConstantSDNode>(N->getOperand(1).getNode()))
    return false;

  // The index should be aligned on a vecWidth-bit boundary.
  uint64_t Index =
    cast<ConstantSDNode>(N->getOperand(1).getNode())->getZExtValue();

  MVT VT = N->getSimpleValueType(0);
  unsigned ElSize = VT.getVectorElementType().getSizeInBits();
  bool Result = (Index * ElSize) % vecWidth == 0;

  return Result;
}

/// isVINSERTIndex - Return true if the specified INSERT_SUBVECTOR
/// operand specifies a subvector insert that is suitable for input to
/// insertion of 128 or 256-bit subvectors
static bool isVINSERTIndex(SDNode *N, unsigned vecWidth) {
  assert((vecWidth == 128 || vecWidth == 256) && "Unexpected vector width");
  if (!isa<ConstantSDNode>(N->getOperand(2).getNode()))
    return false;
  // The index should be aligned on a vecWidth-bit boundary.
  uint64_t Index =
    cast<ConstantSDNode>(N->getOperand(2).getNode())->getZExtValue();

  MVT VT = N->getSimpleValueType(0);
  unsigned ElSize = VT.getVectorElementType().getSizeInBits();
  bool Result = (Index * ElSize) % vecWidth == 0;

  return Result;
}

bool X86::isVINSERT128Index(SDNode *N) {
  return isVINSERTIndex(N, 128);
}

bool X86::isVINSERT256Index(SDNode *N) {
  return isVINSERTIndex(N, 256);
}

bool X86::isVEXTRACT128Index(SDNode *N) {
  return isVEXTRACTIndex(N, 128);
}

bool X86::isVEXTRACT256Index(SDNode *N) {
  return isVEXTRACTIndex(N, 256);
}

/// getShuffleSHUFImmediate - Return the appropriate immediate to shuffle
/// the specified VECTOR_SHUFFLE mask with PSHUF* and SHUFP* instructions.
/// Handles 128-bit and 256-bit.
static unsigned getShuffleSHUFImmediate(ShuffleVectorSDNode *N) {
  MVT VT = N->getSimpleValueType(0);

  assert((VT.getSizeInBits() >= 128) &&
         "Unsupported vector type for PSHUF/SHUFP");

  // Handle 128 and 256-bit vector lengths. AVX defines PSHUF/SHUFP to operate
  // independently on 128-bit lanes.
  unsigned NumElts = VT.getVectorNumElements();
  unsigned NumLanes = VT.getSizeInBits()/128;
  unsigned NumLaneElts = NumElts/NumLanes;

  assert((NumLaneElts == 2 || NumLaneElts == 4 || NumLaneElts == 8) &&
         "Only supports 2, 4 or 8 elements per lane");

  unsigned Shift = (NumLaneElts >= 4) ? 1 : 0;
  unsigned Mask = 0;
  for (unsigned i = 0; i != NumElts; ++i) {
    int Elt = N->getMaskElt(i);
    if (Elt < 0) continue;
    Elt &= NumLaneElts - 1;
    unsigned ShAmt = (i << Shift) % 8;
    Mask |= Elt << ShAmt;
  }

  return Mask;
}

/// getShufflePSHUFHWImmediate - Return the appropriate immediate to shuffle
/// the specified VECTOR_SHUFFLE mask with the PSHUFHW instruction.
static unsigned getShufflePSHUFHWImmediate(ShuffleVectorSDNode *N) {
  MVT VT = N->getSimpleValueType(0);

  assert((VT == MVT::v8i16 || VT == MVT::v16i16) &&
         "Unsupported vector type for PSHUFHW");

  unsigned NumElts = VT.getVectorNumElements();

  unsigned Mask = 0;
  for (unsigned l = 0; l != NumElts; l += 8) {
    // 8 nodes per lane, but we only care about the last 4.
    for (unsigned i = 0; i < 4; ++i) {
      int Elt = N->getMaskElt(l+i+4);
      if (Elt < 0) continue;
      Elt &= 0x3; // only 2-bits.
      Mask |= Elt << (i * 2);
    }
  }

  return Mask;
}

/// getShufflePSHUFLWImmediate - Return the appropriate immediate to shuffle
/// the specified VECTOR_SHUFFLE mask with the PSHUFLW instruction.
static unsigned getShufflePSHUFLWImmediate(ShuffleVectorSDNode *N) {
  MVT VT = N->getSimpleValueType(0);

  assert((VT == MVT::v8i16 || VT == MVT::v16i16) &&
         "Unsupported vector type for PSHUFHW");

  unsigned NumElts = VT.getVectorNumElements();

  unsigned Mask = 0;
  for (unsigned l = 0; l != NumElts; l += 8) {
    // 8 nodes per lane, but we only care about the first 4.
    for (unsigned i = 0; i < 4; ++i) {
      int Elt = N->getMaskElt(l+i);
      if (Elt < 0) continue;
      Elt &= 0x3; // only 2-bits
      Mask |= Elt << (i * 2);
    }
  }

  return Mask;
}

/// \brief Return the appropriate immediate to shuffle the specified
/// VECTOR_SHUFFLE mask with the PALIGNR (if InterLane is false) or with
/// VALIGN (if Interlane is true) instructions.
static unsigned getShuffleAlignrImmediate(ShuffleVectorSDNode *SVOp,
                                           bool InterLane) {
  MVT VT = SVOp->getSimpleValueType(0);
  unsigned EltSize = InterLane ? 1 :
    VT.getVectorElementType().getSizeInBits() >> 3;

  unsigned NumElts = VT.getVectorNumElements();
  unsigned NumLanes = VT.is512BitVector() ? 1 : VT.getSizeInBits()/128;
  unsigned NumLaneElts = NumElts/NumLanes;

  int Val = 0;
  unsigned i;
  for (i = 0; i != NumElts; ++i) {
    Val = SVOp->getMaskElt(i);
    if (Val >= 0)
      break;
  }
  if (Val >= (int)NumElts)
    Val -= NumElts - NumLaneElts;

  assert(Val - i > 0 && "PALIGNR imm should be positive");
  return (Val - i) * EltSize;
}

/// \brief Return the appropriate immediate to shuffle the specified
/// VECTOR_SHUFFLE mask with the PALIGNR instruction.
static unsigned getShufflePALIGNRImmediate(ShuffleVectorSDNode *SVOp) {
  return getShuffleAlignrImmediate(SVOp, false);
}

/// \brief Return the appropriate immediate to shuffle the specified
/// VECTOR_SHUFFLE mask with the VALIGN instruction.
static unsigned getShuffleVALIGNImmediate(ShuffleVectorSDNode *SVOp) {
  return getShuffleAlignrImmediate(SVOp, true);
}


static unsigned getExtractVEXTRACTImmediate(SDNode *N, unsigned vecWidth) {
  assert((vecWidth == 128 || vecWidth == 256) && "Unsupported vector width");
  if (!isa<ConstantSDNode>(N->getOperand(1).getNode()))
    llvm_unreachable("Illegal extract subvector for VEXTRACT");

  uint64_t Index =
    cast<ConstantSDNode>(N->getOperand(1).getNode())->getZExtValue();

  MVT VecVT = N->getOperand(0).getSimpleValueType();
  MVT ElVT = VecVT.getVectorElementType();

  unsigned NumElemsPerChunk = vecWidth / ElVT.getSizeInBits();
  return Index / NumElemsPerChunk;
}

static unsigned getInsertVINSERTImmediate(SDNode *N, unsigned vecWidth) {
  assert((vecWidth == 128 || vecWidth == 256) && "Unsupported vector width");
  if (!isa<ConstantSDNode>(N->getOperand(2).getNode()))
    llvm_unreachable("Illegal insert subvector for VINSERT");

  uint64_t Index =
    cast<ConstantSDNode>(N->getOperand(2).getNode())->getZExtValue();

  MVT VecVT = N->getSimpleValueType(0);
  MVT ElVT = VecVT.getVectorElementType();

  unsigned NumElemsPerChunk = vecWidth / ElVT.getSizeInBits();
  return Index / NumElemsPerChunk;
}

/// getExtractVEXTRACT128Immediate - Return the appropriate immediate
/// to extract the specified EXTRACT_SUBVECTOR index with VEXTRACTF128
/// and VINSERTI128 instructions.
unsigned X86::getExtractVEXTRACT128Immediate(SDNode *N) {
  return getExtractVEXTRACTImmediate(N, 128);
}

/// getExtractVEXTRACT256Immediate - Return the appropriate immediate
/// to extract the specified EXTRACT_SUBVECTOR index with VEXTRACTF64x4
/// and VINSERTI64x4 instructions.
unsigned X86::getExtractVEXTRACT256Immediate(SDNode *N) {
  return getExtractVEXTRACTImmediate(N, 256);
}

/// getInsertVINSERT128Immediate - Return the appropriate immediate
/// to insert at the specified INSERT_SUBVECTOR index with VINSERTF128
/// and VINSERTI128 instructions.
unsigned X86::getInsertVINSERT128Immediate(SDNode *N) {
  return getInsertVINSERTImmediate(N, 128);
}

/// getInsertVINSERT256Immediate - Return the appropriate immediate
/// to insert at the specified INSERT_SUBVECTOR index with VINSERTF46x4
/// and VINSERTI64x4 instructions.
unsigned X86::getInsertVINSERT256Immediate(SDNode *N) {
  return getInsertVINSERTImmediate(N, 256);
}

/// isZero - Returns true if Elt is a constant integer zero
static bool isZero(SDValue V) {
  ConstantSDNode *C = dyn_cast<ConstantSDNode>(V);
  return C && C->isNullValue();
}

/// isZeroNode - Returns true if Elt is a constant zero or a floating point
/// constant +0.0.
bool X86::isZeroNode(SDValue Elt) {
  if (isZero(Elt))
    return true;
  if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(Elt))
    return CFP->getValueAPF().isPosZero();
  return false;
}

/// ShouldXformToMOVHLPS - Return true if the node should be transformed to
/// match movhlps. The lower half elements should come from upper half of
/// V1 (and in order), and the upper half elements should come from the upper
/// half of V2 (and in order).
static bool ShouldXformToMOVHLPS(ArrayRef<int> Mask, MVT VT) {
  if (!VT.is128BitVector())
    return false;
  if (VT.getVectorNumElements() != 4)
    return false;
  for (unsigned i = 0, e = 2; i != e; ++i)
    if (!isUndefOrEqual(Mask[i], i+2))
      return false;
  for (unsigned i = 2; i != 4; ++i)
    if (!isUndefOrEqual(Mask[i], i+4))
      return false;
  return true;
}

/// isScalarLoadToVector - Returns true if the node is a scalar load that
/// is promoted to a vector. It also returns the LoadSDNode by reference if
/// required.
static bool isScalarLoadToVector(SDNode *N, LoadSDNode **LD = nullptr) {
  if (N->getOpcode() != ISD::SCALAR_TO_VECTOR)
    return false;
  N = N->getOperand(0).getNode();
  if (!ISD::isNON_EXTLoad(N))
    return false;
  if (LD)
    *LD = cast<LoadSDNode>(N);
  return true;
}

// Test whether the given value is a vector value which will be legalized
// into a load.
static bool WillBeConstantPoolLoad(SDNode *N) {
  if (N->getOpcode() != ISD::BUILD_VECTOR)
    return false;

  // Check for any non-constant elements.
  for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i)
    switch (N->getOperand(i).getNode()->getOpcode()) {
    case ISD::UNDEF:
    case ISD::ConstantFP:
    case ISD::Constant:
      break;
    default:
      return false;
    }

  // Vectors of all-zeros and all-ones are materialized with special
  // instructions rather than being loaded.
  return !ISD::isBuildVectorAllZeros(N) &&
         !ISD::isBuildVectorAllOnes(N);
}

/// ShouldXformToMOVLP{S|D} - Return true if the node should be transformed to
/// match movlp{s|d}. The lower half elements should come from lower half of
/// V1 (and in order), and the upper half elements should come from the upper
/// half of V2 (and in order). And since V1 will become the source of the
/// MOVLP, it must be either a vector load or a scalar load to vector.
static bool ShouldXformToMOVLP(SDNode *V1, SDNode *V2,
                               ArrayRef<int> Mask, MVT VT) {
  if (!VT.is128BitVector())
    return false;

  if (!ISD::isNON_EXTLoad(V1) && !isScalarLoadToVector(V1))
    return false;
  // Is V2 is a vector load, don't do this transformation. We will try to use
  // load folding shufps op.
  if (ISD::isNON_EXTLoad(V2) || WillBeConstantPoolLoad(V2))
    return false;

  unsigned NumElems = VT.getVectorNumElements();

  if (NumElems != 2 && NumElems != 4)
    return false;
  for (unsigned i = 0, e = NumElems/2; i != e; ++i)
    if (!isUndefOrEqual(Mask[i], i))
      return false;
  for (unsigned i = NumElems/2, e = NumElems; i != e; ++i)
    if (!isUndefOrEqual(Mask[i], i+NumElems))
      return false;
  return true;
}

/// isZeroShuffle - Returns true if N is a VECTOR_SHUFFLE that can be resolved
/// to an zero vector.
/// FIXME: move to dag combiner / method on ShuffleVectorSDNode
static bool isZeroShuffle(ShuffleVectorSDNode *N) {
  SDValue V1 = N->getOperand(0);
  SDValue V2 = N->getOperand(1);
  unsigned NumElems = N->getValueType(0).getVectorNumElements();
  for (unsigned i = 0; i != NumElems; ++i) {
    int Idx = N->getMaskElt(i);
    if (Idx >= (int)NumElems) {
      unsigned Opc = V2.getOpcode();
      if (Opc == ISD::UNDEF || ISD::isBuildVectorAllZeros(V2.getNode()))
        continue;
      if (Opc != ISD::BUILD_VECTOR ||
          !X86::isZeroNode(V2.getOperand(Idx-NumElems)))
        return false;
    } else if (Idx >= 0) {
      unsigned Opc = V1.getOpcode();
      if (Opc == ISD::UNDEF || ISD::isBuildVectorAllZeros(V1.getNode()))
        continue;
      if (Opc != ISD::BUILD_VECTOR ||
          !X86::isZeroNode(V1.getOperand(Idx)))
        return false;
    }
  }
  return true;
}

/// getZeroVector - Returns a vector of specified type with all zero elements.
///
static SDValue getZeroVector(EVT VT, const X86Subtarget *Subtarget,
                             SelectionDAG &DAG, SDLoc dl) {
  assert(VT.isVector() && "Expected a vector type");

  // Always build SSE zero vectors as <4 x i32> bitcasted
  // to their dest type. This ensures they get CSE'd.
  SDValue Vec;
  if (VT.is128BitVector()) {  // SSE
    if (Subtarget->hasSSE2()) {  // SSE2
      SDValue Cst = DAG.getConstant(0, MVT::i32);
      Vec = DAG.getNode(ISD::BUILD_VECTOR, dl, MVT::v4i32, Cst, Cst, Cst, Cst);
    } else { // SSE1
      SDValue Cst = DAG.getConstantFP(+0.0, MVT::f32);
      Vec = DAG.getNode(ISD::BUILD_VECTOR, dl, MVT::v4f32, Cst, Cst, Cst, Cst);
    }
  } else if (VT.is256BitVector()) { // AVX
    if (Subtarget->hasInt256()) { // AVX2
      SDValue Cst = DAG.getConstant(0, MVT::i32);
      SDValue Ops[] = { Cst, Cst, Cst, Cst, Cst, Cst, Cst, Cst };
      Vec = DAG.getNode(ISD::BUILD_VECTOR, dl, MVT::v8i32, Ops);
    } else {
      // 256-bit logic and arithmetic instructions in AVX are all
      // floating-point, no support for integer ops. Emit fp zeroed vectors.
      SDValue Cst = DAG.getConstantFP(+0.0, MVT::f32);
      SDValue Ops[] = { Cst, Cst, Cst, Cst, Cst, Cst, Cst, Cst };
      Vec = DAG.getNode(ISD::BUILD_VECTOR, dl, MVT::v8f32, Ops);
    }
  } else if (VT.is512BitVector()) { // AVX-512
      SDValue Cst = DAG.getConstant(0, MVT::i32);
      SDValue Ops[] = { Cst, Cst, Cst, Cst, Cst, Cst, Cst, Cst,
                        Cst, Cst, Cst, Cst, Cst, Cst, Cst, Cst };
      Vec = DAG.getNode(ISD::BUILD_VECTOR, dl, MVT::v16i32, Ops);
  } else if (VT.getScalarType() == MVT::i1) {
    assert(VT.getVectorNumElements() <= 16 && "Unexpected vector type");
    SDValue Cst = DAG.getConstant(0, MVT::i1);
    SmallVector<SDValue, 16> Ops(VT.getVectorNumElements(), Cst);
    return DAG.getNode(ISD::BUILD_VECTOR, dl, VT, Ops);
  } else
    llvm_unreachable("Unexpected vector type");

  return DAG.getNode(ISD::BITCAST, dl, VT, Vec);
}

/// getOnesVector - Returns a vector of specified type with all bits set.
/// Always build ones vectors as <4 x i32> or <8 x i32>. For 256-bit types with
/// no AVX2 supprt, use two <4 x i32> inserted in a <8 x i32> appropriately.
/// Then bitcast to their original type, ensuring they get CSE'd.
static SDValue getOnesVector(MVT VT, bool HasInt256, SelectionDAG &DAG,
                             SDLoc dl) {
  assert(VT.isVector() && "Expected a vector type");

  SDValue Cst = DAG.getConstant(~0U, MVT::i32);
  SDValue Vec;
  if (VT.is256BitVector()) {
    if (HasInt256) { // AVX2
      SDValue Ops[] = { Cst, Cst, Cst, Cst, Cst, Cst, Cst, Cst };
      Vec = DAG.getNode(ISD::BUILD_VECTOR, dl, MVT::v8i32, Ops);
    } else { // AVX
      Vec = DAG.getNode(ISD::BUILD_VECTOR, dl, MVT::v4i32, Cst, Cst, Cst, Cst);
      Vec = Concat128BitVectors(Vec, Vec, MVT::v8i32, 8, DAG, dl);
    }
  } else if (VT.is128BitVector()) {
    Vec = DAG.getNode(ISD::BUILD_VECTOR, dl, MVT::v4i32, Cst, Cst, Cst, Cst);
  } else
    llvm_unreachable("Unexpected vector type");

  return DAG.getNode(ISD::BITCAST, dl, VT, Vec);
}

/// NormalizeMask - V2 is a splat, modify the mask (if needed) so all elements
/// that point to V2 points to its first element.
static void NormalizeMask(SmallVectorImpl<int> &Mask, unsigned NumElems) {
  for (unsigned i = 0; i != NumElems; ++i) {
    if (Mask[i] > (int)NumElems) {
      Mask[i] = NumElems;
    }
  }
}

/// getMOVLMask - Returns a vector_shuffle mask for an movs{s|d}, movd
/// operation of specified width.
static SDValue getMOVL(SelectionDAG &DAG, SDLoc dl, EVT VT, SDValue V1,
                       SDValue V2) {
  unsigned NumElems = VT.getVectorNumElements();
  SmallVector<int, 8> Mask;
  Mask.push_back(NumElems);
  for (unsigned i = 1; i != NumElems; ++i)
    Mask.push_back(i);
  return DAG.getVectorShuffle(VT, dl, V1, V2, &Mask[0]);
}

/// getUnpackl - Returns a vector_shuffle node for an unpackl operation.
static SDValue getUnpackl(SelectionDAG &DAG, SDLoc dl, MVT VT, SDValue V1,
                          SDValue V2) {
  unsigned NumElems = VT.getVectorNumElements();
  SmallVector<int, 8> Mask;
  for (unsigned i = 0, e = NumElems/2; i != e; ++i) {
    Mask.push_back(i);
    Mask.push_back(i + NumElems);
  }
  return DAG.getVectorShuffle(VT, dl, V1, V2, &Mask[0]);
}

/// getUnpackh - Returns a vector_shuffle node for an unpackh operation.
static SDValue getUnpackh(SelectionDAG &DAG, SDLoc dl, MVT VT, SDValue V1,
                          SDValue V2) {
  unsigned NumElems = VT.getVectorNumElements();
  SmallVector<int, 8> Mask;
  for (unsigned i = 0, Half = NumElems/2; i != Half; ++i) {
    Mask.push_back(i + Half);
    Mask.push_back(i + NumElems + Half);
  }
  return DAG.getVectorShuffle(VT, dl, V1, V2, &Mask[0]);
}

// PromoteSplati8i16 - All i16 and i8 vector types can't be used directly by
// a generic shuffle instruction because the target has no such instructions.
// Generate shuffles which repeat i16 and i8 several times until they can be
// represented by v4f32 and then be manipulated by target suported shuffles.
static SDValue PromoteSplati8i16(SDValue V, SelectionDAG &DAG, int &EltNo) {
  MVT VT = V.getSimpleValueType();
  int NumElems = VT.getVectorNumElements();
  SDLoc dl(V);

  while (NumElems > 4) {
    if (EltNo < NumElems/2) {
      V = getUnpackl(DAG, dl, VT, V, V);
    } else {
      V = getUnpackh(DAG, dl, VT, V, V);
      EltNo -= NumElems/2;
    }
    NumElems >>= 1;
  }
  return V;
}

/// getLegalSplat - Generate a legal splat with supported x86 shuffles
static SDValue getLegalSplat(SelectionDAG &DAG, SDValue V, int EltNo) {
  MVT VT = V.getSimpleValueType();
  SDLoc dl(V);

  if (VT.is128BitVector()) {
    V = DAG.getNode(ISD::BITCAST, dl, MVT::v4f32, V);
    int SplatMask[4] = { EltNo, EltNo, EltNo, EltNo };
    V = DAG.getVectorShuffle(MVT::v4f32, dl, V, DAG.getUNDEF(MVT::v4f32),
                             &SplatMask[0]);
  } else if (VT.is256BitVector()) {
    // To use VPERMILPS to splat scalars, the second half of indicies must
    // refer to the higher part, which is a duplication of the lower one,
    // because VPERMILPS can only handle in-lane permutations.
    int SplatMask[8] = { EltNo, EltNo, EltNo, EltNo,
                         EltNo+4, EltNo+4, EltNo+4, EltNo+4 };

    V = DAG.getNode(ISD::BITCAST, dl, MVT::v8f32, V);
    V = DAG.getVectorShuffle(MVT::v8f32, dl, V, DAG.getUNDEF(MVT::v8f32),
                             &SplatMask[0]);
  } else
    llvm_unreachable("Vector size not supported");

  return DAG.getNode(ISD::BITCAST, dl, VT, V);
}

/// PromoteSplat - Splat is promoted to target supported vector shuffles.
static SDValue PromoteSplat(ShuffleVectorSDNode *SV, SelectionDAG &DAG) {
  MVT SrcVT = SV->getSimpleValueType(0);
  SDValue V1 = SV->getOperand(0);
  SDLoc dl(SV);

  int EltNo = SV->getSplatIndex();
  int NumElems = SrcVT.getVectorNumElements();
  bool Is256BitVec = SrcVT.is256BitVector();

  assert(((SrcVT.is128BitVector() && NumElems > 4) || Is256BitVec) &&
         "Unknown how to promote splat for type");

  // Extract the 128-bit part containing the splat element and update
  // the splat element index when it refers to the higher register.
  if (Is256BitVec) {
    V1 = Extract128BitVector(V1, EltNo, DAG, dl);
    if (EltNo >= NumElems/2)
      EltNo -= NumElems/2;
  }

  // All i16 and i8 vector types can't be used directly by a generic shuffle
  // instruction because the target has no such instruction. Generate shuffles
  // which repeat i16 and i8 several times until they fit in i32, and then can
  // be manipulated by target suported shuffles.
  MVT EltVT = SrcVT.getVectorElementType();
  if (EltVT == MVT::i8 || EltVT == MVT::i16)
    V1 = PromoteSplati8i16(V1, DAG, EltNo);

  // Recreate the 256-bit vector and place the same 128-bit vector
  // into the low and high part. This is necessary because we want
  // to use VPERM* to shuffle the vectors
  if (Is256BitVec) {
    V1 = DAG.getNode(ISD::CONCAT_VECTORS, dl, SrcVT, V1, V1);
  }

  return getLegalSplat(DAG, V1, EltNo);
}

/// getShuffleVectorZeroOrUndef - Return a vector_shuffle of the specified
/// vector of zero or undef vector.  This produces a shuffle where the low
/// element of V2 is swizzled into the zero/undef vector, landing at element
/// Idx.  This produces a shuffle mask like 4,1,2,3 (idx=0) or  0,1,2,4 (idx=3).
static SDValue getShuffleVectorZeroOrUndef(SDValue V2, unsigned Idx,
                                           bool IsZero,
                                           const X86Subtarget *Subtarget,
                                           SelectionDAG &DAG) {
  MVT VT = V2.getSimpleValueType();
  SDValue V1 = IsZero
    ? getZeroVector(VT, Subtarget, DAG, SDLoc(V2)) : DAG.getUNDEF(VT);
  unsigned NumElems = VT.getVectorNumElements();
  SmallVector<int, 16> MaskVec;
  for (unsigned i = 0; i != NumElems; ++i)
    // If this is the insertion idx, put the low elt of V2 here.
    MaskVec.push_back(i == Idx ? NumElems : i);
  return DAG.getVectorShuffle(VT, SDLoc(V2), V1, V2, &MaskVec[0]);
}

/// getTargetShuffleMask - Calculates the shuffle mask corresponding to the
/// target specific opcode. Returns true if the Mask could be calculated. Sets
/// IsUnary to true if only uses one source. Note that this will set IsUnary for
/// shuffles which use a single input multiple times, and in those cases it will
/// adjust the mask to only have indices within that single input.
static bool getTargetShuffleMask(SDNode *N, MVT VT,
                                 SmallVectorImpl<int> &Mask, bool &IsUnary) {
  unsigned NumElems = VT.getVectorNumElements();
  SDValue ImmN;

  IsUnary = false;
  bool IsFakeUnary = false;
  switch(N->getOpcode()) {
  case X86ISD::BLENDI:
    ImmN = N->getOperand(N->getNumOperands()-1);
    DecodeBLENDMask(VT, cast<ConstantSDNode>(ImmN)->getZExtValue(), Mask);
    break;
  case X86ISD::SHUFP:
    ImmN = N->getOperand(N->getNumOperands()-1);
    DecodeSHUFPMask(VT, cast<ConstantSDNode>(ImmN)->getZExtValue(), Mask);
    IsUnary = IsFakeUnary = N->getOperand(0) == N->getOperand(1);
    break;
  case X86ISD::UNPCKH:
    DecodeUNPCKHMask(VT, Mask);
    IsUnary = IsFakeUnary = N->getOperand(0) == N->getOperand(1);
    break;
  case X86ISD::UNPCKL:
    DecodeUNPCKLMask(VT, Mask);
    IsUnary = IsFakeUnary = N->getOperand(0) == N->getOperand(1);
    break;
  case X86ISD::MOVHLPS:
    DecodeMOVHLPSMask(NumElems, Mask);
    IsUnary = IsFakeUnary = N->getOperand(0) == N->getOperand(1);
    break;
  case X86ISD::MOVLHPS:
    DecodeMOVLHPSMask(NumElems, Mask);
    IsUnary = IsFakeUnary = N->getOperand(0) == N->getOperand(1);
    break;
  case X86ISD::PALIGNR:
    ImmN = N->getOperand(N->getNumOperands()-1);
    DecodePALIGNRMask(VT, cast<ConstantSDNode>(ImmN)->getZExtValue(), Mask);
    break;
  case X86ISD::PSHUFD:
  case X86ISD::VPERMILPI:
    ImmN = N->getOperand(N->getNumOperands()-1);
    DecodePSHUFMask(VT, cast<ConstantSDNode>(ImmN)->getZExtValue(), Mask);
    IsUnary = true;
    break;
  case X86ISD::PSHUFHW:
    ImmN = N->getOperand(N->getNumOperands()-1);
    DecodePSHUFHWMask(VT, cast<ConstantSDNode>(ImmN)->getZExtValue(), Mask);
    IsUnary = true;
    break;
  case X86ISD::PSHUFLW:
    ImmN = N->getOperand(N->getNumOperands()-1);
    DecodePSHUFLWMask(VT, cast<ConstantSDNode>(ImmN)->getZExtValue(), Mask);
    IsUnary = true;
    break;
  case X86ISD::PSHUFB: {
    IsUnary = true;
    SDValue MaskNode = N->getOperand(1);
    while (MaskNode->getOpcode() == ISD::BITCAST)
      MaskNode = MaskNode->getOperand(0);

    if (MaskNode->getOpcode() == ISD::BUILD_VECTOR) {
      // If we have a build-vector, then things are easy.
      EVT VT = MaskNode.getValueType();
      assert(VT.isVector() &&
             "Can't produce a non-vector with a build_vector!");
      if (!VT.isInteger())
        return false;

      int NumBytesPerElement = VT.getVectorElementType().getSizeInBits() / 8;

      SmallVector<uint64_t, 32> RawMask;
      for (int i = 0, e = MaskNode->getNumOperands(); i < e; ++i) {
        SDValue Op = MaskNode->getOperand(i);
        if (Op->getOpcode() == ISD::UNDEF) {
          RawMask.push_back((uint64_t)SM_SentinelUndef);
          continue;
        }
        auto *CN = dyn_cast<ConstantSDNode>(Op.getNode());
        if (!CN)
          return false;
        APInt MaskElement = CN->getAPIntValue();

        // We now have to decode the element which could be any integer size and
        // extract each byte of it.
        for (int j = 0; j < NumBytesPerElement; ++j) {
          // Note that this is x86 and so always little endian: the low byte is
          // the first byte of the mask.
          RawMask.push_back(MaskElement.getLoBits(8).getZExtValue());
          MaskElement = MaskElement.lshr(8);
        }
      }
      DecodePSHUFBMask(RawMask, Mask);
      break;
    }

    auto *MaskLoad = dyn_cast<LoadSDNode>(MaskNode);
    if (!MaskLoad)
      return false;

    SDValue Ptr = MaskLoad->getBasePtr();
    if (Ptr->getOpcode() == X86ISD::Wrapper)
      Ptr = Ptr->getOperand(0);

    auto *MaskCP = dyn_cast<ConstantPoolSDNode>(Ptr);
    if (!MaskCP || MaskCP->isMachineConstantPoolEntry())
      return false;

    if (auto *C = dyn_cast<Constant>(MaskCP->getConstVal())) {
      DecodePSHUFBMask(C, Mask);
      if (Mask.empty())
        return false;
      break;
    }

    return false;
  }
  case X86ISD::VPERMI:
    ImmN = N->getOperand(N->getNumOperands()-1);
    DecodeVPERMMask(cast<ConstantSDNode>(ImmN)->getZExtValue(), Mask);
    IsUnary = true;
    break;
  case X86ISD::MOVSS:
  case X86ISD::MOVSD:
    DecodeScalarMoveMask(VT, /* IsLoad */ false, Mask);
    break;
  case X86ISD::VPERM2X128:
    ImmN = N->getOperand(N->getNumOperands()-1);
    DecodeVPERM2X128Mask(VT, cast<ConstantSDNode>(ImmN)->getZExtValue(), Mask);
    if (Mask.empty()) return false;
    break;
  case X86ISD::MOVSLDUP:
    DecodeMOVSLDUPMask(VT, Mask);
    IsUnary = true;
    break;
  case X86ISD::MOVSHDUP:
    DecodeMOVSHDUPMask(VT, Mask);
    IsUnary = true;
    break;
  case X86ISD::MOVDDUP:
    DecodeMOVDDUPMask(VT, Mask);
    IsUnary = true;
    break;
  case X86ISD::MOVLHPD:
  case X86ISD::MOVLPD:
  case X86ISD::MOVLPS:
    // Not yet implemented
    return false;
  default: llvm_unreachable("unknown target shuffle node");
  }

  // If we have a fake unary shuffle, the shuffle mask is spread across two
  // inputs that are actually the same node. Re-map the mask to always point
  // into the first input.
  if (IsFakeUnary)
    for (int &M : Mask)
      if (M >= (int)Mask.size())
        M -= Mask.size();

  return true;
}

/// getShuffleScalarElt - Returns the scalar element that will make up the ith
/// element of the result of the vector shuffle.
static SDValue getShuffleScalarElt(SDNode *N, unsigned Index, SelectionDAG &DAG,
                                   unsigned Depth) {
  if (Depth == 6)
    return SDValue();  // Limit search depth.

  SDValue V = SDValue(N, 0);
  EVT VT = V.getValueType();
  unsigned Opcode = V.getOpcode();

  // Recurse into ISD::VECTOR_SHUFFLE node to find scalars.
  if (const ShuffleVectorSDNode *SV = dyn_cast<ShuffleVectorSDNode>(N)) {
    int Elt = SV->getMaskElt(Index);

    if (Elt < 0)
      return DAG.getUNDEF(VT.getVectorElementType());

    unsigned NumElems = VT.getVectorNumElements();
    SDValue NewV = (Elt < (int)NumElems) ? SV->getOperand(0)
                                         : SV->getOperand(1);
    return getShuffleScalarElt(NewV.getNode(), Elt % NumElems, DAG, Depth+1);
  }

  // Recurse into target specific vector shuffles to find scalars.
  if (isTargetShuffle(Opcode)) {
    MVT ShufVT = V.getSimpleValueType();
    unsigned NumElems = ShufVT.getVectorNumElements();
    SmallVector<int, 16> ShuffleMask;
    bool IsUnary;

    if (!getTargetShuffleMask(N, ShufVT, ShuffleMask, IsUnary))
      return SDValue();

    int Elt = ShuffleMask[Index];
    if (Elt < 0)
      return DAG.getUNDEF(ShufVT.getVectorElementType());

    SDValue NewV = (Elt < (int)NumElems) ? N->getOperand(0)
                                         : N->getOperand(1);
    return getShuffleScalarElt(NewV.getNode(), Elt % NumElems, DAG,
                               Depth+1);
  }

  // Actual nodes that may contain scalar elements
  if (Opcode == ISD::BITCAST) {
    V = V.getOperand(0);
    EVT SrcVT = V.getValueType();
    unsigned NumElems = VT.getVectorNumElements();

    if (!SrcVT.isVector() || SrcVT.getVectorNumElements() != NumElems)
      return SDValue();
  }

  if (V.getOpcode() == ISD::SCALAR_TO_VECTOR)
    return (Index == 0) ? V.getOperand(0)
                        : DAG.getUNDEF(VT.getVectorElementType());

  if (V.getOpcode() == ISD::BUILD_VECTOR)
    return V.getOperand(Index);

  return SDValue();
}

/// getNumOfConsecutiveZeros - Return the number of elements of a vector
/// shuffle operation which come from a consecutively from a zero. The
/// search can start in two different directions, from left or right.
/// We count undefs as zeros until PreferredNum is reached.
static unsigned getNumOfConsecutiveZeros(ShuffleVectorSDNode *SVOp,
                                         unsigned NumElems, bool ZerosFromLeft,
                                         SelectionDAG &DAG,
                                         unsigned PreferredNum = -1U) {
  unsigned NumZeros = 0;
  for (unsigned i = 0; i != NumElems; ++i) {
    unsigned Index = ZerosFromLeft ? i : NumElems - i - 1;
    SDValue Elt = getShuffleScalarElt(SVOp, Index, DAG, 0);
    if (!Elt.getNode())
      break;

    if (X86::isZeroNode(Elt))
      ++NumZeros;
    else if (Elt.getOpcode() == ISD::UNDEF) // Undef as zero up to PreferredNum.
      NumZeros = std::min(NumZeros + 1, PreferredNum);
    else
      break;
  }

  return NumZeros;
}

/// isShuffleMaskConsecutive - Check if the shuffle mask indicies [MaskI, MaskE)
/// correspond consecutively to elements from one of the vector operands,
/// starting from its index OpIdx. Also tell OpNum which source vector operand.
static
bool isShuffleMaskConsecutive(ShuffleVectorSDNode *SVOp,
                              unsigned MaskI, unsigned MaskE, unsigned OpIdx,
                              unsigned NumElems, unsigned &OpNum) {
  bool SeenV1 = false;
  bool SeenV2 = false;

  for (unsigned i = MaskI; i != MaskE; ++i, ++OpIdx) {
    int Idx = SVOp->getMaskElt(i);
    // Ignore undef indicies
    if (Idx < 0)
      continue;

    if (Idx < (int)NumElems)
      SeenV1 = true;
    else
      SeenV2 = true;

    // Only accept consecutive elements from the same vector
    if ((Idx % NumElems != OpIdx) || (SeenV1 && SeenV2))
      return false;
  }

  OpNum = SeenV1 ? 0 : 1;
  return true;
}

/// isVectorShiftRight - Returns true if the shuffle can be implemented as a
/// logical left shift of a vector.
static bool isVectorShiftRight(ShuffleVectorSDNode *SVOp, SelectionDAG &DAG,
                               bool &isLeft, SDValue &ShVal, unsigned &ShAmt) {
  unsigned NumElems =
    SVOp->getSimpleValueType(0).getVectorNumElements();
  unsigned NumZeros = getNumOfConsecutiveZeros(
      SVOp, NumElems, false /* check zeros from right */, DAG,
      SVOp->getMaskElt(0));
  unsigned OpSrc;

  if (!NumZeros)
    return false;

  // Considering the elements in the mask that are not consecutive zeros,
  // check if they consecutively come from only one of the source vectors.
  //
  //               V1 = {X, A, B, C}     0
  //                         \  \  \    /
  //   vector_shuffle V1, V2 <1, 2, 3, X>
  //
  if (!isShuffleMaskConsecutive(SVOp,
            0,                   // Mask Start Index
            NumElems-NumZeros,   // Mask End Index(exclusive)
            NumZeros,            // Where to start looking in the src vector
            NumElems,            // Number of elements in vector
            OpSrc))              // Which source operand ?
    return false;

  isLeft = false;
  ShAmt = NumZeros;
  ShVal = SVOp->getOperand(OpSrc);
  return true;
}

/// isVectorShiftLeft - Returns true if the shuffle can be implemented as a
/// logical left shift of a vector.
static bool isVectorShiftLeft(ShuffleVectorSDNode *SVOp, SelectionDAG &DAG,
                              bool &isLeft, SDValue &ShVal, unsigned &ShAmt) {
  unsigned NumElems =
    SVOp->getSimpleValueType(0).getVectorNumElements();
  unsigned NumZeros = getNumOfConsecutiveZeros(
      SVOp, NumElems, true /* check zeros from left */, DAG,
      NumElems - SVOp->getMaskElt(NumElems - 1) - 1);
  unsigned OpSrc;

  if (!NumZeros)
    return false;

  // Considering the elements in the mask that are not consecutive zeros,
  // check if they consecutively come from only one of the source vectors.
  //
  //                           0    { A, B, X, X } = V2
  //                          / \    /  /
  //   vector_shuffle V1, V2 <X, X, 4, 5>
  //
  if (!isShuffleMaskConsecutive(SVOp,
            NumZeros,     // Mask Start Index
            NumElems,     // Mask End Index(exclusive)
            0,            // Where to start looking in the src vector
            NumElems,     // Number of elements in vector
            OpSrc))       // Which source operand ?
    return false;

  isLeft = true;
  ShAmt = NumZeros;
  ShVal = SVOp->getOperand(OpSrc);
  return true;
}

/// isVectorShift - Returns true if the shuffle can be implemented as a
/// logical left or right shift of a vector.
static bool isVectorShift(ShuffleVectorSDNode *SVOp, SelectionDAG &DAG,
                          bool &isLeft, SDValue &ShVal, unsigned &ShAmt) {
  // Although the logic below support any bitwidth size, there are no
  // shift instructions which handle more than 128-bit vectors.
  if (!SVOp->getSimpleValueType(0).is128BitVector())
    return false;

  if (isVectorShiftLeft(SVOp, DAG, isLeft, ShVal, ShAmt) ||
      isVectorShiftRight(SVOp, DAG, isLeft, ShVal, ShAmt))
    return true;

  return false;
}

/// LowerBuildVectorv16i8 - Custom lower build_vector of v16i8.
///
static SDValue LowerBuildVectorv16i8(SDValue Op, unsigned NonZeros,
                                       unsigned NumNonZero, unsigned NumZero,
                                       SelectionDAG &DAG,
                                       const X86Subtarget* Subtarget,
                                       const TargetLowering &TLI) {
  if (NumNonZero > 8)
    return SDValue();

  SDLoc dl(Op);
  SDValue V;
  bool First = true;
  for (unsigned i = 0; i < 16; ++i) {
    bool ThisIsNonZero = (NonZeros & (1 << i)) != 0;
    if (ThisIsNonZero && First) {
      if (NumZero)
        V = getZeroVector(MVT::v8i16, Subtarget, DAG, dl);
      else
        V = DAG.getUNDEF(MVT::v8i16);
      First = false;
    }

    if ((i & 1) != 0) {
      SDValue ThisElt, LastElt;
      bool LastIsNonZero = (NonZeros & (1 << (i-1))) != 0;
      if (LastIsNonZero) {
        LastElt = DAG.getNode(ISD::ZERO_EXTEND, dl,
                              MVT::i16, Op.getOperand(i-1));
      }
      if (ThisIsNonZero) {
        ThisElt = DAG.getNode(ISD::ZERO_EXTEND, dl, MVT::i16, Op.getOperand(i));
        ThisElt = DAG.getNode(ISD::SHL, dl, MVT::i16,
                              ThisElt, DAG.getConstant(8, MVT::i8));
        if (LastIsNonZero)
          ThisElt = DAG.getNode(ISD::OR, dl, MVT::i16, ThisElt, LastElt);
      } else
        ThisElt = LastElt;

      if (ThisElt.getNode())
        V = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, MVT::v8i16, V, ThisElt,
                        DAG.getIntPtrConstant(i/2));
    }
  }

  return DAG.getNode(ISD::BITCAST, dl, MVT::v16i8, V);
}

/// LowerBuildVectorv8i16 - Custom lower build_vector of v8i16.
///
static SDValue LowerBuildVectorv8i16(SDValue Op, unsigned NonZeros,
                                     unsigned NumNonZero, unsigned NumZero,
                                     SelectionDAG &DAG,
                                     const X86Subtarget* Subtarget,
                                     const TargetLowering &TLI) {
  if (NumNonZero > 4)
    return SDValue();

  SDLoc dl(Op);
  SDValue V;
  bool First = true;
  for (unsigned i = 0; i < 8; ++i) {
    bool isNonZero = (NonZeros & (1 << i)) != 0;
    if (isNonZero) {
      if (First) {
        if (NumZero)
          V = getZeroVector(MVT::v8i16, Subtarget, DAG, dl);
        else
          V = DAG.getUNDEF(MVT::v8i16);
        First = false;
      }
      V = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl,
                      MVT::v8i16, V, Op.getOperand(i),
                      DAG.getIntPtrConstant(i));
    }
  }

  return V;
}

/// LowerBuildVectorv4x32 - Custom lower build_vector of v4i32 or v4f32.
static SDValue LowerBuildVectorv4x32(SDValue Op, SelectionDAG &DAG,
                                     const X86Subtarget *Subtarget,
                                     const TargetLowering &TLI) {
  // Find all zeroable elements.
  std::bitset<4> Zeroable;
  for (int i=0; i < 4; ++i) {
    SDValue Elt = Op->getOperand(i);
    Zeroable[i] = (Elt.getOpcode() == ISD::UNDEF || X86::isZeroNode(Elt));
  }
  assert(Zeroable.size() - Zeroable.count() > 1 &&
         "We expect at least two non-zero elements!");

  // We only know how to deal with build_vector nodes where elements are either
  // zeroable or extract_vector_elt with constant index.
  SDValue FirstNonZero;
  unsigned FirstNonZeroIdx;
  for (unsigned i=0; i < 4; ++i) {
    if (Zeroable[i])
      continue;
    SDValue Elt = Op->getOperand(i);
    if (Elt.getOpcode() != ISD::EXTRACT_VECTOR_ELT ||
        !isa<ConstantSDNode>(Elt.getOperand(1)))
      return SDValue();
    // Make sure that this node is extracting from a 128-bit vector.
    MVT VT = Elt.getOperand(0).getSimpleValueType();
    if (!VT.is128BitVector())
      return SDValue();
    if (!FirstNonZero.getNode()) {
      FirstNonZero = Elt;
      FirstNonZeroIdx = i;
    }
  }

  assert(FirstNonZero.getNode() && "Unexpected build vector of all zeros!");
  SDValue V1 = FirstNonZero.getOperand(0);
  MVT VT = V1.getSimpleValueType();

  // See if this build_vector can be lowered as a blend with zero.
  SDValue Elt;
  unsigned EltMaskIdx, EltIdx;
  int Mask[4];
  for (EltIdx = 0; EltIdx < 4; ++EltIdx) {
    if (Zeroable[EltIdx]) {
      // The zero vector will be on the right hand side.
      Mask[EltIdx] = EltIdx+4;
      continue;
    }

    Elt = Op->getOperand(EltIdx);
    // By construction, Elt is a EXTRACT_VECTOR_ELT with constant index.
    EltMaskIdx = cast<ConstantSDNode>(Elt.getOperand(1))->getZExtValue();
    if (Elt.getOperand(0) != V1 || EltMaskIdx != EltIdx)
      break;
    Mask[EltIdx] = EltIdx;
  }

  if (EltIdx == 4) {
    // Let the shuffle legalizer deal with blend operations.
    SDValue VZero = getZeroVector(VT, Subtarget, DAG, SDLoc(Op));
    if (V1.getSimpleValueType() != VT)
      V1 = DAG.getNode(ISD::BITCAST, SDLoc(V1), VT, V1);
    return DAG.getVectorShuffle(VT, SDLoc(V1), V1, VZero, &Mask[0]);
  }

  // See if we can lower this build_vector to a INSERTPS.
  if (!Subtarget->hasSSE41())
    return SDValue();

  SDValue V2 = Elt.getOperand(0);
  if (Elt == FirstNonZero && EltIdx == FirstNonZeroIdx)
    V1 = SDValue();

  bool CanFold = true;
  for (unsigned i = EltIdx + 1; i < 4 && CanFold; ++i) {
    if (Zeroable[i])
      continue;

    SDValue Current = Op->getOperand(i);
    SDValue SrcVector = Current->getOperand(0);
    if (!V1.getNode())
      V1 = SrcVector;
    CanFold = SrcVector == V1 &&
      cast<ConstantSDNode>(Current.getOperand(1))->getZExtValue() == i;
  }

  if (!CanFold)
    return SDValue();

  assert(V1.getNode() && "Expected at least two non-zero elements!");
  if (V1.getSimpleValueType() != MVT::v4f32)
    V1 = DAG.getNode(ISD::BITCAST, SDLoc(V1), MVT::v4f32, V1);
  if (V2.getSimpleValueType() != MVT::v4f32)
    V2 = DAG.getNode(ISD::BITCAST, SDLoc(V2), MVT::v4f32, V2);

  // Ok, we can emit an INSERTPS instruction.
  unsigned ZMask = Zeroable.to_ulong();

  unsigned InsertPSMask = EltMaskIdx << 6 | EltIdx << 4 | ZMask;
  assert((InsertPSMask & ~0xFFu) == 0 && "Invalid mask!");
  SDValue Result = DAG.getNode(X86ISD::INSERTPS, SDLoc(Op), MVT::v4f32, V1, V2,
                               DAG.getIntPtrConstant(InsertPSMask));
  return DAG.getNode(ISD::BITCAST, SDLoc(Op), VT, Result);
}

/// Return a vector logical shift node.
static SDValue getVShift(bool isLeft, EVT VT, SDValue SrcOp,
                         unsigned NumBits, SelectionDAG &DAG,
                         const TargetLowering &TLI, SDLoc dl) {
  assert(VT.is128BitVector() && "Unknown type for VShift");
  MVT ShVT = MVT::v2i64;
  unsigned Opc = isLeft ? X86ISD::VSHLDQ : X86ISD::VSRLDQ;
  SrcOp = DAG.getNode(ISD::BITCAST, dl, ShVT, SrcOp);
  MVT ScalarShiftTy = TLI.getScalarShiftAmountTy(SrcOp.getValueType());
  assert(NumBits % 8 == 0 && "Only support byte sized shifts");
  SDValue ShiftVal = DAG.getConstant(NumBits/8, ScalarShiftTy);
  return DAG.getNode(ISD::BITCAST, dl, VT,
                     DAG.getNode(Opc, dl, ShVT, SrcOp, ShiftVal));
}

static SDValue
LowerAsSplatVectorLoad(SDValue SrcOp, MVT VT, SDLoc dl, SelectionDAG &DAG) {

  // Check if the scalar load can be widened into a vector load. And if
  // the address is "base + cst" see if the cst can be "absorbed" into
  // the shuffle mask.
  if (LoadSDNode *LD = dyn_cast<LoadSDNode>(SrcOp)) {
    SDValue Ptr = LD->getBasePtr();
    if (!ISD::isNormalLoad(LD) || LD->isVolatile())
      return SDValue();
    EVT PVT = LD->getValueType(0);
    if (PVT != MVT::i32 && PVT != MVT::f32)
      return SDValue();

    int FI = -1;
    int64_t Offset = 0;
    if (FrameIndexSDNode *FINode = dyn_cast<FrameIndexSDNode>(Ptr)) {
      FI = FINode->getIndex();
      Offset = 0;
    } else if (DAG.isBaseWithConstantOffset(Ptr) &&
               isa<FrameIndexSDNode>(Ptr.getOperand(0))) {
      FI = cast<FrameIndexSDNode>(Ptr.getOperand(0))->getIndex();
      Offset = Ptr.getConstantOperandVal(1);
      Ptr = Ptr.getOperand(0);
    } else {
      return SDValue();
    }

    // FIXME: 256-bit vector instructions don't require a strict alignment,
    // improve this code to support it better.
    unsigned RequiredAlign = VT.getSizeInBits()/8;
    SDValue Chain = LD->getChain();
    // Make sure the stack object alignment is at least 16 or 32.
    MachineFrameInfo *MFI = DAG.getMachineFunction().getFrameInfo();
    if (DAG.InferPtrAlignment(Ptr) < RequiredAlign) {
      if (MFI->isFixedObjectIndex(FI)) {
        // Can't change the alignment. FIXME: It's possible to compute
        // the exact stack offset and reference FI + adjust offset instead.
        // If someone *really* cares about this. That's the way to implement it.
        return SDValue();
      } else {
        MFI->setObjectAlignment(FI, RequiredAlign);
      }
    }

    // (Offset % 16 or 32) must be multiple of 4. Then address is then
    // Ptr + (Offset & ~15).
    if (Offset < 0)
      return SDValue();
    if ((Offset % RequiredAlign) & 3)
      return SDValue();
    int64_t StartOffset = Offset & ~(RequiredAlign-1);
    if (StartOffset)
      Ptr = DAG.getNode(ISD::ADD, SDLoc(Ptr), Ptr.getValueType(),
                        Ptr,DAG.getConstant(StartOffset, Ptr.getValueType()));

    int EltNo = (Offset - StartOffset) >> 2;
    unsigned NumElems = VT.getVectorNumElements();

    EVT NVT = EVT::getVectorVT(*DAG.getContext(), PVT, NumElems);
    SDValue V1 = DAG.getLoad(NVT, dl, Chain, Ptr,
                             LD->getPointerInfo().getWithOffset(StartOffset),
                             false, false, false, 0);

    SmallVector<int, 8> Mask(NumElems, EltNo);

    return DAG.getVectorShuffle(NVT, dl, V1, DAG.getUNDEF(NVT), &Mask[0]);
  }

  return SDValue();
}

/// Given the initializing elements 'Elts' of a vector of type 'VT', see if the
/// elements can be replaced by a single large load which has the same value as
/// a build_vector or insert_subvector whose loaded operands are 'Elts'.
///
/// Example: <load i32 *a, load i32 *a+4, undef, undef> -> zextload a
///
/// FIXME: we'd also like to handle the case where the last elements are zero
/// rather than undef via VZEXT_LOAD, but we do not detect that case today.
/// There's even a handy isZeroNode for that purpose.
static SDValue EltsFromConsecutiveLoads(EVT VT, ArrayRef<SDValue> Elts,
                                        SDLoc &DL, SelectionDAG &DAG,
                                        bool isAfterLegalize) {
  unsigned NumElems = Elts.size();

  LoadSDNode *LDBase = nullptr;
  unsigned LastLoadedElt = -1U;

  // For each element in the initializer, see if we've found a load or an undef.
  // If we don't find an initial load element, or later load elements are
  // non-consecutive, bail out.
  for (unsigned i = 0; i < NumElems; ++i) {
    SDValue Elt = Elts[i];
    // Look through a bitcast.
    if (Elt.getNode() && Elt.getOpcode() == ISD::BITCAST)
      Elt = Elt.getOperand(0);
    if (!Elt.getNode() ||
        (Elt.getOpcode() != ISD::UNDEF && !ISD::isNON_EXTLoad(Elt.getNode())))
      return SDValue();
    if (!LDBase) {
      if (Elt.getNode()->getOpcode() == ISD::UNDEF)
        return SDValue();
      LDBase = cast<LoadSDNode>(Elt.getNode());
      LastLoadedElt = i;
      continue;
    }
    if (Elt.getOpcode() == ISD::UNDEF)
      continue;

    LoadSDNode *LD = cast<LoadSDNode>(Elt);
    EVT LdVT = Elt.getValueType();
    // Each loaded element must be the correct fractional portion of the
    // requested vector load.
    if (LdVT.getSizeInBits() != VT.getSizeInBits() / NumElems)
      return SDValue();
    if (!DAG.isConsecutiveLoad(LD, LDBase, LdVT.getSizeInBits() / 8, i))
      return SDValue();
    LastLoadedElt = i;
  }

  // If we have found an entire vector of loads and undefs, then return a large
  // load of the entire vector width starting at the base pointer.  If we found
  // consecutive loads for the low half, generate a vzext_load node.
  if (LastLoadedElt == NumElems - 1) {
    assert(LDBase && "Did not find base load for merging consecutive loads");
    EVT EltVT = LDBase->getValueType(0);
    // Ensure that the input vector size for the merged loads matches the
    // cumulative size of the input elements.
    if (VT.getSizeInBits() != EltVT.getSizeInBits() * NumElems)
      return SDValue();

    if (isAfterLegalize &&
        !DAG.getTargetLoweringInfo().isOperationLegal(ISD::LOAD, VT))
      return SDValue();

    SDValue NewLd = SDValue();

    NewLd = DAG.getLoad(VT, DL, LDBase->getChain(), LDBase->getBasePtr(),
                        LDBase->getPointerInfo(), LDBase->isVolatile(),
                        LDBase->isNonTemporal(), LDBase->isInvariant(),
                        LDBase->getAlignment());

    if (LDBase->hasAnyUseOfValue(1)) {
      SDValue NewChain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other,
                                     SDValue(LDBase, 1),
                                     SDValue(NewLd.getNode(), 1));
      DAG.ReplaceAllUsesOfValueWith(SDValue(LDBase, 1), NewChain);
      DAG.UpdateNodeOperands(NewChain.getNode(), SDValue(LDBase, 1),
                             SDValue(NewLd.getNode(), 1));
    }

    return NewLd;
  }

  //TODO: The code below fires only for for loading the low v2i32 / v2f32
  //of a v4i32 / v4f32. It's probably worth generalizing.
  EVT EltVT = VT.getVectorElementType();
  if (NumElems == 4 && LastLoadedElt == 1 && (EltVT.getSizeInBits() == 32) &&
      DAG.getTargetLoweringInfo().isTypeLegal(MVT::v2i64)) {
    SDVTList Tys = DAG.getVTList(MVT::v2i64, MVT::Other);
    SDValue Ops[] = { LDBase->getChain(), LDBase->getBasePtr() };
    SDValue ResNode =
        DAG.getMemIntrinsicNode(X86ISD::VZEXT_LOAD, DL, Tys, Ops, MVT::i64,
                                LDBase->getPointerInfo(),
                                LDBase->getAlignment(),
                                false/*isVolatile*/, true/*ReadMem*/,
                                false/*WriteMem*/);

    // Make sure the newly-created LOAD is in the same position as LDBase in
    // terms of dependency. We create a TokenFactor for LDBase and ResNode, and
    // update uses of LDBase's output chain to use the TokenFactor.
    if (LDBase->hasAnyUseOfValue(1)) {
      SDValue NewChain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other,
                             SDValue(LDBase, 1), SDValue(ResNode.getNode(), 1));
      DAG.ReplaceAllUsesOfValueWith(SDValue(LDBase, 1), NewChain);
      DAG.UpdateNodeOperands(NewChain.getNode(), SDValue(LDBase, 1),
                             SDValue(ResNode.getNode(), 1));
    }

    return DAG.getNode(ISD::BITCAST, DL, VT, ResNode);
  }
  return SDValue();
}

/// LowerVectorBroadcast - Attempt to use the vbroadcast instruction
/// to generate a splat value for the following cases:
/// 1. A splat BUILD_VECTOR which uses a single scalar load, or a constant.
/// 2. A splat shuffle which uses a scalar_to_vector node which comes from
/// a scalar load, or a constant.
/// The VBROADCAST node is returned when a pattern is found,
/// or SDValue() otherwise.
static SDValue LowerVectorBroadcast(SDValue Op, const X86Subtarget* Subtarget,
                                    SelectionDAG &DAG) {
  // VBROADCAST requires AVX.
  // TODO: Splats could be generated for non-AVX CPUs using SSE
  // instructions, but there's less potential gain for only 128-bit vectors.
  if (!Subtarget->hasAVX())
    return SDValue();

  MVT VT = Op.getSimpleValueType();
  SDLoc dl(Op);

  assert((VT.is128BitVector() || VT.is256BitVector() || VT.is512BitVector()) &&
         "Unsupported vector type for broadcast.");

  SDValue Ld;
  bool ConstSplatVal;

  switch (Op.getOpcode()) {
    default:
      // Unknown pattern found.
      return SDValue();

    case ISD::BUILD_VECTOR: {
      auto *BVOp = cast<BuildVectorSDNode>(Op.getNode());
      BitVector UndefElements;
      SDValue Splat = BVOp->getSplatValue(&UndefElements);

      // We need a splat of a single value to use broadcast, and it doesn't
      // make any sense if the value is only in one element of the vector.
      if (!Splat || (VT.getVectorNumElements() - UndefElements.count()) <= 1)
        return SDValue();

      Ld = Splat;
      ConstSplatVal = (Ld.getOpcode() == ISD::Constant ||
                       Ld.getOpcode() == ISD::ConstantFP);

      // Make sure that all of the users of a non-constant load are from the
      // BUILD_VECTOR node.
      if (!ConstSplatVal && !BVOp->isOnlyUserOf(Ld.getNode()))
        return SDValue();
      break;
    }

    case ISD::VECTOR_SHUFFLE: {
      ShuffleVectorSDNode *SVOp = cast<ShuffleVectorSDNode>(Op);

      // Shuffles must have a splat mask where the first element is
      // broadcasted.
      if ((!SVOp->isSplat()) || SVOp->getMaskElt(0) != 0)
        return SDValue();

      SDValue Sc = Op.getOperand(0);
      if (Sc.getOpcode() != ISD::SCALAR_TO_VECTOR &&
          Sc.getOpcode() != ISD::BUILD_VECTOR) {

        if (!Subtarget->hasInt256())
          return SDValue();

        // Use the register form of the broadcast instruction available on AVX2.
        if (VT.getSizeInBits() >= 256)
          Sc = Extract128BitVector(Sc, 0, DAG, dl);
        return DAG.getNode(X86ISD::VBROADCAST, dl, VT, Sc);
      }

      Ld = Sc.getOperand(0);
      ConstSplatVal = (Ld.getOpcode() == ISD::Constant ||
                       Ld.getOpcode() == ISD::ConstantFP);

      // The scalar_to_vector node and the suspected
      // load node must have exactly one user.
      // Constants may have multiple users.

      // AVX-512 has register version of the broadcast
      bool hasRegVer = Subtarget->hasAVX512() && VT.is512BitVector() &&
        Ld.getValueType().getSizeInBits() >= 32;
      if (!ConstSplatVal && ((!Sc.hasOneUse() || !Ld.hasOneUse()) &&
          !hasRegVer))
        return SDValue();
      break;
    }
  }

  unsigned ScalarSize = Ld.getValueType().getSizeInBits();
  bool IsGE256 = (VT.getSizeInBits() >= 256);

  // When optimizing for size, generate up to 5 extra bytes for a broadcast
  // instruction to save 8 or more bytes of constant pool data.
  // TODO: If multiple splats are generated to load the same constant,
  // it may be detrimental to overall size. There needs to be a way to detect
  // that condition to know if this is truly a size win.
  const Function *F = DAG.getMachineFunction().getFunction();
  bool OptForSize = F->hasFnAttribute(Attribute::OptimizeForSize);

  // Handle broadcasting a single constant scalar from the constant pool
  // into a vector.
  // On Sandybridge (no AVX2), it is still better to load a constant vector
  // from the constant pool and not to broadcast it from a scalar.
  // But override that restriction when optimizing for size.
  // TODO: Check if splatting is recommended for other AVX-capable CPUs.
  if (ConstSplatVal && (Subtarget->hasAVX2() || OptForSize)) {
    EVT CVT = Ld.getValueType();
    assert(!CVT.isVector() && "Must not broadcast a vector type");

    // Splat f32, i32, v4f64, v4i64 in all cases with AVX2.
    // For size optimization, also splat v2f64 and v2i64, and for size opt
    // with AVX2, also splat i8 and i16.
    // With pattern matching, the VBROADCAST node may become a VMOVDDUP.
    if (ScalarSize == 32 || (IsGE256 && ScalarSize == 64) ||
        (OptForSize && (ScalarSize == 64 || Subtarget->hasAVX2()))) {
      const Constant *C = nullptr;
      if (ConstantSDNode *CI = dyn_cast<ConstantSDNode>(Ld))
        C = CI->getConstantIntValue();
      else if (ConstantFPSDNode *CF = dyn_cast<ConstantFPSDNode>(Ld))
        C = CF->getConstantFPValue();

      assert(C && "Invalid constant type");

      const TargetLowering &TLI = DAG.getTargetLoweringInfo();
      SDValue CP = DAG.getConstantPool(C, TLI.getPointerTy());
      unsigned Alignment = cast<ConstantPoolSDNode>(CP)->getAlignment();
      Ld = DAG.getLoad(CVT, dl, DAG.getEntryNode(), CP,
                       MachinePointerInfo::getConstantPool(),
                       false, false, false, Alignment);

      return DAG.getNode(X86ISD::VBROADCAST, dl, VT, Ld);
    }
  }

  bool IsLoad = ISD::isNormalLoad(Ld.getNode());

  // Handle AVX2 in-register broadcasts.
  if (!IsLoad && Subtarget->hasInt256() &&
      (ScalarSize == 32 || (IsGE256 && ScalarSize == 64)))
    return DAG.getNode(X86ISD::VBROADCAST, dl, VT, Ld);

  // The scalar source must be a normal load.
  if (!IsLoad)
    return SDValue();

  if (ScalarSize == 32 || (IsGE256 && ScalarSize == 64) ||
      (Subtarget->hasVLX() && ScalarSize == 64))
    return DAG.getNode(X86ISD::VBROADCAST, dl, VT, Ld);

  // The integer check is needed for the 64-bit into 128-bit so it doesn't match
  // double since there is no vbroadcastsd xmm
  if (Subtarget->hasInt256() && Ld.getValueType().isInteger()) {
    if (ScalarSize == 8 || ScalarSize == 16 || ScalarSize == 64)
      return DAG.getNode(X86ISD::VBROADCAST, dl, VT, Ld);
  }

  // Unsupported broadcast.
  return SDValue();
}

/// \brief For an EXTRACT_VECTOR_ELT with a constant index return the real
/// underlying vector and index.
///
/// Modifies \p ExtractedFromVec to the real vector and returns the real
/// index.
static int getUnderlyingExtractedFromVec(SDValue &ExtractedFromVec,
                                         SDValue ExtIdx) {
  int Idx = cast<ConstantSDNode>(ExtIdx)->getZExtValue();
  if (!isa<ShuffleVectorSDNode>(ExtractedFromVec))
    return Idx;

  // For 256-bit vectors, LowerEXTRACT_VECTOR_ELT_SSE4 may have already
  // lowered this:
  //   (extract_vector_elt (v8f32 %vreg1), Constant<6>)
  // to:
  //   (extract_vector_elt (vector_shuffle<2,u,u,u>
  //                           (extract_subvector (v8f32 %vreg0), Constant<4>),
  //                           undef)
  //                       Constant<0>)
  // In this case the vector is the extract_subvector expression and the index
  // is 2, as specified by the shuffle.
  ShuffleVectorSDNode *SVOp = cast<ShuffleVectorSDNode>(ExtractedFromVec);
  SDValue ShuffleVec = SVOp->getOperand(0);
  MVT ShuffleVecVT = ShuffleVec.getSimpleValueType();
  assert(ShuffleVecVT.getVectorElementType() ==
         ExtractedFromVec.getSimpleValueType().getVectorElementType());

  int ShuffleIdx = SVOp->getMaskElt(Idx);
  if (isUndefOrInRange(ShuffleIdx, 0, ShuffleVecVT.getVectorNumElements())) {
    ExtractedFromVec = ShuffleVec;
    return ShuffleIdx;
  }
  return Idx;
}

static SDValue buildFromShuffleMostly(SDValue Op, SelectionDAG &DAG) {
  MVT VT = Op.getSimpleValueType();

  // Skip if insert_vec_elt is not supported.
  const TargetLowering &TLI = DAG.getTargetLoweringInfo();
  if (!TLI.isOperationLegalOrCustom(ISD::INSERT_VECTOR_ELT, VT))
    return SDValue();

  SDLoc DL(Op);
  unsigned NumElems = Op.getNumOperands();

  SDValue VecIn1;
  SDValue VecIn2;
  SmallVector<unsigned, 4> InsertIndices;
  SmallVector<int, 8> Mask(NumElems, -1);

  for (unsigned i = 0; i != NumElems; ++i) {
    unsigned Opc = Op.getOperand(i).getOpcode();

    if (Opc == ISD::UNDEF)
      continue;

    if (Opc != ISD::EXTRACT_VECTOR_ELT) {
      // Quit if more than 1 elements need inserting.
      if (InsertIndices.size() > 1)
        return SDValue();

      InsertIndices.push_back(i);
      continue;
    }

    SDValue ExtractedFromVec = Op.getOperand(i).getOperand(0);
    SDValue ExtIdx = Op.getOperand(i).getOperand(1);
    // Quit if non-constant index.
    if (!isa<ConstantSDNode>(ExtIdx))
      return SDValue();
    int Idx = getUnderlyingExtractedFromVec(ExtractedFromVec, ExtIdx);

    // Quit if extracted from vector of different type.
    if (ExtractedFromVec.getValueType() != VT)
      return SDValue();

    if (!VecIn1.getNode())
      VecIn1 = ExtractedFromVec;
    else if (VecIn1 != ExtractedFromVec) {
      if (!VecIn2.getNode())
        VecIn2 = ExtractedFromVec;
      else if (VecIn2 != ExtractedFromVec)
        // Quit if more than 2 vectors to shuffle
        return SDValue();
    }

    if (ExtractedFromVec == VecIn1)
      Mask[i] = Idx;
    else if (ExtractedFromVec == VecIn2)
      Mask[i] = Idx + NumElems;
  }

  if (!VecIn1.getNode())
    return SDValue();

  VecIn2 = VecIn2.getNode() ? VecIn2 : DAG.getUNDEF(VT);
  SDValue NV = DAG.getVectorShuffle(VT, DL, VecIn1, VecIn2, &Mask[0]);
  for (unsigned i = 0, e = InsertIndices.size(); i != e; ++i) {
    unsigned Idx = InsertIndices[i];
    NV = DAG.getNode(ISD::INSERT_VECTOR_ELT, DL, VT, NV, Op.getOperand(Idx),
                     DAG.getIntPtrConstant(Idx));
  }

  return NV;
}

// Lower BUILD_VECTOR operation for v8i1 and v16i1 types.
SDValue
X86TargetLowering::LowerBUILD_VECTORvXi1(SDValue Op, SelectionDAG &DAG) const {

  MVT VT = Op.getSimpleValueType();
  assert((VT.getVectorElementType() == MVT::i1) && (VT.getSizeInBits() <= 16) &&
         "Unexpected type in LowerBUILD_VECTORvXi1!");

  SDLoc dl(Op);
  if (ISD::isBuildVectorAllZeros(Op.getNode())) {
    SDValue Cst = DAG.getTargetConstant(0, MVT::i1);
    SmallVector<SDValue, 16> Ops(VT.getVectorNumElements(), Cst);
    return DAG.getNode(ISD::BUILD_VECTOR, dl, VT, Ops);
  }

  if (ISD::isBuildVectorAllOnes(Op.getNode())) {
    SDValue Cst = DAG.getTargetConstant(1, MVT::i1);
    SmallVector<SDValue, 16> Ops(VT.getVectorNumElements(), Cst);
    return DAG.getNode(ISD::BUILD_VECTOR, dl, VT, Ops);
  }

  bool AllContants = true;
  uint64_t Immediate = 0;
  int NonConstIdx = -1;
  bool IsSplat = true;
  unsigned NumNonConsts = 0;
  unsigned NumConsts = 0;
  for (unsigned idx = 0, e = Op.getNumOperands(); idx < e; ++idx) {
    SDValue In = Op.getOperand(idx);
    if (In.getOpcode() == ISD::UNDEF)
      continue;
    if (!isa<ConstantSDNode>(In)) {
      AllContants = false;
      NonConstIdx = idx;
      NumNonConsts++;
    } else {
      NumConsts++;
      if (cast<ConstantSDNode>(In)->getZExtValue())
      Immediate |= (1ULL << idx);
    }
    if (In != Op.getOperand(0))
      IsSplat = false;
  }

  if (AllContants) {
    SDValue FullMask = DAG.getNode(ISD::BITCAST, dl, MVT::v16i1,
      DAG.getConstant(Immediate, MVT::i16));
    return DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, VT, FullMask,
                       DAG.getIntPtrConstant(0));
  }

  if (NumNonConsts == 1 && NonConstIdx != 0) {
    SDValue DstVec;
    if (NumConsts) {
      SDValue VecAsImm = DAG.getConstant(Immediate,
                                         MVT::getIntegerVT(VT.getSizeInBits()));
      DstVec = DAG.getNode(ISD::BITCAST, dl, VT, VecAsImm);
    }
    else
      DstVec = DAG.getUNDEF(VT);
    return DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, VT, DstVec,
                       Op.getOperand(NonConstIdx),
                       DAG.getIntPtrConstant(NonConstIdx));
  }
  if (!IsSplat && (NonConstIdx != 0))
    llvm_unreachable("Unsupported BUILD_VECTOR operation");
  MVT SelectVT = (VT == MVT::v16i1)? MVT::i16 : MVT::i8;
  SDValue Select;
  if (IsSplat)
    Select = DAG.getNode(ISD::SELECT, dl, SelectVT, Op.getOperand(0),
                          DAG.getConstant(-1, SelectVT),
                          DAG.getConstant(0, SelectVT));
  else
    Select = DAG.getNode(ISD::SELECT, dl, SelectVT, Op.getOperand(0),
                         DAG.getConstant((Immediate | 1), SelectVT),
                         DAG.getConstant(Immediate, SelectVT));
  return DAG.getNode(ISD::BITCAST, dl, VT, Select);
}

/// \brief Return true if \p N implements a horizontal binop and return the
/// operands for the horizontal binop into V0 and V1.
///
/// This is a helper function of PerformBUILD_VECTORCombine.
/// This function checks that the build_vector \p N in input implements a
/// horizontal operation. Parameter \p Opcode defines the kind of horizontal
/// operation to match.
/// For example, if \p Opcode is equal to ISD::ADD, then this function
/// checks if \p N implements a horizontal arithmetic add; if instead \p Opcode
/// is equal to ISD::SUB, then this function checks if this is a horizontal
/// arithmetic sub.
///
/// This function only analyzes elements of \p N whose indices are
/// in range [BaseIdx, LastIdx).
static bool isHorizontalBinOp(const BuildVectorSDNode *N, unsigned Opcode,
                              SelectionDAG &DAG,
                              unsigned BaseIdx, unsigned LastIdx,
                              SDValue &V0, SDValue &V1) {
  EVT VT = N->getValueType(0);

  assert(BaseIdx * 2 <= LastIdx && "Invalid Indices in input!");
  assert(VT.isVector() && VT.getVectorNumElements() >= LastIdx &&
         "Invalid Vector in input!");

  bool IsCommutable = (Opcode == ISD::ADD || Opcode == ISD::FADD);
  bool CanFold = true;
  unsigned ExpectedVExtractIdx = BaseIdx;
  unsigned NumElts = LastIdx - BaseIdx;
  V0 = DAG.getUNDEF(VT);
  V1 = DAG.getUNDEF(VT);

  // Check if N implements a horizontal binop.
  for (unsigned i = 0, e = NumElts; i != e && CanFold; ++i) {
    SDValue Op = N->getOperand(i + BaseIdx);

    // Skip UNDEFs.
    if (Op->getOpcode() == ISD::UNDEF) {
      // Update the expected vector extract index.
      if (i * 2 == NumElts)
        ExpectedVExtractIdx = BaseIdx;
      ExpectedVExtractIdx += 2;
      continue;
    }

    CanFold = Op->getOpcode() == Opcode && Op->hasOneUse();

    if (!CanFold)
      break;

    SDValue Op0 = Op.getOperand(0);
    SDValue Op1 = Op.getOperand(1);

    // Try to match the following pattern:
    // (BINOP (extract_vector_elt A, I), (extract_vector_elt A, I+1))
    CanFold = (Op0.getOpcode() == ISD::EXTRACT_VECTOR_ELT &&
        Op1.getOpcode() == ISD::EXTRACT_VECTOR_ELT &&
        Op0.getOperand(0) == Op1.getOperand(0) &&
        isa<ConstantSDNode>(Op0.getOperand(1)) &&
        isa<ConstantSDNode>(Op1.getOperand(1)));
    if (!CanFold)
      break;

    unsigned I0 = cast<ConstantSDNode>(Op0.getOperand(1))->getZExtValue();
    unsigned I1 = cast<ConstantSDNode>(Op1.getOperand(1))->getZExtValue();

    if (i * 2 < NumElts) {
      if (V0.getOpcode() == ISD::UNDEF)
        V0 = Op0.getOperand(0);
    } else {
      if (V1.getOpcode() == ISD::UNDEF)
        V1 = Op0.getOperand(0);
      if (i * 2 == NumElts)
        ExpectedVExtractIdx = BaseIdx;
    }

    SDValue Expected = (i * 2 < NumElts) ? V0 : V1;
    if (I0 == ExpectedVExtractIdx)
      CanFold = I1 == I0 + 1 && Op0.getOperand(0) == Expected;
    else if (IsCommutable && I1 == ExpectedVExtractIdx) {
      // Try to match the following dag sequence:
      // (BINOP (extract_vector_elt A, I+1), (extract_vector_elt A, I))
      CanFold = I0 == I1 + 1 && Op1.getOperand(0) == Expected;
    } else
      CanFold = false;

    ExpectedVExtractIdx += 2;
  }

  return CanFold;
}

/// \brief Emit a sequence of two 128-bit horizontal add/sub followed by
/// a concat_vector.
///
/// This is a helper function of PerformBUILD_VECTORCombine.
/// This function expects two 256-bit vectors called V0 and V1.
/// At first, each vector is split into two separate 128-bit vectors.
/// Then, the resulting 128-bit vectors are used to implement two
/// horizontal binary operations.
///
/// The kind of horizontal binary operation is defined by \p X86Opcode.
///
/// \p Mode specifies how the 128-bit parts of V0 and V1 are passed in input to
/// the two new horizontal binop.
/// When Mode is set, the first horizontal binop dag node would take as input
/// the lower 128-bit of V0 and the upper 128-bit of V0. The second
/// horizontal binop dag node would take as input the lower 128-bit of V1
/// and the upper 128-bit of V1.
///   Example:
///     HADD V0_LO, V0_HI
///     HADD V1_LO, V1_HI
///
/// Otherwise, the first horizontal binop dag node takes as input the lower
/// 128-bit of V0 and the lower 128-bit of V1, and the second horizontal binop
/// dag node takes the the upper 128-bit of V0 and the upper 128-bit of V1.
///   Example:
///     HADD V0_LO, V1_LO
///     HADD V0_HI, V1_HI
///
/// If \p isUndefLO is set, then the algorithm propagates UNDEF to the lower
/// 128-bits of the result. If \p isUndefHI is set, then UNDEF is propagated to
/// the upper 128-bits of the result.
static SDValue ExpandHorizontalBinOp(const SDValue &V0, const SDValue &V1,
                                     SDLoc DL, SelectionDAG &DAG,
                                     unsigned X86Opcode, bool Mode,
                                     bool isUndefLO, bool isUndefHI) {
  EVT VT = V0.getValueType();
  assert(VT.is256BitVector() && VT == V1.getValueType() &&
         "Invalid nodes in input!");

  unsigned NumElts = VT.getVectorNumElements();
  SDValue V0_LO = Extract128BitVector(V0, 0, DAG, DL);
  SDValue V0_HI = Extract128BitVector(V0, NumElts/2, DAG, DL);
  SDValue V1_LO = Extract128BitVector(V1, 0, DAG, DL);
  SDValue V1_HI = Extract128BitVector(V1, NumElts/2, DAG, DL);
  EVT NewVT = V0_LO.getValueType();

  SDValue LO = DAG.getUNDEF(NewVT);
  SDValue HI = DAG.getUNDEF(NewVT);

  if (Mode) {
    // Don't emit a horizontal binop if the result is expected to be UNDEF.
    if (!isUndefLO && V0->getOpcode() != ISD::UNDEF)
      LO = DAG.getNode(X86Opcode, DL, NewVT, V0_LO, V0_HI);
    if (!isUndefHI && V1->getOpcode() != ISD::UNDEF)
      HI = DAG.getNode(X86Opcode, DL, NewVT, V1_LO, V1_HI);
  } else {
    // Don't emit a horizontal binop if the result is expected to be UNDEF.
    if (!isUndefLO && (V0_LO->getOpcode() != ISD::UNDEF ||
                       V1_LO->getOpcode() != ISD::UNDEF))
      LO = DAG.getNode(X86Opcode, DL, NewVT, V0_LO, V1_LO);

    if (!isUndefHI && (V0_HI->getOpcode() != ISD::UNDEF ||
                       V1_HI->getOpcode() != ISD::UNDEF))
      HI = DAG.getNode(X86Opcode, DL, NewVT, V0_HI, V1_HI);
  }

  return DAG.getNode(ISD::CONCAT_VECTORS, DL, VT, LO, HI);
}

/// \brief Try to fold a build_vector that performs an 'addsub' into the
/// sequence of 'vadd + vsub + blendi'.
static SDValue matchAddSub(const BuildVectorSDNode *BV, SelectionDAG &DAG,
                           const X86Subtarget *Subtarget) {
  SDLoc DL(BV);
  EVT VT = BV->getValueType(0);
  unsigned NumElts = VT.getVectorNumElements();
  SDValue InVec0 = DAG.getUNDEF(VT);
  SDValue InVec1 = DAG.getUNDEF(VT);

  assert((VT == MVT::v8f32 || VT == MVT::v4f64 || VT == MVT::v4f32 ||
          VT == MVT::v2f64) && "build_vector with an invalid type found!");

  // Odd-numbered elements in the input build vector are obtained from
  // adding two integer/float elements.
  // Even-numbered elements in the input build vector are obtained from
  // subtracting two integer/float elements.
  unsigned ExpectedOpcode = ISD::FSUB;
  unsigned NextExpectedOpcode = ISD::FADD;
  bool AddFound = false;
  bool SubFound = false;

  for (unsigned i = 0, e = NumElts; i != e; ++i) {
    SDValue Op = BV->getOperand(i);

    // Skip 'undef' values.
    unsigned Opcode = Op.getOpcode();
    if (Opcode == ISD::UNDEF) {
      std::swap(ExpectedOpcode, NextExpectedOpcode);
      continue;
    }

    // Early exit if we found an unexpected opcode.
    if (Opcode != ExpectedOpcode)
      return SDValue();

    SDValue Op0 = Op.getOperand(0);
    SDValue Op1 = Op.getOperand(1);

    // Try to match the following pattern:
    // (BINOP (extract_vector_elt A, i), (extract_vector_elt B, i))
    // Early exit if we cannot match that sequence.
    if (Op0.getOpcode() != ISD::EXTRACT_VECTOR_ELT ||
        Op1.getOpcode() != ISD::EXTRACT_VECTOR_ELT ||
        !isa<ConstantSDNode>(Op0.getOperand(1)) ||
        !isa<ConstantSDNode>(Op1.getOperand(1)) ||
        Op0.getOperand(1) != Op1.getOperand(1))
      return SDValue();

    unsigned I0 = cast<ConstantSDNode>(Op0.getOperand(1))->getZExtValue();
    if (I0 != i)
      return SDValue();

    // We found a valid add/sub node. Update the information accordingly.
    if (i & 1)
      AddFound = true;
    else
      SubFound = true;

    // Update InVec0 and InVec1.
    if (InVec0.getOpcode() == ISD::UNDEF)
      InVec0 = Op0.getOperand(0);
    if (InVec1.getOpcode() == ISD::UNDEF)
      InVec1 = Op1.getOperand(0);

    // Make sure that operands in input to each add/sub node always
    // come from a same pair of vectors.
    if (InVec0 != Op0.getOperand(0)) {
      if (ExpectedOpcode == ISD::FSUB)
        return SDValue();

      // FADD is commutable. Try to commute the operands
      // and then test again.
      std::swap(Op0, Op1);
      if (InVec0 != Op0.getOperand(0))
        return SDValue();
    }

    if (InVec1 != Op1.getOperand(0))
      return SDValue();

    // Update the pair of expected opcodes.
    std::swap(ExpectedOpcode, NextExpectedOpcode);
  }

  // Don't try to fold this build_vector into an ADDSUB if the inputs are undef.
  if (AddFound && SubFound && InVec0.getOpcode() != ISD::UNDEF &&
      InVec1.getOpcode() != ISD::UNDEF)
    return DAG.getNode(X86ISD::ADDSUB, DL, VT, InVec0, InVec1);

  return SDValue();
}

static SDValue PerformBUILD_VECTORCombine(SDNode *N, SelectionDAG &DAG,
                                          const X86Subtarget *Subtarget) {
  SDLoc DL(N);
  EVT VT = N->getValueType(0);
  unsigned NumElts = VT.getVectorNumElements();
  BuildVectorSDNode *BV = cast<BuildVectorSDNode>(N);
  SDValue InVec0, InVec1;

  // Try to match an ADDSUB.
  if ((Subtarget->hasSSE3() && (VT == MVT::v4f32 || VT == MVT::v2f64)) ||
      (Subtarget->hasAVX() && (VT == MVT::v8f32 || VT == MVT::v4f64))) {
    SDValue Value = matchAddSub(BV, DAG, Subtarget);
    if (Value.getNode())
      return Value;
  }

  // Try to match horizontal ADD/SUB.
  unsigned NumUndefsLO = 0;
  unsigned NumUndefsHI = 0;
  unsigned Half = NumElts/2;

  // Count the number of UNDEF operands in the build_vector in input.
  for (unsigned i = 0, e = Half; i != e; ++i)
    if (BV->getOperand(i)->getOpcode() == ISD::UNDEF)
      NumUndefsLO++;

  for (unsigned i = Half, e = NumElts; i != e; ++i)
    if (BV->getOperand(i)->getOpcode() == ISD::UNDEF)
      NumUndefsHI++;

  // Early exit if this is either a build_vector of all UNDEFs or all the
  // operands but one are UNDEF.
  if (NumUndefsLO + NumUndefsHI + 1 >= NumElts)
    return SDValue();

  if ((VT == MVT::v4f32 || VT == MVT::v2f64) && Subtarget->hasSSE3()) {
    // Try to match an SSE3 float HADD/HSUB.
    if (isHorizontalBinOp(BV, ISD::FADD, DAG, 0, NumElts, InVec0, InVec1))
      return DAG.getNode(X86ISD::FHADD, DL, VT, InVec0, InVec1);

    if (isHorizontalBinOp(BV, ISD::FSUB, DAG, 0, NumElts, InVec0, InVec1))
      return DAG.getNode(X86ISD::FHSUB, DL, VT, InVec0, InVec1);
  } else if ((VT == MVT::v4i32 || VT == MVT::v8i16) && Subtarget->hasSSSE3()) {
    // Try to match an SSSE3 integer HADD/HSUB.
    if (isHorizontalBinOp(BV, ISD::ADD, DAG, 0, NumElts, InVec0, InVec1))
      return DAG.getNode(X86ISD::HADD, DL, VT, InVec0, InVec1);

    if (isHorizontalBinOp(BV, ISD::SUB, DAG, 0, NumElts, InVec0, InVec1))
      return DAG.getNode(X86ISD::HSUB, DL, VT, InVec0, InVec1);
  }

  if (!Subtarget->hasAVX())
    return SDValue();

  if ((VT == MVT::v8f32 || VT == MVT::v4f64)) {
    // Try to match an AVX horizontal add/sub of packed single/double
    // precision floating point values from 256-bit vectors.
    SDValue InVec2, InVec3;
    if (isHorizontalBinOp(BV, ISD::FADD, DAG, 0, Half, InVec0, InVec1) &&
        isHorizontalBinOp(BV, ISD::FADD, DAG, Half, NumElts, InVec2, InVec3) &&
        ((InVec0.getOpcode() == ISD::UNDEF ||
          InVec2.getOpcode() == ISD::UNDEF) || InVec0 == InVec2) &&
        ((InVec1.getOpcode() == ISD::UNDEF ||
          InVec3.getOpcode() == ISD::UNDEF) || InVec1 == InVec3))
      return DAG.getNode(X86ISD::FHADD, DL, VT, InVec0, InVec1);

    if (isHorizontalBinOp(BV, ISD::FSUB, DAG, 0, Half, InVec0, InVec1) &&
        isHorizontalBinOp(BV, ISD::FSUB, DAG, Half, NumElts, InVec2, InVec3) &&
        ((InVec0.getOpcode() == ISD::UNDEF ||
          InVec2.getOpcode() == ISD::UNDEF) || InVec0 == InVec2) &&
        ((InVec1.getOpcode() == ISD::UNDEF ||
          InVec3.getOpcode() == ISD::UNDEF) || InVec1 == InVec3))
      return DAG.getNode(X86ISD::FHSUB, DL, VT, InVec0, InVec1);
  } else if (VT == MVT::v8i32 || VT == MVT::v16i16) {
    // Try to match an AVX2 horizontal add/sub of signed integers.
    SDValue InVec2, InVec3;
    unsigned X86Opcode;
    bool CanFold = true;

    if (isHorizontalBinOp(BV, ISD::ADD, DAG, 0, Half, InVec0, InVec1) &&
        isHorizontalBinOp(BV, ISD::ADD, DAG, Half, NumElts, InVec2, InVec3) &&
        ((InVec0.getOpcode() == ISD::UNDEF ||
          InVec2.getOpcode() == ISD::UNDEF) || InVec0 == InVec2) &&
        ((InVec1.getOpcode() == ISD::UNDEF ||
          InVec3.getOpcode() == ISD::UNDEF) || InVec1 == InVec3))
      X86Opcode = X86ISD::HADD;
    else if (isHorizontalBinOp(BV, ISD::SUB, DAG, 0, Half, InVec0, InVec1) &&
        isHorizontalBinOp(BV, ISD::SUB, DAG, Half, NumElts, InVec2, InVec3) &&
        ((InVec0.getOpcode() == ISD::UNDEF ||
          InVec2.getOpcode() == ISD::UNDEF) || InVec0 == InVec2) &&
        ((InVec1.getOpcode() == ISD::UNDEF ||
          InVec3.getOpcode() == ISD::UNDEF) || InVec1 == InVec3))
      X86Opcode = X86ISD::HSUB;
    else
      CanFold = false;

    if (CanFold) {
      // Fold this build_vector into a single horizontal add/sub.
      // Do this only if the target has AVX2.
      if (Subtarget->hasAVX2())
        return DAG.getNode(X86Opcode, DL, VT, InVec0, InVec1);

      // Do not try to expand this build_vector into a pair of horizontal
      // add/sub if we can emit a pair of scalar add/sub.
      if (NumUndefsLO + 1 == Half || NumUndefsHI + 1 == Half)
        return SDValue();

      // Convert this build_vector into a pair of horizontal binop followed by
      // a concat vector.
      bool isUndefLO = NumUndefsLO == Half;
      bool isUndefHI = NumUndefsHI == Half;
      return ExpandHorizontalBinOp(InVec0, InVec1, DL, DAG, X86Opcode, false,
                                   isUndefLO, isUndefHI);
    }
  }

  if ((VT == MVT::v8f32 || VT == MVT::v4f64 || VT == MVT::v8i32 ||
       VT == MVT::v16i16) && Subtarget->hasAVX()) {
    unsigned X86Opcode;
    if (isHorizontalBinOp(BV, ISD::ADD, DAG, 0, NumElts, InVec0, InVec1))
      X86Opcode = X86ISD::HADD;
    else if (isHorizontalBinOp(BV, ISD::SUB, DAG, 0, NumElts, InVec0, InVec1))
      X86Opcode = X86ISD::HSUB;
    else if (isHorizontalBinOp(BV, ISD::FADD, DAG, 0, NumElts, InVec0, InVec1))
      X86Opcode = X86ISD::FHADD;
    else if (isHorizontalBinOp(BV, ISD::FSUB, DAG, 0, NumElts, InVec0, InVec1))
      X86Opcode = X86ISD::FHSUB;
    else
      return SDValue();

    // Don't try to expand this build_vector into a pair of horizontal add/sub
    // if we can simply emit a pair of scalar add/sub.
    if (NumUndefsLO + 1 == Half || NumUndefsHI + 1 == Half)
      return SDValue();

    // Convert this build_vector into two horizontal add/sub followed by
    // a concat vector.
    bool isUndefLO = NumUndefsLO == Half;
    bool isUndefHI = NumUndefsHI == Half;
    return ExpandHorizontalBinOp(InVec0, InVec1, DL, DAG, X86Opcode, true,
                                 isUndefLO, isUndefHI);
  }

  return SDValue();
}

SDValue
X86TargetLowering::LowerBUILD_VECTOR(SDValue Op, SelectionDAG &DAG) const {
  SDLoc dl(Op);

  MVT VT = Op.getSimpleValueType();
  MVT ExtVT = VT.getVectorElementType();
  unsigned NumElems = Op.getNumOperands();

  // Generate vectors for predicate vectors.
  if (VT.getScalarType() == MVT::i1 && Subtarget->hasAVX512())
    return LowerBUILD_VECTORvXi1(Op, DAG);

  // Vectors containing all zeros can be matched by pxor and xorps later
  if (ISD::isBuildVectorAllZeros(Op.getNode())) {
    // Canonicalize this to <4 x i32> to 1) ensure the zero vectors are CSE'd
    // and 2) ensure that i64 scalars are eliminated on x86-32 hosts.
    if (VT == MVT::v4i32 || VT == MVT::v8i32 || VT == MVT::v16i32)
      return Op;

    return getZeroVector(VT, Subtarget, DAG, dl);
  }

  // Vectors containing all ones can be matched by pcmpeqd on 128-bit width
  // vectors or broken into v4i32 operations on 256-bit vectors. AVX2 can use
  // vpcmpeqd on 256-bit vectors.
  if (Subtarget->hasSSE2() && ISD::isBuildVectorAllOnes(Op.getNode())) {
    if (VT == MVT::v4i32 || (VT == MVT::v8i32 && Subtarget->hasInt256()))
      return Op;

    if (!VT.is512BitVector())
      return getOnesVector(VT, Subtarget->hasInt256(), DAG, dl);
  }

  SDValue Broadcast = LowerVectorBroadcast(Op, Subtarget, DAG);
  if (Broadcast.getNode())
    return Broadcast;

  unsigned EVTBits = ExtVT.getSizeInBits();

  unsigned NumZero  = 0;
  unsigned NumNonZero = 0;
  unsigned NonZeros = 0;
  bool IsAllConstants = true;
  SmallSet<SDValue, 8> Values;
  for (unsigned i = 0; i < NumElems; ++i) {
    SDValue Elt = Op.getOperand(i);
    if (Elt.getOpcode() == ISD::UNDEF)
      continue;
    Values.insert(Elt);
    if (Elt.getOpcode() != ISD::Constant &&
        Elt.getOpcode() != ISD::ConstantFP)
      IsAllConstants = false;
    if (X86::isZeroNode(Elt))
      NumZero++;
    else {
      NonZeros |= (1 << i);
      NumNonZero++;
    }
  }

  // All undef vector. Return an UNDEF.  All zero vectors were handled above.
  if (NumNonZero == 0)
    return DAG.getUNDEF(VT);

  // Special case for single non-zero, non-undef, element.
  if (NumNonZero == 1) {
    unsigned Idx = countTrailingZeros(NonZeros);
    SDValue Item = Op.getOperand(Idx);

    // If this is an insertion of an i64 value on x86-32, and if the top bits of
    // the value are obviously zero, truncate the value to i32 and do the
    // insertion that way.  Only do this if the value is non-constant or if the
    // value is a constant being inserted into element 0.  It is cheaper to do
    // a constant pool load than it is to do a movd + shuffle.
    if (ExtVT == MVT::i64 && !Subtarget->is64Bit() &&
        (!IsAllConstants || Idx == 0)) {
      if (DAG.MaskedValueIsZero(Item, APInt::getBitsSet(64, 32, 64))) {
        // Handle SSE only.
        assert(VT == MVT::v2i64 && "Expected an SSE value type!");
        EVT VecVT = MVT::v4i32;
        unsigned VecElts = 4;

        // Truncate the value (which may itself be a constant) to i32, and
        // convert it to a vector with movd (S2V+shuffle to zero extend).
        Item = DAG.getNode(ISD::TRUNCATE, dl, MVT::i32, Item);
        Item = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VecVT, Item);

        // If using the new shuffle lowering, just directly insert this.
        if (ExperimentalVectorShuffleLowering)
          return DAG.getNode(
              ISD::BITCAST, dl, VT,
              getShuffleVectorZeroOrUndef(Item, Idx * 2, true, Subtarget, DAG));

        Item = getShuffleVectorZeroOrUndef(Item, 0, true, Subtarget, DAG);

        // Now we have our 32-bit value zero extended in the low element of
        // a vector.  If Idx != 0, swizzle it into place.
        if (Idx != 0) {
          SmallVector<int, 4> Mask;
          Mask.push_back(Idx);
          for (unsigned i = 1; i != VecElts; ++i)
            Mask.push_back(i);
          Item = DAG.getVectorShuffle(VecVT, dl, Item, DAG.getUNDEF(VecVT),
                                      &Mask[0]);
        }
        return DAG.getNode(ISD::BITCAST, dl, VT, Item);
      }
    }

    // If we have a constant or non-constant insertion into the low element of
    // a vector, we can do this with SCALAR_TO_VECTOR + shuffle of zero into
    // the rest of the elements.  This will be matched as movd/movq/movss/movsd
    // depending on what the source datatype is.
    if (Idx == 0) {
      if (NumZero == 0)
        return DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, Item);

      if (ExtVT == MVT::i32 || ExtVT == MVT::f32 || ExtVT == MVT::f64 ||
          (ExtVT == MVT::i64 && Subtarget->is64Bit())) {
        if (VT.is256BitVector() || VT.is512BitVector()) {
          SDValue ZeroVec = getZeroVector(VT, Subtarget, DAG, dl);
          return DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, VT, ZeroVec,
                             Item, DAG.getIntPtrConstant(0));
        }
        assert(VT.is128BitVector() && "Expected an SSE value type!");
        Item = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, Item);
        // Turn it into a MOVL (i.e. movss, movsd, or movd) to a zero vector.
        return getShuffleVectorZeroOrUndef(Item, 0, true, Subtarget, DAG);
      }

      if (ExtVT == MVT::i16 || ExtVT == MVT::i8) {
        Item = DAG.getNode(ISD::ZERO_EXTEND, dl, MVT::i32, Item);
        Item = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, MVT::v4i32, Item);
        if (VT.is256BitVector()) {
          SDValue ZeroVec = getZeroVector(MVT::v8i32, Subtarget, DAG, dl);
          Item = Insert128BitVector(ZeroVec, Item, 0, DAG, dl);
        } else {
          assert(VT.is128BitVector() && "Expected an SSE value type!");
          Item = getShuffleVectorZeroOrUndef(Item, 0, true, Subtarget, DAG);
        }
        return DAG.getNode(ISD::BITCAST, dl, VT, Item);
      }
    }

    // Is it a vector logical left shift?
    if (NumElems == 2 && Idx == 1 &&
        X86::isZeroNode(Op.getOperand(0)) &&
        !X86::isZeroNode(Op.getOperand(1))) {
      unsigned NumBits = VT.getSizeInBits();
      return getVShift(true, VT,
                       DAG.getNode(ISD::SCALAR_TO_VECTOR, dl,
                                   VT, Op.getOperand(1)),
                       NumBits/2, DAG, *this, dl);
    }

    if (IsAllConstants) // Otherwise, it's better to do a constpool load.
      return SDValue();

    // Otherwise, if this is a vector with i32 or f32 elements, and the element
    // is a non-constant being inserted into an element other than the low one,
    // we can't use a constant pool load.  Instead, use SCALAR_TO_VECTOR (aka
    // movd/movss) to move this into the low element, then shuffle it into
    // place.
    if (EVTBits == 32) {
      Item = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, Item);

      // If using the new shuffle lowering, just directly insert this.
      if (ExperimentalVectorShuffleLowering)
        return getShuffleVectorZeroOrUndef(Item, Idx, NumZero > 0, Subtarget, DAG);

      // Turn it into a shuffle of zero and zero-extended scalar to vector.
      Item = getShuffleVectorZeroOrUndef(Item, 0, NumZero > 0, Subtarget, DAG);
      SmallVector<int, 8> MaskVec;
      for (unsigned i = 0; i != NumElems; ++i)
        MaskVec.push_back(i == Idx ? 0 : 1);
      return DAG.getVectorShuffle(VT, dl, Item, DAG.getUNDEF(VT), &MaskVec[0]);
    }
  }

  // Splat is obviously ok. Let legalizer expand it to a shuffle.
  if (Values.size() == 1) {
    if (EVTBits == 32) {
      // Instead of a shuffle like this:
      // shuffle (scalar_to_vector (load (ptr + 4))), undef, <0, 0, 0, 0>
      // Check if it's possible to issue this instead.
      // shuffle (vload ptr)), undef, <1, 1, 1, 1>
      unsigned Idx = countTrailingZeros(NonZeros);
      SDValue Item = Op.getOperand(Idx);
      if (Op.getNode()->isOnlyUserOf(Item.getNode()))
        return LowerAsSplatVectorLoad(Item, VT, dl, DAG);
    }
    return SDValue();
  }

  // A vector full of immediates; various special cases are already
  // handled, so this is best done with a single constant-pool load.
  if (IsAllConstants)
    return SDValue();

  // For AVX-length vectors, see if we can use a vector load to get all of the
  // elements, otherwise build the individual 128-bit pieces and use
  // shuffles to put them in place.
  if (VT.is256BitVector() || VT.is512BitVector()) {
    SmallVector<SDValue, 64> V(Op->op_begin(), Op->op_begin() + NumElems);

    // Check for a build vector of consecutive loads.
    if (SDValue LD = EltsFromConsecutiveLoads(VT, V, dl, DAG, false))
      return LD;

    EVT HVT = EVT::getVectorVT(*DAG.getContext(), ExtVT, NumElems/2);

    // Build both the lower and upper subvector.
    SDValue Lower = DAG.getNode(ISD::BUILD_VECTOR, dl, HVT,
                                makeArrayRef(&V[0], NumElems/2));
    SDValue Upper = DAG.getNode(ISD::BUILD_VECTOR, dl, HVT,
                                makeArrayRef(&V[NumElems / 2], NumElems/2));

    // Recreate the wider vector with the lower and upper part.
    if (VT.is256BitVector())
      return Concat128BitVectors(Lower, Upper, VT, NumElems, DAG, dl);
    return Concat256BitVectors(Lower, Upper, VT, NumElems, DAG, dl);
  }

  // Let legalizer expand 2-wide build_vectors.
  if (EVTBits == 64) {
    if (NumNonZero == 1) {
      // One half is zero or undef.
      unsigned Idx = countTrailingZeros(NonZeros);
      SDValue V2 = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT,
                                 Op.getOperand(Idx));
      return getShuffleVectorZeroOrUndef(V2, Idx, true, Subtarget, DAG);
    }
    return SDValue();
  }

  // If element VT is < 32 bits, convert it to inserts into a zero vector.
  if (EVTBits == 8 && NumElems == 16) {
    SDValue V = LowerBuildVectorv16i8(Op, NonZeros,NumNonZero,NumZero, DAG,
                                        Subtarget, *this);
    if (V.getNode()) return V;
  }

  if (EVTBits == 16 && NumElems == 8) {
    SDValue V = LowerBuildVectorv8i16(Op, NonZeros,NumNonZero,NumZero, DAG,
                                      Subtarget, *this);
    if (V.getNode()) return V;
  }

  // If element VT is == 32 bits and has 4 elems, try to generate an INSERTPS
  if (EVTBits == 32 && NumElems == 4) {
    SDValue V = LowerBuildVectorv4x32(Op, DAG, Subtarget, *this);
    if (V.getNode())
      return V;
  }

  // If element VT is == 32 bits, turn it into a number of shuffles.
  SmallVector<SDValue, 8> V(NumElems);
  if (NumElems == 4 && NumZero > 0) {
    for (unsigned i = 0; i < 4; ++i) {
      bool isZero = !(NonZeros & (1 << i));
      if (isZero)
        V[i] = getZeroVector(VT, Subtarget, DAG, dl);
      else
        V[i] = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, Op.getOperand(i));
    }

    for (unsigned i = 0; i < 2; ++i) {
      switch ((NonZeros & (0x3 << i*2)) >> (i*2)) {
        default: break;
        case 0:
          V[i] = V[i*2];  // Must be a zero vector.
          break;
        case 1:
          V[i] = getMOVL(DAG, dl, VT, V[i*2+1], V[i*2]);
          break;
        case 2:
          V[i] = getMOVL(DAG, dl, VT, V[i*2], V[i*2+1]);
          break;
        case 3:
          V[i] = getUnpackl(DAG, dl, VT, V[i*2], V[i*2+1]);
          break;
      }
    }

    bool Reverse1 = (NonZeros & 0x3) == 2;
    bool Reverse2 = ((NonZeros & (0x3 << 2)) >> 2) == 2;
    int MaskVec[] = {
      Reverse1 ? 1 : 0,
      Reverse1 ? 0 : 1,
      static_cast<int>(Reverse2 ? NumElems+1 : NumElems),
      static_cast<int>(Reverse2 ? NumElems   : NumElems+1)
    };
    return DAG.getVectorShuffle(VT, dl, V[0], V[1], &MaskVec[0]);
  }

  if (Values.size() > 1 && VT.is128BitVector()) {
    // Check for a build vector of consecutive loads.
    for (unsigned i = 0; i < NumElems; ++i)
      V[i] = Op.getOperand(i);

    // Check for elements which are consecutive loads.
    SDValue LD = EltsFromConsecutiveLoads(VT, V, dl, DAG, false);
    if (LD.getNode())
      return LD;

    // Check for a build vector from mostly shuffle plus few inserting.
    SDValue Sh = buildFromShuffleMostly(Op, DAG);
    if (Sh.getNode())
      return Sh;

    // For SSE 4.1, use insertps to put the high elements into the low element.
    if (Subtarget->hasSSE41()) {
      SDValue Result;
      if (Op.getOperand(0).getOpcode() != ISD::UNDEF)
        Result = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, Op.getOperand(0));
      else
        Result = DAG.getUNDEF(VT);

      for (unsigned i = 1; i < NumElems; ++i) {
        if (Op.getOperand(i).getOpcode() == ISD::UNDEF) continue;
        Result = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, VT, Result,
                             Op.getOperand(i), DAG.getIntPtrConstant(i));
      }
      return Result;
    }

    // Otherwise, expand into a number of unpckl*, start by extending each of
    // our (non-undef) elements to the full vector width with the element in the
    // bottom slot of the vector (which generates no code for SSE).
    for (unsigned i = 0; i < NumElems; ++i) {
      if (Op.getOperand(i).getOpcode() != ISD::UNDEF)
        V[i] = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, Op.getOperand(i));
      else
        V[i] = DAG.getUNDEF(VT);
    }

    // Next, we iteratively mix elements, e.g. for v4f32:
    //   Step 1: unpcklps 0, 2 ==> X: <?, ?, 2, 0>
    //         : unpcklps 1, 3 ==> Y: <?, ?, 3, 1>
    //   Step 2: unpcklps X, Y ==>    <3, 2, 1, 0>
    unsigned EltStride = NumElems >> 1;
    while (EltStride != 0) {
      for (unsigned i = 0; i < EltStride; ++i) {
        // If V[i+EltStride] is undef and this is the first round of mixing,
        // then it is safe to just drop this shuffle: V[i] is already in the
        // right place, the one element (since it's the first round) being
        // inserted as undef can be dropped.  This isn't safe for successive
        // rounds because they will permute elements within both vectors.
        if (V[i+EltStride].getOpcode() == ISD::UNDEF &&
            EltStride == NumElems/2)
          continue;

        V[i] = getUnpackl(DAG, dl, VT, V[i], V[i + EltStride]);
      }
      EltStride >>= 1;
    }
    return V[0];
  }
  return SDValue();
}

// LowerAVXCONCAT_VECTORS - 256-bit AVX can use the vinsertf128 instruction
// to create 256-bit vectors from two other 128-bit ones.
static SDValue LowerAVXCONCAT_VECTORS(SDValue Op, SelectionDAG &DAG) {
  SDLoc dl(Op);
  MVT ResVT = Op.getSimpleValueType();

  assert((ResVT.is256BitVector() ||
          ResVT.is512BitVector()) && "Value type must be 256-/512-bit wide");

  SDValue V1 = Op.getOperand(0);
  SDValue V2 = Op.getOperand(1);
  unsigned NumElems = ResVT.getVectorNumElements();
  if(ResVT.is256BitVector())
    return Concat128BitVectors(V1, V2, ResVT, NumElems, DAG, dl);

  if (Op.getNumOperands() == 4) {
    MVT HalfVT = MVT::getVectorVT(ResVT.getScalarType(),
                                ResVT.getVectorNumElements()/2);
    SDValue V3 = Op.getOperand(2);
    SDValue V4 = Op.getOperand(3);
    return Concat256BitVectors(Concat128BitVectors(V1, V2, HalfVT, NumElems/2, DAG, dl),
      Concat128BitVectors(V3, V4, HalfVT, NumElems/2, DAG, dl), ResVT, NumElems, DAG, dl);
  }
  return Concat256BitVectors(V1, V2, ResVT, NumElems, DAG, dl);
}

static SDValue LowerCONCAT_VECTORS(SDValue Op, SelectionDAG &DAG) {
  MVT LLVM_ATTRIBUTE_UNUSED VT = Op.getSimpleValueType();
  assert((VT.is256BitVector() && Op.getNumOperands() == 2) ||
         (VT.is512BitVector() && (Op.getNumOperands() == 2 ||
          Op.getNumOperands() == 4)));

  // AVX can use the vinsertf128 instruction to create 256-bit vectors
  // from two other 128-bit ones.

  // 512-bit vector may contain 2 256-bit vectors or 4 128-bit vectors
  return LowerAVXCONCAT_VECTORS(Op, DAG);
}


//===----------------------------------------------------------------------===//
// Vector shuffle lowering
//
// This is an experimental code path for lowering vector shuffles on x86. It is
// designed to handle arbitrary vector shuffles and blends, gracefully
// degrading performance as necessary. It works hard to recognize idiomatic
// shuffles and lower them to optimal instruction patterns without leaving
// a framework that allows reasonably efficient handling of all vector shuffle
// patterns.
//===----------------------------------------------------------------------===//

/// \brief Tiny helper function to identify a no-op mask.
///
/// This is a somewhat boring predicate function. It checks whether the mask
/// array input, which is assumed to be a single-input shuffle mask of the kind
/// used by the X86 shuffle instructions (not a fully general
/// ShuffleVectorSDNode mask) requires any shuffles to occur. Both undef and an
/// in-place shuffle are 'no-op's.
static bool isNoopShuffleMask(ArrayRef<int> Mask) {
  for (int i = 0, Size = Mask.size(); i < Size; ++i)
    if (Mask[i] != -1 && Mask[i] != i)
      return false;
  return true;
}

/// \brief Helper function to classify a mask as a single-input mask.
///
/// This isn't a generic single-input test because in the vector shuffle
/// lowering we canonicalize single inputs to be the first input operand. This
/// means we can more quickly test for a single input by only checking whether
/// an input from the second operand exists. We also assume that the size of
/// mask corresponds to the size of the input vectors which isn't true in the
/// fully general case.
static bool isSingleInputShuffleMask(ArrayRef<int> Mask) {
  for (int M : Mask)
    if (M >= (int)Mask.size())
      return false;
  return true;
}

/// \brief Test whether there are elements crossing 128-bit lanes in this
/// shuffle mask.
///
/// X86 divides up its shuffles into in-lane and cross-lane shuffle operations
/// and we routinely test for these.
static bool is128BitLaneCrossingShuffleMask(MVT VT, ArrayRef<int> Mask) {
  int LaneSize = 128 / VT.getScalarSizeInBits();
  int Size = Mask.size();
  for (int i = 0; i < Size; ++i)
    if (Mask[i] >= 0 && (Mask[i] % Size) / LaneSize != i / LaneSize)
      return true;
  return false;
}

/// \brief Test whether a shuffle mask is equivalent within each 128-bit lane.
///
/// This checks a shuffle mask to see if it is performing the same
/// 128-bit lane-relative shuffle in each 128-bit lane. This trivially implies
/// that it is also not lane-crossing. It may however involve a blend from the
/// same lane of a second vector.
///
/// The specific repeated shuffle mask is populated in \p RepeatedMask, as it is
/// non-trivial to compute in the face of undef lanes. The representation is
/// *not* suitable for use with existing 128-bit shuffles as it will contain
/// entries from both V1 and V2 inputs to the wider mask.
static bool
is128BitLaneRepeatedShuffleMask(MVT VT, ArrayRef<int> Mask,
                                SmallVectorImpl<int> &RepeatedMask) {
  int LaneSize = 128 / VT.getScalarSizeInBits();
  RepeatedMask.resize(LaneSize, -1);
  int Size = Mask.size();
  for (int i = 0; i < Size; ++i) {
    if (Mask[i] < 0)
      continue;
    if ((Mask[i] % Size) / LaneSize != i / LaneSize)
      // This entry crosses lanes, so there is no way to model this shuffle.
      return false;

    // Ok, handle the in-lane shuffles by detecting if and when they repeat.
    if (RepeatedMask[i % LaneSize] == -1)
      // This is the first non-undef entry in this slot of a 128-bit lane.
      RepeatedMask[i % LaneSize] =
          Mask[i] < Size ? Mask[i] % LaneSize : Mask[i] % LaneSize + Size;
    else if (RepeatedMask[i % LaneSize] + (i / LaneSize) * LaneSize != Mask[i])
      // Found a mismatch with the repeated mask.
      return false;
  }
  return true;
}

/// \brief Base case helper for testing a single mask element.
static bool isShuffleEquivalentImpl(SDValue V1, SDValue V2,
                                    BuildVectorSDNode *BV1,
                                    BuildVectorSDNode *BV2, ArrayRef<int> Mask,
                                    int i, int Arg) {
  int Size = Mask.size();
  if (Mask[i] != -1 && Mask[i] != Arg) {
    auto *MaskBV = Mask[i] < Size ? BV1 : BV2;
    auto *ArgsBV = Arg < Size ? BV1 : BV2;
    if (!MaskBV || !ArgsBV ||
        MaskBV->getOperand(Mask[i] % Size) != ArgsBV->getOperand(Arg % Size))
      return false;
  }
  return true;
}

/// \brief Recursive helper to peel off and test each mask element.
template <typename... Ts>
static bool isShuffleEquivalentImpl(SDValue V1, SDValue V2,
                                    BuildVectorSDNode *BV1,
                                    BuildVectorSDNode *BV2, ArrayRef<int> Mask,
                                    int i, int Arg, Ts... Args) {
  if (!isShuffleEquivalentImpl(V1, V2, BV1, BV2, Mask, i, Arg))
    return false;

  return isShuffleEquivalentImpl(V1, V2, BV1, BV2, Mask, i + 1, Args...);
}

/// \brief Checks whether a shuffle mask is equivalent to an explicit list of
/// arguments.
///
/// This is a fast way to test a shuffle mask against a fixed pattern:
///
///   if (isShuffleEquivalent(Mask, 3, 2, 1, 0)) { ... }
///
/// It returns true if the mask is exactly as wide as the argument list, and
/// each element of the mask is either -1 (signifying undef) or the value given
/// in the argument.
template <typename... Ts>
static bool isShuffleEquivalent(SDValue V1, SDValue V2, ArrayRef<int> Mask,
                                Ts... Args) {
  if (Mask.size() != sizeof...(Args))
    return false;

  // If the values are build vectors, we can look through them to find
  // equivalent inputs that make the shuffles equivalent.
  auto *BV1 = dyn_cast<BuildVectorSDNode>(V1);
  auto *BV2 = dyn_cast<BuildVectorSDNode>(V2);

  // Recursively peel off arguments and test them against the mask.
  return isShuffleEquivalentImpl(V1, V2, BV1, BV2, Mask, 0, Args...);
}

/// \brief Get a 4-lane 8-bit shuffle immediate for a mask.
///
/// This helper function produces an 8-bit shuffle immediate corresponding to
/// the ubiquitous shuffle encoding scheme used in x86 instructions for
/// shuffling 4 lanes. It can be used with most of the PSHUF instructions for
/// example.
///
/// NB: We rely heavily on "undef" masks preserving the input lane.
static SDValue getV4X86ShuffleImm8ForMask(ArrayRef<int> Mask,
                                          SelectionDAG &DAG) {
  assert(Mask.size() == 4 && "Only 4-lane shuffle masks");
  assert(Mask[0] >= -1 && Mask[0] < 4 && "Out of bound mask element!");
  assert(Mask[1] >= -1 && Mask[1] < 4 && "Out of bound mask element!");
  assert(Mask[2] >= -1 && Mask[2] < 4 && "Out of bound mask element!");
  assert(Mask[3] >= -1 && Mask[3] < 4 && "Out of bound mask element!");

  unsigned Imm = 0;
  Imm |= (Mask[0] == -1 ? 0 : Mask[0]) << 0;
  Imm |= (Mask[1] == -1 ? 1 : Mask[1]) << 2;
  Imm |= (Mask[2] == -1 ? 2 : Mask[2]) << 4;
  Imm |= (Mask[3] == -1 ? 3 : Mask[3]) << 6;
  return DAG.getConstant(Imm, MVT::i8);
}

/// \brief Try to emit a blend instruction for a shuffle using bit math.
///
/// This is used as a fallback approach when first class blend instructions are
/// unavailable. Currently it is only suitable for integer vectors, but could
/// be generalized for floating point vectors if desirable.
static SDValue lowerVectorShuffleAsBitBlend(SDLoc DL, MVT VT, SDValue V1,
                                            SDValue V2, ArrayRef<int> Mask,
                                            SelectionDAG &DAG) {
  assert(VT.isInteger() && "Only supports integer vector types!");
  MVT EltVT = VT.getScalarType();
  int NumEltBits = EltVT.getSizeInBits();
  SDValue Zero = DAG.getConstant(0, EltVT);
  SDValue AllOnes = DAG.getConstant(APInt::getAllOnesValue(NumEltBits), EltVT);
  SmallVector<SDValue, 16> MaskOps;
  for (int i = 0, Size = Mask.size(); i < Size; ++i) {
    if (Mask[i] != -1 && Mask[i] != i && Mask[i] != i + Size)
      return SDValue(); // Shuffled input!
    MaskOps.push_back(Mask[i] < Size ? AllOnes : Zero);
  }

  SDValue V1Mask = DAG.getNode(ISD::BUILD_VECTOR, DL, VT, MaskOps);
  V1 = DAG.getNode(ISD::AND, DL, VT, V1, V1Mask);
  // We have to cast V2 around.
  MVT MaskVT = MVT::getVectorVT(MVT::i64, VT.getSizeInBits() / 64);
  V2 = DAG.getNode(ISD::BITCAST, DL, VT,
                   DAG.getNode(X86ISD::ANDNP, DL, MaskVT,
                               DAG.getNode(ISD::BITCAST, DL, MaskVT, V1Mask),
                               DAG.getNode(ISD::BITCAST, DL, MaskVT, V2)));
  return DAG.getNode(ISD::OR, DL, VT, V1, V2);
}

/// \brief Try to emit a blend instruction for a shuffle.
///
/// This doesn't do any checks for the availability of instructions for blending
/// these values. It relies on the availability of the X86ISD::BLENDI pattern to
/// be matched in the backend with the type given. What it does check for is
/// that the shuffle mask is in fact a blend.
static SDValue lowerVectorShuffleAsBlend(SDLoc DL, MVT VT, SDValue V1,
                                         SDValue V2, ArrayRef<int> Mask,
                                         const X86Subtarget *Subtarget,
                                         SelectionDAG &DAG) {
  unsigned BlendMask = 0;
  for (int i = 0, Size = Mask.size(); i < Size; ++i) {
    if (Mask[i] >= Size) {
      if (Mask[i] != i + Size)
        return SDValue(); // Shuffled V2 input!
      BlendMask |= 1u << i;
      continue;
    }
    if (Mask[i] >= 0 && Mask[i] != i)
      return SDValue(); // Shuffled V1 input!
  }
  switch (VT.SimpleTy) {
  case MVT::v2f64:
  case MVT::v4f32:
  case MVT::v4f64:
  case MVT::v8f32:
    return DAG.getNode(X86ISD::BLENDI, DL, VT, V1, V2,
                       DAG.getConstant(BlendMask, MVT::i8));

  case MVT::v4i64:
  case MVT::v8i32:
    assert(Subtarget->hasAVX2() && "256-bit integer blends require AVX2!");
    // FALLTHROUGH
  case MVT::v2i64:
  case MVT::v4i32:
    // If we have AVX2 it is faster to use VPBLENDD when the shuffle fits into
    // that instruction.
    if (Subtarget->hasAVX2()) {
      // Scale the blend by the number of 32-bit dwords per element.
      int Scale =  VT.getScalarSizeInBits() / 32;
      BlendMask = 0;
      for (int i = 0, Size = Mask.size(); i < Size; ++i)
        if (Mask[i] >= Size)
          for (int j = 0; j < Scale; ++j)
            BlendMask |= 1u << (i * Scale + j);

      MVT BlendVT = VT.getSizeInBits() > 128 ? MVT::v8i32 : MVT::v4i32;
      V1 = DAG.getNode(ISD::BITCAST, DL, BlendVT, V1);
      V2 = DAG.getNode(ISD::BITCAST, DL, BlendVT, V2);
      return DAG.getNode(ISD::BITCAST, DL, VT,
                         DAG.getNode(X86ISD::BLENDI, DL, BlendVT, V1, V2,
                                     DAG.getConstant(BlendMask, MVT::i8)));
    }
    // FALLTHROUGH
  case MVT::v8i16: {
    // For integer shuffles we need to expand the mask and cast the inputs to
    // v8i16s prior to blending.
    int Scale = 8 / VT.getVectorNumElements();
    BlendMask = 0;
    for (int i = 0, Size = Mask.size(); i < Size; ++i)
      if (Mask[i] >= Size)
        for (int j = 0; j < Scale; ++j)
          BlendMask |= 1u << (i * Scale + j);

    V1 = DAG.getNode(ISD::BITCAST, DL, MVT::v8i16, V1);
    V2 = DAG.getNode(ISD::BITCAST, DL, MVT::v8i16, V2);
    return DAG.getNode(ISD::BITCAST, DL, VT,
                       DAG.getNode(X86ISD::BLENDI, DL, MVT::v8i16, V1, V2,
                                   DAG.getConstant(BlendMask, MVT::i8)));
  }

  case MVT::v16i16: {
    assert(Subtarget->hasAVX2() && "256-bit integer blends require AVX2!");
    SmallVector<int, 8> RepeatedMask;
    if (is128BitLaneRepeatedShuffleMask(MVT::v16i16, Mask, RepeatedMask)) {
      // We can lower these with PBLENDW which is mirrored across 128-bit lanes.
      assert(RepeatedMask.size() == 8 && "Repeated mask size doesn't match!");
      BlendMask = 0;
      for (int i = 0; i < 8; ++i)
        if (RepeatedMask[i] >= 16)
          BlendMask |= 1u << i;
      return DAG.getNode(X86ISD::BLENDI, DL, MVT::v16i16, V1, V2,
                         DAG.getConstant(BlendMask, MVT::i8));
    }
  }
    // FALLTHROUGH
  case MVT::v16i8:
  case MVT::v32i8: {
    // Scale the blend by the number of bytes per element.
    int Scale = VT.getScalarSizeInBits() / 8;

    // This form of blend is always done on bytes. Compute the byte vector
    // type.
    MVT BlendVT = MVT::getVectorVT(MVT::i8, VT.getSizeInBits() / 8);

    // Compute the VSELECT mask. Note that VSELECT is really confusing in the
    // mix of LLVM's code generator and the x86 backend. We tell the code
    // generator that boolean values in the elements of an x86 vector register
    // are -1 for true and 0 for false. We then use the LLVM semantics of 'true'
    // mapping a select to operand #1, and 'false' mapping to operand #2. The
    // reality in x86 is that vector masks (pre-AVX-512) use only the high bit
    // of the element (the remaining are ignored) and 0 in that high bit would
    // mean operand #1 while 1 in the high bit would mean operand #2. So while
    // the LLVM model for boolean values in vector elements gets the relevant
    // bit set, it is set backwards and over constrained relative to x86's
    // actual model.
    SmallVector<SDValue, 32> VSELECTMask;
    for (int i = 0, Size = Mask.size(); i < Size; ++i)
      for (int j = 0; j < Scale; ++j)
        VSELECTMask.push_back(
            Mask[i] < 0 ? DAG.getUNDEF(MVT::i8)
                        : DAG.getConstant(Mask[i] < Size ? -1 : 0, MVT::i8));

    V1 = DAG.getNode(ISD::BITCAST, DL, BlendVT, V1);
    V2 = DAG.getNode(ISD::BITCAST, DL, BlendVT, V2);
    return DAG.getNode(
        ISD::BITCAST, DL, VT,
        DAG.getNode(ISD::VSELECT, DL, BlendVT,
                    DAG.getNode(ISD::BUILD_VECTOR, DL, BlendVT, VSELECTMask),
                    V1, V2));
  }

  default:
    llvm_unreachable("Not a supported integer vector type!");
  }
}

/// \brief Try to lower as a blend of elements from two inputs followed by
/// a single-input permutation.
///
/// This matches the pattern where we can blend elements from two inputs and
/// then reduce the shuffle to a single-input permutation.
static SDValue lowerVectorShuffleAsBlendAndPermute(SDLoc DL, MVT VT, SDValue V1,
                                                   SDValue V2,
                                                   ArrayRef<int> Mask,
                                                   SelectionDAG &DAG) {
  // We build up the blend mask while checking whether a blend is a viable way
  // to reduce the shuffle.
  SmallVector<int, 32> BlendMask(Mask.size(), -1);
  SmallVector<int, 32> PermuteMask(Mask.size(), -1);

  for (int i = 0, Size = Mask.size(); i < Size; ++i) {
    if (Mask[i] < 0)
      continue;

    assert(Mask[i] < Size * 2 && "Shuffle input is out of bounds.");

    if (BlendMask[Mask[i] % Size] == -1)
      BlendMask[Mask[i] % Size] = Mask[i];
    else if (BlendMask[Mask[i] % Size] != Mask[i])
      return SDValue(); // Can't blend in the needed input!

    PermuteMask[i] = Mask[i] % Size;
  }

  SDValue V = DAG.getVectorShuffle(VT, DL, V1, V2, BlendMask);
  return DAG.getVectorShuffle(VT, DL, V, DAG.getUNDEF(VT), PermuteMask);
}

/// \brief Generic routine to decompose a shuffle and blend into indepndent
/// blends and permutes.
///
/// This matches the extremely common pattern for handling combined
/// shuffle+blend operations on newer X86 ISAs where we have very fast blend
/// operations. It will try to pick the best arrangement of shuffles and
/// blends.
static SDValue lowerVectorShuffleAsDecomposedShuffleBlend(SDLoc DL, MVT VT,
                                                          SDValue V1,
                                                          SDValue V2,
                                                          ArrayRef<int> Mask,
                                                          SelectionDAG &DAG) {
  // Shuffle the input elements into the desired positions in V1 and V2 and
  // blend them together.
  SmallVector<int, 32> V1Mask(Mask.size(), -1);
  SmallVector<int, 32> V2Mask(Mask.size(), -1);
  SmallVector<int, 32> BlendMask(Mask.size(), -1);
  for (int i = 0, Size = Mask.size(); i < Size; ++i)
    if (Mask[i] >= 0 && Mask[i] < Size) {
      V1Mask[i] = Mask[i];
      BlendMask[i] = i;
    } else if (Mask[i] >= Size) {
      V2Mask[i] = Mask[i] - Size;
      BlendMask[i] = i + Size;
    }

  // Try to lower with the simpler initial blend strategy unless one of the
  // input shuffles would be a no-op. We prefer to shuffle inputs as the
  // shuffle may be able to fold with a load or other benefit. However, when
  // we'll have to do 2x as many shuffles in order to achieve this, blending
  // first is a better strategy.
  if (!isNoopShuffleMask(V1Mask) && !isNoopShuffleMask(V2Mask))
    if (SDValue BlendPerm =
            lowerVectorShuffleAsBlendAndPermute(DL, VT, V1, V2, Mask, DAG))
      return BlendPerm;

  V1 = DAG.getVectorShuffle(VT, DL, V1, DAG.getUNDEF(VT), V1Mask);
  V2 = DAG.getVectorShuffle(VT, DL, V2, DAG.getUNDEF(VT), V2Mask);
  return DAG.getVectorShuffle(VT, DL, V1, V2, BlendMask);
}

/// \brief Try to lower a vector shuffle as a byte rotation.
///
/// SSSE3 has a generic PALIGNR instruction in x86 that will do an arbitrary
/// byte-rotation of the concatenation of two vectors; pre-SSSE3 can use
/// a PSRLDQ/PSLLDQ/POR pattern to get a similar effect. This routine will
/// try to generically lower a vector shuffle through such an pattern. It
/// does not check for the profitability of lowering either as PALIGNR or
/// PSRLDQ/PSLLDQ/POR, only whether the mask is valid to lower in that form.
/// This matches shuffle vectors that look like:
///
///   v8i16 [11, 12, 13, 14, 15, 0, 1, 2]
///
/// Essentially it concatenates V1 and V2, shifts right by some number of
/// elements, and takes the low elements as the result. Note that while this is
/// specified as a *right shift* because x86 is little-endian, it is a *left
/// rotate* of the vector lanes.
static SDValue lowerVectorShuffleAsByteRotate(SDLoc DL, MVT VT, SDValue V1,
                                              SDValue V2,
                                              ArrayRef<int> Mask,
                                              const X86Subtarget *Subtarget,
                                              SelectionDAG &DAG) {
  assert(!isNoopShuffleMask(Mask) && "We shouldn't lower no-op shuffles!");

  int NumElts = Mask.size();
  int NumLanes = VT.getSizeInBits() / 128;
  int NumLaneElts = NumElts / NumLanes;

  // We need to detect various ways of spelling a rotation:
  //   [11, 12, 13, 14, 15,  0,  1,  2]
  //   [-1, 12, 13, 14, -1, -1,  1, -1]
  //   [-1, -1, -1, -1, -1, -1,  1,  2]
  //   [ 3,  4,  5,  6,  7,  8,  9, 10]
  //   [-1,  4,  5,  6, -1, -1,  9, -1]
  //   [-1,  4,  5,  6, -1, -1, -1, -1]
  int Rotation = 0;
  SDValue Lo, Hi;
  for (int l = 0; l < NumElts; l += NumLaneElts) {
    for (int i = 0; i < NumLaneElts; ++i) {
      if (Mask[l + i] == -1)
        continue;
      assert(Mask[l + i] >= 0 && "Only -1 is a valid negative mask element!");

      // Get the mod-Size index and lane correct it.
      int LaneIdx = (Mask[l + i] % NumElts) - l;
      // Make sure it was in this lane.
      if (LaneIdx < 0 || LaneIdx >= NumLaneElts)
        return SDValue();

      // Determine where a rotated vector would have started.
      int StartIdx = i - LaneIdx;
      if (StartIdx == 0)
        // The identity rotation isn't interesting, stop.
        return SDValue();

      // If we found the tail of a vector the rotation must be the missing
      // front. If we found the head of a vector, it must be how much of the
      // head.
      int CandidateRotation = StartIdx < 0 ? -StartIdx : NumLaneElts - StartIdx;

      if (Rotation == 0)
        Rotation = CandidateRotation;
      else if (Rotation != CandidateRotation)
        // The rotations don't match, so we can't match this mask.
        return SDValue();

      // Compute which value this mask is pointing at.
      SDValue MaskV = Mask[l + i] < NumElts ? V1 : V2;

      // Compute which of the two target values this index should be assigned
      // to. This reflects whether the high elements are remaining or the low
      // elements are remaining.
      SDValue &TargetV = StartIdx < 0 ? Hi : Lo;

      // Either set up this value if we've not encountered it before, or check
      // that it remains consistent.
      if (!TargetV)
        TargetV = MaskV;
      else if (TargetV != MaskV)
        // This may be a rotation, but it pulls from the inputs in some
        // unsupported interleaving.
        return SDValue();
    }
  }

  // Check that we successfully analyzed the mask, and normalize the results.
  assert(Rotation != 0 && "Failed to locate a viable rotation!");
  assert((Lo || Hi) && "Failed to find a rotated input vector!");
  if (!Lo)
    Lo = Hi;
  else if (!Hi)
    Hi = Lo;

  // The actual rotate instruction rotates bytes, so we need to scale the
  // rotation based on how many bytes are in the vector lane.
  int Scale = 16 / NumLaneElts;

  // SSSE3 targets can use the palignr instruction.
  if (Subtarget->hasSSSE3()) {
    // Cast the inputs to i8 vector of correct length to match PALIGNR.
    MVT AlignVT = MVT::getVectorVT(MVT::i8, 16 * NumLanes);
    Lo = DAG.getNode(ISD::BITCAST, DL, AlignVT, Lo);
    Hi = DAG.getNode(ISD::BITCAST, DL, AlignVT, Hi);

    return DAG.getNode(ISD::BITCAST, DL, VT,
                       DAG.getNode(X86ISD::PALIGNR, DL, AlignVT, Hi, Lo,
                                   DAG.getConstant(Rotation * Scale, MVT::i8)));
  }

  assert(VT.getSizeInBits() == 128 &&
         "Rotate-based lowering only supports 128-bit lowering!");
  assert(Mask.size() <= 16 &&
         "Can shuffle at most 16 bytes in a 128-bit vector!");

  // Default SSE2 implementation
  int LoByteShift = 16 - Rotation * Scale;
  int HiByteShift = Rotation * Scale;

  // Cast the inputs to v2i64 to match PSLLDQ/PSRLDQ.
  Lo = DAG.getNode(ISD::BITCAST, DL, MVT::v2i64, Lo);
  Hi = DAG.getNode(ISD::BITCAST, DL, MVT::v2i64, Hi);

  SDValue LoShift = DAG.getNode(X86ISD::VSHLDQ, DL, MVT::v2i64, Lo,
                                DAG.getConstant(LoByteShift, MVT::i8));
  SDValue HiShift = DAG.getNode(X86ISD::VSRLDQ, DL, MVT::v2i64, Hi,
                                DAG.getConstant(HiByteShift, MVT::i8));
  return DAG.getNode(ISD::BITCAST, DL, VT,
                     DAG.getNode(ISD::OR, DL, MVT::v2i64, LoShift, HiShift));
}

/// \brief Compute whether each element of a shuffle is zeroable.
///
/// A "zeroable" vector shuffle element is one which can be lowered to zero.
/// Either it is an undef element in the shuffle mask, the element of the input
/// referenced is undef, or the element of the input referenced is known to be
/// zero. Many x86 shuffles can zero lanes cheaply and we often want to handle
/// as many lanes with this technique as possible to simplify the remaining
/// shuffle.
static SmallBitVector computeZeroableShuffleElements(ArrayRef<int> Mask,
                                                     SDValue V1, SDValue V2) {
  SmallBitVector Zeroable(Mask.size(), false);

  while (V1.getOpcode() == ISD::BITCAST)
    V1 = V1->getOperand(0);
  while (V2.getOpcode() == ISD::BITCAST)
    V2 = V2->getOperand(0);

  bool V1IsZero = ISD::isBuildVectorAllZeros(V1.getNode());
  bool V2IsZero = ISD::isBuildVectorAllZeros(V2.getNode());

  for (int i = 0, Size = Mask.size(); i < Size; ++i) {
    int M = Mask[i];
    // Handle the easy cases.
    if (M < 0 || (M >= 0 && M < Size && V1IsZero) || (M >= Size && V2IsZero)) {
      Zeroable[i] = true;
      continue;
    }

    // If this is an index into a build_vector node (which has the same number
    // of elements), dig out the input value and use it.
    SDValue V = M < Size ? V1 : V2;
    if (V.getOpcode() != ISD::BUILD_VECTOR || Size != (int)V.getNumOperands())
      continue;

    SDValue Input = V.getOperand(M % Size);
    // The UNDEF opcode check really should be dead code here, but not quite
    // worth asserting on (it isn't invalid, just unexpected).
    if (Input.getOpcode() == ISD::UNDEF || X86::isZeroNode(Input))
      Zeroable[i] = true;
  }

  return Zeroable;
}

/// \brief Try to emit a bitmask instruction for a shuffle.
///
/// This handles cases where we can model a blend exactly as a bitmask due to
/// one of the inputs being zeroable.
static SDValue lowerVectorShuffleAsBitMask(SDLoc DL, MVT VT, SDValue V1,
                                           SDValue V2, ArrayRef<int> Mask,
                                           SelectionDAG &DAG) {
  MVT EltVT = VT.getScalarType();
  int NumEltBits = EltVT.getSizeInBits();
  MVT IntEltVT = MVT::getIntegerVT(NumEltBits);
  SDValue Zero = DAG.getConstant(0, IntEltVT);
  SDValue AllOnes = DAG.getConstant(APInt::getAllOnesValue(NumEltBits), IntEltVT);
  if (EltVT.isFloatingPoint()) {
    Zero = DAG.getNode(ISD::BITCAST, DL, EltVT, Zero);
    AllOnes = DAG.getNode(ISD::BITCAST, DL, EltVT, AllOnes);
  }
  SmallVector<SDValue, 16> VMaskOps(Mask.size(), Zero);
  SmallBitVector Zeroable = computeZeroableShuffleElements(Mask, V1, V2);
  SDValue V;
  for (int i = 0, Size = Mask.size(); i < Size; ++i) {
    if (Zeroable[i])
      continue;
    if (Mask[i] % Size != i)
      return SDValue(); // Not a blend.
    if (!V)
      V = Mask[i] < Size ? V1 : V2;
    else if (V != (Mask[i] < Size ? V1 : V2))
      return SDValue(); // Can only let one input through the mask.

    VMaskOps[i] = AllOnes;
  }
  if (!V)
    return SDValue(); // No non-zeroable elements!

  SDValue VMask = DAG.getNode(ISD::BUILD_VECTOR, DL, VT, VMaskOps);
  V = DAG.getNode(VT.isFloatingPoint()
                  ? (unsigned) X86ISD::FAND : (unsigned) ISD::AND,
                  DL, VT, V, VMask);
  return V;
}

/// \brief Try to lower a vector shuffle as a bit shift (shifts in zeros).
///
/// Attempts to match a shuffle mask against the PSLL(W/D/Q/DQ) and
/// PSRL(W/D/Q/DQ) SSE2 and AVX2 logical bit-shift instructions. The function
/// matches elements from one of the input vectors shuffled to the left or
/// right with zeroable elements 'shifted in'. It handles both the strictly
/// bit-wise element shifts and the byte shift across an entire 128-bit double
/// quad word lane.
///
/// PSHL : (little-endian) left bit shift.
/// [ zz, 0, zz,  2 ]
/// [ -1, 4, zz, -1 ]
/// PSRL : (little-endian) right bit shift.
/// [  1, zz,  3, zz]
/// [ -1, -1,  7, zz]
/// PSLLDQ : (little-endian) left byte shift
/// [ zz,  0,  1,  2,  3,  4,  5,  6]
/// [ zz, zz, -1, -1,  2,  3,  4, -1]
/// [ zz, zz, zz, zz, zz, zz, -1,  1]
/// PSRLDQ : (little-endian) right byte shift
/// [  5, 6,  7, zz, zz, zz, zz, zz]
/// [ -1, 5,  6,  7, zz, zz, zz, zz]
/// [  1, 2, -1, -1, -1, -1, zz, zz]
static SDValue lowerVectorShuffleAsShift(SDLoc DL, MVT VT, SDValue V1,
                                         SDValue V2, ArrayRef<int> Mask,
                                         SelectionDAG &DAG) {
  SmallBitVector Zeroable = computeZeroableShuffleElements(Mask, V1, V2);

  int Size = Mask.size();
  assert(Size == (int)VT.getVectorNumElements() && "Unexpected mask size");

  auto CheckZeros = [&](int Shift, int Scale, bool Left) {
    for (int i = 0; i < Size; i += Scale)
      for (int j = 0; j < Shift; ++j)
        if (!Zeroable[i + j + (Left ? 0 : (Scale - Shift))])
          return false;

    return true;
  };

  auto MatchShift = [&](int Shift, int Scale, bool Left, SDValue V) {
    for (int i = 0; i != Size; i += Scale) {
      unsigned Pos = Left ? i + Shift : i;
      unsigned Low = Left ? i : i + Shift;
      unsigned Len = Scale - Shift;
      if (!isSequentialOrUndefInRange(Mask, Pos, Len,
                                      Low + (V == V1 ? 0 : Size)))
        return SDValue();
    }

    int ShiftEltBits = VT.getScalarSizeInBits() * Scale;
    bool ByteShift = ShiftEltBits > 64;
    unsigned OpCode = Left ? (ByteShift ? X86ISD::VSHLDQ : X86ISD::VSHLI)
                           : (ByteShift ? X86ISD::VSRLDQ : X86ISD::VSRLI);
    int ShiftAmt = Shift * VT.getScalarSizeInBits() / (ByteShift ? 8 : 1);

    // Normalize the scale for byte shifts to still produce an i64 element
    // type.
    Scale = ByteShift ? Scale / 2 : Scale;

    // We need to round trip through the appropriate type for the shift.
    MVT ShiftSVT = MVT::getIntegerVT(VT.getScalarSizeInBits() * Scale);
    MVT ShiftVT = MVT::getVectorVT(ShiftSVT, Size / Scale);
    assert(DAG.getTargetLoweringInfo().isTypeLegal(ShiftVT) &&
           "Illegal integer vector type");
    V = DAG.getNode(ISD::BITCAST, DL, ShiftVT, V);

    V = DAG.getNode(OpCode, DL, ShiftVT, V, DAG.getConstant(ShiftAmt, MVT::i8));
    return DAG.getNode(ISD::BITCAST, DL, VT, V);
  };

  // SSE/AVX supports logical shifts up to 64-bit integers - so we can just
  // keep doubling the size of the integer elements up to that. We can
  // then shift the elements of the integer vector by whole multiples of
  // their width within the elements of the larger integer vector. Test each
  // multiple to see if we can find a match with the moved element indices
  // and that the shifted in elements are all zeroable.
  for (int Scale = 2; Scale * VT.getScalarSizeInBits() <= 128; Scale *= 2)
    for (int Shift = 1; Shift != Scale; ++Shift)
      for (bool Left : {true, false})
        if (CheckZeros(Shift, Scale, Left))
          for (SDValue V : {V1, V2})
            if (SDValue Match = MatchShift(Shift, Scale, Left, V))
              return Match;

  // no match
  return SDValue();
}

/// \brief Lower a vector shuffle as a zero or any extension.
///
/// Given a specific number of elements, element bit width, and extension
/// stride, produce either a zero or any extension based on the available
/// features of the subtarget.
static SDValue lowerVectorShuffleAsSpecificZeroOrAnyExtend(
    SDLoc DL, MVT VT, int Scale, bool AnyExt, SDValue InputV,
    const X86Subtarget *Subtarget, SelectionDAG &DAG) {
  assert(Scale > 1 && "Need a scale to extend.");
  int NumElements = VT.getVectorNumElements();
  int EltBits = VT.getScalarSizeInBits();
  assert((EltBits == 8 || EltBits == 16 || EltBits == 32) &&
         "Only 8, 16, and 32 bit elements can be extended.");
  assert(Scale * EltBits <= 64 && "Cannot zero extend past 64 bits.");

  // Found a valid zext mask! Try various lowering strategies based on the
  // input type and available ISA extensions.
  if (Subtarget->hasSSE41()) {
    MVT ExtVT = MVT::getVectorVT(MVT::getIntegerVT(EltBits * Scale),
                                 NumElements / Scale);
    return DAG.getNode(ISD::BITCAST, DL, VT,
                       DAG.getNode(X86ISD::VZEXT, DL, ExtVT, InputV));
  }

  // For any extends we can cheat for larger element sizes and use shuffle
  // instructions that can fold with a load and/or copy.
  if (AnyExt && EltBits == 32) {
    int PSHUFDMask[4] = {0, -1, 1, -1};
    return DAG.getNode(
        ISD::BITCAST, DL, VT,
        DAG.getNode(X86ISD::PSHUFD, DL, MVT::v4i32,
                    DAG.getNode(ISD::BITCAST, DL, MVT::v4i32, InputV),
                    getV4X86ShuffleImm8ForMask(PSHUFDMask, DAG)));
  }
  if (AnyExt && EltBits == 16 && Scale > 2) {
    int PSHUFDMask[4] = {0, -1, 0, -1};
    InputV = DAG.getNode(X86ISD::PSHUFD, DL, MVT::v4i32,
                         DAG.getNode(ISD::BITCAST, DL, MVT::v4i32, InputV),
                         getV4X86ShuffleImm8ForMask(PSHUFDMask, DAG));
    int PSHUFHWMask[4] = {1, -1, -1, -1};
    return DAG.getNode(
        ISD::BITCAST, DL, VT,
        DAG.getNode(X86ISD::PSHUFHW, DL, MVT::v8i16,
                    DAG.getNode(ISD::BITCAST, DL, MVT::v8i16, InputV),
                    getV4X86ShuffleImm8ForMask(PSHUFHWMask, DAG)));
  }

  // If this would require more than 2 unpack instructions to expand, use
  // pshufb when available. We can only use more than 2 unpack instructions
  // when zero extending i8 elements which also makes it easier to use pshufb.
  if (Scale > 4 && EltBits == 8 && Subtarget->hasSSSE3()) {
    assert(NumElements == 16 && "Unexpected byte vector width!");
    SDValue PSHUFBMask[16];
    for (int i = 0; i < 16; ++i)
      PSHUFBMask[i] =
          DAG.getConstant((i % Scale == 0) ? i / Scale : 0x80, MVT::i8);
    InputV = DAG.getNode(ISD::BITCAST, DL, MVT::v16i8, InputV);
    return DAG.getNode(ISD::BITCAST, DL, VT,
                       DAG.getNode(X86ISD::PSHUFB, DL, MVT::v16i8, InputV,
                                   DAG.getNode(ISD::BUILD_VECTOR, DL,
                                               MVT::v16i8, PSHUFBMask)));
  }

  // Otherwise emit a sequence of unpacks.
  do {
    MVT InputVT = MVT::getVectorVT(MVT::getIntegerVT(EltBits), NumElements);
    SDValue Ext = AnyExt ? DAG.getUNDEF(InputVT)
                         : getZeroVector(InputVT, Subtarget, DAG, DL);
    InputV = DAG.getNode(ISD::BITCAST, DL, InputVT, InputV);
    InputV = DAG.getNode(X86ISD::UNPCKL, DL, InputVT, InputV, Ext);
    Scale /= 2;
    EltBits *= 2;
    NumElements /= 2;
  } while (Scale > 1);
  return DAG.getNode(ISD::BITCAST, DL, VT, InputV);
}

/// \brief Try to lower a vector shuffle as a zero extension on any microarch.
///
/// This routine will try to do everything in its power to cleverly lower
/// a shuffle which happens to match the pattern of a zero extend. It doesn't
/// check for the profitability of this lowering,  it tries to aggressively
/// match this pattern. It will use all of the micro-architectural details it
/// can to emit an efficient lowering. It handles both blends with all-zero
/// inputs to explicitly zero-extend and undef-lanes (sometimes undef due to
/// masking out later).
///
/// The reason we have dedicated lowering for zext-style shuffles is that they
/// are both incredibly common and often quite performance sensitive.
static SDValue lowerVectorShuffleAsZeroOrAnyExtend(
    SDLoc DL, MVT VT, SDValue V1, SDValue V2, ArrayRef<int> Mask,
    const X86Subtarget *Subtarget, SelectionDAG &DAG) {
  SmallBitVector Zeroable = computeZeroableShuffleElements(Mask, V1, V2);

  int Bits = VT.getSizeInBits();
  int NumElements = VT.getVectorNumElements();
  assert(VT.getScalarSizeInBits() <= 32 &&
         "Exceeds 32-bit integer zero extension limit");
  assert((int)Mask.size() == NumElements && "Unexpected shuffle mask size");

  // Define a helper function to check a particular ext-scale and lower to it if
  // valid.
  auto Lower = [&](int Scale) -> SDValue {
    SDValue InputV;
    bool AnyExt = true;
    for (int i = 0; i < NumElements; ++i) {
      if (Mask[i] == -1)
        continue; // Valid anywhere but doesn't tell us anything.
      if (i % Scale != 0) {
        // Each of the extended elements need to be zeroable.
        if (!Zeroable[i])
          return SDValue();

        // We no longer are in the anyext case.
        AnyExt = false;
        continue;
      }

      // Each of the base elements needs to be consecutive indices into the
      // same input vector.
      SDValue V = Mask[i] < NumElements ? V1 : V2;
      if (!InputV)
        InputV = V;
      else if (InputV != V)
        return SDValue(); // Flip-flopping inputs.

      if (Mask[i] % NumElements != i / Scale)
        return SDValue(); // Non-consecutive strided elements.
    }

    // If we fail to find an input, we have a zero-shuffle which should always
    // have already been handled.
    // FIXME: Maybe handle this here in case during blending we end up with one?
    if (!InputV)
      return SDValue();

    return lowerVectorShuffleAsSpecificZeroOrAnyExtend(
        DL, VT, Scale, AnyExt, InputV, Subtarget, DAG);
  };

  // The widest scale possible for extending is to a 64-bit integer.
  assert(Bits % 64 == 0 &&
         "The number of bits in a vector must be divisible by 64 on x86!");
  int NumExtElements = Bits / 64;

  // Each iteration, try extending the elements half as much, but into twice as
  // many elements.
  for (; NumExtElements < NumElements; NumExtElements *= 2) {
    assert(NumElements % NumExtElements == 0 &&
           "The input vector size must be divisible by the extended size.");
    if (SDValue V = Lower(NumElements / NumExtElements))
      return V;
  }

  // General extends failed, but 128-bit vectors may be able to use MOVQ.
  if (Bits != 128)
    return SDValue();

  // Returns one of the source operands if the shuffle can be reduced to a
  // MOVQ, copying the lower 64-bits and zero-extending to the upper 64-bits.
  auto CanZExtLowHalf = [&]() {
    for (int i = NumElements / 2; i != NumElements; ++i)
      if (!Zeroable[i])
        return SDValue();
    if (isSequentialOrUndefInRange(Mask, 0, NumElements / 2, 0))
      return V1;
    if (isSequentialOrUndefInRange(Mask, 0, NumElements / 2, NumElements))
      return V2;
    return SDValue();
  };

  if (SDValue V = CanZExtLowHalf()) {
    V = DAG.getNode(ISD::BITCAST, DL, MVT::v2i64, V);
    V = DAG.getNode(X86ISD::VZEXT_MOVL, DL, MVT::v2i64, V);
    return DAG.getNode(ISD::BITCAST, DL, VT, V);
  }

  // No viable ext lowering found.
  return SDValue();
}

/// \brief Try to get a scalar value for a specific element of a vector.
///
/// Looks through BUILD_VECTOR and SCALAR_TO_VECTOR nodes to find a scalar.
static SDValue getScalarValueForVectorElement(SDValue V, int Idx,
                                              SelectionDAG &DAG) {
  MVT VT = V.getSimpleValueType();
  MVT EltVT = VT.getVectorElementType();
  while (V.getOpcode() == ISD::BITCAST)
    V = V.getOperand(0);
  // If the bitcasts shift the element size, we can't extract an equivalent
  // element from it.
  MVT NewVT = V.getSimpleValueType();
  if (!NewVT.isVector() || NewVT.getScalarSizeInBits() != VT.getScalarSizeInBits())
    return SDValue();

  if (V.getOpcode() == ISD::BUILD_VECTOR ||
      (Idx == 0 && V.getOpcode() == ISD::SCALAR_TO_VECTOR))
    return DAG.getNode(ISD::BITCAST, SDLoc(V), EltVT, V.getOperand(Idx));

  return SDValue();
}

/// \brief Helper to test for a load that can be folded with x86 shuffles.
///
/// This is particularly important because the set of instructions varies
/// significantly based on whether the operand is a load or not.
static bool isShuffleFoldableLoad(SDValue V) {
  while (V.getOpcode() == ISD::BITCAST)
    V = V.getOperand(0);

  return ISD::isNON_EXTLoad(V.getNode());
}

/// \brief Try to lower insertion of a single element into a zero vector.
///
/// This is a common pattern that we have especially efficient patterns to lower
/// across all subtarget feature sets.
static SDValue lowerVectorShuffleAsElementInsertion(
    MVT VT, SDLoc DL, SDValue V1, SDValue V2, ArrayRef<int> Mask,
    const X86Subtarget *Subtarget, SelectionDAG &DAG) {
  SmallBitVector Zeroable = computeZeroableShuffleElements(Mask, V1, V2);
  MVT ExtVT = VT;
  MVT EltVT = VT.getVectorElementType();

  int V2Index = std::find_if(Mask.begin(), Mask.end(),
                             [&Mask](int M) { return M >= (int)Mask.size(); }) -
                Mask.begin();
  bool IsV1Zeroable = true;
  for (int i = 0, Size = Mask.size(); i < Size; ++i)
    if (i != V2Index && !Zeroable[i]) {
      IsV1Zeroable = false;
      break;
    }

  // Check for a single input from a SCALAR_TO_VECTOR node.
  // FIXME: All of this should be canonicalized into INSERT_VECTOR_ELT and
  // all the smarts here sunk into that routine. However, the current
  // lowering of BUILD_VECTOR makes that nearly impossible until the old
  // vector shuffle lowering is dead.
  if (SDValue V2S = getScalarValueForVectorElement(
          V2, Mask[V2Index] - Mask.size(), DAG)) {
    // We need to zext the scalar if it is smaller than an i32.
    V2S = DAG.getNode(ISD::BITCAST, DL, EltVT, V2S);
    if (EltVT == MVT::i8 || EltVT == MVT::i16) {
      // Using zext to expand a narrow element won't work for non-zero
      // insertions.
      if (!IsV1Zeroable)
        return SDValue();

      // Zero-extend directly to i32.
      ExtVT = MVT::v4i32;
      V2S = DAG.getNode(ISD::ZERO_EXTEND, DL, MVT::i32, V2S);
    }
    V2 = DAG.getNode(ISD::SCALAR_TO_VECTOR, DL, ExtVT, V2S);
  } else if (Mask[V2Index] != (int)Mask.size() || EltVT == MVT::i8 ||
             EltVT == MVT::i16) {
    // Either not inserting from the low element of the input or the input
    // element size is too small to use VZEXT_MOVL to clear the high bits.
    return SDValue();
  }

  if (!IsV1Zeroable) {
    // If V1 can't be treated as a zero vector we have fewer options to lower
    // this. We can't support integer vectors or non-zero targets cheaply, and
    // the V1 elements can't be permuted in any way.
    assert(VT == ExtVT && "Cannot change extended type when non-zeroable!");
    if (!VT.isFloatingPoint() || V2Index != 0)
      return SDValue();
    SmallVector<int, 8> V1Mask(Mask.begin(), Mask.end());
    V1Mask[V2Index] = -1;
    if (!isNoopShuffleMask(V1Mask))
      return SDValue();
    // This is essentially a special case blend operation, but if we have
    // general purpose blend operations, they are always faster. Bail and let
    // the rest of the lowering handle these as blends.
    if (Subtarget->hasSSE41())
      return SDValue();

    // Otherwise, use MOVSD or MOVSS.
    assert((EltVT == MVT::f32 || EltVT == MVT::f64) &&
           "Only two types of floating point element types to handle!");
    return DAG.getNode(EltVT == MVT::f32 ? X86ISD::MOVSS : X86ISD::MOVSD, DL,
                       ExtVT, V1, V2);
  }

  // This lowering only works for the low element with floating point vectors.
  if (VT.isFloatingPoint() && V2Index != 0)
    return SDValue();

  V2 = DAG.getNode(X86ISD::VZEXT_MOVL, DL, ExtVT, V2);
  if (ExtVT != VT)
    V2 = DAG.getNode(ISD::BITCAST, DL, VT, V2);

  if (V2Index != 0) {
    // If we have 4 or fewer lanes we can cheaply shuffle the element into
    // the desired position. Otherwise it is more efficient to do a vector
    // shift left. We know that we can do a vector shift left because all
    // the inputs are zero.
    if (VT.isFloatingPoint() || VT.getVectorNumElements() <= 4) {
      SmallVector<int, 4> V2Shuffle(Mask.size(), 1);
      V2Shuffle[V2Index] = 0;
      V2 = DAG.getVectorShuffle(VT, DL, V2, DAG.getUNDEF(VT), V2Shuffle);
    } else {
      V2 = DAG.getNode(ISD::BITCAST, DL, MVT::v2i64, V2);
      V2 = DAG.getNode(
          X86ISD::VSHLDQ, DL, MVT::v2i64, V2,
          DAG.getConstant(
              V2Index * EltVT.getSizeInBits()/8,
              DAG.getTargetLoweringInfo().getScalarShiftAmountTy(MVT::v2i64)));
      V2 = DAG.getNode(ISD::BITCAST, DL, VT, V2);
    }
  }
  return V2;
}

/// \brief Try to lower broadcast of a single element.
///
/// For convenience, this code also bundles all of the subtarget feature set
/// filtering. While a little annoying to re-dispatch on type here, there isn't
/// a convenient way to factor it out.
static SDValue lowerVectorShuffleAsBroadcast(MVT VT, SDLoc DL, SDValue V,
                                             ArrayRef<int> Mask,
                                             const X86Subtarget *Subtarget,
                                             SelectionDAG &DAG) {
  if (!Subtarget->hasAVX())
    return SDValue();
  if (VT.isInteger() && !Subtarget->hasAVX2())
    return SDValue();

  // Check that the mask is a broadcast.
  int BroadcastIdx = -1;
  for (int M : Mask)
    if (M >= 0 && BroadcastIdx == -1)
      BroadcastIdx = M;
    else if (M >= 0 && M != BroadcastIdx)
      return SDValue();

  assert(BroadcastIdx < (int)Mask.size() && "We only expect to be called with "
                                            "a sorted mask where the broadcast "
                                            "comes from V1.");

  // Go up the chain of (vector) values to try and find a scalar load that
  // we can combine with the broadcast.
  for (;;) {
    switch (V.getOpcode()) {
    case ISD::CONCAT_VECTORS: {
      int OperandSize = Mask.size() / V.getNumOperands();
      V = V.getOperand(BroadcastIdx / OperandSize);
      BroadcastIdx %= OperandSize;
      continue;
    }

    case ISD::INSERT_SUBVECTOR: {
      SDValue VOuter = V.getOperand(0), VInner = V.getOperand(1);
      auto ConstantIdx = dyn_cast<ConstantSDNode>(V.getOperand(2));
      if (!ConstantIdx)
        break;

      int BeginIdx = (int)ConstantIdx->getZExtValue();
      int EndIdx =
          BeginIdx + (int)VInner.getValueType().getVectorNumElements();
      if (BroadcastIdx >= BeginIdx && BroadcastIdx < EndIdx) {
        BroadcastIdx -= BeginIdx;
        V = VInner;
      } else {
        V = VOuter;
      }
      continue;
    }
    }
    break;
  }

  // Check if this is a broadcast of a scalar. We special case lowering
  // for scalars so that we can more effectively fold with loads.
  if (V.getOpcode() == ISD::BUILD_VECTOR ||
      (V.getOpcode() == ISD::SCALAR_TO_VECTOR && BroadcastIdx == 0)) {
    V = V.getOperand(BroadcastIdx);

    // If the scalar isn't a load we can't broadcast from it in AVX1, only with
    // AVX2.
    if (!Subtarget->hasAVX2() && !isShuffleFoldableLoad(V))
      return SDValue();
  } else if (BroadcastIdx != 0 || !Subtarget->hasAVX2()) {
    // We can't broadcast from a vector register w/o AVX2, and we can only
    // broadcast from the zero-element of a vector register.
    return SDValue();
  }

  return DAG.getNode(X86ISD::VBROADCAST, DL, VT, V);
}

// Check for whether we can use INSERTPS to perform the shuffle. We only use
// INSERTPS when the V1 elements are already in the correct locations
// because otherwise we can just always use two SHUFPS instructions which
// are much smaller to encode than a SHUFPS and an INSERTPS. We can also
// perform INSERTPS if a single V1 element is out of place and all V2
// elements are zeroable.
static SDValue lowerVectorShuffleAsInsertPS(SDValue Op, SDValue V1, SDValue V2,
                                            ArrayRef<int> Mask,
                                            SelectionDAG &DAG) {
  assert(Op.getSimpleValueType() == MVT::v4f32 && "Bad shuffle type!");
  assert(V1.getSimpleValueType() == MVT::v4f32 && "Bad operand type!");
  assert(V2.getSimpleValueType() == MVT::v4f32 && "Bad operand type!");
  assert(Mask.size() == 4 && "Unexpected mask size for v4 shuffle!");

  SmallBitVector Zeroable = computeZeroableShuffleElements(Mask, V1, V2);

  unsigned ZMask = 0;
  int V1DstIndex = -1;
  int V2DstIndex = -1;
  bool V1UsedInPlace = false;

  for (int i = 0; i < 4; ++i) {
    // Synthesize a zero mask from the zeroable elements (includes undefs).
    if (Zeroable[i]) {
      ZMask |= 1 << i;
      continue;
    }

    // Flag if we use any V1 inputs in place.
    if (i == Mask[i]) {
      V1UsedInPlace = true;
      continue;
    }

    // We can only insert a single non-zeroable element.
    if (V1DstIndex != -1 || V2DstIndex != -1)
      return SDValue();

    if (Mask[i] < 4) {
      // V1 input out of place for insertion.
      V1DstIndex = i;
    } else {
      // V2 input for insertion.
      V2DstIndex = i;
    }
  }

  // Don't bother if we have no (non-zeroable) element for insertion.
  if (V1DstIndex == -1 && V2DstIndex == -1)
    return SDValue();

  // Determine element insertion src/dst indices. The src index is from the
  // start of the inserted vector, not the start of the concatenated vector.
  unsigned V2SrcIndex = 0;
  if (V1DstIndex != -1) {
    // If we have a V1 input out of place, we use V1 as the V2 element insertion
    // and don't use the original V2 at all.
    V2SrcIndex = Mask[V1DstIndex];
    V2DstIndex = V1DstIndex;
    V2 = V1;
  } else {
    V2SrcIndex = Mask[V2DstIndex] - 4;
  }

  // If no V1 inputs are used in place, then the result is created only from
  // the zero mask and the V2 insertion - so remove V1 dependency.
  if (!V1UsedInPlace)
    V1 = DAG.getUNDEF(MVT::v4f32);

  unsigned InsertPSMask = V2SrcIndex << 6 | V2DstIndex << 4 | ZMask;
  assert((InsertPSMask & ~0xFFu) == 0 && "Invalid mask!");

  // Insert the V2 element into the desired position.
  SDLoc DL(Op);
  return DAG.getNode(X86ISD::INSERTPS, DL, MVT::v4f32, V1, V2,
                     DAG.getConstant(InsertPSMask, MVT::i8));
}

/// \brief Try to lower a shuffle as a permute of the inputs followed by an
/// UNPCK instruction.
///
/// This specifically targets cases where we end up with alternating between
/// the two inputs, and so can permute them into something that feeds a single
/// UNPCK instruction. Note that this routine only targets integer vectors
/// because for floating point vectors we have a generalized SHUFPS lowering
/// strategy that handles everything that doesn't *exactly* match an unpack,
/// making this clever lowering unnecessary.
static SDValue lowerVectorShuffleAsUnpack(MVT VT, SDLoc DL, SDValue V1,
                                          SDValue V2, ArrayRef<int> Mask,
                                          SelectionDAG &DAG) {
  assert(!VT.isFloatingPoint() &&
         "This routine only supports integer vectors.");
  assert(!isSingleInputShuffleMask(Mask) &&
         "This routine should only be used when blending two inputs.");
  assert(Mask.size() >= 2 && "Single element masks are invalid.");

  int Size = Mask.size();

  int NumLoInputs = std::count_if(Mask.begin(), Mask.end(), [Size](int M) {
    return M >= 0 && M % Size < Size / 2;
  });
  int NumHiInputs = std::count_if(
      Mask.begin(), Mask.end(), [Size](int M) { return M % Size > Size / 2; });

  bool UnpackLo = NumLoInputs >= NumHiInputs;

  auto TryUnpack = [&](MVT UnpackVT, int Scale) {
    SmallVector<int, 32> V1Mask(Mask.size(), -1);
    SmallVector<int, 32> V2Mask(Mask.size(), -1);

    for (int i = 0; i < Size; ++i) {
      if (Mask[i] < 0)
        continue;

      // Each element of the unpack contains Scale elements from this mask.
      int UnpackIdx = i / Scale;

      // We only handle the case where V1 feeds the first slots of the unpack.
      // We rely on canonicalization to ensure this is the case.
      if ((UnpackIdx % 2 == 0) != (Mask[i] < Size))
        return SDValue();

      // Setup the mask for this input. The indexing is tricky as we have to
      // handle the unpack stride.
      SmallVectorImpl<int> &VMask = (UnpackIdx % 2 == 0) ? V1Mask : V2Mask;
      VMask[(UnpackIdx / 2) * Scale + i % Scale + (UnpackLo ? 0 : Size / 2)] =
          Mask[i] % Size;
    }

    // Shuffle the inputs into place.
    V1 = DAG.getVectorShuffle(VT, DL, V1, DAG.getUNDEF(VT), V1Mask);
    V2 = DAG.getVectorShuffle(VT, DL, V2, DAG.getUNDEF(VT), V2Mask);

    // Cast the inputs to the type we will use to unpack them.
    V1 = DAG.getNode(ISD::BITCAST, DL, UnpackVT, V1);
    V2 = DAG.getNode(ISD::BITCAST, DL, UnpackVT, V2);

    // Unpack the inputs and cast the result back to the desired type.
    return DAG.getNode(ISD::BITCAST, DL, VT,
                       DAG.getNode(UnpackLo ? X86ISD::UNPCKL : X86ISD::UNPCKH,
                                   DL, UnpackVT, V1, V2));
  };

  // We try each unpack from the largest to the smallest to try and find one
  // that fits this mask.
  int OrigNumElements = VT.getVectorNumElements();
  int OrigScalarSize = VT.getScalarSizeInBits();
  for (int ScalarSize = 64; ScalarSize >= OrigScalarSize; ScalarSize /= 2) {
    int Scale = ScalarSize / OrigScalarSize;
    int NumElements = OrigNumElements / Scale;
    MVT UnpackVT = MVT::getVectorVT(MVT::getIntegerVT(ScalarSize), NumElements);
    if (SDValue Unpack = TryUnpack(UnpackVT, Scale))
      return Unpack;
  }

  return SDValue();
}

/// \brief Handle lowering of 2-lane 64-bit floating point shuffles.
///
/// This is the basis function for the 2-lane 64-bit shuffles as we have full
/// support for floating point shuffles but not integer shuffles. These
/// instructions will incur a domain crossing penalty on some chips though so
/// it is better to avoid lowering through this for integer vectors where
/// possible.
static SDValue lowerV2F64VectorShuffle(SDValue Op, SDValue V1, SDValue V2,
                                       const X86Subtarget *Subtarget,
                                       SelectionDAG &DAG) {
  SDLoc DL(Op);
  assert(Op.getSimpleValueType() == MVT::v2f64 && "Bad shuffle type!");
  assert(V1.getSimpleValueType() == MVT::v2f64 && "Bad operand type!");
  assert(V2.getSimpleValueType() == MVT::v2f64 && "Bad operand type!");
  ShuffleVectorSDNode *SVOp = cast<ShuffleVectorSDNode>(Op);
  ArrayRef<int> Mask = SVOp->getMask();
  assert(Mask.size() == 2 && "Unexpected mask size for v2 shuffle!");

  if (isSingleInputShuffleMask(Mask)) {
    // Use low duplicate instructions for masks that match their pattern.
    if (Subtarget->hasSSE3())
      if (isShuffleEquivalent(V1, V2, Mask, 0, 0))
        return DAG.getNode(X86ISD::MOVDDUP, DL, MVT::v2f64, V1);

    // Straight shuffle of a single input vector. Simulate this by using the
    // single input as both of the "inputs" to this instruction..
    unsigned SHUFPDMask = (Mask[0] == 1) | ((Mask[1] == 1) << 1);

    if (Subtarget->hasAVX()) {
      // If we have AVX, we can use VPERMILPS which will allow folding a load
      // into the shuffle.
      return DAG.getNode(X86ISD::VPERMILPI, DL, MVT::v2f64, V1,
                         DAG.getConstant(SHUFPDMask, MVT::i8));
    }

    return DAG.getNode(X86ISD::SHUFP, SDLoc(Op), MVT::v2f64, V1, V1,
                       DAG.getConstant(SHUFPDMask, MVT::i8));
  }
  assert(Mask[0] >= 0 && Mask[0] < 2 && "Non-canonicalized blend!");
  assert(Mask[1] >= 2 && "Non-canonicalized blend!");

  // If we have a single input, insert that into V1 if we can do so cheaply.
  if ((Mask[0] >= 2) + (Mask[1] >= 2) == 1) {
    if (SDValue Insertion = lowerVectorShuffleAsElementInsertion(
            MVT::v2f64, DL, V1, V2, Mask, Subtarget, DAG))
      return Insertion;
    // Try inverting the insertion since for v2 masks it is easy to do and we
    // can't reliably sort the mask one way or the other.
    int InverseMask[2] = {Mask[0] < 0 ? -1 : (Mask[0] ^ 2),
                          Mask[1] < 0 ? -1 : (Mask[1] ^ 2)};
    if (SDValue Insertion = lowerVectorShuffleAsElementInsertion(
            MVT::v2f64, DL, V2, V1, InverseMask, Subtarget, DAG))
      return Insertion;
  }

  // Try to use one of the special instruction patterns to handle two common
  // blend patterns if a zero-blend above didn't work.
  if (isShuffleEquivalent(V1, V2, Mask, 0, 3) || isShuffleEquivalent(V1, V2, Mask, 1, 3))
    if (SDValue V1S = getScalarValueForVectorElement(V1, Mask[0], DAG))
      // We can either use a special instruction to load over the low double or
      // to move just the low double.
      return DAG.getNode(
          isShuffleFoldableLoad(V1S) ? X86ISD::MOVLPD : X86ISD::MOVSD,
          DL, MVT::v2f64, V2,
          DAG.getNode(ISD::SCALAR_TO_VECTOR, DL, MVT::v2f64, V1S));

  if (Subtarget->hasSSE41())
    if (SDValue Blend = lowerVectorShuffleAsBlend(DL, MVT::v2f64, V1, V2, Mask,
                                                  Subtarget, DAG))
      return Blend;

  // Use dedicated unpack instructions for masks that match their pattern.
  if (isShuffleEquivalent(V1, V2, Mask, 0, 2))
    return DAG.getNode(X86ISD::UNPCKL, DL, MVT::v2f64, V1, V2);
  if (isShuffleEquivalent(V1, V2, Mask, 1, 3))
    return DAG.getNode(X86ISD::UNPCKH, DL, MVT::v2f64, V1, V2);

  unsigned SHUFPDMask = (Mask[0] == 1) | (((Mask[1] - 2) == 1) << 1);
  return DAG.getNode(X86ISD::SHUFP, SDLoc(Op), MVT::v2f64, V1, V2,
                     DAG.getConstant(SHUFPDMask, MVT::i8));
}

/// \brief Handle lowering of 2-lane 64-bit integer shuffles.
///
/// Tries to lower a 2-lane 64-bit shuffle using shuffle operations provided by
/// the integer unit to minimize domain crossing penalties. However, for blends
/// it falls back to the floating point shuffle operation with appropriate bit
/// casting.
static SDValue lowerV2I64VectorShuffle(SDValue Op, SDValue V1, SDValue V2,
                                       const X86Subtarget *Subtarget,
                                       SelectionDAG &DAG) {
  SDLoc DL(Op);
  assert(Op.getSimpleValueType() == MVT::v2i64 && "Bad shuffle type!");
  assert(V1.getSimpleValueType() == MVT::v2i64 && "Bad operand type!");
  assert(V2.getSimpleValueType() == MVT::v2i64 && "Bad operand type!");
  ShuffleVectorSDNode *SVOp = cast<ShuffleVectorSDNode>(Op);
  ArrayRef<int> Mask = SVOp->getMask();
  assert(Mask.size() == 2 && "Unexpected mask size for v2 shuffle!");

  if (isSingleInputShuffleMask(Mask)) {
    // Check for being able to broadcast a single element.
    if (SDValue Broadcast = lowerVectorShuffleAsBroadcast(MVT::v2i64, DL, V1,
                                                          Mask, Subtarget, DAG))
      return Broadcast;

    // Straight shuffle of a single input vector. For everything from SSE2
    // onward this has a single fast instruction with no scary immediates.
    // We have to map the mask as it is actually a v4i32 shuffle instruction.
    V1 = DAG.getNode(ISD::BITCAST, DL, MVT::v4i32, V1);
    int WidenedMask[4] = {
        std::max(Mask[0], 0) * 2, std::max(Mask[0], 0) * 2 + 1,
        std::max(Mask[1], 0) * 2, std::max(Mask[1], 0) * 2 + 1};
    return DAG.getNode(
        ISD::BITCAST, DL, MVT::v2i64,
        DAG.getNode(X86ISD::PSHUFD, SDLoc(Op), MVT::v4i32, V1,
                    getV4X86ShuffleImm8ForMask(WidenedMask, DAG)));
  }
  assert(Mask[0] != -1 && "No undef lanes in multi-input v2 shuffles!");
  assert(Mask[1] != -1 && "No undef lanes in multi-input v2 shuffles!");
  assert(Mask[0] < 2 && "We sort V1 to be the first input.");
  assert(Mask[1] >= 2 && "We sort V2 to be the second input.");

  // Try to use shift instructions.
  if (SDValue Shift =
          lowerVectorShuffleAsShift(DL, MVT::v2i64, V1, V2, Mask, DAG))
    return Shift;

  // When loading a scalar and then shuffling it into a vector we can often do
  // the insertion cheaply.
  if (SDValue Insertion = lowerVectorShuffleAsElementInsertion(
          MVT::v2i64, DL, V1, V2, Mask, Subtarget, DAG))
    return Insertion;
  // Try inverting the insertion since for v2 masks it is easy to do and we
  // can't reliably sort the mask one way or the other.
  int InverseMask[2] = {Mask[0] ^ 2, Mask[1] ^ 2};
  if (SDValue Insertion = lowerVectorShuffleAsElementInsertion(
          MVT::v2i64, DL, V2, V1, InverseMask, Subtarget, DAG))
    return Insertion;

  // We have different paths for blend lowering, but they all must use the
  // *exact* same predicate.
  bool IsBlendSupported = Subtarget->hasSSE41();
  if (IsBlendSupported)
    if (SDValue Blend = lowerVectorShuffleAsBlend(DL, MVT::v2i64, V1, V2, Mask,
                                                  Subtarget, DAG))
      return Blend;

  // Use dedicated unpack instructions for masks that match their pattern.
  if (isShuffleEquivalent(V1, V2, Mask, 0, 2))
    return DAG.getNode(X86ISD::UNPCKL, DL, MVT::v2i64, V1, V2);
  if (isShuffleEquivalent(V1, V2, Mask, 1, 3))
    return DAG.getNode(X86ISD::UNPCKH, DL, MVT::v2i64, V1, V2);

  // Try to use byte rotation instructions.
  // Its more profitable for pre-SSSE3 to use shuffles/unpacks.
  if (Subtarget->hasSSSE3())
    if (SDValue Rotate = lowerVectorShuffleAsByteRotate(
            DL, MVT::v2i64, V1, V2, Mask, Subtarget, DAG))
      return Rotate;

  // If we have direct support for blends, we should lower by decomposing into
  // a permute. That will be faster than the domain cross.
  if (IsBlendSupported)
    return lowerVectorShuffleAsDecomposedShuffleBlend(DL, MVT::v2i64, V1, V2,
                                                      Mask, DAG);

  // We implement this with SHUFPD which is pretty lame because it will likely
  // incur 2 cycles of stall for integer vectors on Nehalem and older chips.
  // However, all the alternatives are still more cycles and newer chips don't
  // have this problem. It would be really nice if x86 had better shuffles here.
  V1 = DAG.getNode(ISD::BITCAST, DL, MVT::v2f64, V1);
  V2 = DAG.getNode(ISD::BITCAST, DL, MVT::v2f64, V2);
  return DAG.getNode(ISD::BITCAST, DL, MVT::v2i64,
                     DAG.getVectorShuffle(MVT::v2f64, DL, V1, V2, Mask));
}

/// \brief Test whether this can be lowered with a single SHUFPS instruction.
///
/// This is used to disable more specialized lowerings when the shufps lowering
/// will happen to be efficient.
static bool isSingleSHUFPSMask(ArrayRef<int> Mask) {
  // This routine only handles 128-bit shufps.
  assert(Mask.size() == 4 && "Unsupported mask size!");

  // To lower with a single SHUFPS we need to have the low half and high half
  // each requiring a single input.
  if (Mask[0] != -1 && Mask[1] != -1 && (Mask[0] < 4) != (Mask[1] < 4))
    return false;
  if (Mask[2] != -1 && Mask[3] != -1 && (Mask[2] < 4) != (Mask[3] < 4))
    return false;

  return true;
}

/// \brief Lower a vector shuffle using the SHUFPS instruction.
///
/// This is a helper routine dedicated to lowering vector shuffles using SHUFPS.
/// It makes no assumptions about whether this is the *best* lowering, it simply
/// uses it.
static SDValue lowerVectorShuffleWithSHUFPS(SDLoc DL, MVT VT,
                                            ArrayRef<int> Mask, SDValue V1,
                                            SDValue V2, SelectionDAG &DAG) {
  SDValue LowV = V1, HighV = V2;
  int NewMask[4] = {Mask[0], Mask[1], Mask[2], Mask[3]};

  int NumV2Elements =
      std::count_if(Mask.begin(), Mask.end(), [](int M) { return M >= 4; });

  if (NumV2Elements == 1) {
    int V2Index =
        std::find_if(Mask.begin(), Mask.end(), [](int M) { return M >= 4; }) -
        Mask.begin();

    // Compute the index adjacent to V2Index and in the same half by toggling
    // the low bit.
    int V2AdjIndex = V2Index ^ 1;

    if (Mask[V2AdjIndex] == -1) {
      // Handles all the cases where we have a single V2 element and an undef.
      // This will only ever happen in the high lanes because we commute the
      // vector otherwise.
      if (V2Index < 2)
        std::swap(LowV, HighV);
      NewMask[V2Index] -= 4;
    } else {
      // Handle the case where the V2 element ends up adjacent to a V1 element.
      // To make this work, blend them together as the first step.
      int V1Index = V2AdjIndex;
      int BlendMask[4] = {Mask[V2Index] - 4, 0, Mask[V1Index], 0};
      V2 = DAG.getNode(X86ISD::SHUFP, DL, VT, V2, V1,
                       getV4X86ShuffleImm8ForMask(BlendMask, DAG));

      // Now proceed to reconstruct the final blend as we have the necessary
      // high or low half formed.
      if (V2Index < 2) {
        LowV = V2;
        HighV = V1;
      } else {
        HighV = V2;
      }
      NewMask[V1Index] = 2; // We put the V1 element in V2[2].
      NewMask[V2Index] = 0; // We shifted the V2 element into V2[0].
    }
  } else if (NumV2Elements == 2) {
    if (Mask[0] < 4 && Mask[1] < 4) {
      // Handle the easy case where we have V1 in the low lanes and V2 in the
      // high lanes.
      NewMask[2] -= 4;
      NewMask[3] -= 4;
    } else if (Mask[2] < 4 && Mask[3] < 4) {
      // We also handle the reversed case because this utility may get called
      // when we detect a SHUFPS pattern but can't easily commute the shuffle to
      // arrange things in the right direction.
      NewMask[0] -= 4;
      NewMask[1] -= 4;
      HighV = V1;
      LowV = V2;
    } else {
      // We have a mixture of V1 and V2 in both low and high lanes. Rather than
      // trying to place elements directly, just blend them and set up the final
      // shuffle to place them.

      // The first two blend mask elements are for V1, the second two are for
      // V2.
      int BlendMask[4] = {Mask[0] < 4 ? Mask[0] : Mask[1],
                          Mask[2] < 4 ? Mask[2] : Mask[3],
                          (Mask[0] >= 4 ? Mask[0] : Mask[1]) - 4,
                          (Mask[2] >= 4 ? Mask[2] : Mask[3]) - 4};
      V1 = DAG.getNode(X86ISD::SHUFP, DL, VT, V1, V2,
                       getV4X86ShuffleImm8ForMask(BlendMask, DAG));

      // Now we do a normal shuffle of V1 by giving V1 as both operands to
      // a blend.
      LowV = HighV = V1;
      NewMask[0] = Mask[0] < 4 ? 0 : 2;
      NewMask[1] = Mask[0] < 4 ? 2 : 0;
      NewMask[2] = Mask[2] < 4 ? 1 : 3;
      NewMask[3] = Mask[2] < 4 ? 3 : 1;
    }
  }
  return DAG.getNode(X86ISD::SHUFP, DL, VT, LowV, HighV,
                     getV4X86ShuffleImm8ForMask(NewMask, DAG));
}

/// \brief Lower 4-lane 32-bit floating point shuffles.
///
/// Uses instructions exclusively from the floating point unit to minimize
/// domain crossing penalties, as these are sufficient to implement all v4f32
/// shuffles.
static SDValue lowerV4F32VectorShuffle(SDValue Op, SDValue V1, SDValue V2,
                                       const X86Subtarget *Subtarget,
                                       SelectionDAG &DAG) {
  SDLoc DL(Op);
  assert(Op.getSimpleValueType() == MVT::v4f32 && "Bad shuffle type!");
  assert(V1.getSimpleValueType() == MVT::v4f32 && "Bad operand type!");
  assert(V2.getSimpleValueType() == MVT::v4f32 && "Bad operand type!");
  ShuffleVectorSDNode *SVOp = cast<ShuffleVectorSDNode>(Op);
  ArrayRef<int> Mask = SVOp->getMask();
  assert(Mask.size() == 4 && "Unexpected mask size for v4 shuffle!");

  int NumV2Elements =
      std::count_if(Mask.begin(), Mask.end(), [](int M) { return M >= 4; });

  if (NumV2Elements == 0) {
    // Check for being able to broadcast a single element.
    if (SDValue Broadcast = lowerVectorShuffleAsBroadcast(MVT::v4f32, DL, V1,
                                                          Mask, Subtarget, DAG))
      return Broadcast;

    // Use even/odd duplicate instructions for masks that match their pattern.
    if (Subtarget->hasSSE3()) {
      if (isShuffleEquivalent(V1, V2, Mask, 0, 0, 2, 2))
        return DAG.getNode(X86ISD::MOVSLDUP, DL, MVT::v4f32, V1);
      if (isShuffleEquivalent(V1, V2, Mask, 1, 1, 3, 3))
        return DAG.getNode(X86ISD::MOVSHDUP, DL, MVT::v4f32, V1);
    }

    if (Subtarget->hasAVX()) {
      // If we have AVX, we can use VPERMILPS which will allow folding a load
      // into the shuffle.
      return DAG.getNode(X86ISD::VPERMILPI, DL, MVT::v4f32, V1,
                         getV4X86ShuffleImm8ForMask(Mask, DAG));
    }

    // Otherwise, use a straight shuffle of a single input vector. We pass the
    // input vector to both operands to simulate this with a SHUFPS.
    return DAG.getNode(X86ISD::SHUFP, DL, MVT::v4f32, V1, V1,
                       getV4X86ShuffleImm8ForMask(Mask, DAG));
  }

  // There are special ways we can lower some single-element blends. However, we
  // have custom ways we can lower more complex single-element blends below that
  // we defer to if both this and BLENDPS fail to match, so restrict this to
  // when the V2 input is targeting element 0 of the mask -- that is the fast
  // case here.
  if (NumV2Elements == 1 && Mask[0] >= 4)
    if (SDValue V = lowerVectorShuffleAsElementInsertion(MVT::v4f32, DL, V1, V2,
                                                         Mask, Subtarget, DAG))
      return V;

  if (Subtarget->hasSSE41()) {
    if (SDValue Blend = lowerVectorShuffleAsBlend(DL, MVT::v4f32, V1, V2, Mask,
                                                  Subtarget, DAG))
      return Blend;

    // Use INSERTPS if we can complete the shuffle efficiently.
    if (SDValue V = lowerVectorShuffleAsInsertPS(Op, V1, V2, Mask, DAG))
      return V;

    if (!isSingleSHUFPSMask(Mask))
      if (SDValue BlendPerm = lowerVectorShuffleAsBlendAndPermute(
              DL, MVT::v4f32, V1, V2, Mask, DAG))
        return BlendPerm;
  }

  // Use dedicated unpack instructions for masks that match their pattern.
  if (isShuffleEquivalent(V1, V2, Mask, 0, 4, 1, 5))
    return DAG.getNode(X86ISD::UNPCKL, DL, MVT::v4f32, V1, V2);
  if (isShuffleEquivalent(V1, V2, Mask, 2, 6, 3, 7))
    return DAG.getNode(X86ISD::UNPCKH, DL, MVT::v4f32, V1, V2);
  if (isShuffleEquivalent(V1, V2, Mask, 4, 0, 5, 1))
    return DAG.getNode(X86ISD::UNPCKL, DL, MVT::v4f32, V2, V1);
  if (isShuffleEquivalent(V1, V2, Mask, 6, 2, 7, 3))
    return DAG.getNode(X86ISD::UNPCKH, DL, MVT::v4f32, V2, V1);

  // Otherwise fall back to a SHUFPS lowering strategy.
  return lowerVectorShuffleWithSHUFPS(DL, MVT::v4f32, Mask, V1, V2, DAG);
}

/// \brief Lower 4-lane i32 vector shuffles.
///
/// We try to handle these with integer-domain shuffles where we can, but for
/// blends we use the floating point domain blend instructions.
static SDValue lowerV4I32VectorShuffle(SDValue Op, SDValue V1, SDValue V2,
                                       const X86Subtarget *Subtarget,
                                       SelectionDAG &DAG) {
  SDLoc DL(Op);
  assert(Op.getSimpleValueType() == MVT::v4i32 && "Bad shuffle type!");
  assert(V1.getSimpleValueType() == MVT::v4i32 && "Bad operand type!");
  assert(V2.getSimpleValueType() == MVT::v4i32 && "Bad operand type!");
  ShuffleVectorSDNode *SVOp = cast<ShuffleVectorSDNode>(Op);
  ArrayRef<int> Mask = SVOp->getMask();
  assert(Mask.size() == 4 && "Unexpected mask size for v4 shuffle!");

  // Whenever we can lower this as a zext, that instruction is strictly faster
  // than any alternative. It also allows us to fold memory operands into the
  // shuffle in many cases.
  if (SDValue ZExt = lowerVectorShuffleAsZeroOrAnyExtend(DL, MVT::v4i32, V1, V2,
                                                         Mask, Subtarget, DAG))
    return ZExt;

  int NumV2Elements =
      std::count_if(Mask.begin(), Mask.end(), [](int M) { return M >= 4; });

  if (NumV2Elements == 0) {
    // Check for being able to broadcast a single element.
    if (SDValue Broadcast = lowerVectorShuffleAsBroadcast(MVT::v4i32, DL, V1,
                                                          Mask, Subtarget, DAG))
      return Broadcast;

    // Straight shuffle of a single input vector. For everything from SSE2
    // onward this has a single fast instruction with no scary immediates.
    // We coerce the shuffle pattern to be compatible with UNPCK instructions
    // but we aren't actually going to use the UNPCK instruction because doing
    // so prevents folding a load into this instruction or making a copy.
    const int UnpackLoMask[] = {0, 0, 1, 1};
    const int UnpackHiMask[] = {2, 2, 3, 3};
    if (isShuffleEquivalent(V1, V2, Mask, 0, 0, 1, 1))
      Mask = UnpackLoMask;
    else if (isShuffleEquivalent(V1, V2, Mask, 2, 2, 3, 3))
      Mask = UnpackHiMask;

    return DAG.getNode(X86ISD::PSHUFD, DL, MVT::v4i32, V1,
                       getV4X86ShuffleImm8ForMask(Mask, DAG));
  }

  // Try to use shift instructions.
  if (SDValue Shift =
          lowerVectorShuffleAsShift(DL, MVT::v4i32, V1, V2, Mask, DAG))
    return Shift;

  // There are special ways we can lower some single-element blends.
  if (NumV2Elements == 1)
    if (SDValue V = lowerVectorShuffleAsElementInsertion(MVT::v4i32, DL, V1, V2,
                                                         Mask, Subtarget, DAG))
      return V;

  // We have different paths for blend lowering, but they all must use the
  // *exact* same predicate.
  bool IsBlendSupported = Subtarget->hasSSE41();
  if (IsBlendSupported)
    if (SDValue Blend = lowerVectorShuffleAsBlend(DL, MVT::v4i32, V1, V2, Mask,
                                                  Subtarget, DAG))
      return Blend;

  if (SDValue Masked =
          lowerVectorShuffleAsBitMask(DL, MVT::v4i32, V1, V2, Mask, DAG))
    return Masked;

  // Use dedicated unpack instructions for masks that match their pattern.
  if (isShuffleEquivalent(V1, V2, Mask, 0, 4, 1, 5))
    return DAG.getNode(X86ISD::UNPCKL, DL, MVT::v4i32, V1, V2);
  if (isShuffleEquivalent(V1, V2, Mask, 2, 6, 3, 7))
    return DAG.getNode(X86ISD::UNPCKH, DL, MVT::v4i32, V1, V2);
  if (isShuffleEquivalent(V1, V2, Mask, 4, 0, 5, 1))
    return DAG.getNode(X86ISD::UNPCKL, DL, MVT::v4i32, V2, V1);
  if (isShuffleEquivalent(V1, V2, Mask, 6, 2, 7, 3))
    return DAG.getNode(X86ISD::UNPCKH, DL, MVT::v4i32, V2, V1);

  // Try to use byte rotation instructions.
  // Its more profitable for pre-SSSE3 to use shuffles/unpacks.
  if (Subtarget->hasSSSE3())
    if (SDValue Rotate = lowerVectorShuffleAsByteRotate(
            DL, MVT::v4i32, V1, V2, Mask, Subtarget, DAG))
      return Rotate;

  // If we have direct support for blends, we should lower by decomposing into
  // a permute. That will be faster than the domain cross.
  if (IsBlendSupported)
    return lowerVectorShuffleAsDecomposedShuffleBlend(DL, MVT::v4i32, V1, V2,
                                                      Mask, DAG);

  // Try to lower by permuting the inputs into an unpack instruction.
  if (SDValue Unpack =
          lowerVectorShuffleAsUnpack(MVT::v4i32, DL, V1, V2, Mask, DAG))
    return Unpack;

  // We implement this with SHUFPS because it can blend from two vectors.
  // Because we're going to eventually use SHUFPS, we use SHUFPS even to build
  // up the inputs, bypassing domain shift penalties that we would encur if we
  // directly used PSHUFD on Nehalem and older. For newer chips, this isn't
  // relevant.
  return DAG.getNode(ISD::BITCAST, DL, MVT::v4i32,
                     DAG.getVectorShuffle(
                         MVT::v4f32, DL,
                         DAG.getNode(ISD::BITCAST, DL, MVT::v4f32, V1),
                         DAG.getNode(ISD::BITCAST, DL, MVT::v4f32, V2), Mask));
}

/// \brief Lowering of single-input v8i16 shuffles is the cornerstone of SSE2
/// shuffle lowering, and the most complex part.
///
/// The lowering strategy is to try to form pairs of input lanes which are
/// targeted at the same half of the final vector, and then use a dword shuffle
/// to place them onto the right half, and finally unpack the paired lanes into
/// their final position.
///
/// The exact breakdown of how to form these dword pairs and align them on the
/// correct sides is really tricky. See the comments within the function for
/// more of the details.
static SDValue lowerV8I16SingleInputVectorShuffle(
    SDLoc DL, SDValue V, MutableArrayRef<int> Mask,
    const X86Subtarget *Subtarget, SelectionDAG &DAG) {
  assert(V.getSimpleValueType() == MVT::v8i16 && "Bad input type!");
  MutableArrayRef<int> LoMask = Mask.slice(0, 4);
  MutableArrayRef<int> HiMask = Mask.slice(4, 4);

  SmallVector<int, 4> LoInputs;
  std::copy_if(LoMask.begin(), LoMask.end(), std::back_inserter(LoInputs),
               [](int M) { return M >= 0; });
  std::sort(LoInputs.begin(), LoInputs.end());
  LoInputs.erase(std::unique(LoInputs.begin(), LoInputs.end()), LoInputs.end());
  SmallVector<int, 4> HiInputs;
  std::copy_if(HiMask.begin(), HiMask.end(), std::back_inserter(HiInputs),
               [](int M) { return M >= 0; });
  std::sort(HiInputs.begin(), HiInputs.end());
  HiInputs.erase(std::unique(HiInputs.begin(), HiInputs.end()), HiInputs.end());
  int NumLToL =
      std::lower_bound(LoInputs.begin(), LoInputs.end(), 4) - LoInputs.begin();
  int NumHToL = LoInputs.size() - NumLToL;
  int NumLToH =
      std::lower_bound(HiInputs.begin(), HiInputs.end(), 4) - HiInputs.begin();
  int NumHToH = HiInputs.size() - NumLToH;
  MutableArrayRef<int> LToLInputs(LoInputs.data(), NumLToL);
  MutableArrayRef<int> LToHInputs(HiInputs.data(), NumLToH);
  MutableArrayRef<int> HToLInputs(LoInputs.data() + NumLToL, NumHToL);
  MutableArrayRef<int> HToHInputs(HiInputs.data() + NumLToH, NumHToH);

  // Check for being able to broadcast a single element.
  if (SDValue Broadcast = lowerVectorShuffleAsBroadcast(MVT::v8i16, DL, V,
                                                        Mask, Subtarget, DAG))
    return Broadcast;

  // Try to use shift instructions.
  if (SDValue Shift =
          lowerVectorShuffleAsShift(DL, MVT::v8i16, V, V, Mask, DAG))
    return Shift;

  // Use dedicated unpack instructions for masks that match their pattern.
  if (isShuffleEquivalent(V, V, Mask, 0, 0, 1, 1, 2, 2, 3, 3))
    return DAG.getNode(X86ISD::UNPCKL, DL, MVT::v8i16, V, V);
  if (isShuffleEquivalent(V, V, Mask, 4, 4, 5, 5, 6, 6, 7, 7))
    return DAG.getNode(X86ISD::UNPCKH, DL, MVT::v8i16, V, V);

  // Try to use byte rotation instructions.
  if (SDValue Rotate = lowerVectorShuffleAsByteRotate(
          DL, MVT::v8i16, V, V, Mask, Subtarget, DAG))
    return Rotate;

  // Simplify the 1-into-3 and 3-into-1 cases with a single pshufd. For all
  // such inputs we can swap two of the dwords across the half mark and end up
  // with <=2 inputs to each half in each half. Once there, we can fall through
  // to the generic code below. For example:
  //
  // Input: [a, b, c, d, e, f, g, h] -PSHUFD[0,2,1,3]-> [a, b, e, f, c, d, g, h]
  // Mask:  [0, 1, 2, 7, 4, 5, 6, 3] -----------------> [0, 1, 4, 7, 2, 3, 6, 5]
  //
  // However in some very rare cases we have a 1-into-3 or 3-into-1 on one half
  // and an existing 2-into-2 on the other half. In this case we may have to
  // pre-shuffle the 2-into-2 half to avoid turning it into a 3-into-1 or
  // 1-into-3 which could cause us to cycle endlessly fixing each side in turn.
  // Fortunately, we don't have to handle anything but a 2-into-2 pattern
  // because any other situation (including a 3-into-1 or 1-into-3 in the other
  // half than the one we target for fixing) will be fixed when we re-enter this
  // path. We will also combine away any sequence of PSHUFD instructions that
  // result into a single instruction. Here is an example of the tricky case:
  //
  // Input: [a, b, c, d, e, f, g, h] -PSHUFD[0,2,1,3]-> [a, b, e, f, c, d, g, h]
  // Mask:  [3, 7, 1, 0, 2, 7, 3, 5] -THIS-IS-BAD!!!!-> [5, 7, 1, 0, 4, 7, 5, 3]
  //
  // This now has a 1-into-3 in the high half! Instead, we do two shuffles:
  //
  // Input: [a, b, c, d, e, f, g, h] PSHUFHW[0,2,1,3]-> [a, b, c, d, e, g, f, h]
  // Mask:  [3, 7, 1, 0, 2, 7, 3, 5] -----------------> [3, 7, 1, 0, 2, 7, 3, 6]
  //
  // Input: [a, b, c, d, e, g, f, h] -PSHUFD[0,2,1,3]-> [a, b, e, g, c, d, f, h]
  // Mask:  [3, 7, 1, 0, 2, 7, 3, 6] -----------------> [5, 7, 1, 0, 4, 7, 5, 6]
  //
  // The result is fine to be handled by the generic logic.
  auto balanceSides = [&](ArrayRef<int> AToAInputs, ArrayRef<int> BToAInputs,
                          ArrayRef<int> BToBInputs, ArrayRef<int> AToBInputs,
                          int AOffset, int BOffset) {
    assert((AToAInputs.size() == 3 || AToAInputs.size() == 1) &&
           "Must call this with A having 3 or 1 inputs from the A half.");
    assert((BToAInputs.size() == 1 || BToAInputs.size() == 3) &&
           "Must call this with B having 1 or 3 inputs from the B half.");
    assert(AToAInputs.size() + BToAInputs.size() == 4 &&
           "Must call this with either 3:1 or 1:3 inputs (summing to 4).");

    // Compute the index of dword with only one word among the three inputs in
    // a half by taking the sum of the half with three inputs and subtracting
    // the sum of the actual three inputs. The difference is the remaining
    // slot.
    int ADWord, BDWord;
    int &TripleDWord = AToAInputs.size() == 3 ? ADWord : BDWord;
    int &OneInputDWord = AToAInputs.size() == 3 ? BDWord : ADWord;
    int TripleInputOffset = AToAInputs.size() == 3 ? AOffset : BOffset;
    ArrayRef<int> TripleInputs = AToAInputs.size() == 3 ? AToAInputs : BToAInputs;
    int OneInput = AToAInputs.size() == 3 ? BToAInputs[0] : AToAInputs[0];
    int TripleInputSum = 0 + 1 + 2 + 3 + (4 * TripleInputOffset);
    int TripleNonInputIdx =
        TripleInputSum - std::accumulate(TripleInputs.begin(), TripleInputs.end(), 0);
    TripleDWord = TripleNonInputIdx / 2;

    // We use xor with one to compute the adjacent DWord to whichever one the
    // OneInput is in.
    OneInputDWord = (OneInput / 2) ^ 1;

    // Check for one tricky case: We're fixing a 3<-1 or a 1<-3 shuffle for AToA
    // and BToA inputs. If there is also such a problem with the BToB and AToB
    // inputs, we don't try to fix it necessarily -- we'll recurse and see it in
    // the next pass. However, if we have a 2<-2 in the BToB and AToB inputs, it
    // is essential that we don't *create* a 3<-1 as then we might oscillate.
    if (BToBInputs.size() == 2 && AToBInputs.size() == 2) {
      // Compute how many inputs will be flipped by swapping these DWords. We
      // need
      // to balance this to ensure we don't form a 3-1 shuffle in the other
      // half.
      int NumFlippedAToBInputs =
          std::count(AToBInputs.begin(), AToBInputs.end(), 2 * ADWord) +
          std::count(AToBInputs.begin(), AToBInputs.end(), 2 * ADWord + 1);
      int NumFlippedBToBInputs =
          std::count(BToBInputs.begin(), BToBInputs.end(), 2 * BDWord) +
          std::count(BToBInputs.begin(), BToBInputs.end(), 2 * BDWord + 1);
      if ((NumFlippedAToBInputs == 1 &&
           (NumFlippedBToBInputs == 0 || NumFlippedBToBInputs == 2)) ||
          (NumFlippedBToBInputs == 1 &&
           (NumFlippedAToBInputs == 0 || NumFlippedAToBInputs == 2))) {
        // We choose whether to fix the A half or B half based on whether that
        // half has zero flipped inputs. At zero, we may not be able to fix it
        // with that half. We also bias towards fixing the B half because that
        // will more commonly be the high half, and we have to bias one way.
        auto FixFlippedInputs = [&V, &DL, &Mask, &DAG](int PinnedIdx, int DWord,
                                                       ArrayRef<int> Inputs) {
          int FixIdx = PinnedIdx ^ 1; // The adjacent slot to the pinned slot.
          bool IsFixIdxInput = std::find(Inputs.begin(), Inputs.end(),
                                         PinnedIdx ^ 1) != Inputs.end();
          // Determine whether the free index is in the flipped dword or the
          // unflipped dword based on where the pinned index is. We use this bit
          // in an xor to conditionally select the adjacent dword.
          int FixFreeIdx = 2 * (DWord ^ (PinnedIdx / 2 == DWord));
          bool IsFixFreeIdxInput = std::find(Inputs.begin(), Inputs.end(),
                                             FixFreeIdx) != Inputs.end();
          if (IsFixIdxInput == IsFixFreeIdxInput)
            FixFreeIdx += 1;
          IsFixFreeIdxInput = std::find(Inputs.begin(), Inputs.end(),
                                        FixFreeIdx) != Inputs.end();
          assert(IsFixIdxInput != IsFixFreeIdxInput &&
                 "We need to be changing the number of flipped inputs!");
          int PSHUFHalfMask[] = {0, 1, 2, 3};
          std::swap(PSHUFHalfMask[FixFreeIdx % 4], PSHUFHalfMask[FixIdx % 4]);
          V = DAG.getNode(FixIdx < 4 ? X86ISD::PSHUFLW : X86ISD::PSHUFHW, DL,
                          MVT::v8i16, V,
                          getV4X86ShuffleImm8ForMask(PSHUFHalfMask, DAG));

          for (int &M : Mask)
            if (M != -1 && M == FixIdx)
              M = FixFreeIdx;
            else if (M != -1 && M == FixFreeIdx)
              M = FixIdx;
        };
        if (NumFlippedBToBInputs != 0) {
          int BPinnedIdx =
              BToAInputs.size() == 3 ? TripleNonInputIdx : OneInput;
          FixFlippedInputs(BPinnedIdx, BDWord, BToBInputs);
        } else {
          assert(NumFlippedAToBInputs != 0 && "Impossible given predicates!");
          int APinnedIdx =
              AToAInputs.size() == 3 ? TripleNonInputIdx : OneInput;
          FixFlippedInputs(APinnedIdx, ADWord, AToBInputs);
        }
      }
    }

    int PSHUFDMask[] = {0, 1, 2, 3};
    PSHUFDMask[ADWord] = BDWord;
    PSHUFDMask[BDWord] = ADWord;
    V = DAG.getNode(ISD::BITCAST, DL, MVT::v8i16,
                    DAG.getNode(X86ISD::PSHUFD, DL, MVT::v4i32,
                                DAG.getNode(ISD::BITCAST, DL, MVT::v4i32, V),
                                getV4X86ShuffleImm8ForMask(PSHUFDMask, DAG)));

    // Adjust the mask to match the new locations of A and B.
    for (int &M : Mask)
      if (M != -1 && M/2 == ADWord)
        M = 2 * BDWord + M % 2;
      else if (M != -1 && M/2 == BDWord)
        M = 2 * ADWord + M % 2;

    // Recurse back into this routine to re-compute state now that this isn't
    // a 3 and 1 problem.
    return DAG.getVectorShuffle(MVT::v8i16, DL, V, DAG.getUNDEF(MVT::v8i16),
                                Mask);
  };
  if ((NumLToL == 3 && NumHToL == 1) || (NumLToL == 1 && NumHToL == 3))
    return balanceSides(LToLInputs, HToLInputs, HToHInputs, LToHInputs, 0, 4);
  else if ((NumHToH == 3 && NumLToH == 1) || (NumHToH == 1 && NumLToH == 3))
    return balanceSides(HToHInputs, LToHInputs, LToLInputs, HToLInputs, 4, 0);

  // At this point there are at most two inputs to the low and high halves from
  // each half. That means the inputs can always be grouped into dwords and
  // those dwords can then be moved to the correct half with a dword shuffle.
  // We use at most one low and one high word shuffle to collect these paired
  // inputs into dwords, and finally a dword shuffle to place them.
  int PSHUFLMask[4] = {-1, -1, -1, -1};
  int PSHUFHMask[4] = {-1, -1, -1, -1};
  int PSHUFDMask[4] = {-1, -1, -1, -1};

  // First fix the masks for all the inputs that are staying in their
  // original halves. This will then dictate the targets of the cross-half
  // shuffles.
  auto fixInPlaceInputs =
      [&PSHUFDMask](ArrayRef<int> InPlaceInputs, ArrayRef<int> IncomingInputs,
                    MutableArrayRef<int> SourceHalfMask,
                    MutableArrayRef<int> HalfMask, int HalfOffset) {
    if (InPlaceInputs.empty())
      return;
    if (InPlaceInputs.size() == 1) {
      SourceHalfMask[InPlaceInputs[0] - HalfOffset] =
          InPlaceInputs[0] - HalfOffset;
      PSHUFDMask[InPlaceInputs[0] / 2] = InPlaceInputs[0] / 2;
      return;
    }
    if (IncomingInputs.empty()) {
      // Just fix all of the in place inputs.
      for (int Input : InPlaceInputs) {
        SourceHalfMask[Input - HalfOffset] = Input - HalfOffset;
        PSHUFDMask[Input / 2] = Input / 2;
      }
      return;
    }

    assert(InPlaceInputs.size() == 2 && "Cannot handle 3 or 4 inputs!");
    SourceHalfMask[InPlaceInputs[0] - HalfOffset] =
        InPlaceInputs[0] - HalfOffset;
    // Put the second input next to the first so that they are packed into
    // a dword. We find the adjacent index by toggling the low bit.
    int AdjIndex = InPlaceInputs[0] ^ 1;
    SourceHalfMask[AdjIndex - HalfOffset] = InPlaceInputs[1] - HalfOffset;
    std::replace(HalfMask.begin(), HalfMask.end(), InPlaceInputs[1], AdjIndex);
    PSHUFDMask[AdjIndex / 2] = AdjIndex / 2;
  };
  fixInPlaceInputs(LToLInputs, HToLInputs, PSHUFLMask, LoMask, 0);
  fixInPlaceInputs(HToHInputs, LToHInputs, PSHUFHMask, HiMask, 4);

  // Now gather the cross-half inputs and place them into a free dword of
  // their target half.
  // FIXME: This operation could almost certainly be simplified dramatically to
  // look more like the 3-1 fixing operation.
  auto moveInputsToRightHalf = [&PSHUFDMask](
      MutableArrayRef<int> IncomingInputs, ArrayRef<int> ExistingInputs,
      MutableArrayRef<int> SourceHalfMask, MutableArrayRef<int> HalfMask,
      MutableArrayRef<int> FinalSourceHalfMask, int SourceOffset,
      int DestOffset) {
    auto isWordClobbered = [](ArrayRef<int> SourceHalfMask, int Word) {
      return SourceHalfMask[Word] != -1 && SourceHalfMask[Word] != Word;
    };
    auto isDWordClobbered = [&isWordClobbered](ArrayRef<int> SourceHalfMask,
                                               int Word) {
      int LowWord = Word & ~1;
      int HighWord = Word | 1;
      return isWordClobbered(SourceHalfMask, LowWord) ||
             isWordClobbered(SourceHalfMask, HighWord);
    };

    if (IncomingInputs.empty())
      return;

    if (ExistingInputs.empty()) {
      // Map any dwords with inputs from them into the right half.
      for (int Input : IncomingInputs) {
        // If the source half mask maps over the inputs, turn those into
        // swaps and use the swapped lane.
        if (isWordClobbered(SourceHalfMask, Input - SourceOffset)) {
          if (SourceHalfMask[SourceHalfMask[Input - SourceOffset]] == -1) {
            SourceHalfMask[SourceHalfMask[Input - SourceOffset]] =
                Input - SourceOffset;
            // We have to swap the uses in our half mask in one sweep.
            for (int &M : HalfMask)
              if (M == SourceHalfMask[Input - SourceOffset] + SourceOffset)
                M = Input;
              else if (M == Input)
                M = SourceHalfMask[Input - SourceOffset] + SourceOffset;
          } else {
            assert(SourceHalfMask[SourceHalfMask[Input - SourceOffset]] ==
                       Input - SourceOffset &&
                   "Previous placement doesn't match!");
          }
          // Note that this correctly re-maps both when we do a swap and when
          // we observe the other side of the swap above. We rely on that to
          // avoid swapping the members of the input list directly.
          Input = SourceHalfMask[Input - SourceOffset] + SourceOffset;
        }

        // Map the input's dword into the correct half.
        if (PSHUFDMask[(Input - SourceOffset + DestOffset) / 2] == -1)
          PSHUFDMask[(Input - SourceOffset + DestOffset) / 2] = Input / 2;
        else
          assert(PSHUFDMask[(Input - SourceOffset + DestOffset) / 2] ==
                     Input / 2 &&
                 "Previous placement doesn't match!");
      }

      // And just directly shift any other-half mask elements to be same-half
      // as we will have mirrored the dword containing the element into the
      // same position within that half.
      for (int &M : HalfMask)
        if (M >= SourceOffset && M < SourceOffset + 4) {
          M = M - SourceOffset + DestOffset;
          assert(M >= 0 && "This should never wrap below zero!");
        }
      return;
    }

    // Ensure we have the input in a viable dword of its current half. This
    // is particularly tricky because the original position may be clobbered
    // by inputs being moved and *staying* in that half.
    if (IncomingInputs.size() == 1) {
      if (isWordClobbered(SourceHalfMask, IncomingInputs[0] - SourceOffset)) {
        int InputFixed = std::find(std::begin(SourceHalfMask),
                                   std::end(SourceHalfMask), -1) -
                         std::begin(SourceHalfMask) + SourceOffset;
        SourceHalfMask[InputFixed - SourceOffset] =
            IncomingInputs[0] - SourceOffset;
        std::replace(HalfMask.begin(), HalfMask.end(), IncomingInputs[0],
                     InputFixed);
        IncomingInputs[0] = InputFixed;
      }
    } else if (IncomingInputs.size() == 2) {
      if (IncomingInputs[0] / 2 != IncomingInputs[1] / 2 ||
          isDWordClobbered(SourceHalfMask, IncomingInputs[0] - SourceOffset)) {
        // We have two non-adjacent or clobbered inputs we need to extract from
        // the source half. To do this, we need to map them into some adjacent
        // dword slot in the source mask.
        int InputsFixed[2] = {IncomingInputs[0] - SourceOffset,
                              IncomingInputs[1] - SourceOffset};

        // If there is a free slot in the source half mask adjacent to one of
        // the inputs, place the other input in it. We use (Index XOR 1) to
        // compute an adjacent index.
        if (!isWordClobbered(SourceHalfMask, InputsFixed[0]) &&
            SourceHalfMask[InputsFixed[0] ^ 1] == -1) {
          SourceHalfMask[InputsFixed[0]] = InputsFixed[0];
          SourceHalfMask[InputsFixed[0] ^ 1] = InputsFixed[1];
          InputsFixed[1] = InputsFixed[0] ^ 1;
        } else if (!isWordClobbered(SourceHalfMask, InputsFixed[1]) &&
                   SourceHalfMask[InputsFixed[1] ^ 1] == -1) {
          SourceHalfMask[InputsFixed[1]] = InputsFixed[1];
          SourceHalfMask[InputsFixed[1] ^ 1] = InputsFixed[0];
          InputsFixed[0] = InputsFixed[1] ^ 1;
        } else if (SourceHalfMask[2 * ((InputsFixed[0] / 2) ^ 1)] == -1 &&
                   SourceHalfMask[2 * ((InputsFixed[0] / 2) ^ 1) + 1] == -1) {
          // The two inputs are in the same DWord but it is clobbered and the
          // adjacent DWord isn't used at all. Move both inputs to the free
          // slot.
          SourceHalfMask[2 * ((InputsFixed[0] / 2) ^ 1)] = InputsFixed[0];
          SourceHalfMask[2 * ((InputsFixed[0] / 2) ^ 1) + 1] = InputsFixed[1];
          InputsFixed[0] = 2 * ((InputsFixed[0] / 2) ^ 1);
          InputsFixed[1] = 2 * ((InputsFixed[0] / 2) ^ 1) + 1;
        } else {
          // The only way we hit this point is if there is no clobbering
          // (because there are no off-half inputs to this half) and there is no
          // free slot adjacent to one of the inputs. In this case, we have to
          // swap an input with a non-input.
          for (int i = 0; i < 4; ++i)
            assert((SourceHalfMask[i] == -1 || SourceHalfMask[i] == i) &&
                   "We can't handle any clobbers here!");
          assert(InputsFixed[1] != (InputsFixed[0] ^ 1) &&
                 "Cannot have adjacent inputs here!");

          SourceHalfMask[InputsFixed[0] ^ 1] = InputsFixed[1];
          SourceHalfMask[InputsFixed[1]] = InputsFixed[0] ^ 1;

          // We also have to update the final source mask in this case because
          // it may need to undo the above swap.
          for (int &M : FinalSourceHalfMask)
            if (M == (InputsFixed[0] ^ 1) + SourceOffset)
              M = InputsFixed[1] + SourceOffset;
            else if (M == InputsFixed[1] + SourceOffset)
              M = (InputsFixed[0] ^ 1) + SourceOffset;

          InputsFixed[1] = InputsFixed[0] ^ 1;
        }

        // Point everything at the fixed inputs.
        for (int &M : HalfMask)
          if (M == IncomingInputs[0])
            M = InputsFixed[0] + SourceOffset;
          else if (M == IncomingInputs[1])
            M = InputsFixed[1] + SourceOffset;

        IncomingInputs[0] = InputsFixed[0] + SourceOffset;
        IncomingInputs[1] = InputsFixed[1] + SourceOffset;
      }
    } else {
      llvm_unreachable("Unhandled input size!");
    }

    // Now hoist the DWord down to the right half.
    int FreeDWord = (PSHUFDMask[DestOffset / 2] == -1 ? 0 : 1) + DestOffset / 2;
    assert(PSHUFDMask[FreeDWord] == -1 && "DWord not free");
    PSHUFDMask[FreeDWord] = IncomingInputs[0] / 2;
    for (int &M : HalfMask)
      for (int Input : IncomingInputs)
        if (M == Input)
          M = FreeDWord * 2 + Input % 2;
  };
  moveInputsToRightHalf(HToLInputs, LToLInputs, PSHUFHMask, LoMask, HiMask,
                        /*SourceOffset*/ 4, /*DestOffset*/ 0);
  moveInputsToRightHalf(LToHInputs, HToHInputs, PSHUFLMask, HiMask, LoMask,
                        /*SourceOffset*/ 0, /*DestOffset*/ 4);

  // Now enact all the shuffles we've computed to move the inputs into their
  // target half.
  if (!isNoopShuffleMask(PSHUFLMask))
    V = DAG.getNode(X86ISD::PSHUFLW, DL, MVT::v8i16, V,
                    getV4X86ShuffleImm8ForMask(PSHUFLMask, DAG));
  if (!isNoopShuffleMask(PSHUFHMask))
    V = DAG.getNode(X86ISD::PSHUFHW, DL, MVT::v8i16, V,
                    getV4X86ShuffleImm8ForMask(PSHUFHMask, DAG));
  if (!isNoopShuffleMask(PSHUFDMask))
    V = DAG.getNode(ISD::BITCAST, DL, MVT::v8i16,
                    DAG.getNode(X86ISD::PSHUFD, DL, MVT::v4i32,
                                DAG.getNode(ISD::BITCAST, DL, MVT::v4i32, V),
                                getV4X86ShuffleImm8ForMask(PSHUFDMask, DAG)));

  // At this point, each half should contain all its inputs, and we can then
  // just shuffle them into their final position.
  assert(std::count_if(LoMask.begin(), LoMask.end(),
                       [](int M) { return M >= 4; }) == 0 &&
         "Failed to lift all the high half inputs to the low mask!");
  assert(std::count_if(HiMask.begin(), HiMask.end(),
                       [](int M) { return M >= 0 && M < 4; }) == 0 &&
         "Failed to lift all the low half inputs to the high mask!");

  // Do a half shuffle for the low mask.
  if (!isNoopShuffleMask(LoMask))
    V = DAG.getNode(X86ISD::PSHUFLW, DL, MVT::v8i16, V,
                    getV4X86ShuffleImm8ForMask(LoMask, DAG));

  // Do a half shuffle with the high mask after shifting its values down.
  for (int &M : HiMask)
    if (M >= 0)
      M -= 4;
  if (!isNoopShuffleMask(HiMask))
    V = DAG.getNode(X86ISD::PSHUFHW, DL, MVT::v8i16, V,
                    getV4X86ShuffleImm8ForMask(HiMask, DAG));

  return V;
}

/// \brief Detect whether the mask pattern should be lowered through
/// interleaving.
///
/// This essentially tests whether viewing the mask as an interleaving of two
/// sub-sequences reduces the cross-input traffic of a blend operation. If so,
/// lowering it through interleaving is a significantly better strategy.
static bool shouldLowerAsInterleaving(ArrayRef<int> Mask) {
  int NumEvenInputs[2] = {0, 0};
  int NumOddInputs[2] = {0, 0};
  int NumLoInputs[2] = {0, 0};
  int NumHiInputs[2] = {0, 0};
  for (int i = 0, Size = Mask.size(); i < Size; ++i) {
    if (Mask[i] < 0)
      continue;

    int InputIdx = Mask[i] >= Size;

    if (i < Size / 2)
      ++NumLoInputs[InputIdx];
    else
      ++NumHiInputs[InputIdx];

    if ((i % 2) == 0)
      ++NumEvenInputs[InputIdx];
    else
      ++NumOddInputs[InputIdx];
  }

  // The minimum number of cross-input results for both the interleaved and
  // split cases. If interleaving results in fewer cross-input results, return
  // true.
  int InterleavedCrosses = std::min(NumEvenInputs[1] + NumOddInputs[0],
                                    NumEvenInputs[0] + NumOddInputs[1]);
  int SplitCrosses = std::min(NumLoInputs[1] + NumHiInputs[0],
                              NumLoInputs[0] + NumHiInputs[1]);
  return InterleavedCrosses < SplitCrosses;
}

/// \brief Blend two v8i16 vectors using a naive unpack strategy.
///
/// This strategy only works when the inputs from each vector fit into a single
/// half of that vector, and generally there are not so many inputs as to leave
/// the in-place shuffles required highly constrained (and thus expensive). It
/// shifts all the inputs into a single side of both input vectors and then
/// uses an unpack to interleave these inputs in a single vector. At that
/// point, we will fall back on the generic single input shuffle lowering.
static SDValue lowerV8I16BasicBlendVectorShuffle(SDLoc DL, SDValue V1,
                                                 SDValue V2,
                                                 MutableArrayRef<int> Mask,
                                                 const X86Subtarget *Subtarget,
                                                 SelectionDAG &DAG) {
  assert(V1.getSimpleValueType() == MVT::v8i16 && "Bad input type!");
  assert(V2.getSimpleValueType() == MVT::v8i16 && "Bad input type!");
  SmallVector<int, 3> LoV1Inputs, HiV1Inputs, LoV2Inputs, HiV2Inputs;
  for (int i = 0; i < 8; ++i)
    if (Mask[i] >= 0 && Mask[i] < 4)
      LoV1Inputs.push_back(i);
    else if (Mask[i] >= 4 && Mask[i] < 8)
      HiV1Inputs.push_back(i);
    else if (Mask[i] >= 8 && Mask[i] < 12)
      LoV2Inputs.push_back(i);
    else if (Mask[i] >= 12)
      HiV2Inputs.push_back(i);

  int NumV1Inputs = LoV1Inputs.size() + HiV1Inputs.size();
  int NumV2Inputs = LoV2Inputs.size() + HiV2Inputs.size();
  (void)NumV1Inputs;
  (void)NumV2Inputs;
  assert(NumV1Inputs > 0 && NumV1Inputs <= 3 && "At most 3 inputs supported");
  assert(NumV2Inputs > 0 && NumV2Inputs <= 3 && "At most 3 inputs supported");
  assert(NumV1Inputs + NumV2Inputs <= 4 && "At most 4 combined inputs");

  bool MergeFromLo = LoV1Inputs.size() + LoV2Inputs.size() >=
                     HiV1Inputs.size() + HiV2Inputs.size();

  auto moveInputsToHalf = [&](SDValue V, ArrayRef<int> LoInputs,
                              ArrayRef<int> HiInputs, bool MoveToLo,
                              int MaskOffset) {
    ArrayRef<int> GoodInputs = MoveToLo ? LoInputs : HiInputs;
    ArrayRef<int> BadInputs = MoveToLo ? HiInputs : LoInputs;
    if (BadInputs.empty())
      return V;

    int MoveMask[] = {-1, -1, -1, -1, -1, -1, -1, -1};
    int MoveOffset = MoveToLo ? 0 : 4;

    if (GoodInputs.empty()) {
      for (int BadInput : BadInputs) {
        MoveMask[Mask[BadInput] % 4 + MoveOffset] = Mask[BadInput] - MaskOffset;
        Mask[BadInput] = Mask[BadInput] % 4 + MoveOffset + MaskOffset;
      }
    } else {
      if (GoodInputs.size() == 2) {
        // If the low inputs are spread across two dwords, pack them into
        // a single dword.
        MoveMask[MoveOffset] = Mask[GoodInputs[0]] - MaskOffset;
        MoveMask[MoveOffset + 1] = Mask[GoodInputs[1]] - MaskOffset;
        Mask[GoodInputs[0]] = MoveOffset + MaskOffset;
        Mask[GoodInputs[1]] = MoveOffset + 1 + MaskOffset;
      } else {
        // Otherwise pin the good inputs.
        for (int GoodInput : GoodInputs)
          MoveMask[Mask[GoodInput] - MaskOffset] = Mask[GoodInput] - MaskOffset;
      }

      if (BadInputs.size() == 2) {
        // If we have two bad inputs then there may be either one or two good
        // inputs fixed in place. Find a fixed input, and then find the *other*
        // two adjacent indices by using modular arithmetic.
        int GoodMaskIdx =
            std::find_if(std::begin(MoveMask) + MoveOffset, std::end(MoveMask),
                         [](int M) { return M >= 0; }) -
            std::begin(MoveMask);
        int MoveMaskIdx =
            ((((GoodMaskIdx - MoveOffset) & ~1) + 2) % 4) + MoveOffset;
        assert(MoveMask[MoveMaskIdx] == -1 && "Expected empty slot");
        assert(MoveMask[MoveMaskIdx + 1] == -1 && "Expected empty slot");
        MoveMask[MoveMaskIdx] = Mask[BadInputs[0]] - MaskOffset;
        MoveMask[MoveMaskIdx + 1] = Mask[BadInputs[1]] - MaskOffset;
        Mask[BadInputs[0]] = MoveMaskIdx + MaskOffset;
        Mask[BadInputs[1]] = MoveMaskIdx + 1 + MaskOffset;
      } else {
        assert(BadInputs.size() == 1 && "All sizes handled");
        int MoveMaskIdx = std::find(std::begin(MoveMask) + MoveOffset,
                                    std::end(MoveMask), -1) -
                          std::begin(MoveMask);
        MoveMask[MoveMaskIdx] = Mask[BadInputs[0]] - MaskOffset;
        Mask[BadInputs[0]] = MoveMaskIdx + MaskOffset;
      }
    }

    return DAG.getVectorShuffle(MVT::v8i16, DL, V, DAG.getUNDEF(MVT::v8i16),
                                MoveMask);
  };
  V1 = moveInputsToHalf(V1, LoV1Inputs, HiV1Inputs, MergeFromLo,
                        /*MaskOffset*/ 0);
  V2 = moveInputsToHalf(V2, LoV2Inputs, HiV2Inputs, MergeFromLo,
                        /*MaskOffset*/ 8);

  // FIXME: Select an interleaving of the merge of V1 and V2 that minimizes
  // cross-half traffic in the final shuffle.

  // Munge the mask to be a single-input mask after the unpack merges the
  // results.
  for (int &M : Mask)
    if (M != -1)
      M = 2 * (M % 4) + (M / 8);

  return DAG.getVectorShuffle(
      MVT::v8i16, DL, DAG.getNode(MergeFromLo ? X86ISD::UNPCKL : X86ISD::UNPCKH,
                                  DL, MVT::v8i16, V1, V2),
      DAG.getUNDEF(MVT::v8i16), Mask);
}

/// \brief Generic lowering of 8-lane i16 shuffles.
///
/// This handles both single-input shuffles and combined shuffle/blends with
/// two inputs. The single input shuffles are immediately delegated to
/// a dedicated lowering routine.
///
/// The blends are lowered in one of three fundamental ways. If there are few
/// enough inputs, it delegates to a basic UNPCK-based strategy. If the shuffle
/// of the input is significantly cheaper when lowered as an interleaving of
/// the two inputs, try to interleave them. Otherwise, blend the low and high
/// halves of the inputs separately (making them have relatively few inputs)
/// and then concatenate them.
static SDValue lowerV8I16VectorShuffle(SDValue Op, SDValue V1, SDValue V2,
                                       const X86Subtarget *Subtarget,
                                       SelectionDAG &DAG) {
  SDLoc DL(Op);
  assert(Op.getSimpleValueType() == MVT::v8i16 && "Bad shuffle type!");
  assert(V1.getSimpleValueType() == MVT::v8i16 && "Bad operand type!");
  assert(V2.getSimpleValueType() == MVT::v8i16 && "Bad operand type!");
  ShuffleVectorSDNode *SVOp = cast<ShuffleVectorSDNode>(Op);
  ArrayRef<int> OrigMask = SVOp->getMask();
  int MaskStorage[8] = {OrigMask[0], OrigMask[1], OrigMask[2], OrigMask[3],
                        OrigMask[4], OrigMask[5], OrigMask[6], OrigMask[7]};
  MutableArrayRef<int> Mask(MaskStorage);

  assert(Mask.size() == 8 && "Unexpected mask size for v8 shuffle!");

  // Whenever we can lower this as a zext, that instruction is strictly faster
  // than any alternative.
  if (SDValue ZExt = lowerVectorShuffleAsZeroOrAnyExtend(
          DL, MVT::v8i16, V1, V2, OrigMask, Subtarget, DAG))
    return ZExt;

  auto isV1 = [](int M) { return M >= 0 && M < 8; };
  auto isV2 = [](int M) { return M >= 8; };

  int NumV1Inputs = std::count_if(Mask.begin(), Mask.end(), isV1);
  int NumV2Inputs = std::count_if(Mask.begin(), Mask.end(), isV2);

  if (NumV2Inputs == 0)
    return lowerV8I16SingleInputVectorShuffle(DL, V1, Mask, Subtarget, DAG);

  assert(NumV1Inputs > 0 && "All single-input shuffles should be canonicalized "
                            "to be V1-input shuffles.");

  // Try to use shift instructions.
  if (SDValue Shift =
          lowerVectorShuffleAsShift(DL, MVT::v8i16, V1, V2, Mask, DAG))
    return Shift;

  // There are special ways we can lower some single-element blends.
  if (NumV2Inputs == 1)
    if (SDValue V = lowerVectorShuffleAsElementInsertion(MVT::v8i16, DL, V1, V2,
                                                         Mask, Subtarget, DAG))
      return V;

  // We have different paths for blend lowering, but they all must use the
  // *exact* same predicate.
  bool IsBlendSupported = Subtarget->hasSSE41();
  if (IsBlendSupported)
    if (SDValue Blend = lowerVectorShuffleAsBlend(DL, MVT::v8i16, V1, V2, Mask,
                                                  Subtarget, DAG))
      return Blend;

  if (SDValue Masked =
          lowerVectorShuffleAsBitMask(DL, MVT::v8i16, V1, V2, Mask, DAG))
    return Masked;

  // Use dedicated unpack instructions for masks that match their pattern.
  if (isShuffleEquivalent(V1, V2, Mask, 0, 8, 1, 9, 2, 10, 3, 11))
    return DAG.getNode(X86ISD::UNPCKL, DL, MVT::v8i16, V1, V2);
  if (isShuffleEquivalent(V1, V2, Mask, 4, 12, 5, 13, 6, 14, 7, 15))
    return DAG.getNode(X86ISD::UNPCKH, DL, MVT::v8i16, V1, V2);

  // Try to use byte rotation instructions.
  if (SDValue Rotate = lowerVectorShuffleAsByteRotate(
          DL, MVT::v8i16, V1, V2, Mask, Subtarget, DAG))
    return Rotate;

  if (SDValue BitBlend =
          lowerVectorShuffleAsBitBlend(DL, MVT::v8i16, V1, V2, Mask, DAG))
    return BitBlend;

  if (NumV1Inputs + NumV2Inputs <= 4)
    return lowerV8I16BasicBlendVectorShuffle(DL, V1, V2, Mask, Subtarget, DAG);

  // Check whether an interleaving lowering is likely to be more efficient.
  // This isn't perfect but it is a strong heuristic that tends to work well on
  // the kinds of shuffles that show up in practice.
  //
  // FIXME: Handle 1x, 2x, and 4x interleaving.
  if (shouldLowerAsInterleaving(Mask)) {
    // FIXME: Figure out whether we should pack these into the low or high
    // halves.

    int EMask[8], OMask[8];
    for (int i = 0; i < 4; ++i) {
      EMask[i] = Mask[2*i];
      OMask[i] = Mask[2*i + 1];
      EMask[i + 4] = -1;
      OMask[i + 4] = -1;
    }

    SDValue Evens = DAG.getVectorShuffle(MVT::v8i16, DL, V1, V2, EMask);
    SDValue Odds = DAG.getVectorShuffle(MVT::v8i16, DL, V1, V2, OMask);

    return DAG.getNode(X86ISD::UNPCKL, DL, MVT::v8i16, Evens, Odds);
  }

  // If we have direct support for blends, we should lower by decomposing into
  // a permute.
  if (IsBlendSupported)
    return lowerVectorShuffleAsDecomposedShuffleBlend(DL, MVT::v8i16, V1, V2,
                                                      Mask, DAG);

  // Try to lower by permuting the inputs into an unpack instruction.
  if (SDValue Unpack =
          lowerVectorShuffleAsUnpack(MVT::v8i16, DL, V1, V2, Mask, DAG))
    return Unpack;

  int LoBlendMask[8] = {-1, -1, -1, -1, -1, -1, -1, -1};
  int HiBlendMask[8] = {-1, -1, -1, -1, -1, -1, -1, -1};

  for (int i = 0; i < 4; ++i) {
    LoBlendMask[i] = Mask[i];
    HiBlendMask[i] = Mask[i + 4];
  }

  SDValue LoV = DAG.getVectorShuffle(MVT::v8i16, DL, V1, V2, LoBlendMask);
  SDValue HiV = DAG.getVectorShuffle(MVT::v8i16, DL, V1, V2, HiBlendMask);
  LoV = DAG.getNode(ISD::BITCAST, DL, MVT::v2i64, LoV);
  HiV = DAG.getNode(ISD::BITCAST, DL, MVT::v2i64, HiV);

  return DAG.getNode(ISD::BITCAST, DL, MVT::v8i16,
                     DAG.getNode(X86ISD::UNPCKL, DL, MVT::v2i64, LoV, HiV));
}

/// \brief Check whether a compaction lowering can be done by dropping even
/// elements and compute how many times even elements must be dropped.
///
/// This handles shuffles which take every Nth element where N is a power of
/// two. Example shuffle masks:
///
///  N = 1:  0,  2,  4,  6,  8, 10, 12, 14,  0,  2,  4,  6,  8, 10, 12, 14
///  N = 1:  0,  2,  4,  6,  8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30
///  N = 2:  0,  4,  8, 12,  0,  4,  8, 12,  0,  4,  8, 12,  0,  4,  8, 12
///  N = 2:  0,  4,  8, 12, 16, 20, 24, 28,  0,  4,  8, 12, 16, 20, 24, 28
///  N = 3:  0,  8,  0,  8,  0,  8,  0,  8,  0,  8,  0,  8,  0,  8,  0,  8
///  N = 3:  0,  8, 16, 24,  0,  8, 16, 24,  0,  8, 16, 24,  0,  8, 16, 24
///
/// Any of these lanes can of course be undef.
///
/// This routine only supports N <= 3.
/// FIXME: Evaluate whether either AVX or AVX-512 have any opportunities here
/// for larger N.
///
/// \returns N above, or the number of times even elements must be dropped if
/// there is such a number. Otherwise returns zero.
static int canLowerByDroppingEvenElements(ArrayRef<int> Mask) {
  // Figure out whether we're looping over two inputs or just one.
  bool IsSingleInput = isSingleInputShuffleMask(Mask);

  // The modulus for the shuffle vector entries is based on whether this is
  // a single input or not.
  int ShuffleModulus = Mask.size() * (IsSingleInput ? 1 : 2);
  assert(isPowerOf2_32((uint32_t)ShuffleModulus) &&
         "We should only be called with masks with a power-of-2 size!");

  uint64_t ModMask = (uint64_t)ShuffleModulus - 1;

  // We track whether the input is viable for all power-of-2 strides 2^1, 2^2,
  // and 2^3 simultaneously. This is because we may have ambiguity with
  // partially undef inputs.
  bool ViableForN[3] = {true, true, true};

  for (int i = 0, e = Mask.size(); i < e; ++i) {
    // Ignore undef lanes, we'll optimistically collapse them to the pattern we
    // want.
    if (Mask[i] == -1)
      continue;

    bool IsAnyViable = false;
    for (unsigned j = 0; j != array_lengthof(ViableForN); ++j)
      if (ViableForN[j]) {
        uint64_t N = j + 1;

        // The shuffle mask must be equal to (i * 2^N) % M.
        if ((uint64_t)Mask[i] == (((uint64_t)i << N) & ModMask))
          IsAnyViable = true;
        else
          ViableForN[j] = false;
      }
    // Early exit if we exhaust the possible powers of two.
    if (!IsAnyViable)
      break;
  }

  for (unsigned j = 0; j != array_lengthof(ViableForN); ++j)
    if (ViableForN[j])
      return j + 1;

  // Return 0 as there is no viable power of two.
  return 0;
}

/// \brief Generic lowering of v16i8 shuffles.
///
/// This is a hybrid strategy to lower v16i8 vectors. It first attempts to
/// detect any complexity reducing interleaving. If that doesn't help, it uses
/// UNPCK to spread the i8 elements across two i16-element vectors, and uses
/// the existing lowering for v8i16 blends on each half, finally PACK-ing them
/// back together.
static SDValue lowerV16I8VectorShuffle(SDValue Op, SDValue V1, SDValue V2,
                                       const X86Subtarget *Subtarget,
                                       SelectionDAG &DAG) {
  SDLoc DL(Op);
  assert(Op.getSimpleValueType() == MVT::v16i8 && "Bad shuffle type!");
  assert(V1.getSimpleValueType() == MVT::v16i8 && "Bad operand type!");
  assert(V2.getSimpleValueType() == MVT::v16i8 && "Bad operand type!");
  ShuffleVectorSDNode *SVOp = cast<ShuffleVectorSDNode>(Op);
  ArrayRef<int> OrigMask = SVOp->getMask();
  assert(OrigMask.size() == 16 && "Unexpected mask size for v16 shuffle!");

  // Try to use shift instructions.
  if (SDValue Shift =
          lowerVectorShuffleAsShift(DL, MVT::v16i8, V1, V2, OrigMask, DAG))
    return Shift;

  // Try to use byte rotation instructions.
  if (SDValue Rotate = lowerVectorShuffleAsByteRotate(
          DL, MVT::v16i8, V1, V2, OrigMask, Subtarget, DAG))
    return Rotate;

  // Try to use a zext lowering.
  if (SDValue ZExt = lowerVectorShuffleAsZeroOrAnyExtend(
          DL, MVT::v16i8, V1, V2, OrigMask, Subtarget, DAG))
    return ZExt;

  int MaskStorage[16] = {
      OrigMask[0],  OrigMask[1],  OrigMask[2],  OrigMask[3],
      OrigMask[4],  OrigMask[5],  OrigMask[6],  OrigMask[7],
      OrigMask[8],  OrigMask[9],  OrigMask[10], OrigMask[11],
      OrigMask[12], OrigMask[13], OrigMask[14], OrigMask[15]};
  MutableArrayRef<int> Mask(MaskStorage);
  MutableArrayRef<int> LoMask = Mask.slice(0, 8);
  MutableArrayRef<int> HiMask = Mask.slice(8, 8);

  int NumV2Elements =
      std::count_if(Mask.begin(), Mask.end(), [](int M) { return M >= 16; });

  // For single-input shuffles, there are some nicer lowering tricks we can use.
  if (NumV2Elements == 0) {
    // Check for being able to broadcast a single element.
    if (SDValue Broadcast = lowerVectorShuffleAsBroadcast(MVT::v16i8, DL, V1,
                                                          Mask, Subtarget, DAG))
      return Broadcast;

    // Check whether we can widen this to an i16 shuffle by duplicating bytes.
    // Notably, this handles splat and partial-splat shuffles more efficiently.
    // However, it only makes sense if the pre-duplication shuffle simplifies
    // things significantly. Currently, this means we need to be able to
    // express the pre-duplication shuffle as an i16 shuffle.
    //
    // FIXME: We should check for other patterns which can be widened into an
    // i16 shuffle as well.
    auto canWidenViaDuplication = [](ArrayRef<int> Mask) {
      for (int i = 0; i < 16; i += 2)
        if (Mask[i] != -1 && Mask[i + 1] != -1 && Mask[i] != Mask[i + 1])
          return false;

      return true;
    };
    auto tryToWidenViaDuplication = [&]() -> SDValue {
      if (!canWidenViaDuplication(Mask))
        return SDValue();
      SmallVector<int, 4> LoInputs;
      std::copy_if(Mask.begin(), Mask.end(), std::back_inserter(LoInputs),
                   [](int M) { return M >= 0 && M < 8; });
      std::sort(LoInputs.begin(), LoInputs.end());
      LoInputs.erase(std::unique(LoInputs.begin(), LoInputs.end()),
                     LoInputs.end());
      SmallVector<int, 4> HiInputs;
      std::copy_if(Mask.begin(), Mask.end(), std::back_inserter(HiInputs),
                   [](int M) { return M >= 8; });
      std::sort(HiInputs.begin(), HiInputs.end());
      HiInputs.erase(std::unique(HiInputs.begin(), HiInputs.end()),
                     HiInputs.end());

      bool TargetLo = LoInputs.size() >= HiInputs.size();
      ArrayRef<int> InPlaceInputs = TargetLo ? LoInputs : HiInputs;
      ArrayRef<int> MovingInputs = TargetLo ? HiInputs : LoInputs;

      int PreDupI16Shuffle[] = {-1, -1, -1, -1, -1, -1, -1, -1};
      SmallDenseMap<int, int, 8> LaneMap;
      for (int I : InPlaceInputs) {
        PreDupI16Shuffle[I/2] = I/2;
        LaneMap[I] = I;
      }
      int j = TargetLo ? 0 : 4, je = j + 4;
      for (int i = 0, ie = MovingInputs.size(); i < ie; ++i) {
        // Check if j is already a shuffle of this input. This happens when
        // there are two adjacent bytes after we move the low one.
        if (PreDupI16Shuffle[j] != MovingInputs[i] / 2) {
          // If we haven't yet mapped the input, search for a slot into which
          // we can map it.
          while (j < je && PreDupI16Shuffle[j] != -1)
            ++j;

          if (j == je)
            // We can't place the inputs into a single half with a simple i16 shuffle, so bail.
            return SDValue();

          // Map this input with the i16 shuffle.
          PreDupI16Shuffle[j] = MovingInputs[i] / 2;
        }

        // Update the lane map based on the mapping we ended up with.
        LaneMap[MovingInputs[i]] = 2 * j + MovingInputs[i] % 2;
      }
      V1 = DAG.getNode(
          ISD::BITCAST, DL, MVT::v16i8,
          DAG.getVectorShuffle(MVT::v8i16, DL,
                               DAG.getNode(ISD::BITCAST, DL, MVT::v8i16, V1),
                               DAG.getUNDEF(MVT::v8i16), PreDupI16Shuffle));

      // Unpack the bytes to form the i16s that will be shuffled into place.
      V1 = DAG.getNode(TargetLo ? X86ISD::UNPCKL : X86ISD::UNPCKH, DL,
                       MVT::v16i8, V1, V1);

      int PostDupI16Shuffle[8] = {-1, -1, -1, -1, -1, -1, -1, -1};
      for (int i = 0; i < 16; ++i)
        if (Mask[i] != -1) {
          int MappedMask = LaneMap[Mask[i]] - (TargetLo ? 0 : 8);
          assert(MappedMask < 8 && "Invalid v8 shuffle mask!");
          if (PostDupI16Shuffle[i / 2] == -1)
            PostDupI16Shuffle[i / 2] = MappedMask;
          else
            assert(PostDupI16Shuffle[i / 2] == MappedMask &&
                   "Conflicting entrties in the original shuffle!");
        }
      return DAG.getNode(
          ISD::BITCAST, DL, MVT::v16i8,
          DAG.getVectorShuffle(MVT::v8i16, DL,
                               DAG.getNode(ISD::BITCAST, DL, MVT::v8i16, V1),
                               DAG.getUNDEF(MVT::v8i16), PostDupI16Shuffle));
    };
    if (SDValue V = tryToWidenViaDuplication())
      return V;
  }

  // Check whether an interleaving lowering is likely to be more efficient.
  // This isn't perfect but it is a strong heuristic that tends to work well on
  // the kinds of shuffles that show up in practice.
  //
  // FIXME: We need to handle other interleaving widths (i16, i32, ...).
  if (shouldLowerAsInterleaving(Mask)) {
    int NumLoHalf = std::count_if(Mask.begin(), Mask.end(), [](int M) {
      return (M >= 0 && M < 8) || (M >= 16 && M < 24);
    });
    int NumHiHalf = std::count_if(Mask.begin(), Mask.end(), [](int M) {
      return (M >= 8 && M < 16) || M >= 24;
    });
    int EMask[16] = {-1, -1, -1, -1, -1, -1, -1, -1,
                     -1, -1, -1, -1, -1, -1, -1, -1};
    int OMask[16] = {-1, -1, -1, -1, -1, -1, -1, -1,
                     -1, -1, -1, -1, -1, -1, -1, -1};
    bool UnpackLo = NumLoHalf >= NumHiHalf;
    MutableArrayRef<int> TargetEMask(UnpackLo ? EMask : EMask + 8, 8);
    MutableArrayRef<int> TargetOMask(UnpackLo ? OMask : OMask + 8, 8);
    for (int i = 0; i < 8; ++i) {
      TargetEMask[i] = Mask[2 * i];
      TargetOMask[i] = Mask[2 * i + 1];
    }

    SDValue Evens = DAG.getVectorShuffle(MVT::v16i8, DL, V1, V2, EMask);
    SDValue Odds = DAG.getVectorShuffle(MVT::v16i8, DL, V1, V2, OMask);

    return DAG.getNode(UnpackLo ? X86ISD::UNPCKL : X86ISD::UNPCKH, DL,
                       MVT::v16i8, Evens, Odds);
  }

  // Check for SSSE3 which lets us lower all v16i8 shuffles much more directly
  // with PSHUFB. It is important to do this before we attempt to generate any
  // blends but after all of the single-input lowerings. If the single input
  // lowerings can find an instruction sequence that is faster than a PSHUFB, we
  // want to preserve that and we can DAG combine any longer sequences into
  // a PSHUFB in the end. But once we start blending from multiple inputs,
  // the complexity of DAG combining bad patterns back into PSHUFB is too high,
  // and there are *very* few patterns that would actually be faster than the
  // PSHUFB approach because of its ability to zero lanes.
  //
  // FIXME: The only exceptions to the above are blends which are exact
  // interleavings with direct instructions supporting them. We currently don't
  // handle those well here.
  if (Subtarget->hasSSSE3()) {
    SDValue V1Mask[16];
    SDValue V2Mask[16];
    bool V1InUse = false;
    bool V2InUse = false;
    SmallBitVector Zeroable = computeZeroableShuffleElements(Mask, V1, V2);

    for (int i = 0; i < 16; ++i) {
      if (Mask[i] == -1) {
        V1Mask[i] = V2Mask[i] = DAG.getUNDEF(MVT::i8);
      } else {
        const int ZeroMask = 0x80;
        int V1Idx = (Mask[i] < 16 ? Mask[i] : ZeroMask);
        int V2Idx = (Mask[i] < 16 ? ZeroMask : Mask[i] - 16);
        if (Zeroable[i])
          V1Idx = V2Idx = ZeroMask;
        V1Mask[i] = DAG.getConstant(V1Idx, MVT::i8);
        V2Mask[i] = DAG.getConstant(V2Idx, MVT::i8);
        V1InUse |= (ZeroMask != V1Idx);
        V2InUse |= (ZeroMask != V2Idx);
      }
    }

    // If both V1 and V2 are in use and we can use a direct blend, do so. This
    // avoids using blends to handle blends-with-zero which is important as
    // a single pshufb is significantly faster for that.
    if (V1InUse && V2InUse && Subtarget->hasSSE41())
      if (SDValue Blend = lowerVectorShuffleAsBlend(DL, MVT::v16i8, V1, V2, Mask,
                                                    Subtarget, DAG))
        return Blend;


    if (V1InUse)
      V1 = DAG.getNode(X86ISD::PSHUFB, DL, MVT::v16i8, V1,
                       DAG.getNode(ISD::BUILD_VECTOR, DL, MVT::v16i8, V1Mask));
    if (V2InUse)
      V2 = DAG.getNode(X86ISD::PSHUFB, DL, MVT::v16i8, V2,
                       DAG.getNode(ISD::BUILD_VECTOR, DL, MVT::v16i8, V2Mask));

    // If we need shuffled inputs from both, blend the two.
    if (V1InUse && V2InUse)
      return DAG.getNode(ISD::OR, DL, MVT::v16i8, V1, V2);
    if (V1InUse)
      return V1; // Single inputs are easy.
    if (V2InUse)
      return V2; // Single inputs are easy.
    // Shuffling to a zeroable vector.
    return getZeroVector(MVT::v16i8, Subtarget, DAG, DL);
  }

  // There are special ways we can lower some single-element blends.
  if (NumV2Elements == 1)
    if (SDValue V = lowerVectorShuffleAsElementInsertion(MVT::v16i8, DL, V1, V2,
                                                         Mask, Subtarget, DAG))
      return V;

  if (SDValue BitBlend =
          lowerVectorShuffleAsBitBlend(DL, MVT::v16i8, V1, V2, Mask, DAG))
    return BitBlend;

  // Check whether a compaction lowering can be done. This handles shuffles
  // which take every Nth element for some even N. See the helper function for
  // details.
  //
  // We special case these as they can be particularly efficiently handled with
  // the PACKUSB instruction on x86 and they show up in common patterns of
  // rearranging bytes to truncate wide elements.
  if (int NumEvenDrops = canLowerByDroppingEvenElements(Mask)) {
    // NumEvenDrops is the power of two stride of the elements. Another way of
    // thinking about it is that we need to drop the even elements this many
    // times to get the original input.
    bool IsSingleInput = isSingleInputShuffleMask(Mask);

    // First we need to zero all the dropped bytes.
    assert(NumEvenDrops <= 3 &&
           "No support for dropping even elements more than 3 times.");
    // We use the mask type to pick which bytes are preserved based on how many
    // elements are dropped.
    MVT MaskVTs[] = { MVT::v8i16, MVT::v4i32, MVT::v2i64 };
    SDValue ByteClearMask =
        DAG.getNode(ISD::BITCAST, DL, MVT::v16i8,
                    DAG.getConstant(0xFF, MaskVTs[NumEvenDrops - 1]));
    V1 = DAG.getNode(ISD::AND, DL, MVT::v16i8, V1, ByteClearMask);
    if (!IsSingleInput)
      V2 = DAG.getNode(ISD::AND, DL, MVT::v16i8, V2, ByteClearMask);

    // Now pack things back together.
    V1 = DAG.getNode(ISD::BITCAST, DL, MVT::v8i16, V1);
    V2 = IsSingleInput ? V1 : DAG.getNode(ISD::BITCAST, DL, MVT::v8i16, V2);
    SDValue Result = DAG.getNode(X86ISD::PACKUS, DL, MVT::v16i8, V1, V2);
    for (int i = 1; i < NumEvenDrops; ++i) {
      Result = DAG.getNode(ISD::BITCAST, DL, MVT::v8i16, Result);
      Result = DAG.getNode(X86ISD::PACKUS, DL, MVT::v16i8, Result, Result);
    }

    return Result;
  }

  int V1LoBlendMask[8] = {-1, -1, -1, -1, -1, -1, -1, -1};
  int V1HiBlendMask[8] = {-1, -1, -1, -1, -1, -1, -1, -1};
  int V2LoBlendMask[8] = {-1, -1, -1, -1, -1, -1, -1, -1};
  int V2HiBlendMask[8] = {-1, -1, -1, -1, -1, -1, -1, -1};

  auto buildBlendMasks = [](MutableArrayRef<int> HalfMask,
                            MutableArrayRef<int> V1HalfBlendMask,
                            MutableArrayRef<int> V2HalfBlendMask) {
    for (int i = 0; i < 8; ++i)
      if (HalfMask[i] >= 0 && HalfMask[i] < 16) {
        V1HalfBlendMask[i] = HalfMask[i];
        HalfMask[i] = i;
      } else if (HalfMask[i] >= 16) {
        V2HalfBlendMask[i] = HalfMask[i] - 16;
        HalfMask[i] = i + 8;
      }
  };
  buildBlendMasks(LoMask, V1LoBlendMask, V2LoBlendMask);
  buildBlendMasks(HiMask, V1HiBlendMask, V2HiBlendMask);

  SDValue Zero = getZeroVector(MVT::v8i16, Subtarget, DAG, DL);

  auto buildLoAndHiV8s = [&](SDValue V, MutableArrayRef<int> LoBlendMask,
                             MutableArrayRef<int> HiBlendMask) {
    SDValue V1, V2;
    // Check if any of the odd lanes in the v16i8 are used. If not, we can mask
    // them out and avoid using UNPCK{L,H} to extract the elements of V as
    // i16s.
    if (std::none_of(LoBlendMask.begin(), LoBlendMask.end(),
                     [](int M) { return M >= 0 && M % 2 == 1; }) &&
        std::none_of(HiBlendMask.begin(), HiBlendMask.end(),
                     [](int M) { return M >= 0 && M % 2 == 1; })) {
      // Use a mask to drop the high bytes.
      V1 = DAG.getNode(ISD::BITCAST, DL, MVT::v8i16, V);
      V1 = DAG.getNode(ISD::AND, DL, MVT::v8i16, V1,
                       DAG.getConstant(0x00FF, MVT::v8i16));

      // This will be a single vector shuffle instead of a blend so nuke V2.
      V2 = DAG.getUNDEF(MVT::v8i16);

      // Squash the masks to point directly into V1.
      for (int &M : LoBlendMask)
        if (M >= 0)
          M /= 2;
      for (int &M : HiBlendMask)
        if (M >= 0)
          M /= 2;
    } else {
      // Otherwise just unpack the low half of V into V1 and the high half into
      // V2 so that we can blend them as i16s.
      V1 = DAG.getNode(ISD::BITCAST, DL, MVT::v8i16,
                       DAG.getNode(X86ISD::UNPCKL, DL, MVT::v16i8, V, Zero));
      V2 = DAG.getNode(ISD::BITCAST, DL, MVT::v8i16,
                       DAG.getNode(X86ISD::UNPCKH, DL, MVT::v16i8, V, Zero));
    }

    SDValue BlendedLo = DAG.getVectorShuffle(MVT::v8i16, DL, V1, V2, LoBlendMask);
    SDValue BlendedHi = DAG.getVectorShuffle(MVT::v8i16, DL, V1, V2, HiBlendMask);
    return std::make_pair(BlendedLo, BlendedHi);
  };
  SDValue V1Lo, V1Hi, V2Lo, V2Hi;
  std::tie(V1Lo, V1Hi) = buildLoAndHiV8s(V1, V1LoBlendMask, V1HiBlendMask);
  std::tie(V2Lo, V2Hi) = buildLoAndHiV8s(V2, V2LoBlendMask, V2HiBlendMask);

  SDValue LoV = DAG.getVectorShuffle(MVT::v8i16, DL, V1Lo, V2Lo, LoMask);
  SDValue HiV = DAG.getVectorShuffle(MVT::v8i16, DL, V1Hi, V2Hi, HiMask);

  return DAG.getNode(X86ISD::PACKUS, DL, MVT::v16i8, LoV, HiV);
}

/// \brief Dispatching routine to lower various 128-bit x86 vector shuffles.
///
/// This routine breaks down the specific type of 128-bit shuffle and
/// dispatches to the lowering routines accordingly.
static SDValue lower128BitVectorShuffle(SDValue Op, SDValue V1, SDValue V2,
                                        MVT VT, const X86Subtarget *Subtarget,
                                        SelectionDAG &DAG) {
  switch (VT.SimpleTy) {
  case MVT::v2i64:
    return lowerV2I64VectorShuffle(Op, V1, V2, Subtarget, DAG);
  case MVT::v2f64:
    return lowerV2F64VectorShuffle(Op, V1, V2, Subtarget, DAG);
  case MVT::v4i32:
    return lowerV4I32VectorShuffle(Op, V1, V2, Subtarget, DAG);
  case MVT::v4f32:
    return lowerV4F32VectorShuffle(Op, V1, V2, Subtarget, DAG);
  case MVT::v8i16:
    return lowerV8I16VectorShuffle(Op, V1, V2, Subtarget, DAG);
  case MVT::v16i8:
    return lowerV16I8VectorShuffle(Op, V1, V2, Subtarget, DAG);

  default:
    llvm_unreachable("Unimplemented!");
  }
}

/// \brief Helper function to test whether a shuffle mask could be
/// simplified by widening the elements being shuffled.
///
/// Appends the mask for wider elements in WidenedMask if valid. Otherwise
/// leaves it in an unspecified state.
///
/// NOTE: This must handle normal vector shuffle masks and *target* vector
/// shuffle masks. The latter have the special property of a '-2' representing
/// a zero-ed lane of a vector.
static bool canWidenShuffleElements(ArrayRef<int> Mask,
                                    SmallVectorImpl<int> &WidenedMask) {
  for (int i = 0, Size = Mask.size(); i < Size; i += 2) {
    // If both elements are undef, its trivial.
    if (Mask[i] == SM_SentinelUndef && Mask[i + 1] == SM_SentinelUndef) {
      WidenedMask.push_back(SM_SentinelUndef);
      continue;
    }

    // Check for an undef mask and a mask value properly aligned to fit with
    // a pair of values. If we find such a case, use the non-undef mask's value.
    if (Mask[i] == SM_SentinelUndef && Mask[i + 1] >= 0 && Mask[i + 1] % 2 == 1) {
      WidenedMask.push_back(Mask[i + 1] / 2);
      continue;
    }
    if (Mask[i + 1] == SM_SentinelUndef && Mask[i] >= 0 && Mask[i] % 2 == 0) {
      WidenedMask.push_back(Mask[i] / 2);
      continue;
    }

    // When zeroing, we need to spread the zeroing across both lanes to widen.
    if (Mask[i] == SM_SentinelZero || Mask[i + 1] == SM_SentinelZero) {
      if ((Mask[i] == SM_SentinelZero || Mask[i] == SM_SentinelUndef) &&
          (Mask[i + 1] == SM_SentinelZero || Mask[i + 1] == SM_SentinelUndef)) {
        WidenedMask.push_back(SM_SentinelZero);
        continue;
      }
      return false;
    }

    // Finally check if the two mask values are adjacent and aligned with
    // a pair.
    if (Mask[i] != SM_SentinelUndef && Mask[i] % 2 == 0 && Mask[i] + 1 == Mask[i + 1]) {
      WidenedMask.push_back(Mask[i] / 2);
      continue;
    }

    // Otherwise we can't safely widen the elements used in this shuffle.
    return false;
  }
  assert(WidenedMask.size() == Mask.size() / 2 &&
         "Incorrect size of mask after widening the elements!");

  return true;
}

/// \brief Generic routine to split vector shuffle into half-sized shuffles.
///
/// This routine just extracts two subvectors, shuffles them independently, and
/// then concatenates them back together. This should work effectively with all
/// AVX vector shuffle types.
static SDValue splitAndLowerVectorShuffle(SDLoc DL, MVT VT, SDValue V1,
                                          SDValue V2, ArrayRef<int> Mask,
                                          SelectionDAG &DAG) {
  assert(VT.getSizeInBits() >= 256 &&
         "Only for 256-bit or wider vector shuffles!");
  assert(V1.getSimpleValueType() == VT && "Bad operand type!");
  assert(V2.getSimpleValueType() == VT && "Bad operand type!");

  ArrayRef<int> LoMask = Mask.slice(0, Mask.size() / 2);
  ArrayRef<int> HiMask = Mask.slice(Mask.size() / 2);

  int NumElements = VT.getVectorNumElements();
  int SplitNumElements = NumElements / 2;
  MVT ScalarVT = VT.getScalarType();
  MVT SplitVT = MVT::getVectorVT(ScalarVT, NumElements / 2);

  // Rather than splitting build-vectors, just build two narrower build
  // vectors. This helps shuffling with splats and zeros.
  auto SplitVector = [&](SDValue V) {
    while (V.getOpcode() == ISD::BITCAST)
      V = V->getOperand(0);

    MVT OrigVT = V.getSimpleValueType();
    int OrigNumElements = OrigVT.getVectorNumElements();
    int OrigSplitNumElements = OrigNumElements / 2;
    MVT OrigScalarVT = OrigVT.getScalarType();
    MVT OrigSplitVT = MVT::getVectorVT(OrigScalarVT, OrigNumElements / 2);

    SDValue LoV, HiV;

    auto *BV = dyn_cast<BuildVectorSDNode>(V);
    if (!BV) {
      LoV = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, OrigSplitVT, V,
                        DAG.getIntPtrConstant(0));
      HiV = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, OrigSplitVT, V,
                        DAG.getIntPtrConstant(OrigSplitNumElements));
    } else {

      SmallVector<SDValue, 16> LoOps, HiOps;
      for (int i = 0; i < OrigSplitNumElements; ++i) {
        LoOps.push_back(BV->getOperand(i));
        HiOps.push_back(BV->getOperand(i + OrigSplitNumElements));
      }
      LoV = DAG.getNode(ISD::BUILD_VECTOR, DL, OrigSplitVT, LoOps);
      HiV = DAG.getNode(ISD::BUILD_VECTOR, DL, OrigSplitVT, HiOps);
    }
    return std::make_pair(DAG.getNode(ISD::BITCAST, DL, SplitVT, LoV),
                          DAG.getNode(ISD::BITCAST, DL, SplitVT, HiV));
  };

  SDValue LoV1, HiV1, LoV2, HiV2;
  std::tie(LoV1, HiV1) = SplitVector(V1);
  std::tie(LoV2, HiV2) = SplitVector(V2);

  // Now create two 4-way blends of these half-width vectors.
  auto HalfBlend = [&](ArrayRef<int> HalfMask) {
    bool UseLoV1 = false, UseHiV1 = false, UseLoV2 = false, UseHiV2 = false;
    SmallVector<int, 32> V1BlendMask, V2BlendMask, BlendMask;
    for (int i = 0; i < SplitNumElements; ++i) {
      int M = HalfMask[i];
      if (M >= NumElements) {
        if (M >= NumElements + SplitNumElements)
          UseHiV2 = true;
        else
          UseLoV2 = true;
        V2BlendMask.push_back(M - NumElements);
        V1BlendMask.push_back(-1);
        BlendMask.push_back(SplitNumElements + i);
      } else if (M >= 0) {
        if (M >= SplitNumElements)
          UseHiV1 = true;
        else
          UseLoV1 = true;
        V2BlendMask.push_back(-1);
        V1BlendMask.push_back(M);
        BlendMask.push_back(i);
      } else {
        V2BlendMask.push_back(-1);
        V1BlendMask.push_back(-1);
        BlendMask.push_back(-1);
      }
    }

    // Because the lowering happens after all combining takes place, we need to
    // manually combine these blend masks as much as possible so that we create
    // a minimal number of high-level vector shuffle nodes.

    // First try just blending the halves of V1 or V2.
    if (!UseLoV1 && !UseHiV1 && !UseLoV2 && !UseHiV2)
      return DAG.getUNDEF(SplitVT);
    if (!UseLoV2 && !UseHiV2)
      return DAG.getVectorShuffle(SplitVT, DL, LoV1, HiV1, V1BlendMask);
    if (!UseLoV1 && !UseHiV1)
      return DAG.getVectorShuffle(SplitVT, DL, LoV2, HiV2, V2BlendMask);

    SDValue V1Blend, V2Blend;
    if (UseLoV1 && UseHiV1) {
      V1Blend =
        DAG.getVectorShuffle(SplitVT, DL, LoV1, HiV1, V1BlendMask);
    } else {
      // We only use half of V1 so map the usage down into the final blend mask.
      V1Blend = UseLoV1 ? LoV1 : HiV1;
      for (int i = 0; i < SplitNumElements; ++i)
        if (BlendMask[i] >= 0 && BlendMask[i] < SplitNumElements)
          BlendMask[i] = V1BlendMask[i] - (UseLoV1 ? 0 : SplitNumElements);
    }
    if (UseLoV2 && UseHiV2) {
      V2Blend =
        DAG.getVectorShuffle(SplitVT, DL, LoV2, HiV2, V2BlendMask);
    } else {
      // We only use half of V2 so map the usage down into the final blend mask.
      V2Blend = UseLoV2 ? LoV2 : HiV2;
      for (int i = 0; i < SplitNumElements; ++i)
        if (BlendMask[i] >= SplitNumElements)
          BlendMask[i] = V2BlendMask[i] + (UseLoV2 ? SplitNumElements : 0);
    }
    return DAG.getVectorShuffle(SplitVT, DL, V1Blend, V2Blend, BlendMask);
  };
  SDValue Lo = HalfBlend(LoMask);
  SDValue Hi = HalfBlend(HiMask);
  return DAG.getNode(ISD::CONCAT_VECTORS, DL, VT, Lo, Hi);
}

/// \brief Either split a vector in halves or decompose the shuffles and the
/// blend.
///
/// This is provided as a good fallback for many lowerings of non-single-input
/// shuffles with more than one 128-bit lane. In those cases, we want to select
/// between splitting the shuffle into 128-bit components and stitching those
/// back together vs. extracting the single-input shuffles and blending those
/// results.
static SDValue lowerVectorShuffleAsSplitOrBlend(SDLoc DL, MVT VT, SDValue V1,
                                                SDValue V2, ArrayRef<int> Mask,
                                                SelectionDAG &DAG) {
  assert(!isSingleInputShuffleMask(Mask) && "This routine must not be used to "
                                            "lower single-input shuffles as it "
                                            "could then recurse on itself.");
  int Size = Mask.size();

  // If this can be modeled as a broadcast of two elements followed by a blend,
  // prefer that lowering. This is especially important because broadcasts can
  // often fold with memory operands.
  auto DoBothBroadcast = [&] {
    int V1BroadcastIdx = -1, V2BroadcastIdx = -1;
    for (int M : Mask)
      if (M >= Size) {
        if (V2BroadcastIdx == -1)
          V2BroadcastIdx = M - Size;
        else if (M - Size != V2BroadcastIdx)
          return false;
      } else if (M >= 0) {
        if (V1BroadcastIdx == -1)
          V1BroadcastIdx = M;
        else if (M != V1BroadcastIdx)
          return false;
      }
    return true;
  };
  if (DoBothBroadcast())
    return lowerVectorShuffleAsDecomposedShuffleBlend(DL, VT, V1, V2, Mask,
                                                      DAG);

  // If the inputs all stem from a single 128-bit lane of each input, then we
  // split them rather than blending because the split will decompose to
  // unusually few instructions.
  int LaneCount = VT.getSizeInBits() / 128;
  int LaneSize = Size / LaneCount;
  SmallBitVector LaneInputs[2];
  LaneInputs[0].resize(LaneCount, false);
  LaneInputs[1].resize(LaneCount, false);
  for (int i = 0; i < Size; ++i)
    if (Mask[i] >= 0)
      LaneInputs[Mask[i] / Size][(Mask[i] % Size) / LaneSize] = true;
  if (LaneInputs[0].count() <= 1 && LaneInputs[1].count() <= 1)
    return splitAndLowerVectorShuffle(DL, VT, V1, V2, Mask, DAG);

  // Otherwise, just fall back to decomposed shuffles and a blend. This requires
  // that the decomposed single-input shuffles don't end up here.
  return lowerVectorShuffleAsDecomposedShuffleBlend(DL, VT, V1, V2, Mask, DAG);
}

/// \brief Lower a vector shuffle crossing multiple 128-bit lanes as
/// a permutation and blend of those lanes.
///
/// This essentially blends the out-of-lane inputs to each lane into the lane
/// from a permuted copy of the vector. This lowering strategy results in four
/// instructions in the worst case for a single-input cross lane shuffle which
/// is lower than any other fully general cross-lane shuffle strategy I'm aware
/// of. Special cases for each particular shuffle pattern should be handled
/// prior to trying this lowering.
static SDValue lowerVectorShuffleAsLanePermuteAndBlend(SDLoc DL, MVT VT,
                                                       SDValue V1, SDValue V2,
                                                       ArrayRef<int> Mask,
                                                       SelectionDAG &DAG) {
  // FIXME: This should probably be generalized for 512-bit vectors as well.
  assert(VT.getSizeInBits() == 256 && "Only for 256-bit vector shuffles!");
  int LaneSize = Mask.size() / 2;

  // If there are only inputs from one 128-bit lane, splitting will in fact be
  // less expensive. The flags track wether the given lane contains an element
  // that crosses to another lane.
  bool LaneCrossing[2] = {false, false};
  for (int i = 0, Size = Mask.size(); i < Size; ++i)
    if (Mask[i] >= 0 && (Mask[i] % Size) / LaneSize != i / LaneSize)
      LaneCrossing[(Mask[i] % Size) / LaneSize] = true;
  if (!LaneCrossing[0] || !LaneCrossing[1])
    return splitAndLowerVectorShuffle(DL, VT, V1, V2, Mask, DAG);

  if (isSingleInputShuffleMask(Mask)) {
    SmallVector<int, 32> FlippedBlendMask;
    for (int i = 0, Size = Mask.size(); i < Size; ++i)
      FlippedBlendMask.push_back(
          Mask[i] < 0 ? -1 : (((Mask[i] % Size) / LaneSize == i / LaneSize)
                                  ? Mask[i]
                                  : Mask[i] % LaneSize +
                                        (i / LaneSize) * LaneSize + Size));

    // Flip the vector, and blend the results which should now be in-lane. The
    // VPERM2X128 mask uses the low 2 bits for the low source and bits 4 and
    // 5 for the high source. The value 3 selects the high half of source 2 and
    // the value 2 selects the low half of source 2. We only use source 2 to
    // allow folding it into a memory operand.
    unsigned PERMMask = 3 | 2 << 4;
    SDValue Flipped = DAG.getNode(X86ISD::VPERM2X128, DL, VT, DAG.getUNDEF(VT),
                                  V1, DAG.getConstant(PERMMask, MVT::i8));
    return DAG.getVectorShuffle(VT, DL, V1, Flipped, FlippedBlendMask);
  }

  // This now reduces to two single-input shuffles of V1 and V2 which at worst
  // will be handled by the above logic and a blend of the results, much like
  // other patterns in AVX.
  return lowerVectorShuffleAsDecomposedShuffleBlend(DL, VT, V1, V2, Mask, DAG);
}

/// \brief Handle lowering 2-lane 128-bit shuffles.
static SDValue lowerV2X128VectorShuffle(SDLoc DL, MVT VT, SDValue V1,
                                        SDValue V2, ArrayRef<int> Mask,
                                        const X86Subtarget *Subtarget,
                                        SelectionDAG &DAG) {
  // Blends are faster and handle all the non-lane-crossing cases.
  if (SDValue Blend = lowerVectorShuffleAsBlend(DL, VT, V1, V2, Mask,
                                                Subtarget, DAG))
    return Blend;

  MVT SubVT = MVT::getVectorVT(VT.getVectorElementType(),
                               VT.getVectorNumElements() / 2);
  // Check for patterns which can be matched with a single insert of a 128-bit
  // subvector.
  if (isShuffleEquivalent(V1, V2, Mask, 0, 1, 0, 1) ||
      isShuffleEquivalent(V1, V2, Mask, 0, 1, 4, 5)) {
    SDValue LoV = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, SubVT, V1,
                              DAG.getIntPtrConstant(0));
    SDValue HiV = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, SubVT,
                              Mask[2] < 4 ? V1 : V2, DAG.getIntPtrConstant(0));
    return DAG.getNode(ISD::CONCAT_VECTORS, DL, VT, LoV, HiV);
  }
  if (isShuffleEquivalent(V1, V2, Mask, 0, 1, 6, 7)) {
    SDValue LoV = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, SubVT, V1,
                              DAG.getIntPtrConstant(0));
    SDValue HiV = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, SubVT, V2,
                              DAG.getIntPtrConstant(2));
    return DAG.getNode(ISD::CONCAT_VECTORS, DL, VT, LoV, HiV);
  }

  // Otherwise form a 128-bit permutation.
  // FIXME: Detect zero-vector inputs and use the VPERM2X128 to zero that half.
  unsigned PermMask = Mask[0] / 2 | (Mask[2] / 2) << 4;
  return DAG.getNode(X86ISD::VPERM2X128, DL, VT, V1, V2,
                     DAG.getConstant(PermMask, MVT::i8));
}

/// \brief Lower a vector shuffle by first fixing the 128-bit lanes and then
/// shuffling each lane.
///
/// This will only succeed when the result of fixing the 128-bit lanes results
/// in a single-input non-lane-crossing shuffle with a repeating shuffle mask in
/// each 128-bit lanes. This handles many cases where we can quickly blend away
/// the lane crosses early and then use simpler shuffles within each lane.
///
/// FIXME: It might be worthwhile at some point to support this without
/// requiring the 128-bit lane-relative shuffles to be repeating, but currently
/// in x86 only floating point has interesting non-repeating shuffles, and even
/// those are still *marginally* more expensive.
static SDValue lowerVectorShuffleByMerging128BitLanes(
    SDLoc DL, MVT VT, SDValue V1, SDValue V2, ArrayRef<int> Mask,
    const X86Subtarget *Subtarget, SelectionDAG &DAG) {
  assert(!isSingleInputShuffleMask(Mask) &&
         "This is only useful with multiple inputs.");

  int Size = Mask.size();
  int LaneSize = 128 / VT.getScalarSizeInBits();
  int NumLanes = Size / LaneSize;
  assert(NumLanes > 1 && "Only handles 256-bit and wider shuffles.");

  // See if we can build a hypothetical 128-bit lane-fixing shuffle mask. Also
  // check whether the in-128-bit lane shuffles share a repeating pattern.
  SmallVector<int, 4> Lanes;
  Lanes.resize(NumLanes, -1);
  SmallVector<int, 4> InLaneMask;
  InLaneMask.resize(LaneSize, -1);
  for (int i = 0; i < Size; ++i) {
    if (Mask[i] < 0)
      continue;

    int j = i / LaneSize;

    if (Lanes[j] < 0) {
      // First entry we've seen for this lane.
      Lanes[j] = Mask[i] / LaneSize;
    } else if (Lanes[j] != Mask[i] / LaneSize) {
      // This doesn't match the lane selected previously!
      return SDValue();
    }

    // Check that within each lane we have a consistent shuffle mask.
    int k = i % LaneSize;
    if (InLaneMask[k] < 0) {
      InLaneMask[k] = Mask[i] % LaneSize;
    } else if (InLaneMask[k] != Mask[i] % LaneSize) {
      // This doesn't fit a repeating in-lane mask.
      return SDValue();
    }
  }

  // First shuffle the lanes into place.
  MVT LaneVT = MVT::getVectorVT(VT.isFloatingPoint() ? MVT::f64 : MVT::i64,
                                VT.getSizeInBits() / 64);
  SmallVector<int, 8> LaneMask;
  LaneMask.resize(NumLanes * 2, -1);
  for (int i = 0; i < NumLanes; ++i)
    if (Lanes[i] >= 0) {
      LaneMask[2 * i + 0] = 2*Lanes[i] + 0;
      LaneMask[2 * i + 1] = 2*Lanes[i] + 1;
    }

  V1 = DAG.getNode(ISD::BITCAST, DL, LaneVT, V1);
  V2 = DAG.getNode(ISD::BITCAST, DL, LaneVT, V2);
  SDValue LaneShuffle = DAG.getVectorShuffle(LaneVT, DL, V1, V2, LaneMask);

  // Cast it back to the type we actually want.
  LaneShuffle = DAG.getNode(ISD::BITCAST, DL, VT, LaneShuffle);

  // Now do a simple shuffle that isn't lane crossing.
  SmallVector<int, 8> NewMask;
  NewMask.resize(Size, -1);
  for (int i = 0; i < Size; ++i)
    if (Mask[i] >= 0)
      NewMask[i] = (i / LaneSize) * LaneSize + Mask[i] % LaneSize;
  assert(!is128BitLaneCrossingShuffleMask(VT, NewMask) &&
         "Must not introduce lane crosses at this point!");

  return DAG.getVectorShuffle(VT, DL, LaneShuffle, DAG.getUNDEF(VT), NewMask);
}

/// \brief Test whether the specified input (0 or 1) is in-place blended by the
/// given mask.
///
/// This returns true if the elements from a particular input are already in the
/// slot required by the given mask and require no permutation.
static bool isShuffleMaskInputInPlace(int Input, ArrayRef<int> Mask) {
  assert((Input == 0 || Input == 1) && "Only two inputs to shuffles.");
  int Size = Mask.size();
  for (int i = 0; i < Size; ++i)
    if (Mask[i] >= 0 && Mask[i] / Size == Input && Mask[i] % Size != i)
      return false;

  return true;
}

/// \brief Handle lowering of 4-lane 64-bit floating point shuffles.
///
/// Also ends up handling lowering of 4-lane 64-bit integer shuffles when AVX2
/// isn't available.
static SDValue lowerV4F64VectorShuffle(SDValue Op, SDValue V1, SDValue V2,
                                       const X86Subtarget *Subtarget,
                                       SelectionDAG &DAG) {
  SDLoc DL(Op);
  assert(V1.getSimpleValueType() == MVT::v4f64 && "Bad operand type!");
  assert(V2.getSimpleValueType() == MVT::v4f64 && "Bad operand type!");
  ShuffleVectorSDNode *SVOp = cast<ShuffleVectorSDNode>(Op);
  ArrayRef<int> Mask = SVOp->getMask();
  assert(Mask.size() == 4 && "Unexpected mask size for v4 shuffle!");

  SmallVector<int, 4> WidenedMask;
  if (canWidenShuffleElements(Mask, WidenedMask))
    return lowerV2X128VectorShuffle(DL, MVT::v4f64, V1, V2, Mask, Subtarget,
                                    DAG);

  if (isSingleInputShuffleMask(Mask)) {
    // Check for being able to broadcast a single element.
    if (SDValue Broadcast = lowerVectorShuffleAsBroadcast(MVT::v4f64, DL, V1,
                                                          Mask, Subtarget, DAG))
      return Broadcast;

    // Use low duplicate instructions for masks that match their pattern.
    if (isShuffleEquivalent(V1, V2, Mask, 0, 0, 2, 2))
      return DAG.getNode(X86ISD::MOVDDUP, DL, MVT::v4f64, V1);

    if (!is128BitLaneCrossingShuffleMask(MVT::v4f64, Mask)) {
      // Non-half-crossing single input shuffles can be lowerid with an
      // interleaved permutation.
      unsigned VPERMILPMask = (Mask[0] == 1) | ((Mask[1] == 1) << 1) |
                              ((Mask[2] == 3) << 2) | ((Mask[3] == 3) << 3);
      return DAG.getNode(X86ISD::VPERMILPI, DL, MVT::v4f64, V1,
                         DAG.getConstant(VPERMILPMask, MVT::i8));
    }

    // With AVX2 we have direct support for this permutation.
    if (Subtarget->hasAVX2())
      return DAG.getNode(X86ISD::VPERMI, DL, MVT::v4f64, V1,
                         getV4X86ShuffleImm8ForMask(Mask, DAG));

    // Otherwise, fall back.
    return lowerVectorShuffleAsLanePermuteAndBlend(DL, MVT::v4f64, V1, V2, Mask,
                                                   DAG);
  }

  // X86 has dedicated unpack instructions that can handle specific blend
  // operations: UNPCKH and UNPCKL.
  if (isShuffleEquivalent(V1, V2, Mask, 0, 4, 2, 6))
    return DAG.getNode(X86ISD::UNPCKL, DL, MVT::v4f64, V1, V2);
  if (isShuffleEquivalent(V1, V2, Mask, 1, 5, 3, 7))
    return DAG.getNode(X86ISD::UNPCKH, DL, MVT::v4f64, V1, V2);
  if (isShuffleEquivalent(V1, V2, Mask, 4, 0, 6, 2))
    return DAG.getNode(X86ISD::UNPCKL, DL, MVT::v4f64, V2, V1);
  if (isShuffleEquivalent(V1, V2, Mask, 5, 1, 7, 3))
    return DAG.getNode(X86ISD::UNPCKH, DL, MVT::v4f64, V2, V1);

  // If we have a single input to the zero element, insert that into V1 if we
  // can do so cheaply.
  int NumV2Elements =
      std::count_if(Mask.begin(), Mask.end(), [](int M) { return M >= 4; });
  if (NumV2Elements == 1 && Mask[0] >= 4)
    if (SDValue Insertion = lowerVectorShuffleAsElementInsertion(
            MVT::v4f64, DL, V1, V2, Mask, Subtarget, DAG))
      return Insertion;

  if (SDValue Blend = lowerVectorShuffleAsBlend(DL, MVT::v4f64, V1, V2, Mask,
                                                Subtarget, DAG))
    return Blend;

  // Check if the blend happens to exactly fit that of SHUFPD.
  if ((Mask[0] == -1 || Mask[0] < 2) &&
      (Mask[1] == -1 || (Mask[1] >= 4 && Mask[1] < 6)) &&
      (Mask[2] == -1 || (Mask[2] >= 2 && Mask[2] < 4)) &&
      (Mask[3] == -1 || Mask[3] >= 6)) {
    unsigned SHUFPDMask = (Mask[0] == 1) | ((Mask[1] == 5) << 1) |
                          ((Mask[2] == 3) << 2) | ((Mask[3] == 7) << 3);
    return DAG.getNode(X86ISD::SHUFP, DL, MVT::v4f64, V1, V2,
                       DAG.getConstant(SHUFPDMask, MVT::i8));
  }
  if ((Mask[0] == -1 || (Mask[0] >= 4 && Mask[0] < 6)) &&
      (Mask[1] == -1 || Mask[1] < 2) &&
      (Mask[2] == -1 || Mask[2] >= 6) &&
      (Mask[3] == -1 || (Mask[3] >= 2 && Mask[3] < 4))) {
    unsigned SHUFPDMask = (Mask[0] == 5) | ((Mask[1] == 1) << 1) |
                          ((Mask[2] == 7) << 2) | ((Mask[3] == 3) << 3);
    return DAG.getNode(X86ISD::SHUFP, DL, MVT::v4f64, V2, V1,
                       DAG.getConstant(SHUFPDMask, MVT::i8));
  }

  // Try to simplify this by merging 128-bit lanes to enable a lane-based
  // shuffle. However, if we have AVX2 and either inputs are already in place,
  // we will be able to shuffle even across lanes the other input in a single
  // instruction so skip this pattern.
  if (!(Subtarget->hasAVX2() && (isShuffleMaskInputInPlace(0, Mask) ||
                                 isShuffleMaskInputInPlace(1, Mask))))
    if (SDValue Result = lowerVectorShuffleByMerging128BitLanes(
            DL, MVT::v4f64, V1, V2, Mask, Subtarget, DAG))
      return Result;

  // If we have AVX2 then we always want to lower with a blend because an v4 we
  // can fully permute the elements.
  if (Subtarget->hasAVX2())
    return lowerVectorShuffleAsDecomposedShuffleBlend(DL, MVT::v4f64, V1, V2,
                                                      Mask, DAG);

  // Otherwise fall back on generic lowering.
  return lowerVectorShuffleAsSplitOrBlend(DL, MVT::v4f64, V1, V2, Mask, DAG);
}

/// \brief Handle lowering of 4-lane 64-bit integer shuffles.
///
/// This routine is only called when we have AVX2 and thus a reasonable
/// instruction set for v4i64 shuffling..
static SDValue lowerV4I64VectorShuffle(SDValue Op, SDValue V1, SDValue V2,
                                       const X86Subtarget *Subtarget,
                                       SelectionDAG &DAG) {
  SDLoc DL(Op);
  assert(V1.getSimpleValueType() == MVT::v4i64 && "Bad operand type!");
  assert(V2.getSimpleValueType() == MVT::v4i64 && "Bad operand type!");
  ShuffleVectorSDNode *SVOp = cast<ShuffleVectorSDNode>(Op);
  ArrayRef<int> Mask = SVOp->getMask();
  assert(Mask.size() == 4 && "Unexpected mask size for v4 shuffle!");
  assert(Subtarget->hasAVX2() && "We can only lower v4i64 with AVX2!");

  SmallVector<int, 4> WidenedMask;
  if (canWidenShuffleElements(Mask, WidenedMask))
    return lowerV2X128VectorShuffle(DL, MVT::v4i64, V1, V2, Mask, Subtarget,
                                    DAG);

  if (SDValue Blend = lowerVectorShuffleAsBlend(DL, MVT::v4i64, V1, V2, Mask,
                                                Subtarget, DAG))
    return Blend;

  // Check for being able to broadcast a single element.
  if (SDValue Broadcast = lowerVectorShuffleAsBroadcast(MVT::v4i64, DL, V1,
                                                        Mask, Subtarget, DAG))
    return Broadcast;

  // When the shuffle is mirrored between the 128-bit lanes of the unit, we can
  // use lower latency instructions that will operate on both 128-bit lanes.
  SmallVector<int, 2> RepeatedMask;
  if (is128BitLaneRepeatedShuffleMask(MVT::v4i64, Mask, RepeatedMask)) {
    if (isSingleInputShuffleMask(Mask)) {
      int PSHUFDMask[] = {-1, -1, -1, -1};
      for (int i = 0; i < 2; ++i)
        if (RepeatedMask[i] >= 0) {
          PSHUFDMask[2 * i] = 2 * RepeatedMask[i];
          PSHUFDMask[2 * i + 1] = 2 * RepeatedMask[i] + 1;
        }
      return DAG.getNode(
          ISD::BITCAST, DL, MVT::v4i64,
          DAG.getNode(X86ISD::PSHUFD, DL, MVT::v8i32,
                      DAG.getNode(ISD::BITCAST, DL, MVT::v8i32, V1),
                      getV4X86ShuffleImm8ForMask(PSHUFDMask, DAG)));
    }
  }

  // AVX2 provides a direct instruction for permuting a single input across
  // lanes.
  if (isSingleInputShuffleMask(Mask))
    return DAG.getNode(X86ISD::VPERMI, DL, MVT::v4i64, V1,
                       getV4X86ShuffleImm8ForMask(Mask, DAG));

  // Try to use shift instructions.
  if (SDValue Shift =
          lowerVectorShuffleAsShift(DL, MVT::v4i64, V1, V2, Mask, DAG))
    return Shift;

  // Use dedicated unpack instructions for masks that match their pattern.
  if (isShuffleEquivalent(V1, V2, Mask, 0, 4, 2, 6))
    return DAG.getNode(X86ISD::UNPCKL, DL, MVT::v4i64, V1, V2);
  if (isShuffleEquivalent(V1, V2, Mask, 1, 5, 3, 7))
    return DAG.getNode(X86ISD::UNPCKH, DL, MVT::v4i64, V1, V2);
  if (isShuffleEquivalent(V1, V2, Mask, 4, 0, 6, 2))
    return DAG.getNode(X86ISD::UNPCKL, DL, MVT::v4i64, V2, V1);
  if (isShuffleEquivalent(V1, V2, Mask, 5, 1, 7, 3))
    return DAG.getNode(X86ISD::UNPCKH, DL, MVT::v4i64, V2, V1);

  // Try to simplify this by merging 128-bit lanes to enable a lane-based
  // shuffle. However, if we have AVX2 and either inputs are already in place,
  // we will be able to shuffle even across lanes the other input in a single
  // instruction so skip this pattern.
  if (!(Subtarget->hasAVX2() && (isShuffleMaskInputInPlace(0, Mask) ||
                                 isShuffleMaskInputInPlace(1, Mask))))
    if (SDValue Result = lowerVectorShuffleByMerging128BitLanes(
            DL, MVT::v4i64, V1, V2, Mask, Subtarget, DAG))
      return Result;

  // Otherwise fall back on generic blend lowering.
  return lowerVectorShuffleAsDecomposedShuffleBlend(DL, MVT::v4i64, V1, V2,
                                                    Mask, DAG);
}

/// \brief Handle lowering of 8-lane 32-bit floating point shuffles.
///
/// Also ends up handling lowering of 8-lane 32-bit integer shuffles when AVX2
/// isn't available.
static SDValue lowerV8F32VectorShuffle(SDValue Op, SDValue V1, SDValue V2,
                                       const X86Subtarget *Subtarget,
                                       SelectionDAG &DAG) {
  SDLoc DL(Op);
  assert(V1.getSimpleValueType() == MVT::v8f32 && "Bad operand type!");
  assert(V2.getSimpleValueType() == MVT::v8f32 && "Bad operand type!");
  ShuffleVectorSDNode *SVOp = cast<ShuffleVectorSDNode>(Op);
  ArrayRef<int> Mask = SVOp->getMask();
  assert(Mask.size() == 8 && "Unexpected mask size for v8 shuffle!");

  if (SDValue Blend = lowerVectorShuffleAsBlend(DL, MVT::v8f32, V1, V2, Mask,
                                                Subtarget, DAG))
    return Blend;

  // Check for being able to broadcast a single element.
  if (SDValue Broadcast = lowerVectorShuffleAsBroadcast(MVT::v8f32, DL, V1,
                                                        Mask, Subtarget, DAG))
    return Broadcast;

  // If the shuffle mask is repeated in each 128-bit lane, we have many more
  // options to efficiently lower the shuffle.
  SmallVector<int, 4> RepeatedMask;
  if (is128BitLaneRepeatedShuffleMask(MVT::v8f32, Mask, RepeatedMask)) {
    assert(RepeatedMask.size() == 4 &&
           "Repeated masks must be half the mask width!");

    // Use even/odd duplicate instructions for masks that match their pattern.
    if (isShuffleEquivalent(V1, V2, Mask, 0, 0, 2, 2, 4, 4, 6, 6))
      return DAG.getNode(X86ISD::MOVSLDUP, DL, MVT::v8f32, V1);
    if (isShuffleEquivalent(V1, V2, Mask, 1, 1, 3, 3, 5, 5, 7, 7))
      return DAG.getNode(X86ISD::MOVSHDUP, DL, MVT::v8f32, V1);

    if (isSingleInputShuffleMask(Mask))
      return DAG.getNode(X86ISD::VPERMILPI, DL, MVT::v8f32, V1,
                         getV4X86ShuffleImm8ForMask(RepeatedMask, DAG));

    // Use dedicated unpack instructions for masks that match their pattern.
    if (isShuffleEquivalent(V1, V2, Mask, 0, 8, 1, 9, 4, 12, 5, 13))
      return DAG.getNode(X86ISD::UNPCKL, DL, MVT::v8f32, V1, V2);
    if (isShuffleEquivalent(V1, V2, Mask, 2, 10, 3, 11, 6, 14, 7, 15))
      return DAG.getNode(X86ISD::UNPCKH, DL, MVT::v8f32, V1, V2);
    if (isShuffleEquivalent(V1, V2, Mask, 8, 0, 9, 1, 12, 4, 13, 5))
      return DAG.getNode(X86ISD::UNPCKL, DL, MVT::v8f32, V2, V1);
    if (isShuffleEquivalent(V1, V2, Mask, 10, 2, 11, 3, 14, 6, 15, 7))
      return DAG.getNode(X86ISD::UNPCKH, DL, MVT::v8f32, V2, V1);

    // Otherwise, fall back to a SHUFPS sequence. Here it is important that we
    // have already handled any direct blends. We also need to squash the
    // repeated mask into a simulated v4f32 mask.
    for (int i = 0; i < 4; ++i)
      if (RepeatedMask[i] >= 8)
        RepeatedMask[i] -= 4;
    return lowerVectorShuffleWithSHUFPS(DL, MVT::v8f32, RepeatedMask, V1, V2, DAG);
  }

  // If we have a single input shuffle with different shuffle patterns in the
  // two 128-bit lanes use the variable mask to VPERMILPS.
  if (isSingleInputShuffleMask(Mask)) {
    SDValue VPermMask[8];
    for (int i = 0; i < 8; ++i)
      VPermMask[i] = Mask[i] < 0 ? DAG.getUNDEF(MVT::i32)
                                 : DAG.getConstant(Mask[i], MVT::i32);
    if (!is128BitLaneCrossingShuffleMask(MVT::v8f32, Mask))
      return DAG.getNode(
          X86ISD::VPERMILPV, DL, MVT::v8f32, V1,
          DAG.getNode(ISD::BUILD_VECTOR, DL, MVT::v8i32, VPermMask));

    if (Subtarget->hasAVX2())
      return DAG.getNode(X86ISD::VPERMV, DL, MVT::v8f32,
                         DAG.getNode(ISD::BITCAST, DL, MVT::v8f32,
                                     DAG.getNode(ISD::BUILD_VECTOR, DL,
                                                 MVT::v8i32, VPermMask)),
                         V1);

    // Otherwise, fall back.
    return lowerVectorShuffleAsLanePermuteAndBlend(DL, MVT::v8f32, V1, V2, Mask,
                                                   DAG);
  }

  // Try to simplify this by merging 128-bit lanes to enable a lane-based
  // shuffle.
  if (SDValue Result = lowerVectorShuffleByMerging128BitLanes(
          DL, MVT::v8f32, V1, V2, Mask, Subtarget, DAG))
    return Result;

  // If we have AVX2 then we always want to lower with a blend because at v8 we
  // can fully permute the elements.
  if (Subtarget->hasAVX2())
    return lowerVectorShuffleAsDecomposedShuffleBlend(DL, MVT::v8f32, V1, V2,
                                                      Mask, DAG);

  // Otherwise fall back on generic lowering.
  return lowerVectorShuffleAsSplitOrBlend(DL, MVT::v8f32, V1, V2, Mask, DAG);
}

/// \brief Handle lowering of 8-lane 32-bit integer shuffles.
///
/// This routine is only called when we have AVX2 and thus a reasonable
/// instruction set for v8i32 shuffling..
static SDValue lowerV8I32VectorShuffle(SDValue Op, SDValue V1, SDValue V2,
                                       const X86Subtarget *Subtarget,
                                       SelectionDAG &DAG) {
  SDLoc DL(Op);
  assert(V1.getSimpleValueType() == MVT::v8i32 && "Bad operand type!");
  assert(V2.getSimpleValueType() == MVT::v8i32 && "Bad operand type!");
  ShuffleVectorSDNode *SVOp = cast<ShuffleVectorSDNode>(Op);
  ArrayRef<int> Mask = SVOp->getMask();
  assert(Mask.size() == 8 && "Unexpected mask size for v8 shuffle!");
  assert(Subtarget->hasAVX2() && "We can only lower v8i32 with AVX2!");

  // Whenever we can lower this as a zext, that instruction is strictly faster
  // than any alternative. It also allows us to fold memory operands into the
  // shuffle in many cases.
  if (SDValue ZExt = lowerVectorShuffleAsZeroOrAnyExtend(DL, MVT::v8i32, V1, V2,
                                                         Mask, Subtarget, DAG))
    return ZExt;

  if (SDValue Blend = lowerVectorShuffleAsBlend(DL, MVT::v8i32, V1, V2, Mask,
                                                Subtarget, DAG))
    return Blend;

  // Check for being able to broadcast a single element.
  if (SDValue Broadcast = lowerVectorShuffleAsBroadcast(MVT::v8i32, DL, V1,
                                                        Mask, Subtarget, DAG))
    return Broadcast;

  // If the shuffle mask is repeated in each 128-bit lane we can use more
  // efficient instructions that mirror the shuffles across the two 128-bit
  // lanes.
  SmallVector<int, 4> RepeatedMask;
  if (is128BitLaneRepeatedShuffleMask(MVT::v8i32, Mask, RepeatedMask)) {
    assert(RepeatedMask.size() == 4 && "Unexpected repeated mask size!");
    if (isSingleInputShuffleMask(Mask))
      return DAG.getNode(X86ISD::PSHUFD, DL, MVT::v8i32, V1,
                         getV4X86ShuffleImm8ForMask(RepeatedMask, DAG));

    // Use dedicated unpack instructions for masks that match their pattern.
    if (isShuffleEquivalent(V1, V2, Mask, 0, 8, 1, 9, 4, 12, 5, 13))
      return DAG.getNode(X86ISD::UNPCKL, DL, MVT::v8i32, V1, V2);
    if (isShuffleEquivalent(V1, V2, Mask, 2, 10, 3, 11, 6, 14, 7, 15))
      return DAG.getNode(X86ISD::UNPCKH, DL, MVT::v8i32, V1, V2);
    if (isShuffleEquivalent(V1, V2, Mask, 8, 0, 9, 1, 12, 4, 13, 5))
      return DAG.getNode(X86ISD::UNPCKL, DL, MVT::v8i32, V2, V1);
    if (isShuffleEquivalent(V1, V2, Mask, 10, 2, 11, 3, 14, 6, 15, 7))
      return DAG.getNode(X86ISD::UNPCKH, DL, MVT::v8i32, V2, V1);
  }

  // Try to use shift instructions.
  if (SDValue Shift =
          lowerVectorShuffleAsShift(DL, MVT::v8i32, V1, V2, Mask, DAG))
    return Shift;

  if (SDValue Rotate = lowerVectorShuffleAsByteRotate(
          DL, MVT::v8i32, V1, V2, Mask, Subtarget, DAG))
    return Rotate;

  // If the shuffle patterns aren't repeated but it is a single input, directly
  // generate a cross-lane VPERMD instruction.
  if (isSingleInputShuffleMask(Mask)) {
    SDValue VPermMask[8];
    for (int i = 0; i < 8; ++i)
      VPermMask[i] = Mask[i] < 0 ? DAG.getUNDEF(MVT::i32)
                                 : DAG.getConstant(Mask[i], MVT::i32);
    return DAG.getNode(
        X86ISD::VPERMV, DL, MVT::v8i32,
        DAG.getNode(ISD::BUILD_VECTOR, DL, MVT::v8i32, VPermMask), V1);
  }

  // Try to simplify this by merging 128-bit lanes to enable a lane-based
  // shuffle.
  if (SDValue Result = lowerVectorShuffleByMerging128BitLanes(
          DL, MVT::v8i32, V1, V2, Mask, Subtarget, DAG))
    return Result;

  // Otherwise fall back on generic blend lowering.
  return lowerVectorShuffleAsDecomposedShuffleBlend(DL, MVT::v8i32, V1, V2,
                                                    Mask, DAG);
}

/// \brief Handle lowering of 16-lane 16-bit integer shuffles.
///
/// This routine is only called when we have AVX2 and thus a reasonable
/// instruction set for v16i16 shuffling..
static SDValue lowerV16I16VectorShuffle(SDValue Op, SDValue V1, SDValue V2,
                                        const X86Subtarget *Subtarget,
                                        SelectionDAG &DAG) {
  SDLoc DL(Op);
  assert(V1.getSimpleValueType() == MVT::v16i16 && "Bad operand type!");
  assert(V2.getSimpleValueType() == MVT::v16i16 && "Bad operand type!");
  ShuffleVectorSDNode *SVOp = cast<ShuffleVectorSDNode>(Op);
  ArrayRef<int> Mask = SVOp->getMask();
  assert(Mask.size() == 16 && "Unexpected mask size for v16 shuffle!");
  assert(Subtarget->hasAVX2() && "We can only lower v16i16 with AVX2!");

  // Whenever we can lower this as a zext, that instruction is strictly faster
  // than any alternative. It also allows us to fold memory operands into the
  // shuffle in many cases.
  if (SDValue ZExt = lowerVectorShuffleAsZeroOrAnyExtend(DL, MVT::v16i16, V1, V2,
                                                         Mask, Subtarget, DAG))
    return ZExt;

  // Check for being able to broadcast a single element.
  if (SDValue Broadcast = lowerVectorShuffleAsBroadcast(MVT::v16i16, DL, V1,
                                                        Mask, Subtarget, DAG))
    return Broadcast;

  if (SDValue Blend = lowerVectorShuffleAsBlend(DL, MVT::v16i16, V1, V2, Mask,
                                                Subtarget, DAG))
    return Blend;

  // Use dedicated unpack instructions for masks that match their pattern.
  if (isShuffleEquivalent(V1, V2, Mask,
                          // First 128-bit lane:
                          0, 16, 1, 17, 2, 18, 3, 19,
                          // Second 128-bit lane:
                          8, 24, 9, 25, 10, 26, 11, 27))
    return DAG.getNode(X86ISD::UNPCKL, DL, MVT::v16i16, V1, V2);
  if (isShuffleEquivalent(V1, V2, Mask,
                          // First 128-bit lane:
                          4, 20, 5, 21, 6, 22, 7, 23,
                          // Second 128-bit lane:
                          12, 28, 13, 29, 14, 30, 15, 31))
    return DAG.getNode(X86ISD::UNPCKH, DL, MVT::v16i16, V1, V2);

  // Try to use shift instructions.
  if (SDValue Shift =
          lowerVectorShuffleAsShift(DL, MVT::v16i16, V1, V2, Mask, DAG))
    return Shift;

  // Try to use byte rotation instructions.
  if (SDValue Rotate = lowerVectorShuffleAsByteRotate(
          DL, MVT::v16i16, V1, V2, Mask, Subtarget, DAG))
    return Rotate;

  if (isSingleInputShuffleMask(Mask)) {
    // There are no generalized cross-lane shuffle operations available on i16
    // element types.
    if (is128BitLaneCrossingShuffleMask(MVT::v16i16, Mask))
      return lowerVectorShuffleAsLanePermuteAndBlend(DL, MVT::v16i16, V1, V2,
                                                     Mask, DAG);

    SDValue PSHUFBMask[32];
    for (int i = 0; i < 16; ++i) {
      if (Mask[i] == -1) {
        PSHUFBMask[2 * i] = PSHUFBMask[2 * i + 1] = DAG.getUNDEF(MVT::i8);
        continue;
      }

      int M = i < 8 ? Mask[i] : Mask[i] - 8;
      assert(M >= 0 && M < 8 && "Invalid single-input mask!");
      PSHUFBMask[2 * i] = DAG.getConstant(2 * M, MVT::i8);
      PSHUFBMask[2 * i + 1] = DAG.getConstant(2 * M + 1, MVT::i8);
    }
    return DAG.getNode(
        ISD::BITCAST, DL, MVT::v16i16,
        DAG.getNode(
            X86ISD::PSHUFB, DL, MVT::v32i8,
            DAG.getNode(ISD::BITCAST, DL, MVT::v32i8, V1),
            DAG.getNode(ISD::BUILD_VECTOR, DL, MVT::v32i8, PSHUFBMask)));
  }

  // Try to simplify this by merging 128-bit lanes to enable a lane-based
  // shuffle.
  if (SDValue Result = lowerVectorShuffleByMerging128BitLanes(
          DL, MVT::v16i16, V1, V2, Mask, Subtarget, DAG))
    return Result;

  // Otherwise fall back on generic lowering.
  return lowerVectorShuffleAsSplitOrBlend(DL, MVT::v16i16, V1, V2, Mask, DAG);
}

/// \brief Handle lowering of 32-lane 8-bit integer shuffles.
///
/// This routine is only called when we have AVX2 and thus a reasonable
/// instruction set for v32i8 shuffling..
static SDValue lowerV32I8VectorShuffle(SDValue Op, SDValue V1, SDValue V2,
                                       const X86Subtarget *Subtarget,
                                       SelectionDAG &DAG) {
  SDLoc DL(Op);
  assert(V1.getSimpleValueType() == MVT::v32i8 && "Bad operand type!");
  assert(V2.getSimpleValueType() == MVT::v32i8 && "Bad operand type!");
  ShuffleVectorSDNode *SVOp = cast<ShuffleVectorSDNode>(Op);
  ArrayRef<int> Mask = SVOp->getMask();
  assert(Mask.size() == 32 && "Unexpected mask size for v32 shuffle!");
  assert(Subtarget->hasAVX2() && "We can only lower v32i8 with AVX2!");

  // Whenever we can lower this as a zext, that instruction is strictly faster
  // than any alternative. It also allows us to fold memory operands into the
  // shuffle in many cases.
  if (SDValue ZExt = lowerVectorShuffleAsZeroOrAnyExtend(DL, MVT::v32i8, V1, V2,
                                                         Mask, Subtarget, DAG))
    return ZExt;

  // Check for being able to broadcast a single element.
  if (SDValue Broadcast = lowerVectorShuffleAsBroadcast(MVT::v32i8, DL, V1,
                                                        Mask, Subtarget, DAG))
    return Broadcast;

  if (SDValue Blend = lowerVectorShuffleAsBlend(DL, MVT::v32i8, V1, V2, Mask,
                                                Subtarget, DAG))
    return Blend;

  // Use dedicated unpack instructions for masks that match their pattern.
  // Note that these are repeated 128-bit lane unpacks, not unpacks across all
  // 256-bit lanes.
  if (isShuffleEquivalent(
          V1, V2, Mask,
          // First 128-bit lane:
          0, 32, 1, 33, 2, 34, 3, 35, 4, 36, 5, 37, 6, 38, 7, 39,
          // Second 128-bit lane:
          16, 48, 17, 49, 18, 50, 19, 51, 20, 52, 21, 53, 22, 54, 23, 55))
    return DAG.getNode(X86ISD::UNPCKL, DL, MVT::v32i8, V1, V2);
  if (isShuffleEquivalent(
          V1, V2, Mask,
          // First 128-bit lane:
          8, 40, 9, 41, 10, 42, 11, 43, 12, 44, 13, 45, 14, 46, 15, 47,
          // Second 128-bit lane:
          24, 56, 25, 57, 26, 58, 27, 59, 28, 60, 29, 61, 30, 62, 31, 63))
    return DAG.getNode(X86ISD::UNPCKH, DL, MVT::v32i8, V1, V2);

  // Try to use shift instructions.
  if (SDValue Shift =
          lowerVectorShuffleAsShift(DL, MVT::v32i8, V1, V2, Mask, DAG))
    return Shift;

  // Try to use byte rotation instructions.
  if (SDValue Rotate = lowerVectorShuffleAsByteRotate(
          DL, MVT::v32i8, V1, V2, Mask, Subtarget, DAG))
    return Rotate;

  if (isSingleInputShuffleMask(Mask)) {
    // There are no generalized cross-lane shuffle operations available on i8
    // element types.
    if (is128BitLaneCrossingShuffleMask(MVT::v32i8, Mask))
      return lowerVectorShuffleAsLanePermuteAndBlend(DL, MVT::v32i8, V1, V2,
                                                     Mask, DAG);

    SDValue PSHUFBMask[32];
    for (int i = 0; i < 32; ++i)
      PSHUFBMask[i] =
          Mask[i] < 0
              ? DAG.getUNDEF(MVT::i8)
              : DAG.getConstant(Mask[i] < 16 ? Mask[i] : Mask[i] - 16, MVT::i8);

    return DAG.getNode(
        X86ISD::PSHUFB, DL, MVT::v32i8, V1,
        DAG.getNode(ISD::BUILD_VECTOR, DL, MVT::v32i8, PSHUFBMask));
  }

  // Try to simplify this by merging 128-bit lanes to enable a lane-based
  // shuffle.
  if (SDValue Result = lowerVectorShuffleByMerging128BitLanes(
          DL, MVT::v32i8, V1, V2, Mask, Subtarget, DAG))
    return Result;

  // Otherwise fall back on generic lowering.
  return lowerVectorShuffleAsSplitOrBlend(DL, MVT::v32i8, V1, V2, Mask, DAG);
}

/// \brief High-level routine to lower various 256-bit x86 vector shuffles.
///
/// This routine either breaks down the specific type of a 256-bit x86 vector
/// shuffle or splits it into two 128-bit shuffles and fuses the results back
/// together based on the available instructions.
static SDValue lower256BitVectorShuffle(SDValue Op, SDValue V1, SDValue V2,
                                        MVT VT, const X86Subtarget *Subtarget,
                                        SelectionDAG &DAG) {
  SDLoc DL(Op);
  ShuffleVectorSDNode *SVOp = cast<ShuffleVectorSDNode>(Op);
  ArrayRef<int> Mask = SVOp->getMask();

  // There is a really nice hard cut-over between AVX1 and AVX2 that means we can
  // check for those subtargets here and avoid much of the subtarget querying in
  // the per-vector-type lowering routines. With AVX1 we have essentially *zero*
  // ability to manipulate a 256-bit vector with integer types. Since we'll use
  // floating point types there eventually, just immediately cast everything to
  // a float and operate entirely in that domain.
  if (VT.isInteger() && !Subtarget->hasAVX2()) {
    int ElementBits = VT.getScalarSizeInBits();
    if (ElementBits < 32)
      // No floating point type available, decompose into 128-bit vectors.
      return splitAndLowerVectorShuffle(DL, VT, V1, V2, Mask, DAG);

    MVT FpVT = MVT::getVectorVT(MVT::getFloatingPointVT(ElementBits),
                                VT.getVectorNumElements());
    V1 = DAG.getNode(ISD::BITCAST, DL, FpVT, V1);
    V2 = DAG.getNode(ISD::BITCAST, DL, FpVT, V2);
    return DAG.getNode(ISD::BITCAST, DL, VT,
                       DAG.getVectorShuffle(FpVT, DL, V1, V2, Mask));
  }

  switch (VT.SimpleTy) {
  case MVT::v4f64:
    return lowerV4F64VectorShuffle(Op, V1, V2, Subtarget, DAG);
  case MVT::v4i64:
    return lowerV4I64VectorShuffle(Op, V1, V2, Subtarget, DAG);
  case MVT::v8f32:
    return lowerV8F32VectorShuffle(Op, V1, V2, Subtarget, DAG);
  case MVT::v8i32:
    return lowerV8I32VectorShuffle(Op, V1, V2, Subtarget, DAG);
  case MVT::v16i16:
    return lowerV16I16VectorShuffle(Op, V1, V2, Subtarget, DAG);
  case MVT::v32i8:
    return lowerV32I8VectorShuffle(Op, V1, V2, Subtarget, DAG);

  default:
    llvm_unreachable("Not a valid 256-bit x86 vector type!");
  }
}

/// \brief Handle lowering of 8-lane 64-bit floating point shuffles.
static SDValue lowerV8F64VectorShuffle(SDValue Op, SDValue V1, SDValue V2,
                                       const X86Subtarget *Subtarget,
                                       SelectionDAG &DAG) {
  SDLoc DL(Op);
  assert(V1.getSimpleValueType() == MVT::v8f64 && "Bad operand type!");
  assert(V2.getSimpleValueType() == MVT::v8f64 && "Bad operand type!");
  ShuffleVectorSDNode *SVOp = cast<ShuffleVectorSDNode>(Op);
  ArrayRef<int> Mask = SVOp->getMask();
  assert(Mask.size() == 8 && "Unexpected mask size for v8 shuffle!");

  // X86 has dedicated unpack instructions that can handle specific blend
  // operations: UNPCKH and UNPCKL.
  if (isShuffleEquivalent(V1, V2, Mask, 0, 8, 2, 10, 4, 12, 6, 14))
    return DAG.getNode(X86ISD::UNPCKL, DL, MVT::v8f64, V1, V2);
  if (isShuffleEquivalent(V1, V2, Mask, 1, 9, 3, 11, 5, 13, 7, 15))
    return DAG.getNode(X86ISD::UNPCKH, DL, MVT::v8f64, V1, V2);

  // FIXME: Implement direct support for this type!
  return splitAndLowerVectorShuffle(DL, MVT::v8f64, V1, V2, Mask, DAG);
}

/// \brief Handle lowering of 16-lane 32-bit floating point shuffles.
static SDValue lowerV16F32VectorShuffle(SDValue Op, SDValue V1, SDValue V2,
                                       const X86Subtarget *Subtarget,
                                       SelectionDAG &DAG) {
  SDLoc DL(Op);
  assert(V1.getSimpleValueType() == MVT::v16f32 && "Bad operand type!");
  assert(V2.getSimpleValueType() == MVT::v16f32 && "Bad operand type!");
  ShuffleVectorSDNode *SVOp = cast<ShuffleVectorSDNode>(Op);
  ArrayRef<int> Mask = SVOp->getMask();
  assert(Mask.size() == 16 && "Unexpected mask size for v16 shuffle!");

  // Use dedicated unpack instructions for masks that match their pattern.
  if (isShuffleEquivalent(V1, V2, Mask,
                          0, 16, 1, 17, 4, 20, 5, 21,
                          8, 24, 9, 25, 12, 28, 13, 29))
    return DAG.getNode(X86ISD::UNPCKL, DL, MVT::v16f32, V1, V2);
  if (isShuffleEquivalent(V1, V2, Mask,
                          2, 18, 3, 19, 6, 22, 7, 23,
                          10, 26, 11, 27, 14, 30, 15, 31))
    return DAG.getNode(X86ISD::UNPCKH, DL, MVT::v16f32, V1, V2);

  // FIXME: Implement direct support for this type!
  return splitAndLowerVectorShuffle(DL, MVT::v16f32, V1, V2, Mask, DAG);
}

/// \brief Handle lowering of 8-lane 64-bit integer shuffles.
static SDValue lowerV8I64VectorShuffle(SDValue Op, SDValue V1, SDValue V2,
                                       const X86Subtarget *Subtarget,
                                       SelectionDAG &DAG) {
  SDLoc DL(Op);
  assert(V1.getSimpleValueType() == MVT::v8i64 && "Bad operand type!");
  assert(V2.getSimpleValueType() == MVT::v8i64 && "Bad operand type!");
  ShuffleVectorSDNode *SVOp = cast<ShuffleVectorSDNode>(Op);
  ArrayRef<int> Mask = SVOp->getMask();
  assert(Mask.size() == 8 && "Unexpected mask size for v8 shuffle!");

  // X86 has dedicated unpack instructions that can handle specific blend
  // operations: UNPCKH and UNPCKL.
  if (isShuffleEquivalent(V1, V2, Mask, 0, 8, 2, 10, 4, 12, 6, 14))
    return DAG.getNode(X86ISD::UNPCKL, DL, MVT::v8i64, V1, V2);
  if (isShuffleEquivalent(V1, V2, Mask, 1, 9, 3, 11, 5, 13, 7, 15))
    return DAG.getNode(X86ISD::UNPCKH, DL, MVT::v8i64, V1, V2);

  // FIXME: Implement direct support for this type!
  return splitAndLowerVectorShuffle(DL, MVT::v8i64, V1, V2, Mask, DAG);
}

/// \brief Handle lowering of 16-lane 32-bit integer shuffles.
static SDValue lowerV16I32VectorShuffle(SDValue Op, SDValue V1, SDValue V2,
                                       const X86Subtarget *Subtarget,
                                       SelectionDAG &DAG) {
  SDLoc DL(Op);
  assert(V1.getSimpleValueType() == MVT::v16i32 && "Bad operand type!");
  assert(V2.getSimpleValueType() == MVT::v16i32 && "Bad operand type!");
  ShuffleVectorSDNode *SVOp = cast<ShuffleVectorSDNode>(Op);
  ArrayRef<int> Mask = SVOp->getMask();
  assert(Mask.size() == 16 && "Unexpected mask size for v16 shuffle!");

  // Use dedicated unpack instructions for masks that match their pattern.
  if (isShuffleEquivalent(V1, V2, Mask,
                          0, 16, 1, 17, 4, 20, 5, 21,
                          8, 24, 9, 25, 12, 28, 13, 29))
    return DAG.getNode(X86ISD::UNPCKL, DL, MVT::v16i32, V1, V2);
  if (isShuffleEquivalent(V1, V2, Mask,
                          2, 18, 3, 19, 6, 22, 7, 23,
                          10, 26, 11, 27, 14, 30, 15, 31))
    return DAG.getNode(X86ISD::UNPCKH, DL, MVT::v16i32, V1, V2);

  // FIXME: Implement direct support for this type!
  return splitAndLowerVectorShuffle(DL, MVT::v16i32, V1, V2, Mask, DAG);
}

/// \brief Handle lowering of 32-lane 16-bit integer shuffles.
static SDValue lowerV32I16VectorShuffle(SDValue Op, SDValue V1, SDValue V2,
                                        const X86Subtarget *Subtarget,
                                        SelectionDAG &DAG) {
  SDLoc DL(Op);
  assert(V1.getSimpleValueType() == MVT::v32i16 && "Bad operand type!");
  assert(V2.getSimpleValueType() == MVT::v32i16 && "Bad operand type!");
  ShuffleVectorSDNode *SVOp = cast<ShuffleVectorSDNode>(Op);
  ArrayRef<int> Mask = SVOp->getMask();
  assert(Mask.size() == 32 && "Unexpected mask size for v32 shuffle!");
  assert(Subtarget->hasBWI() && "We can only lower v32i16 with AVX-512-BWI!");

  // FIXME: Implement direct support for this type!
  return splitAndLowerVectorShuffle(DL, MVT::v32i16, V1, V2, Mask, DAG);
}

/// \brief Handle lowering of 64-lane 8-bit integer shuffles.
static SDValue lowerV64I8VectorShuffle(SDValue Op, SDValue V1, SDValue V2,
                                       const X86Subtarget *Subtarget,
                                       SelectionDAG &DAG) {
  SDLoc DL(Op);
  assert(V1.getSimpleValueType() == MVT::v64i8 && "Bad operand type!");
  assert(V2.getSimpleValueType() == MVT::v64i8 && "Bad operand type!");
  ShuffleVectorSDNode *SVOp = cast<ShuffleVectorSDNode>(Op);
  ArrayRef<int> Mask = SVOp->getMask();
  assert(Mask.size() == 64 && "Unexpected mask size for v64 shuffle!");
  assert(Subtarget->hasBWI() && "We can only lower v64i8 with AVX-512-BWI!");

  // FIXME: Implement direct support for this type!
  return splitAndLowerVectorShuffle(DL, MVT::v64i8, V1, V2, Mask, DAG);
}

/// \brief High-level routine to lower various 512-bit x86 vector shuffles.
///
/// This routine either breaks down the specific type of a 512-bit x86 vector
/// shuffle or splits it into two 256-bit shuffles and fuses the results back
/// together based on the available instructions.
static SDValue lower512BitVectorShuffle(SDValue Op, SDValue V1, SDValue V2,
                                        MVT VT, const X86Subtarget *Subtarget,
                                        SelectionDAG &DAG) {
  SDLoc DL(Op);
  ShuffleVectorSDNode *SVOp = cast<ShuffleVectorSDNode>(Op);
  ArrayRef<int> Mask = SVOp->getMask();
  assert(Subtarget->hasAVX512() &&
         "Cannot lower 512-bit vectors w/ basic ISA!");

  // Check for being able to broadcast a single element.
  if (SDValue Broadcast = lowerVectorShuffleAsBroadcast(VT.SimpleTy, DL, V1,
                                                        Mask, Subtarget, DAG))
    return Broadcast;

  // Dispatch to each element type for lowering. If we don't have supprot for
  // specific element type shuffles at 512 bits, immediately split them and
  // lower them. Each lowering routine of a given type is allowed to assume that
  // the requisite ISA extensions for that element type are available.
  switch (VT.SimpleTy) {
  case MVT::v8f64:
    return lowerV8F64VectorShuffle(Op, V1, V2, Subtarget, DAG);
  case MVT::v16f32:
    return lowerV16F32VectorShuffle(Op, V1, V2, Subtarget, DAG);
  case MVT::v8i64:
    return lowerV8I64VectorShuffle(Op, V1, V2, Subtarget, DAG);
  case MVT::v16i32:
    return lowerV16I32VectorShuffle(Op, V1, V2, Subtarget, DAG);
  case MVT::v32i16:
    if (Subtarget->hasBWI())
      return lowerV32I16VectorShuffle(Op, V1, V2, Subtarget, DAG);
    break;
  case MVT::v64i8:
    if (Subtarget->hasBWI())
      return lowerV64I8VectorShuffle(Op, V1, V2, Subtarget, DAG);
    break;

  default:
    llvm_unreachable("Not a valid 512-bit x86 vector type!");
  }

  // Otherwise fall back on splitting.
  return splitAndLowerVectorShuffle(DL, VT, V1, V2, Mask, DAG);
}

/// \brief Top-level lowering for x86 vector shuffles.
///
/// This handles decomposition, canonicalization, and lowering of all x86
/// vector shuffles. Most of the specific lowering strategies are encapsulated
/// above in helper routines. The canonicalization attempts to widen shuffles
/// to involve fewer lanes of wider elements, consolidate symmetric patterns
/// s.t. only one of the two inputs needs to be tested, etc.
static SDValue lowerVectorShuffle(SDValue Op, const X86Subtarget *Subtarget,
                                  SelectionDAG &DAG) {
  ShuffleVectorSDNode *SVOp = cast<ShuffleVectorSDNode>(Op);
  ArrayRef<int> Mask = SVOp->getMask();
  SDValue V1 = Op.getOperand(0);
  SDValue V2 = Op.getOperand(1);
  MVT VT = Op.getSimpleValueType();
  int NumElements = VT.getVectorNumElements();
  SDLoc dl(Op);

  assert(VT.getSizeInBits() != 64 && "Can't lower MMX shuffles");

  bool V1IsUndef = V1.getOpcode() == ISD::UNDEF;
  bool V2IsUndef = V2.getOpcode() == ISD::UNDEF;
  if (V1IsUndef && V2IsUndef)
    return DAG.getUNDEF(VT);

  // When we create a shuffle node we put the UNDEF node to second operand,
  // but in some cases the first operand may be transformed to UNDEF.
  // In this case we should just commute the node.
  if (V1IsUndef)
    return DAG.getCommutedVectorShuffle(*SVOp);

  // Check for non-undef masks pointing at an undef vector and make the masks
  // undef as well. This makes it easier to match the shuffle based solely on
  // the mask.
  if (V2IsUndef)
    for (int M : Mask)
      if (M >= NumElements) {
        SmallVector<int, 8> NewMask(Mask.begin(), Mask.end());
        for (int &M : NewMask)
          if (M >= NumElements)
            M = -1;
        return DAG.getVectorShuffle(VT, dl, V1, V2, NewMask);
      }

  // We actually see shuffles that are entirely re-arrangements of a set of
  // zero inputs. This mostly happens while decomposing complex shuffles into
  // simple ones. Directly lower these as a buildvector of zeros.
  SmallBitVector Zeroable = computeZeroableShuffleElements(Mask, V1, V2);
  if (Zeroable.all())
    return getZeroVector(VT, Subtarget, DAG, dl);

  // Try to collapse shuffles into using a vector type with fewer elements but
  // wider element types. We cap this to not form integers or floating point
  // elements wider than 64 bits, but it might be interesting to form i128
  // integers to handle flipping the low and high halves of AVX 256-bit vectors.
  SmallVector<int, 16> WidenedMask;
  if (VT.getScalarSizeInBits() < 64 &&
      canWidenShuffleElements(Mask, WidenedMask)) {
    MVT NewEltVT = VT.isFloatingPoint()
                       ? MVT::getFloatingPointVT(VT.getScalarSizeInBits() * 2)
                       : MVT::getIntegerVT(VT.getScalarSizeInBits() * 2);
    MVT NewVT = MVT::getVectorVT(NewEltVT, VT.getVectorNumElements() / 2);
    // Make sure that the new vector type is legal. For example, v2f64 isn't
    // legal on SSE1.
    if (DAG.getTargetLoweringInfo().isTypeLegal(NewVT)) {
      V1 = DAG.getNode(ISD::BITCAST, dl, NewVT, V1);
      V2 = DAG.getNode(ISD::BITCAST, dl, NewVT, V2);
      return DAG.getNode(ISD::BITCAST, dl, VT,
                         DAG.getVectorShuffle(NewVT, dl, V1, V2, WidenedMask));
    }
  }

  int NumV1Elements = 0, NumUndefElements = 0, NumV2Elements = 0;
  for (int M : SVOp->getMask())
    if (M < 0)
      ++NumUndefElements;
    else if (M < NumElements)
      ++NumV1Elements;
    else
      ++NumV2Elements;

  // Commute the shuffle as needed such that more elements come from V1 than
  // V2. This allows us to match the shuffle pattern strictly on how many
  // elements come from V1 without handling the symmetric cases.
  if (NumV2Elements > NumV1Elements)
    return DAG.getCommutedVectorShuffle(*SVOp);

  // When the number of V1 and V2 elements are the same, try to minimize the
  // number of uses of V2 in the low half of the vector. When that is tied,
  // ensure that the sum of indices for V1 is equal to or lower than the sum
  // indices for V2. When those are equal, try to ensure that the number of odd
  // indices for V1 is lower than the number of odd indices for V2.
  if (NumV1Elements == NumV2Elements) {
    int LowV1Elements = 0, LowV2Elements = 0;
    for (int M : SVOp->getMask().slice(0, NumElements / 2))
      if (M >= NumElements)
        ++LowV2Elements;
      else if (M >= 0)
        ++LowV1Elements;
    if (LowV2Elements > LowV1Elements) {
      return DAG.getCommutedVectorShuffle(*SVOp);
    } else if (LowV2Elements == LowV1Elements) {
      int SumV1Indices = 0, SumV2Indices = 0;
      for (int i = 0, Size = SVOp->getMask().size(); i < Size; ++i)
        if (SVOp->getMask()[i] >= NumElements)
          SumV2Indices += i;
        else if (SVOp->getMask()[i] >= 0)
          SumV1Indices += i;
      if (SumV2Indices < SumV1Indices) {
        return DAG.getCommutedVectorShuffle(*SVOp);
      } else if (SumV2Indices == SumV1Indices) {
        int NumV1OddIndices = 0, NumV2OddIndices = 0;
        for (int i = 0, Size = SVOp->getMask().size(); i < Size; ++i)
          if (SVOp->getMask()[i] >= NumElements)
            NumV2OddIndices += i % 2;
          else if (SVOp->getMask()[i] >= 0)
            NumV1OddIndices += i % 2;
        if (NumV2OddIndices < NumV1OddIndices)
          return DAG.getCommutedVectorShuffle(*SVOp);
      }
    }
  }

  // For each vector width, delegate to a specialized lowering routine.
  if (VT.getSizeInBits() == 128)
    return lower128BitVectorShuffle(Op, V1, V2, VT, Subtarget, DAG);

  if (VT.getSizeInBits() == 256)
    return lower256BitVectorShuffle(Op, V1, V2, VT, Subtarget, DAG);

  // Force AVX-512 vectors to be scalarized for now.
  // FIXME: Implement AVX-512 support!
  if (VT.getSizeInBits() == 512)
    return lower512BitVectorShuffle(Op, V1, V2, VT, Subtarget, DAG);

  llvm_unreachable("Unimplemented!");
}


//===----------------------------------------------------------------------===//
// Legacy vector shuffle lowering
//
// This code is the legacy code handling vector shuffles until the above
// replaces its functionality and performance.
//===----------------------------------------------------------------------===//

static bool isBlendMask(ArrayRef<int> MaskVals, MVT VT, bool hasSSE41,
                        bool hasInt256, unsigned *MaskOut = nullptr) {
  MVT EltVT = VT.getVectorElementType();

  // There is no blend with immediate in AVX-512.
  if (VT.is512BitVector())
    return false;

  if (!hasSSE41 || EltVT == MVT::i8)
    return false;
  if (!hasInt256 && VT == MVT::v16i16)
    return false;

  unsigned MaskValue = 0;
  unsigned NumElems = VT.getVectorNumElements();
  // There are 2 lanes if (NumElems > 8), and 1 lane otherwise.
  unsigned NumLanes = (NumElems - 1) / 8 + 1;
  unsigned NumElemsInLane = NumElems / NumLanes;

  // Blend for v16i16 should be symmetric for both lanes.
  for (unsigned i = 0; i < NumElemsInLane; ++i) {

    int SndLaneEltIdx = (NumLanes == 2) ? MaskVals[i + NumElemsInLane] : -1;
    int EltIdx = MaskVals[i];

    if ((EltIdx < 0 || EltIdx == (int)i) &&
        (SndLaneEltIdx < 0 || SndLaneEltIdx == (int)(i + NumElemsInLane)))
      continue;

    if (((unsigned)EltIdx == (i + NumElems)) &&
        (SndLaneEltIdx < 0 ||
         (unsigned)SndLaneEltIdx == i + NumElems + NumElemsInLane))
      MaskValue |= (1 << i);
    else
      return false;
  }

  if (MaskOut)
    *MaskOut = MaskValue;
  return true;
}

// Try to lower a shuffle node into a simple blend instruction.
// This function assumes isBlendMask returns true for this
// SuffleVectorSDNode
static SDValue LowerVECTOR_SHUFFLEtoBlend(ShuffleVectorSDNode *SVOp,
                                          unsigned MaskValue,
                                          const X86Subtarget *Subtarget,
                                          SelectionDAG &DAG) {
  MVT VT = SVOp->getSimpleValueType(0);
  MVT EltVT = VT.getVectorElementType();
  assert(isBlendMask(SVOp->getMask(), VT, Subtarget->hasSSE41(),
                     Subtarget->hasInt256() && "Trying to lower a "
                                               "VECTOR_SHUFFLE to a Blend but "
                                               "with the wrong mask"));
  SDValue V1 = SVOp->getOperand(0);
  SDValue V2 = SVOp->getOperand(1);
  SDLoc dl(SVOp);
  unsigned NumElems = VT.getVectorNumElements();

  // Convert i32 vectors to floating point if it is not AVX2.
  // AVX2 introduced VPBLENDD instruction for 128 and 256-bit vectors.
  MVT BlendVT = VT;
  if (EltVT == MVT::i64 || (EltVT == MVT::i32 && !Subtarget->hasInt256())) {
    BlendVT = MVT::getVectorVT(MVT::getFloatingPointVT(EltVT.getSizeInBits()),
                               NumElems);
    V1 = DAG.getNode(ISD::BITCAST, dl, VT, V1);
    V2 = DAG.getNode(ISD::BITCAST, dl, VT, V2);
  }

  SDValue Ret = DAG.getNode(X86ISD::BLENDI, dl, BlendVT, V1, V2,
                            DAG.getConstant(MaskValue, MVT::i32));
  return DAG.getNode(ISD::BITCAST, dl, VT, Ret);
}

/// In vector type \p VT, return true if the element at index \p InputIdx
/// falls on a different 128-bit lane than \p OutputIdx.
static bool ShuffleCrosses128bitLane(MVT VT, unsigned InputIdx,
                                     unsigned OutputIdx) {
  unsigned EltSize = VT.getVectorElementType().getSizeInBits();
  return InputIdx * EltSize / 128 != OutputIdx * EltSize / 128;
}

/// Generate a PSHUFB if possible.  Selects elements from \p V1 according to
/// \p MaskVals.  MaskVals[OutputIdx] = InputIdx specifies that we want to
/// shuffle the element at InputIdx in V1 to OutputIdx in the result.  If \p
/// MaskVals refers to elements outside of \p V1 or is undef (-1), insert a
/// zero.
static SDValue getPSHUFB(ArrayRef<int> MaskVals, SDValue V1, SDLoc &dl,
                         SelectionDAG &DAG) {
  MVT VT = V1.getSimpleValueType();
  assert(VT.is128BitVector() || VT.is256BitVector());

  MVT EltVT = VT.getVectorElementType();
  unsigned EltSizeInBytes = EltVT.getSizeInBits() / 8;
  unsigned NumElts = VT.getVectorNumElements();

  SmallVector<SDValue, 32> PshufbMask;
  for (unsigned OutputIdx = 0; OutputIdx < NumElts; ++OutputIdx) {
    int InputIdx = MaskVals[OutputIdx];
    unsigned InputByteIdx;

    if (InputIdx < 0 || NumElts <= (unsigned)InputIdx)
      InputByteIdx = 0x80;
    else {
      // Cross lane is not allowed.
      if (ShuffleCrosses128bitLane(VT, InputIdx, OutputIdx))
        return SDValue();
      InputByteIdx = InputIdx * EltSizeInBytes;
      // Index is an byte offset within the 128-bit lane.
      InputByteIdx &= 0xf;
    }

    for (unsigned j = 0; j < EltSizeInBytes; ++j) {
      PshufbMask.push_back(DAG.getConstant(InputByteIdx, MVT::i8));
      if (InputByteIdx != 0x80)
        ++InputByteIdx;
    }
  }

  MVT ShufVT = MVT::getVectorVT(MVT::i8, PshufbMask.size());
  if (ShufVT != VT)
    V1 = DAG.getNode(ISD::BITCAST, dl, ShufVT, V1);
  return DAG.getNode(X86ISD::PSHUFB, dl, ShufVT, V1,
                     DAG.getNode(ISD::BUILD_VECTOR, dl, ShufVT, PshufbMask));
}

// v8i16 shuffles - Prefer shuffles in the following order:
// 1. [all]   pshuflw, pshufhw, optional move
// 2. [ssse3] 1 x pshufb
// 3. [ssse3] 2 x pshufb + 1 x por
// 4. [all]   mov + pshuflw + pshufhw + N x (pextrw + pinsrw)
static SDValue
LowerVECTOR_SHUFFLEv8i16(SDValue Op, const X86Subtarget *Subtarget,
                         SelectionDAG &DAG) {
  ShuffleVectorSDNode *SVOp = cast<ShuffleVectorSDNode>(Op);
  SDValue V1 = SVOp->getOperand(0);
  SDValue V2 = SVOp->getOperand(1);
  SDLoc dl(SVOp);
  SmallVector<int, 8> MaskVals;

  // Determine if more than 1 of the words in each of the low and high quadwords
  // of the result come from the same quadword of one of the two inputs.  Undef
  // mask values count as coming from any quadword, for better codegen.
  //
  // Lo/HiQuad[i] = j indicates how many words from the ith quad of the input
  // feeds this quad.  For i, 0 and 1 refer to V1, 2 and 3 refer to V2.
  unsigned LoQuad[] = { 0, 0, 0, 0 };
  unsigned HiQuad[] = { 0, 0, 0, 0 };
  // Indices of quads used.
  std::bitset<4> InputQuads;
  for (unsigned i = 0; i < 8; ++i) {
    unsigned *Quad = i < 4 ? LoQuad : HiQuad;
    int EltIdx = SVOp->getMaskElt(i);
    MaskVals.push_back(EltIdx);
    if (EltIdx < 0) {
      ++Quad[0];
      ++Quad[1];
      ++Quad[2];
      ++Quad[3];
      continue;
    }
    ++Quad[EltIdx / 4];
    InputQuads.set(EltIdx / 4);
  }

  int BestLoQuad = -1;
  unsigned MaxQuad = 1;
  for (unsigned i = 0; i < 4; ++i) {
    if (LoQuad[i] > MaxQuad) {
      BestLoQuad = i;
      MaxQuad = LoQuad[i];
    }
  }

  int BestHiQuad = -1;
  MaxQuad = 1;
  for (unsigned i = 0; i < 4; ++i) {
    if (HiQuad[i] > MaxQuad) {
      BestHiQuad = i;
      MaxQuad = HiQuad[i];
    }
  }

  // For SSSE3, If all 8 words of the result come from only 1 quadword of each
  // of the two input vectors, shuffle them into one input vector so only a
  // single pshufb instruction is necessary. If there are more than 2 input
  // quads, disable the next transformation since it does not help SSSE3.
  bool V1Used = InputQuads[0] || InputQuads[1];
  bool V2Used = InputQuads[2] || InputQuads[3];
  if (Subtarget->hasSSSE3()) {
    if (InputQuads.count() == 2 && V1Used && V2Used) {
      BestLoQuad = InputQuads[0] ? 0 : 1;
      BestHiQuad = InputQuads[2] ? 2 : 3;
    }
    if (InputQuads.count() > 2) {
      BestLoQuad = -1;
      BestHiQuad = -1;
    }
  }

  // If BestLoQuad or BestHiQuad are set, shuffle the quads together and update
  // the shuffle mask.  If a quad is scored as -1, that means that it contains
  // words from all 4 input quadwords.
  SDValue NewV;
  if (BestLoQuad >= 0 || BestHiQuad >= 0) {
    int MaskV[] = {
      BestLoQuad < 0 ? 0 : BestLoQuad,
      BestHiQuad < 0 ? 1 : BestHiQuad
    };
    NewV = DAG.getVectorShuffle(MVT::v2i64, dl,
                  DAG.getNode(ISD::BITCAST, dl, MVT::v2i64, V1),
                  DAG.getNode(ISD::BITCAST, dl, MVT::v2i64, V2), &MaskV[0]);
    NewV = DAG.getNode(ISD::BITCAST, dl, MVT::v8i16, NewV);

    // Rewrite the MaskVals and assign NewV to V1 if NewV now contains all the
    // source words for the shuffle, to aid later transformations.
    bool AllWordsInNewV = true;
    bool InOrder[2] = { true, true };
    for (unsigned i = 0; i != 8; ++i) {
      int idx = MaskVals[i];
      if (idx != (int)i)
        InOrder[i/4] = false;
      if (idx < 0 || (idx/4) == BestLoQuad || (idx/4) == BestHiQuad)
        continue;
      AllWordsInNewV = false;
      break;
    }

    bool pshuflw = AllWordsInNewV, pshufhw = AllWordsInNewV;
    if (AllWordsInNewV) {
      for (int i = 0; i != 8; ++i) {
        int idx = MaskVals[i];
        if (idx < 0)
          continue;
        idx = MaskVals[i] = (idx / 4) == BestLoQuad ? (idx & 3) : (idx & 3) + 4;
        if ((idx != i) && idx < 4)
          pshufhw = false;
        if ((idx != i) && idx > 3)
          pshuflw = false;
      }
      V1 = NewV;
      V2Used = false;
      BestLoQuad = 0;
      BestHiQuad = 1;
    }

    // If we've eliminated the use of V2, and the new mask is a pshuflw or
    // pshufhw, that's as cheap as it gets.  Return the new shuffle.
    if ((pshufhw && InOrder[0]) || (pshuflw && InOrder[1])) {
      unsigned Opc = pshufhw ? X86ISD::PSHUFHW : X86ISD::PSHUFLW;
      unsigned TargetMask = 0;
      NewV = DAG.getVectorShuffle(MVT::v8i16, dl, NewV,
                                  DAG.getUNDEF(MVT::v8i16), &MaskVals[0]);
      ShuffleVectorSDNode *SVOp = cast<ShuffleVectorSDNode>(NewV.getNode());
      TargetMask = pshufhw ? getShufflePSHUFHWImmediate(SVOp):
                             getShufflePSHUFLWImmediate(SVOp);
      V1 = NewV.getOperand(0);
      return getTargetShuffleNode(Opc, dl, MVT::v8i16, V1, TargetMask, DAG);
    }
  }

  // Promote splats to a larger type which usually leads to more efficient code.
  // FIXME: Is this true if pshufb is available?
  if (SVOp->isSplat())
    return PromoteSplat(SVOp, DAG);

  // If we have SSSE3, and all words of the result are from 1 input vector,
  // case 2 is generated, otherwise case 3 is generated.  If no SSSE3
  // is present, fall back to case 4.
  if (Subtarget->hasSSSE3()) {
    SmallVector<SDValue,16> pshufbMask;

    // If we have elements from both input vectors, set the high bit of the
    // shuffle mask element to zero out elements that come from V2 in the V1
    // mask, and elements that come from V1 in the V2 mask, so that the two
    // results can be OR'd together.
    bool TwoInputs = V1Used && V2Used;
    V1 = getPSHUFB(MaskVals, V1, dl, DAG);
    if (!TwoInputs)
      return DAG.getNode(ISD::BITCAST, dl, MVT::v8i16, V1);

    // Calculate the shuffle mask for the second input, shuffle it, and
    // OR it with the first shuffled input.
    CommuteVectorShuffleMask(MaskVals, 8);
    V2 = getPSHUFB(MaskVals, V2, dl, DAG);
    V1 = DAG.getNode(ISD::OR, dl, MVT::v16i8, V1, V2);
    return DAG.getNode(ISD::BITCAST, dl, MVT::v8i16, V1);
  }

  // If BestLoQuad >= 0, generate a pshuflw to put the low elements in order,
  // and update MaskVals with new element order.
  std::bitset<8> InOrder;
  if (BestLoQuad >= 0) {
    int MaskV[] = { -1, -1, -1, -1, 4, 5, 6, 7 };
    for (int i = 0; i != 4; ++i) {
      int idx = MaskVals[i];
      if (idx < 0) {
        InOrder.set(i);
      } else if ((idx / 4) == BestLoQuad) {
        MaskV[i] = idx & 3;
        InOrder.set(i);
      }
    }
    NewV = DAG.getVectorShuffle(MVT::v8i16, dl, NewV, DAG.getUNDEF(MVT::v8i16),
                                &MaskV[0]);

    if (NewV.getOpcode() == ISD::VECTOR_SHUFFLE && Subtarget->hasSSE2()) {
      ShuffleVectorSDNode *SVOp = cast<ShuffleVectorSDNode>(NewV.getNode());
      NewV = getTargetShuffleNode(X86ISD::PSHUFLW, dl, MVT::v8i16,
                                  NewV.getOperand(0),
                                  getShufflePSHUFLWImmediate(SVOp), DAG);
    }
  }

  // If BestHi >= 0, generate a pshufhw to put the high elements in order,
  // and update MaskVals with the new element order.
  if (BestHiQuad >= 0) {
    int MaskV[] = { 0, 1, 2, 3, -1, -1, -1, -1 };
    for (unsigned i = 4; i != 8; ++i) {
      int idx = MaskVals[i];
      if (idx < 0) {
        InOrder.set(i);
      } else if ((idx / 4) == BestHiQuad) {
        MaskV[i] = (idx & 3) + 4;
        InOrder.set(i);
      }
    }
    NewV = DAG.getVectorShuffle(MVT::v8i16, dl, NewV, DAG.getUNDEF(MVT::v8i16),
                                &MaskV[0]);

    if (NewV.getOpcode() == ISD::VECTOR_SHUFFLE && Subtarget->hasSSE2()) {
      ShuffleVectorSDNode *SVOp = cast<ShuffleVectorSDNode>(NewV.getNode());
      NewV = getTargetShuffleNode(X86ISD::PSHUFHW, dl, MVT::v8i16,
                                  NewV.getOperand(0),
                                  getShufflePSHUFHWImmediate(SVOp), DAG);
    }
  }

  // In case BestHi & BestLo were both -1, which means each quadword has a word
  // from each of the four input quadwords, calculate the InOrder bitvector now
  // before falling through to the insert/extract cleanup.
  if (BestLoQuad == -1 && BestHiQuad == -1) {
    NewV = V1;
    for (int i = 0; i != 8; ++i)
      if (MaskVals[i] < 0 || MaskVals[i] == i)
        InOrder.set(i);
  }

  // The other elements are put in the right place using pextrw and pinsrw.
  for (unsigned i = 0; i != 8; ++i) {
    if (InOrder[i])
      continue;
    int EltIdx = MaskVals[i];
    if (EltIdx < 0)
      continue;
    SDValue ExtOp = (EltIdx < 8) ?
      DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, MVT::i16, V1,
                  DAG.getIntPtrConstant(EltIdx)) :
      DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, MVT::i16, V2,
                  DAG.getIntPtrConstant(EltIdx - 8));
    NewV = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, MVT::v8i16, NewV, ExtOp,
                       DAG.getIntPtrConstant(i));
  }
  return NewV;
}

/// \brief v16i16 shuffles
///
/// FIXME: We only support generation of a single pshufb currently.  We can
/// generalize the other applicable cases from LowerVECTOR_SHUFFLEv8i16 as
/// well (e.g 2 x pshufb + 1 x por).
static SDValue
LowerVECTOR_SHUFFLEv16i16(SDValue Op, SelectionDAG &DAG) {
  ShuffleVectorSDNode *SVOp = cast<ShuffleVectorSDNode>(Op);
  SDValue V1 = SVOp->getOperand(0);
  SDValue V2 = SVOp->getOperand(1);
  SDLoc dl(SVOp);

  if (V2.getOpcode() != ISD::UNDEF)
    return SDValue();

  SmallVector<int, 16> MaskVals(SVOp->getMask().begin(), SVOp->getMask().end());
  return getPSHUFB(MaskVals, V1, dl, DAG);
}

// v16i8 shuffles - Prefer shuffles in the following order:
// 1. [ssse3] 1 x pshufb
// 2. [ssse3] 2 x pshufb + 1 x por
// 3. [all]   v8i16 shuffle + N x pextrw + rotate + pinsrw
static SDValue LowerVECTOR_SHUFFLEv16i8(ShuffleVectorSDNode *SVOp,
                                        const X86Subtarget* Subtarget,
                                        SelectionDAG &DAG) {
  const TargetLowering &TLI = DAG.getTargetLoweringInfo();
  SDValue V1 = SVOp->getOperand(0);
  SDValue V2 = SVOp->getOperand(1);
  SDLoc dl(SVOp);
  ArrayRef<int> MaskVals = SVOp->getMask();

  // Promote splats to a larger type which usually leads to more efficient code.
  // FIXME: Is this true if pshufb is available?
  if (SVOp->isSplat())
    return PromoteSplat(SVOp, DAG);

  // If we have SSSE3, case 1 is generated when all result bytes come from
  // one of  the inputs.  Otherwise, case 2 is generated.  If no SSSE3 is
  // present, fall back to case 3.

  // If SSSE3, use 1 pshufb instruction per vector with elements in the result.
  if (Subtarget->hasSSSE3()) {
    SmallVector<SDValue,16> pshufbMask;

    // If all result elements are from one input vector, then only translate
    // undef mask values to 0x80 (zero out result) in the pshufb mask.
    //
    // Otherwise, we have elements from both input vectors, and must zero out
    // elements that come from V2 in the first mask, and V1 in the second mask
    // so that we can OR them together.
    for (unsigned i = 0; i != 16; ++i) {
      int EltIdx = MaskVals[i];
      if (EltIdx < 0 || EltIdx >= 16)
        EltIdx = 0x80;
      pshufbMask.push_back(DAG.getConstant(EltIdx, MVT::i8));
    }
    V1 = DAG.getNode(X86ISD::PSHUFB, dl, MVT::v16i8, V1,
                     DAG.getNode(ISD::BUILD_VECTOR, dl,
                                 MVT::v16i8, pshufbMask));

    // As PSHUFB will zero elements with negative indices, it's safe to ignore
    // the 2nd operand if it's undefined or zero.
    if (V2.getOpcode() == ISD::UNDEF ||
        ISD::isBuildVectorAllZeros(V2.getNode()))
      return V1;

    // Calculate the shuffle mask for the second input, shuffle it, and
    // OR it with the first shuffled input.
    pshufbMask.clear();
    for (unsigned i = 0; i != 16; ++i) {
      int EltIdx = MaskVals[i];
      EltIdx = (EltIdx < 16) ? 0x80 : EltIdx - 16;
      pshufbMask.push_back(DAG.getConstant(EltIdx, MVT::i8));
    }
    V2 = DAG.getNode(X86ISD::PSHUFB, dl, MVT::v16i8, V2,
                     DAG.getNode(ISD::BUILD_VECTOR, dl,
                                 MVT::v16i8, pshufbMask));
    return DAG.getNode(ISD::OR, dl, MVT::v16i8, V1, V2);
  }

  // No SSSE3 - Calculate in place words and then fix all out of place words
  // With 0-16 extracts & inserts.  Worst case is 16 bytes out of order from
  // the 16 different words that comprise the two doublequadword input vectors.
  V1 = DAG.getNode(ISD::BITCAST, dl, MVT::v8i16, V1);
  V2 = DAG.getNode(ISD::BITCAST, dl, MVT::v8i16, V2);
  SDValue NewV = V1;
  for (int i = 0; i != 8; ++i) {
    int Elt0 = MaskVals[i*2];
    int Elt1 = MaskVals[i*2+1];

    // This word of the result is all undef, skip it.
    if (Elt0 < 0 && Elt1 < 0)
      continue;

    // This word of the result is already in the correct place, skip it.
    if ((Elt0 == i*2) && (Elt1 == i*2+1))
      continue;

    SDValue Elt0Src = Elt0 < 16 ? V1 : V2;
    SDValue Elt1Src = Elt1 < 16 ? V1 : V2;
    SDValue InsElt;

    // If Elt0 and Elt1 are defined, are consecutive, and can be load
    // using a single extract together, load it and store it.
    if ((Elt0 >= 0) && ((Elt0 + 1) == Elt1) && ((Elt0 & 1) == 0)) {
      InsElt = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, MVT::i16, Elt1Src,
                           DAG.getIntPtrConstant(Elt1 / 2));
      NewV = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, MVT::v8i16, NewV, InsElt,
                        DAG.getIntPtrConstant(i));
      continue;
    }

    // If Elt1 is defined, extract it from the appropriate source.  If the
    // source byte is not also odd, shift the extracted word left 8 bits
    // otherwise clear the bottom 8 bits if we need to do an or.
    if (Elt1 >= 0) {
      InsElt = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, MVT::i16, Elt1Src,
                           DAG.getIntPtrConstant(Elt1 / 2));
      if ((Elt1 & 1) == 0)
        InsElt = DAG.getNode(ISD::SHL, dl, MVT::i16, InsElt,
                             DAG.getConstant(8,
                                  TLI.getShiftAmountTy(InsElt.getValueType())));
      else if (Elt0 >= 0)
        InsElt = DAG.getNode(ISD::AND, dl, MVT::i16, InsElt,
                             DAG.getConstant(0xFF00, MVT::i16));
    }
    // If Elt0 is defined, extract it from the appropriate source.  If the
    // source byte is not also even, shift the extracted word right 8 bits. If
    // Elt1 was also defined, OR the extracted values together before
    // inserting them in the result.
    if (Elt0 >= 0) {
      SDValue InsElt0 = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, MVT::i16,
                                    Elt0Src, DAG.getIntPtrConstant(Elt0 / 2));
      if ((Elt0 & 1) != 0)
        InsElt0 = DAG.getNode(ISD::SRL, dl, MVT::i16, InsElt0,
                              DAG.getConstant(8,
                                 TLI.getShiftAmountTy(InsElt0.getValueType())));
      else if (Elt1 >= 0)
        InsElt0 = DAG.getNode(ISD::AND, dl, MVT::i16, InsElt0,
                             DAG.getConstant(0x00FF, MVT::i16));
      InsElt = Elt1 >= 0 ? DAG.getNode(ISD::OR, dl, MVT::i16, InsElt, InsElt0)
                         : InsElt0;
    }
    NewV = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, MVT::v8i16, NewV, InsElt,
                       DAG.getIntPtrConstant(i));
  }
  return DAG.getNode(ISD::BITCAST, dl, MVT::v16i8, NewV);
}

// v32i8 shuffles - Translate to VPSHUFB if possible.
static
SDValue LowerVECTOR_SHUFFLEv32i8(ShuffleVectorSDNode *SVOp,
                                 const X86Subtarget *Subtarget,
                                 SelectionDAG &DAG) {
  MVT VT = SVOp->getSimpleValueType(0);
  SDValue V1 = SVOp->getOperand(0);
  SDValue V2 = SVOp->getOperand(1);
  SDLoc dl(SVOp);
  SmallVector<int, 32> MaskVals(SVOp->getMask().begin(), SVOp->getMask().end());

  bool V2IsUndef = V2.getOpcode() == ISD::UNDEF;
  bool V1IsAllZero = ISD::isBuildVectorAllZeros(V1.getNode());
  bool V2IsAllZero = ISD::isBuildVectorAllZeros(V2.getNode());

  // VPSHUFB may be generated if
  // (1) one of input vector is undefined or zeroinitializer.
  // The mask value 0x80 puts 0 in the corresponding slot of the vector.
  // And (2) the mask indexes don't cross the 128-bit lane.
  if (VT != MVT::v32i8 || !Subtarget->hasInt256() ||
      (!V2IsUndef && !V2IsAllZero && !V1IsAllZero))
    return SDValue();

  if (V1IsAllZero && !V2IsAllZero) {
    CommuteVectorShuffleMask(MaskVals, 32);
    V1 = V2;
  }
  return getPSHUFB(MaskVals, V1, dl, DAG);
}

/// RewriteAsNarrowerShuffle - Try rewriting v8i16 and v16i8 shuffles as 4 wide
/// ones, or rewriting v4i32 / v4f32 as 2 wide ones if possible. This can be
/// done when every pair / quad of shuffle mask elements point to elements in
/// the right sequence. e.g.
/// vector_shuffle X, Y, <2, 3, | 10, 11, | 0, 1, | 14, 15>
static
SDValue RewriteAsNarrowerShuffle(ShuffleVectorSDNode *SVOp,
                                 SelectionDAG &DAG) {
  MVT VT = SVOp->getSimpleValueType(0);
  SDLoc dl(SVOp);
  unsigned NumElems = VT.getVectorNumElements();
  MVT NewVT;
  unsigned Scale;
  switch (VT.SimpleTy) {
  default: llvm_unreachable("Unexpected!");
  case MVT::v2i64:
  case MVT::v2f64:
           return SDValue(SVOp, 0);
  case MVT::v4f32:  NewVT = MVT::v2f64; Scale = 2; break;
  case MVT::v4i32:  NewVT = MVT::v2i64; Scale = 2; break;
  case MVT::v8i16:  NewVT = MVT::v4i32; Scale = 2; break;
  case MVT::v16i8:  NewVT = MVT::v4i32; Scale = 4; break;
  case MVT::v16i16: NewVT = MVT::v8i32; Scale = 2; break;
  case MVT::v32i8:  NewVT = MVT::v8i32; Scale = 4; break;
  }

  SmallVector<int, 8> MaskVec;
  for (unsigned i = 0; i != NumElems; i += Scale) {
    int StartIdx = -1;
    for (unsigned j = 0; j != Scale; ++j) {
      int EltIdx = SVOp->getMaskElt(i+j);
      if (EltIdx < 0)
        continue;
      if (StartIdx < 0)
        StartIdx = (EltIdx / Scale);
      if (EltIdx != (int)(StartIdx*Scale + j))
        return SDValue();
    }
    MaskVec.push_back(StartIdx);
  }

  SDValue V1 = DAG.getNode(ISD::BITCAST, dl, NewVT, SVOp->getOperand(0));
  SDValue V2 = DAG.getNode(ISD::BITCAST, dl, NewVT, SVOp->getOperand(1));
  return DAG.getVectorShuffle(NewVT, dl, V1, V2, &MaskVec[0]);
}

/// getVZextMovL - Return a zero-extending vector move low node.
///
static SDValue getVZextMovL(MVT VT, MVT OpVT,
                            SDValue SrcOp, SelectionDAG &DAG,
                            const X86Subtarget *Subtarget, SDLoc dl) {
  if (VT == MVT::v2f64 || VT == MVT::v4f32) {
    LoadSDNode *LD = nullptr;
    if (!isScalarLoadToVector(SrcOp.getNode(), &LD))
      LD = dyn_cast<LoadSDNode>(SrcOp);
    if (!LD) {
      // movssrr and movsdrr do not clear top bits. Try to use movd, movq
      // instead.
      MVT ExtVT = (OpVT == MVT::v2f64) ? MVT::i64 : MVT::i32;
      if ((ExtVT != MVT::i64 || Subtarget->is64Bit()) &&
          SrcOp.getOpcode() == ISD::SCALAR_TO_VECTOR &&
          SrcOp.getOperand(0).getOpcode() == ISD::BITCAST &&
          SrcOp.getOperand(0).getOperand(0).getValueType() == ExtVT) {
        // PR2108
        OpVT = (OpVT == MVT::v2f64) ? MVT::v2i64 : MVT::v4i32;
        return DAG.getNode(ISD::BITCAST, dl, VT,
                           DAG.getNode(X86ISD::VZEXT_MOVL, dl, OpVT,
                                       DAG.getNode(ISD::SCALAR_TO_VECTOR, dl,
                                                   OpVT,
                                                   SrcOp.getOperand(0)
                                                          .getOperand(0))));
      }
    }
  }

  return DAG.getNode(ISD::BITCAST, dl, VT,
                     DAG.getNode(X86ISD::VZEXT_MOVL, dl, OpVT,
                                 DAG.getNode(ISD::BITCAST, dl,
                                             OpVT, SrcOp)));
}

/// LowerVECTOR_SHUFFLE_256 - Handle all 256-bit wide vectors shuffles
/// which could not be matched by any known target speficic shuffle
static SDValue
LowerVECTOR_SHUFFLE_256(ShuffleVectorSDNode *SVOp, SelectionDAG &DAG) {

  SDValue NewOp = Compact8x32ShuffleNode(SVOp, DAG);
  if (NewOp.getNode())
    return NewOp;

  MVT VT = SVOp->getSimpleValueType(0);

  unsigned NumElems = VT.getVectorNumElements();
  unsigned NumLaneElems = NumElems / 2;

  SDLoc dl(SVOp);
  MVT EltVT = VT.getVectorElementType();
  MVT NVT = MVT::getVectorVT(EltVT, NumLaneElems);
  SDValue Output[2];

  SmallVector<int, 16> Mask;
  for (unsigned l = 0; l < 2; ++l) {
    // Build a shuffle mask for the output, discovering on the fly which
    // input vectors to use as shuffle operands (recorded in InputUsed).
    // If building a suitable shuffle vector proves too hard, then bail
    // out with UseBuildVector set.
    bool UseBuildVector = false;
    int InputUsed[2] = { -1, -1 }; // Not yet discovered.
    unsigned LaneStart = l * NumLaneElems;
    for (unsigned i = 0; i != NumLaneElems; ++i) {
      // The mask element.  This indexes into the input.
      int Idx = SVOp->getMaskElt(i+LaneStart);
      if (Idx < 0) {
        // the mask element does not index into any input vector.
        Mask.push_back(-1);
        continue;
      }

      // The input vector this mask element indexes into.
      int Input = Idx / NumLaneElems;

      // Turn the index into an offset from the start of the input vector.
      Idx -= Input * NumLaneElems;

      // Find or create a shuffle vector operand to hold this input.
      unsigned OpNo;
      for (OpNo = 0; OpNo < array_lengthof(InputUsed); ++OpNo) {
        if (InputUsed[OpNo] == Input)
          // This input vector is already an operand.
          break;
        if (InputUsed[OpNo] < 0) {
          // Create a new operand for this input vector.
          InputUsed[OpNo] = Input;
          break;
        }
      }

      if (OpNo >= array_lengthof(InputUsed)) {
        // More than two input vectors used!  Give up on trying to create a
        // shuffle vector.  Insert all elements into a BUILD_VECTOR instead.
        UseBuildVector = true;
        break;
      }

      // Add the mask index for the new shuffle vector.
      Mask.push_back(Idx + OpNo * NumLaneElems);
    }

    if (UseBuildVector) {
      SmallVector<SDValue, 16> SVOps;
      for (unsigned i = 0; i != NumLaneElems; ++i) {
        // The mask element.  This indexes into the input.
        int Idx = SVOp->getMaskElt(i+LaneStart);
        if (Idx < 0) {
          SVOps.push_back(DAG.getUNDEF(EltVT));
          continue;
        }

        // The input vector this mask element indexes into.
        int Input = Idx / NumElems;

        // Turn the index into an offset from the start of the input vector.
        Idx -= Input * NumElems;

        // Extract the vector element by hand.
        SVOps.push_back(DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, EltVT,
                                    SVOp->getOperand(Input),
                                    DAG.getIntPtrConstant(Idx)));
      }

      // Construct the output using a BUILD_VECTOR.
      Output[l] = DAG.getNode(ISD::BUILD_VECTOR, dl, NVT, SVOps);
    } else if (InputUsed[0] < 0) {
      // No input vectors were used! The result is undefined.
      Output[l] = DAG.getUNDEF(NVT);
    } else {
      SDValue Op0 = Extract128BitVector(SVOp->getOperand(InputUsed[0] / 2),
                                        (InputUsed[0] % 2) * NumLaneElems,
                                        DAG, dl);
      // If only one input was used, use an undefined vector for the other.
      SDValue Op1 = (InputUsed[1] < 0) ? DAG.getUNDEF(NVT) :
        Extract128BitVector(SVOp->getOperand(InputUsed[1] / 2),
                            (InputUsed[1] % 2) * NumLaneElems, DAG, dl);
      // At least one input vector was used. Create a new shuffle vector.
      Output[l] = DAG.getVectorShuffle(NVT, dl, Op0, Op1, &Mask[0]);
    }

    Mask.clear();
  }

  // Concatenate the result back
  return DAG.getNode(ISD::CONCAT_VECTORS, dl, VT, Output[0], Output[1]);
}

/// LowerVECTOR_SHUFFLE_128v4 - Handle all 128-bit wide vectors with
/// 4 elements, and match them with several different shuffle types.
static SDValue
LowerVECTOR_SHUFFLE_128v4(ShuffleVectorSDNode *SVOp, SelectionDAG &DAG) {
  SDValue V1 = SVOp->getOperand(0);
  SDValue V2 = SVOp->getOperand(1);
  SDLoc dl(SVOp);
  MVT VT = SVOp->getSimpleValueType(0);

  assert(VT.is128BitVector() && "Unsupported vector size");

  std::pair<int, int> Locs[4];
  int Mask1[] = { -1, -1, -1, -1 };
  SmallVector<int, 8> PermMask(SVOp->getMask().begin(), SVOp->getMask().end());

  unsigned NumHi = 0;
  unsigned NumLo = 0;
  for (unsigned i = 0; i != 4; ++i) {
    int Idx = PermMask[i];
    if (Idx < 0) {
      Locs[i] = std::make_pair(-1, -1);
    } else {
      assert(Idx < 8 && "Invalid VECTOR_SHUFFLE index!");
      if (Idx < 4) {
        Locs[i] = std::make_pair(0, NumLo);
        Mask1[NumLo] = Idx;
        NumLo++;
      } else {
        Locs[i] = std::make_pair(1, NumHi);
        if (2+NumHi < 4)
          Mask1[2+NumHi] = Idx;
        NumHi++;
      }
    }
  }

  if (NumLo <= 2 && NumHi <= 2) {
    // If no more than two elements come from either vector. This can be
    // implemented with two shuffles. First shuffle gather the elements.
    // The second shuffle, which takes the first shuffle as both of its
    // vector operands, put the elements into the right order.
    V1 = DAG.getVectorShuffle(VT, dl, V1, V2, &Mask1[0]);

    int Mask2[] = { -1, -1, -1, -1 };

    for (unsigned i = 0; i != 4; ++i)
      if (Locs[i].first != -1) {
        unsigned Idx = (i < 2) ? 0 : 4;
        Idx += Locs[i].first * 2 + Locs[i].second;
        Mask2[i] = Idx;
      }

    return DAG.getVectorShuffle(VT, dl, V1, V1, &Mask2[0]);
  }

  if (NumLo == 3 || NumHi == 3) {
    // Otherwise, we must have three elements from one vector, call it X, and
    // one element from the other, call it Y.  First, use a shufps to build an
    // intermediate vector with the one element from Y and the element from X
    // that will be in the same half in the final destination (the indexes don't
    // matter). Then, use a shufps to build the final vector, taking the half
    // containing the element from Y from the intermediate, and the other half
    // from X.
    if (NumHi == 3) {
      // Normalize it so the 3 elements come from V1.
      CommuteVectorShuffleMask(PermMask, 4);
      std::swap(V1, V2);
    }

    // Find the element from V2.
    unsigned HiIndex;
    for (HiIndex = 0; HiIndex < 3; ++HiIndex) {
      int Val = PermMask[HiIndex];
      if (Val < 0)
        continue;
      if (Val >= 4)
        break;
    }

    Mask1[0] = PermMask[HiIndex];
    Mask1[1] = -1;
    Mask1[2] = PermMask[HiIndex^1];
    Mask1[3] = -1;
    V2 = DAG.getVectorShuffle(VT, dl, V1, V2, &Mask1[0]);

    if (HiIndex >= 2) {
      Mask1[0] = PermMask[0];
      Mask1[1] = PermMask[1];
      Mask1[2] = HiIndex & 1 ? 6 : 4;
      Mask1[3] = HiIndex & 1 ? 4 : 6;
      return DAG.getVectorShuffle(VT, dl, V1, V2, &Mask1[0]);
    }

    Mask1[0] = HiIndex & 1 ? 2 : 0;
    Mask1[1] = HiIndex & 1 ? 0 : 2;
    Mask1[2] = PermMask[2];
    Mask1[3] = PermMask[3];
    if (Mask1[2] >= 0)
      Mask1[2] += 4;
    if (Mask1[3] >= 0)
      Mask1[3] += 4;
    return DAG.getVectorShuffle(VT, dl, V2, V1, &Mask1[0]);
  }

  // Break it into (shuffle shuffle_hi, shuffle_lo).
  int LoMask[] = { -1, -1, -1, -1 };
  int HiMask[] = { -1, -1, -1, -1 };

  int *MaskPtr = LoMask;
  unsigned MaskIdx = 0;
  unsigned LoIdx = 0;
  unsigned HiIdx = 2;
  for (unsigned i = 0; i != 4; ++i) {
    if (i == 2) {
      MaskPtr = HiMask;
      MaskIdx = 1;
      LoIdx = 0;
      HiIdx = 2;
    }
    int Idx = PermMask[i];
    if (Idx < 0) {
      Locs[i] = std::make_pair(-1, -1);
    } else if (Idx < 4) {
      Locs[i] = std::make_pair(MaskIdx, LoIdx);
      MaskPtr[LoIdx] = Idx;
      LoIdx++;
    } else {
      Locs[i] = std::make_pair(MaskIdx, HiIdx);
      MaskPtr[HiIdx] = Idx;
      HiIdx++;
    }
  }

  SDValue LoShuffle = DAG.getVectorShuffle(VT, dl, V1, V2, &LoMask[0]);
  SDValue HiShuffle = DAG.getVectorShuffle(VT, dl, V1, V2, &HiMask[0]);
  int MaskOps[] = { -1, -1, -1, -1 };
  for (unsigned i = 0; i != 4; ++i)
    if (Locs[i].first != -1)
      MaskOps[i] = Locs[i].first * 4 + Locs[i].second;
  return DAG.getVectorShuffle(VT, dl, LoShuffle, HiShuffle, &MaskOps[0]);
}

static bool MayFoldVectorLoad(SDValue V) {
  while (V.hasOneUse() && V.getOpcode() == ISD::BITCAST)
    V = V.getOperand(0);

  if (V.hasOneUse() && V.getOpcode() == ISD::SCALAR_TO_VECTOR)
    V = V.getOperand(0);
  if (V.hasOneUse() && V.getOpcode() == ISD::BUILD_VECTOR &&
      V.getNumOperands() == 2 && V.getOperand(1).getOpcode() == ISD::UNDEF)
    // BUILD_VECTOR (load), undef
    V = V.getOperand(0);

  return MayFoldLoad(V);
}

static
SDValue getMOVDDup(SDValue &Op, SDLoc &dl, SDValue V1, SelectionDAG &DAG) {
  MVT VT = Op.getSimpleValueType();

  // Canonicalize to v2f64.
  V1 = DAG.getNode(ISD::BITCAST, dl, MVT::v2f64, V1);
  return DAG.getNode(ISD::BITCAST, dl, VT,
                     getTargetShuffleNode(X86ISD::MOVDDUP, dl, MVT::v2f64,
                                          V1, DAG));
}

static
SDValue getMOVLowToHigh(SDValue &Op, SDLoc &dl, SelectionDAG &DAG,
                        bool HasSSE2) {
  SDValue V1 = Op.getOperand(0);
  SDValue V2 = Op.getOperand(1);
  MVT VT = Op.getSimpleValueType();

  assert(VT != MVT::v2i64 && "unsupported shuffle type");

  if (HasSSE2 && VT == MVT::v2f64)
    return getTargetShuffleNode(X86ISD::MOVLHPD, dl, VT, V1, V2, DAG);

  // v4f32 or v4i32: canonicalize to v4f32 (which is legal for SSE1)
  return DAG.getNode(ISD::BITCAST, dl, VT,
                     getTargetShuffleNode(X86ISD::MOVLHPS, dl, MVT::v4f32,
                           DAG.getNode(ISD::BITCAST, dl, MVT::v4f32, V1),
                           DAG.getNode(ISD::BITCAST, dl, MVT::v4f32, V2), DAG));
}

static
SDValue getMOVHighToLow(SDValue &Op, SDLoc &dl, SelectionDAG &DAG) {
  SDValue V1 = Op.getOperand(0);
  SDValue V2 = Op.getOperand(1);
  MVT VT = Op.getSimpleValueType();

  assert((VT == MVT::v4i32 || VT == MVT::v4f32) &&
         "unsupported shuffle type");

  if (V2.getOpcode() == ISD::UNDEF)
    V2 = V1;

  // v4i32 or v4f32
  return getTargetShuffleNode(X86ISD::MOVHLPS, dl, VT, V1, V2, DAG);
}

static
SDValue getMOVLP(SDValue &Op, SDLoc &dl, SelectionDAG &DAG, bool HasSSE2) {
  SDValue V1 = Op.getOperand(0);
  SDValue V2 = Op.getOperand(1);
  MVT VT = Op.getSimpleValueType();
  unsigned NumElems = VT.getVectorNumElements();

  // Use MOVLPS and MOVLPD in case V1 or V2 are loads. During isel, the second
  // operand of these instructions is only memory, so check if there's a
  // potencial load folding here, otherwise use SHUFPS or MOVSD to match the
  // same masks.
  bool CanFoldLoad = false;

  // Trivial case, when V2 comes from a load.
  if (MayFoldVectorLoad(V2))
    CanFoldLoad = true;

  // When V1 is a load, it can be folded later into a store in isel, example:
  //  (store (v4f32 (X86Movlps (load addr:$src1), VR128:$src2)), addr:$src1)
  //    turns into:
  //  (MOVLPSmr addr:$src1, VR128:$src2)
  // So, recognize this potential and also use MOVLPS or MOVLPD
  else if (MayFoldVectorLoad(V1) && MayFoldIntoStore(Op))
    CanFoldLoad = true;

  ShuffleVectorSDNode *SVOp = cast<ShuffleVectorSDNode>(Op);
  if (CanFoldLoad) {
    if (HasSSE2 && NumElems == 2)
      return getTargetShuffleNode(X86ISD::MOVLPD, dl, VT, V1, V2, DAG);

    if (NumElems == 4)
      // If we don't care about the second element, proceed to use movss.
      if (SVOp->getMaskElt(1) != -1)
        return getTargetShuffleNode(X86ISD::MOVLPS, dl, VT, V1, V2, DAG);
  }

  // movl and movlp will both match v2i64, but v2i64 is never matched by
  // movl earlier because we make it strict to avoid messing with the movlp load
  // folding logic (see the code above getMOVLP call). Match it here then,
  // this is horrible, but will stay like this until we move all shuffle
  // matching to x86 specific nodes. Note that for the 1st condition all
  // types are matched with movsd.
  if (HasSSE2) {
    // FIXME: isMOVLMask should be checked and matched before getMOVLP,
    // as to remove this logic from here, as much as possible
    if (NumElems == 2 || !isMOVLMask(SVOp->getMask(), VT))
      return getTargetShuffleNode(X86ISD::MOVSD, dl, VT, V1, V2, DAG);
    return getTargetShuffleNode(X86ISD::MOVSS, dl, VT, V1, V2, DAG);
  }

  assert(VT != MVT::v4i32 && "unsupported shuffle type");

  // Invert the operand order and use SHUFPS to match it.
  return getTargetShuffleNode(X86ISD::SHUFP, dl, VT, V2, V1,
                              getShuffleSHUFImmediate(SVOp), DAG);
}

static SDValue NarrowVectorLoadToElement(LoadSDNode *Load, unsigned Index,
                                         SelectionDAG &DAG) {
  SDLoc dl(Load);
  MVT VT = Load->getSimpleValueType(0);
  MVT EVT = VT.getVectorElementType();
  SDValue Addr = Load->getOperand(1);
  SDValue NewAddr = DAG.getNode(
      ISD::ADD, dl, Addr.getSimpleValueType(), Addr,
      DAG.getConstant(Index * EVT.getStoreSize(), Addr.getSimpleValueType()));

  SDValue NewLoad =
      DAG.getLoad(EVT, dl, Load->getChain(), NewAddr,
                  DAG.getMachineFunction().getMachineMemOperand(
                      Load->getMemOperand(), 0, EVT.getStoreSize()));
  return NewLoad;
}

// It is only safe to call this function if isINSERTPSMask is true for
// this shufflevector mask.
static SDValue getINSERTPS(ShuffleVectorSDNode *SVOp, SDLoc &dl,
                           SelectionDAG &DAG) {
  // Generate an insertps instruction when inserting an f32 from memory onto a
  // v4f32 or when copying a member from one v4f32 to another.
  // We also use it for transferring i32 from one register to another,
  // since it simply copies the same bits.
  // If we're transferring an i32 from memory to a specific element in a
  // register, we output a generic DAG that will match the PINSRD
  // instruction.
  MVT VT = SVOp->getSimpleValueType(0);
  MVT EVT = VT.getVectorElementType();
  SDValue V1 = SVOp->getOperand(0);
  SDValue V2 = SVOp->getOperand(1);
  auto Mask = SVOp->getMask();
  assert((VT == MVT::v4f32 || VT == MVT::v4i32) &&
         "unsupported vector type for insertps/pinsrd");

  auto FromV1Predicate = [](const int &i) { return i < 4 && i > -1; };
  auto FromV2Predicate = [](const int &i) { return i >= 4; };
  int FromV1 = std::count_if(Mask.begin(), Mask.end(), FromV1Predicate);

  SDValue From;
  SDValue To;
  unsigned DestIndex;
  if (FromV1 == 1) {
    From = V1;
    To = V2;
    DestIndex = std::find_if(Mask.begin(), Mask.end(), FromV1Predicate) -
                Mask.begin();

    // If we have 1 element from each vector, we have to check if we're
    // changing V1's element's place. If so, we're done. Otherwise, we
    // should assume we're changing V2's element's place and behave
    // accordingly.
    int FromV2 = std::count_if(Mask.begin(), Mask.end(), FromV2Predicate);
    assert(DestIndex <= INT32_MAX && "truncated destination index");
    if (FromV1 == FromV2 &&
        static_cast<int>(DestIndex) == Mask[DestIndex] % 4) {
      From = V2;
      To = V1;
      DestIndex =
          std::find_if(Mask.begin(), Mask.end(), FromV2Predicate) - Mask.begin();
    }
  } else {
    assert(std::count_if(Mask.begin(), Mask.end(), FromV2Predicate) == 1 &&
           "More than one element from V1 and from V2, or no elements from one "
           "of the vectors. This case should not have returned true from "
           "isINSERTPSMask");
    From = V2;
    To = V1;
    DestIndex =
        std::find_if(Mask.begin(), Mask.end(), FromV2Predicate) - Mask.begin();
  }

  // Get an index into the source vector in the range [0,4) (the mask is
  // in the range [0,8) because it can address V1 and V2)
  unsigned SrcIndex = Mask[DestIndex] % 4;
  if (MayFoldLoad(From)) {
    // Trivial case, when From comes from a load and is only used by the
    // shuffle. Make it use insertps from the vector that we need from that
    // load.
    SDValue NewLoad =
        NarrowVectorLoadToElement(cast<LoadSDNode>(From), SrcIndex, DAG);
    if (!NewLoad.getNode())
      return SDValue();

    if (EVT == MVT::f32) {
      // Create this as a scalar to vector to match the instruction pattern.
      SDValue LoadScalarToVector =
          DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, NewLoad);
      SDValue InsertpsMask = DAG.getIntPtrConstant(DestIndex << 4);
      return DAG.getNode(X86ISD::INSERTPS, dl, VT, To, LoadScalarToVector,
                         InsertpsMask);
    } else { // EVT == MVT::i32
      // If we're getting an i32 from memory, use an INSERT_VECTOR_ELT
      // instruction, to match the PINSRD instruction, which loads an i32 to a
      // certain vector element.
      return DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, VT, To, NewLoad,
                         DAG.getConstant(DestIndex, MVT::i32));
    }
  }

  // Vector-element-to-vector
  SDValue InsertpsMask = DAG.getIntPtrConstant(DestIndex << 4 | SrcIndex << 6);
  return DAG.getNode(X86ISD::INSERTPS, dl, VT, To, From, InsertpsMask);
}

// Reduce a vector shuffle to zext.
static SDValue LowerVectorIntExtend(SDValue Op, const X86Subtarget *Subtarget,
                                    SelectionDAG &DAG) {
  // PMOVZX is only available from SSE41.
  if (!Subtarget->hasSSE41())
    return SDValue();

  MVT VT = Op.getSimpleValueType();

  // Only AVX2 support 256-bit vector integer extending.
  if (!Subtarget->hasInt256() && VT.is256BitVector())
    return SDValue();

  ShuffleVectorSDNode *SVOp = cast<ShuffleVectorSDNode>(Op);
  SDLoc DL(Op);
  SDValue V1 = Op.getOperand(0);
  SDValue V2 = Op.getOperand(1);
  unsigned NumElems = VT.getVectorNumElements();

  // Extending is an unary operation and the element type of the source vector
  // won't be equal to or larger than i64.
  if (V2.getOpcode() != ISD::UNDEF || !VT.isInteger() ||
      VT.getVectorElementType() == MVT::i64)
    return SDValue();

  // Find the expansion ratio, e.g. expanding from i8 to i32 has a ratio of 4.
  unsigned Shift = 1; // Start from 2, i.e. 1 << 1.
  while ((1U << Shift) < NumElems) {
    if (SVOp->getMaskElt(1U << Shift) == 1)
      break;
    Shift += 1;
    // The maximal ratio is 8, i.e. from i8 to i64.
    if (Shift > 3)
      return SDValue();
  }

  // Check the shuffle mask.
  unsigned Mask = (1U << Shift) - 1;
  for (unsigned i = 0; i != NumElems; ++i) {
    int EltIdx = SVOp->getMaskElt(i);
    if ((i & Mask) != 0 && EltIdx != -1)
      return SDValue();
    if ((i & Mask) == 0 && (unsigned)EltIdx != (i >> Shift))
      return SDValue();
  }

  unsigned NBits = VT.getVectorElementType().getSizeInBits() << Shift;
  MVT NeVT = MVT::getIntegerVT(NBits);
  MVT NVT = MVT::getVectorVT(NeVT, NumElems >> Shift);

  if (!DAG.getTargetLoweringInfo().isTypeLegal(NVT))
    return SDValue();

  return DAG.getNode(ISD::BITCAST, DL, VT,
                     DAG.getNode(X86ISD::VZEXT, DL, NVT, V1));
}

static SDValue NormalizeVectorShuffle(SDValue Op, const X86Subtarget *Subtarget,
                                      SelectionDAG &DAG) {
  ShuffleVectorSDNode *SVOp = cast<ShuffleVectorSDNode>(Op);
  MVT VT = Op.getSimpleValueType();
  SDLoc dl(Op);
  SDValue V1 = Op.getOperand(0);
  SDValue V2 = Op.getOperand(1);

  if (isZeroShuffle(SVOp))
    return getZeroVector(VT, Subtarget, DAG, dl);

  // Handle splat operations
  if (SVOp->isSplat()) {
    // Use vbroadcast whenever the splat comes from a foldable load
    SDValue Broadcast = LowerVectorBroadcast(Op, Subtarget, DAG);
    if (Broadcast.getNode())
      return Broadcast;
  }

  // Check integer expanding shuffles.
  SDValue NewOp = LowerVectorIntExtend(Op, Subtarget, DAG);
  if (NewOp.getNode())
    return NewOp;

  // If the shuffle can be profitably rewritten as a narrower shuffle, then
  // do it!
  if (VT == MVT::v8i16 || VT == MVT::v16i8 || VT == MVT::v16i16 ||
      VT == MVT::v32i8) {
    SDValue NewOp = RewriteAsNarrowerShuffle(SVOp, DAG);
    if (NewOp.getNode())
      return DAG.getNode(ISD::BITCAST, dl, VT, NewOp);
  } else if (VT.is128BitVector() && Subtarget->hasSSE2()) {
    // FIXME: Figure out a cleaner way to do this.
    if (ISD::isBuildVectorAllZeros(V2.getNode())) {
      SDValue NewOp = RewriteAsNarrowerShuffle(SVOp, DAG);
      if (NewOp.getNode()) {
        MVT NewVT = NewOp.getSimpleValueType();
        if (isCommutedMOVLMask(cast<ShuffleVectorSDNode>(NewOp)->getMask(),
                               NewVT, true, false))
          return getVZextMovL(VT, NewVT, NewOp.getOperand(0), DAG, Subtarget,
                              dl);
      }
    } else if (ISD::isBuildVectorAllZeros(V1.getNode())) {
      SDValue NewOp = RewriteAsNarrowerShuffle(SVOp, DAG);
      if (NewOp.getNode()) {
        MVT NewVT = NewOp.getSimpleValueType();
        if (isMOVLMask(cast<ShuffleVectorSDNode>(NewOp)->getMask(), NewVT))
          return getVZextMovL(VT, NewVT, NewOp.getOperand(1), DAG, Subtarget,
                              dl);
      }
    }
  }
  return SDValue();
}

SDValue
X86TargetLowering::LowerVECTOR_SHUFFLE(SDValue Op, SelectionDAG &DAG) const {
  ShuffleVectorSDNode *SVOp = cast<ShuffleVectorSDNode>(Op);
  SDValue V1 = Op.getOperand(0);
  SDValue V2 = Op.getOperand(1);
  MVT VT = Op.getSimpleValueType();
  SDLoc dl(Op);
  unsigned NumElems = VT.getVectorNumElements();
  bool V1IsUndef = V1.getOpcode() == ISD::UNDEF;
  bool V2IsUndef = V2.getOpcode() == ISD::UNDEF;
  bool V1IsSplat = false;
  bool V2IsSplat = false;
  bool HasSSE2 = Subtarget->hasSSE2();
  bool HasFp256    = Subtarget->hasFp256();
  bool HasInt256   = Subtarget->hasInt256();
  MachineFunction &MF = DAG.getMachineFunction();
  bool OptForSize =
      MF.getFunction()->hasFnAttribute(Attribute::OptimizeForSize);

  // Check if we should use the experimental vector shuffle lowering. If so,
  // delegate completely to that code path.
  if (ExperimentalVectorShuffleLowering)
    return lowerVectorShuffle(Op, Subtarget, DAG);

  assert(VT.getSizeInBits() != 64 && "Can't lower MMX shuffles");

  if (V1IsUndef && V2IsUndef)
    return DAG.getUNDEF(VT);

  // When we create a shuffle node we put the UNDEF node to second operand,
  // but in some cases the first operand may be transformed to UNDEF.
  // In this case we should just commute the node.
  if (V1IsUndef)
    return DAG.getCommutedVectorShuffle(*SVOp);

  // Vector shuffle lowering takes 3 steps:
  //
  // 1) Normalize the input vectors. Here splats, zeroed vectors, profitable
  //    narrowing and commutation of operands should be handled.
  // 2) Matching of shuffles with known shuffle masks to x86 target specific
  //    shuffle nodes.
  // 3) Rewriting of unmatched masks into new generic shuffle operations,
  //    so the shuffle can be broken into other shuffles and the legalizer can
  //    try the lowering again.
  //
  // The general idea is that no vector_shuffle operation should be left to
  // be matched during isel, all of them must be converted to a target specific
  // node here.

  // Normalize the input vectors. Here splats, zeroed vectors, profitable
  // narrowing and commutation of operands should be handled. The actual code
  // doesn't include all of those, work in progress...
  SDValue NewOp = NormalizeVectorShuffle(Op, Subtarget, DAG);
  if (NewOp.getNode())
    return NewOp;

  SmallVector<int, 8> M(SVOp->getMask().begin(), SVOp->getMask().end());

  // NOTE: isPSHUFDMask can also match both masks below (unpckl_undef and
  // unpckh_undef). Only use pshufd if speed is more important than size.
  if (OptForSize && isUNPCKL_v_undef_Mask(M, VT, HasInt256))
    return getTargetShuffleNode(X86ISD::UNPCKL, dl, VT, V1, V1, DAG);
  if (OptForSize && isUNPCKH_v_undef_Mask(M, VT, HasInt256))
    return getTargetShuffleNode(X86ISD::UNPCKH, dl, VT, V1, V1, DAG);

  if (isMOVDDUPMask(M, VT) && Subtarget->hasSSE3() &&
      V2IsUndef && MayFoldVectorLoad(V1))
    return getMOVDDup(Op, dl, V1, DAG);

  if (isMOVHLPS_v_undef_Mask(M, VT))
    return getMOVHighToLow(Op, dl, DAG);

  // Use to match splats
  if (HasSSE2 && isUNPCKHMask(M, VT, HasInt256) && V2IsUndef &&
      (VT == MVT::v2f64 || VT == MVT::v2i64))
    return getTargetShuffleNode(X86ISD::UNPCKH, dl, VT, V1, V1, DAG);

  if (isPSHUFDMask(M, VT)) {
    // The actual implementation will match the mask in the if above and then
    // during isel it can match several different instructions, not only pshufd
    // as its name says, sad but true, emulate the behavior for now...
    if (isMOVDDUPMask(M, VT) && ((VT == MVT::v4f32 || VT == MVT::v2i64)))
      return getTargetShuffleNode(X86ISD::MOVLHPS, dl, VT, V1, V1, DAG);

    unsigned TargetMask = getShuffleSHUFImmediate(SVOp);

    if (HasSSE2 && (VT == MVT::v4f32 || VT == MVT::v4i32))
      return getTargetShuffleNode(X86ISD::PSHUFD, dl, VT, V1, TargetMask, DAG);

    if (HasFp256 && (VT == MVT::v4f32 || VT == MVT::v2f64))
      return getTargetShuffleNode(X86ISD::VPERMILPI, dl, VT, V1, TargetMask,
                                  DAG);

    return getTargetShuffleNode(X86ISD::SHUFP, dl, VT, V1, V1,
                                TargetMask, DAG);
  }

  if (isPALIGNRMask(M, VT, Subtarget))
    return getTargetShuffleNode(X86ISD::PALIGNR, dl, VT, V1, V2,
                                getShufflePALIGNRImmediate(SVOp),
                                DAG);

  if (isVALIGNMask(M, VT, Subtarget))
    return getTargetShuffleNode(X86ISD::VALIGN, dl, VT, V1, V2,
                                getShuffleVALIGNImmediate(SVOp),
                                DAG);

  // Check if this can be converted into a logical shift.
  bool isLeft = false;
  unsigned ShAmt = 0;
  SDValue ShVal;
  bool isShift = HasSSE2 && isVectorShift(SVOp, DAG, isLeft, ShVal, ShAmt);
  if (isShift && ShVal.hasOneUse()) {
    // If the shifted value has multiple uses, it may be cheaper to use
    // v_set0 + movlhps or movhlps, etc.
    MVT EltVT = VT.getVectorElementType();
    ShAmt *= EltVT.getSizeInBits();
    return getVShift(isLeft, VT, ShVal, ShAmt, DAG, *this, dl);
  }

  if (isMOVLMask(M, VT)) {
    if (ISD::isBuildVectorAllZeros(V1.getNode()))
      return getVZextMovL(VT, VT, V2, DAG, Subtarget, dl);
    if (!isMOVLPMask(M, VT)) {
      if (HasSSE2 && (VT == MVT::v2i64 || VT == MVT::v2f64))
        return getTargetShuffleNode(X86ISD::MOVSD, dl, VT, V1, V2, DAG);

      if (VT == MVT::v4i32 || VT == MVT::v4f32)
        return getTargetShuffleNode(X86ISD::MOVSS, dl, VT, V1, V2, DAG);
    }
  }

  // FIXME: fold these into legal mask.
  if (isMOVLHPSMask(M, VT) && !isUNPCKLMask(M, VT, HasInt256))
    return getMOVLowToHigh(Op, dl, DAG, HasSSE2);

  if (isMOVHLPSMask(M, VT))
    return getMOVHighToLow(Op, dl, DAG);

  if (V2IsUndef && isMOVSHDUPMask(M, VT, Subtarget))
    return getTargetShuffleNode(X86ISD::MOVSHDUP, dl, VT, V1, DAG);

  if (V2IsUndef && isMOVSLDUPMask(M, VT, Subtarget))
    return getTargetShuffleNode(X86ISD::MOVSLDUP, dl, VT, V1, DAG);

  if (isMOVLPMask(M, VT))
    return getMOVLP(Op, dl, DAG, HasSSE2);

  if (ShouldXformToMOVHLPS(M, VT) ||
      ShouldXformToMOVLP(V1.getNode(), V2.getNode(), M, VT))
    return DAG.getCommutedVectorShuffle(*SVOp);

  if (isShift) {
    // No better options. Use a vshldq / vsrldq.
    MVT EltVT = VT.getVectorElementType();
    ShAmt *= EltVT.getSizeInBits();
    return getVShift(isLeft, VT, ShVal, ShAmt, DAG, *this, dl);
  }

  bool Commuted = false;
  // FIXME: This should also accept a bitcast of a splat?  Be careful, not
  // 1,1,1,1 -> v8i16 though.
  BitVector UndefElements;
  if (auto *BVOp = dyn_cast<BuildVectorSDNode>(V1.getNode()))
    if (BVOp->getConstantSplatNode(&UndefElements) && UndefElements.none())
      V1IsSplat = true;
  if (auto *BVOp = dyn_cast<BuildVectorSDNode>(V2.getNode()))
    if (BVOp->getConstantSplatNode(&UndefElements) && UndefElements.none())
      V2IsSplat = true;

  // Canonicalize the splat or undef, if present, to be on the RHS.
  if (!V2IsUndef && V1IsSplat && !V2IsSplat) {
    CommuteVectorShuffleMask(M, NumElems);
    std::swap(V1, V2);
    std::swap(V1IsSplat, V2IsSplat);
    Commuted = true;
  }

  if (isCommutedMOVLMask(M, VT, V2IsSplat, V2IsUndef)) {
    // Shuffling low element of v1 into undef, just return v1.
    if (V2IsUndef)
      return V1;
    // If V2 is a splat, the mask may be malformed such as <4,3,3,3>, which
    // the instruction selector will not match, so get a canonical MOVL with
    // swapped operands to undo the commute.
    return getMOVL(DAG, dl, VT, V2, V1);
  }

  if (isUNPCKLMask(M, VT, HasInt256))
    return getTargetShuffleNode(X86ISD::UNPCKL, dl, VT, V1, V2, DAG);

  if (isUNPCKHMask(M, VT, HasInt256))
    return getTargetShuffleNode(X86ISD::UNPCKH, dl, VT, V1, V2, DAG);

  if (V2IsSplat) {
    // Normalize mask so all entries that point to V2 points to its first
    // element then try to match unpck{h|l} again. If match, return a
    // new vector_shuffle with the corrected mask.p
    SmallVector<int, 8> NewMask(M.begin(), M.end());
    NormalizeMask(NewMask, NumElems);
    if (isUNPCKLMask(NewMask, VT, HasInt256, true))
      return getTargetShuffleNode(X86ISD::UNPCKL, dl, VT, V1, V2, DAG);
    if (isUNPCKHMask(NewMask, VT, HasInt256, true))
      return getTargetShuffleNode(X86ISD::UNPCKH, dl, VT, V1, V2, DAG);
  }

  if (Commuted) {
    // Commute is back and try unpck* again.
    // FIXME: this seems wrong.
    CommuteVectorShuffleMask(M, NumElems);
    std::swap(V1, V2);
    std::swap(V1IsSplat, V2IsSplat);

    if (isUNPCKLMask(M, VT, HasInt256))
      return getTargetShuffleNode(X86ISD::UNPCKL, dl, VT, V1, V2, DAG);

    if (isUNPCKHMask(M, VT, HasInt256))
      return getTargetShuffleNode(X86ISD::UNPCKH, dl, VT, V1, V2, DAG);
  }

  // Normalize the node to match x86 shuffle ops if needed
  if (!V2IsUndef && (isSHUFPMask(M, VT, /* Commuted */ true)))
    return DAG.getCommutedVectorShuffle(*SVOp);

  // The checks below are all present in isShuffleMaskLegal, but they are
  // inlined here right now to enable us to directly emit target specific
  // nodes, and remove one by one until they don't return Op anymore.

  if (ShuffleVectorSDNode::isSplatMask(&M[0], VT) &&
      SVOp->getSplatIndex() == 0 && V2IsUndef) {
    if (VT == MVT::v2f64 || VT == MVT::v2i64)
      return getTargetShuffleNode(X86ISD::UNPCKL, dl, VT, V1, V1, DAG);
  }

  if (isPSHUFHWMask(M, VT, HasInt256))
    return getTargetShuffleNode(X86ISD::PSHUFHW, dl, VT, V1,
                                getShufflePSHUFHWImmediate(SVOp),
                                DAG);

  if (isPSHUFLWMask(M, VT, HasInt256))
    return getTargetShuffleNode(X86ISD::PSHUFLW, dl, VT, V1,
                                getShufflePSHUFLWImmediate(SVOp),
                                DAG);

  unsigned MaskValue;
  if (isBlendMask(M, VT, Subtarget->hasSSE41(), HasInt256, &MaskValue))
    return LowerVECTOR_SHUFFLEtoBlend(SVOp, MaskValue, Subtarget, DAG);

  if (isSHUFPMask(M, VT))
    return getTargetShuffleNode(X86ISD::SHUFP, dl, VT, V1, V2,
                                getShuffleSHUFImmediate(SVOp), DAG);

  if (isUNPCKL_v_undef_Mask(M, VT, HasInt256))
    return getTargetShuffleNode(X86ISD::UNPCKL, dl, VT, V1, V1, DAG);
  if (isUNPCKH_v_undef_Mask(M, VT, HasInt256))
    return getTargetShuffleNode(X86ISD::UNPCKH, dl, VT, V1, V1, DAG);

  //===--------------------------------------------------------------------===//
  // Generate target specific nodes for 128 or 256-bit shuffles only
  // supported in the AVX instruction set.
  //

  // Handle VMOVDDUPY permutations
  if (V2IsUndef && isMOVDDUPYMask(M, VT, HasFp256))
    return getTargetShuffleNode(X86ISD::MOVDDUP, dl, VT, V1, DAG);

  // Handle VPERMILPS/D* permutations
  if (isVPERMILPMask(M, VT)) {
    if ((HasInt256 && VT == MVT::v8i32) || VT == MVT::v16i32)
      return getTargetShuffleNode(X86ISD::PSHUFD, dl, VT, V1,
                                  getShuffleSHUFImmediate(SVOp), DAG);
    return getTargetShuffleNode(X86ISD::VPERMILPI, dl, VT, V1,
                                getShuffleSHUFImmediate(SVOp), DAG);
  }

  unsigned Idx;
  if (VT.is512BitVector() && isINSERT64x4Mask(M, VT, &Idx))
    return Insert256BitVector(V1, Extract256BitVector(V2, 0, DAG, dl),
                              Idx*(NumElems/2), DAG, dl);

  // Handle VPERM2F128/VPERM2I128 permutations
  if (isVPERM2X128Mask(M, VT, HasFp256))
    return getTargetShuffleNode(X86ISD::VPERM2X128, dl, VT, V1,
                                V2, getShuffleVPERM2X128Immediate(SVOp), DAG);

  if (Subtarget->hasSSE41() && isINSERTPSMask(M, VT))
    return getINSERTPS(SVOp, dl, DAG);

  unsigned Imm8;
  if (V2IsUndef && HasInt256 && isPermImmMask(M, VT, Imm8))
    return getTargetShuffleNode(X86ISD::VPERMI, dl, VT, V1, Imm8, DAG);

  if ((V2IsUndef && HasInt256 && VT.is256BitVector() && NumElems == 8) ||
      VT.is512BitVector()) {
    MVT MaskEltVT = MVT::getIntegerVT(VT.getVectorElementType().getSizeInBits());
    MVT MaskVectorVT = MVT::getVectorVT(MaskEltVT, NumElems);
    SmallVector<SDValue, 16> permclMask;
    for (unsigned i = 0; i != NumElems; ++i) {
      permclMask.push_back(DAG.getConstant((M[i]>=0) ? M[i] : 0, MaskEltVT));
    }

    SDValue Mask = DAG.getNode(ISD::BUILD_VECTOR, dl, MaskVectorVT, permclMask);
    if (V2IsUndef)
      // Bitcast is for VPERMPS since mask is v8i32 but node takes v8f32
      return DAG.getNode(X86ISD::VPERMV, dl, VT,
                          DAG.getNode(ISD::BITCAST, dl, VT, Mask), V1);
    return DAG.getNode(X86ISD::VPERMV3, dl, VT, V1,
                       DAG.getNode(ISD::BITCAST, dl, VT, Mask), V2);
  }

  //===--------------------------------------------------------------------===//
  // Since no target specific shuffle was selected for this generic one,
  // lower it into other known shuffles. FIXME: this isn't true yet, but
  // this is the plan.
  //

  // Handle v8i16 specifically since SSE can do byte extraction and insertion.
  if (VT == MVT::v8i16) {
    SDValue NewOp = LowerVECTOR_SHUFFLEv8i16(Op, Subtarget, DAG);
    if (NewOp.getNode())
      return NewOp;
  }

  if (VT == MVT::v16i16 && HasInt256) {
    SDValue NewOp = LowerVECTOR_SHUFFLEv16i16(Op, DAG);
    if (NewOp.getNode())
      return NewOp;
  }

  if (VT == MVT::v16i8) {
    SDValue NewOp = LowerVECTOR_SHUFFLEv16i8(SVOp, Subtarget, DAG);
    if (NewOp.getNode())
      return NewOp;
  }

  if (VT == MVT::v32i8) {
    SDValue NewOp = LowerVECTOR_SHUFFLEv32i8(SVOp, Subtarget, DAG);
    if (NewOp.getNode())
      return NewOp;
  }

  // Handle all 128-bit wide vectors with 4 elements, and match them with
  // several different shuffle types.
  if (NumElems == 4 && VT.is128BitVector())
    return LowerVECTOR_SHUFFLE_128v4(SVOp, DAG);

  // Handle general 256-bit shuffles
  if (VT.is256BitVector())
    return LowerVECTOR_SHUFFLE_256(SVOp, DAG);

  return SDValue();
}

// This function assumes its argument is a BUILD_VECTOR of constants or
// undef SDNodes. i.e: ISD::isBuildVectorOfConstantSDNodes(BuildVector) is
// true.
static bool BUILD_VECTORtoBlendMask(BuildVectorSDNode *BuildVector,
                                    unsigned &MaskValue) {
  MaskValue = 0;
  unsigned NumElems = BuildVector->getNumOperands();
  // There are 2 lanes if (NumElems > 8), and 1 lane otherwise.
  unsigned NumLanes = (NumElems - 1) / 8 + 1;
  unsigned NumElemsInLane = NumElems / NumLanes;

  // Blend for v16i16 should be symetric for the both lanes.
  for (unsigned i = 0; i < NumElemsInLane; ++i) {
    SDValue EltCond = BuildVector->getOperand(i);
    SDValue SndLaneEltCond =
        (NumLanes == 2) ? BuildVector->getOperand(i + NumElemsInLane) : EltCond;

    int Lane1Cond = -1, Lane2Cond = -1;
    if (isa<ConstantSDNode>(EltCond))
      Lane1Cond = !isZero(EltCond);
    if (isa<ConstantSDNode>(SndLaneEltCond))
      Lane2Cond = !isZero(SndLaneEltCond);

    if (Lane1Cond == Lane2Cond || Lane2Cond < 0)
      // Lane1Cond != 0, means we want the first argument.
      // Lane1Cond == 0, means we want the second argument.
      // The encoding of this argument is 0 for the first argument, 1
      // for the second. Therefore, invert the condition.
      MaskValue |= !Lane1Cond << i;
    else if (Lane1Cond < 0)
      MaskValue |= !Lane2Cond << i;
    else
      return false;
  }
  return true;
}

/// \brief Try to lower a VSELECT instruction to a vector shuffle.
static SDValue lowerVSELECTtoVectorShuffle(SDValue Op,
                                           const X86Subtarget *Subtarget,
                                           SelectionDAG &DAG) {
  SDValue Cond = Op.getOperand(0);
  SDValue LHS = Op.getOperand(1);
  SDValue RHS = Op.getOperand(2);
  SDLoc dl(Op);
  MVT VT = Op.getSimpleValueType();

  if (!ISD::isBuildVectorOfConstantSDNodes(Cond.getNode()))
    return SDValue();
  auto *CondBV = cast<BuildVectorSDNode>(Cond);

  // Only non-legal VSELECTs reach this lowering, convert those into generic
  // shuffles and re-use the shuffle lowering path for blends.
  SmallVector<int, 32> Mask;
  for (int i = 0, Size = VT.getVectorNumElements(); i < Size; ++i) {
    SDValue CondElt = CondBV->getOperand(i);
    Mask.push_back(
        isa<ConstantSDNode>(CondElt) ? i + (isZero(CondElt) ? Size : 0) : -1);
  }
  return DAG.getVectorShuffle(VT, dl, LHS, RHS, Mask);
}

SDValue X86TargetLowering::LowerVSELECT(SDValue Op, SelectionDAG &DAG) const {
  // A vselect where all conditions and data are constants can be optimized into
  // a single vector load by SelectionDAGLegalize::ExpandBUILD_VECTOR().
  if (ISD::isBuildVectorOfConstantSDNodes(Op.getOperand(0).getNode()) &&
      ISD::isBuildVectorOfConstantSDNodes(Op.getOperand(1).getNode()) &&
      ISD::isBuildVectorOfConstantSDNodes(Op.getOperand(2).getNode()))
    return SDValue();

  // Try to lower this to a blend-style vector shuffle. This can handle all
  // constant condition cases.
  SDValue BlendOp = lowerVSELECTtoVectorShuffle(Op, Subtarget, DAG);
  if (BlendOp.getNode())
    return BlendOp;

  // Variable blends are only legal from SSE4.1 onward.
  if (!Subtarget->hasSSE41())
    return SDValue();

  // Some types for vselect were previously set to Expand, not Legal or
  // Custom. Return an empty SDValue so we fall-through to Expand, after
  // the Custom lowering phase.
  MVT VT = Op.getSimpleValueType();
  switch (VT.SimpleTy) {
  default:
    break;
  case MVT::v8i16:
  case MVT::v16i16:
    if (Subtarget->hasBWI() && Subtarget->hasVLX())
      break;
    return SDValue();
  }

  // We couldn't create a "Blend with immediate" node.
  // This node should still be legal, but we'll have to emit a blendv*
  // instruction.
  return Op;
}

static SDValue LowerEXTRACT_VECTOR_ELT_SSE4(SDValue Op, SelectionDAG &DAG) {
  MVT VT = Op.getSimpleValueType();
  SDLoc dl(Op);

  if (!Op.getOperand(0).getSimpleValueType().is128BitVector())
    return SDValue();

  if (VT.getSizeInBits() == 8) {
    SDValue Extract = DAG.getNode(X86ISD::PEXTRB, dl, MVT::i32,
                                  Op.getOperand(0), Op.getOperand(1));
    SDValue Assert  = DAG.getNode(ISD::AssertZext, dl, MVT::i32, Extract,
                                  DAG.getValueType(VT));
    return DAG.getNode(ISD::TRUNCATE, dl, VT, Assert);
  }

  if (VT.getSizeInBits() == 16) {
    unsigned Idx = cast<ConstantSDNode>(Op.getOperand(1))->getZExtValue();
    // If Idx is 0, it's cheaper to do a move instead of a pextrw.
    if (Idx == 0)
      return DAG.getNode(ISD::TRUNCATE, dl, MVT::i16,
                         DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, MVT::i32,
                                     DAG.getNode(ISD::BITCAST, dl,
                                                 MVT::v4i32,
                                                 Op.getOperand(0)),
                                     Op.getOperand(1)));
    SDValue Extract = DAG.getNode(X86ISD::PEXTRW, dl, MVT::i32,
                                  Op.getOperand(0), Op.getOperand(1));
    SDValue Assert  = DAG.getNode(ISD::AssertZext, dl, MVT::i32, Extract,
                                  DAG.getValueType(VT));
    return DAG.getNode(ISD::TRUNCATE, dl, VT, Assert);
  }

  if (VT == MVT::f32) {
    // EXTRACTPS outputs to a GPR32 register which will require a movd to copy
    // the result back to FR32 register. It's only worth matching if the
    // result has a single use which is a store or a bitcast to i32.  And in
    // the case of a store, it's not worth it if the index is a constant 0,
    // because a MOVSSmr can be used instead, which is smaller and faster.
    if (!Op.hasOneUse())
      return SDValue();
    SDNode *User = *Op.getNode()->use_begin();
    if ((User->getOpcode() != ISD::STORE ||
         (isa<ConstantSDNode>(Op.getOperand(1)) &&
          cast<ConstantSDNode>(Op.getOperand(1))->isNullValue())) &&
        (User->getOpcode() != ISD::BITCAST ||
         User->getValueType(0) != MVT::i32))
      return SDValue();
    SDValue Extract = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, MVT::i32,
                                  DAG.getNode(ISD::BITCAST, dl, MVT::v4i32,
                                              Op.getOperand(0)),
                                              Op.getOperand(1));
    return DAG.getNode(ISD::BITCAST, dl, MVT::f32, Extract);
  }

  if (VT == MVT::i32 || VT == MVT::i64) {
    // ExtractPS/pextrq works with constant index.
    if (isa<ConstantSDNode>(Op.getOperand(1)))
      return Op;
  }
  return SDValue();
}

/// Extract one bit from mask vector, like v16i1 or v8i1.
/// AVX-512 feature.
SDValue
X86TargetLowering::ExtractBitFromMaskVector(SDValue Op, SelectionDAG &DAG) const {
  SDValue Vec = Op.getOperand(0);
  SDLoc dl(Vec);
  MVT VecVT = Vec.getSimpleValueType();
  SDValue Idx = Op.getOperand(1);
  MVT EltVT = Op.getSimpleValueType();

  assert((EltVT == MVT::i1) && "Unexpected operands in ExtractBitFromMaskVector");
  assert((VecVT.getVectorNumElements() <= 16 || Subtarget->hasBWI()) &&
         "Unexpected vector type in ExtractBitFromMaskVector");

  // variable index can't be handled in mask registers,
  // extend vector to VR512
  if (!isa<ConstantSDNode>(Idx)) {
    MVT ExtVT = (VecVT == MVT::v8i1 ?  MVT::v8i64 : MVT::v16i32);
    SDValue Ext = DAG.getNode(ISD::ZERO_EXTEND, dl, ExtVT, Vec);
    SDValue Elt = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl,
                              ExtVT.getVectorElementType(), Ext, Idx);
    return DAG.getNode(ISD::TRUNCATE, dl, EltVT, Elt);
  }

  unsigned IdxVal = cast<ConstantSDNode>(Idx)->getZExtValue();
  const TargetRegisterClass* rc = getRegClassFor(VecVT);
  if (!Subtarget->hasDQI() && (VecVT.getVectorNumElements() <= 8))
    rc = getRegClassFor(MVT::v16i1);
  unsigned MaxSift = rc->getSize()*8 - 1;
  Vec = DAG.getNode(X86ISD::VSHLI, dl, VecVT, Vec,
                    DAG.getConstant(MaxSift - IdxVal, MVT::i8));
  Vec = DAG.getNode(X86ISD::VSRLI, dl, VecVT, Vec,
                    DAG.getConstant(MaxSift, MVT::i8));
  return DAG.getNode(X86ISD::VEXTRACT, dl, MVT::i1, Vec,
                       DAG.getIntPtrConstant(0));
}

SDValue
X86TargetLowering::LowerEXTRACT_VECTOR_ELT(SDValue Op,
                                           SelectionDAG &DAG) const {
  SDLoc dl(Op);
  SDValue Vec = Op.getOperand(0);
  MVT VecVT = Vec.getSimpleValueType();
  SDValue Idx = Op.getOperand(1);

  if (Op.getSimpleValueType() == MVT::i1)
    return ExtractBitFromMaskVector(Op, DAG);

  if (!isa<ConstantSDNode>(Idx)) {
    if (VecVT.is512BitVector() ||
        (VecVT.is256BitVector() && Subtarget->hasInt256() &&
         VecVT.getVectorElementType().getSizeInBits() == 32)) {

      MVT MaskEltVT =
        MVT::getIntegerVT(VecVT.getVectorElementType().getSizeInBits());
      MVT MaskVT = MVT::getVectorVT(MaskEltVT, VecVT.getSizeInBits() /
                                    MaskEltVT.getSizeInBits());

      Idx = DAG.getZExtOrTrunc(Idx, dl, MaskEltVT);
      SDValue Mask = DAG.getNode(X86ISD::VINSERT, dl, MaskVT,
                                getZeroVector(MaskVT, Subtarget, DAG, dl),
                                Idx, DAG.getConstant(0, getPointerTy()));
      SDValue Perm = DAG.getNode(X86ISD::VPERMV, dl, VecVT, Mask, Vec);
      return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, Op.getValueType(),
                        Perm, DAG.getConstant(0, getPointerTy()));
    }
    return SDValue();
  }

  // If this is a 256-bit vector result, first extract the 128-bit vector and
  // then extract the element from the 128-bit vector.
  if (VecVT.is256BitVector() || VecVT.is512BitVector()) {

    unsigned IdxVal = cast<ConstantSDNode>(Idx)->getZExtValue();
    // Get the 128-bit vector.
    Vec = Extract128BitVector(Vec, IdxVal, DAG, dl);
    MVT EltVT = VecVT.getVectorElementType();

    unsigned ElemsPerChunk = 128 / EltVT.getSizeInBits();

    //if (IdxVal >= NumElems/2)
    //  IdxVal -= NumElems/2;
    IdxVal -= (IdxVal/ElemsPerChunk)*ElemsPerChunk;
    return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, Op.getValueType(), Vec,
                       DAG.getConstant(IdxVal, MVT::i32));
  }

  assert(VecVT.is128BitVector() && "Unexpected vector length");

  if (Subtarget->hasSSE41()) {
    SDValue Res = LowerEXTRACT_VECTOR_ELT_SSE4(Op, DAG);
    if (Res.getNode())
      return Res;
  }

  MVT VT = Op.getSimpleValueType();
  // TODO: handle v16i8.
  if (VT.getSizeInBits() == 16) {
    SDValue Vec = Op.getOperand(0);
    unsigned Idx = cast<ConstantSDNode>(Op.getOperand(1))->getZExtValue();
    if (Idx == 0)
      return DAG.getNode(ISD::TRUNCATE, dl, MVT::i16,
                         DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, MVT::i32,
                                     DAG.getNode(ISD::BITCAST, dl,
                                                 MVT::v4i32, Vec),
                                     Op.getOperand(1)));
    // Transform it so it match pextrw which produces a 32-bit result.
    MVT EltVT = MVT::i32;
    SDValue Extract = DAG.getNode(X86ISD::PEXTRW, dl, EltVT,
                                  Op.getOperand(0), Op.getOperand(1));
    SDValue Assert  = DAG.getNode(ISD::AssertZext, dl, EltVT, Extract,
                                  DAG.getValueType(VT));
    return DAG.getNode(ISD::TRUNCATE, dl, VT, Assert);
  }

  if (VT.getSizeInBits() == 32) {
    unsigned Idx = cast<ConstantSDNode>(Op.getOperand(1))->getZExtValue();
    if (Idx == 0)
      return Op;

    // SHUFPS the element to the lowest double word, then movss.
    int Mask[4] = { static_cast<int>(Idx), -1, -1, -1 };
    MVT VVT = Op.getOperand(0).getSimpleValueType();
    SDValue Vec = DAG.getVectorShuffle(VVT, dl, Op.getOperand(0),
                                       DAG.getUNDEF(VVT), Mask);
    return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, VT, Vec,
                       DAG.getIntPtrConstant(0));
  }

  if (VT.getSizeInBits() == 64) {
    // FIXME: .td only matches this for <2 x f64>, not <2 x i64> on 32b
    // FIXME: seems like this should be unnecessary if mov{h,l}pd were taught
    //        to match extract_elt for f64.
    unsigned Idx = cast<ConstantSDNode>(Op.getOperand(1))->getZExtValue();
    if (Idx == 0)
      return Op;

    // UNPCKHPD the element to the lowest double word, then movsd.
    // Note if the lower 64 bits of the result of the UNPCKHPD is then stored
    // to a f64mem, the whole operation is folded into a single MOVHPDmr.
    int Mask[2] = { 1, -1 };
    MVT VVT = Op.getOperand(0).getSimpleValueType();
    SDValue Vec = DAG.getVectorShuffle(VVT, dl, Op.getOperand(0),
                                       DAG.getUNDEF(VVT), Mask);
    return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, VT, Vec,
                       DAG.getIntPtrConstant(0));
  }

  return SDValue();
}

/// Insert one bit to mask vector, like v16i1 or v8i1.
/// AVX-512 feature.
SDValue
X86TargetLowering::InsertBitToMaskVector(SDValue Op, SelectionDAG &DAG) const {
  SDLoc dl(Op);
  SDValue Vec = Op.getOperand(0);
  SDValue Elt = Op.getOperand(1);
  SDValue Idx = Op.getOperand(2);
  MVT VecVT = Vec.getSimpleValueType();

  if (!isa<ConstantSDNode>(Idx)) {
    // Non constant index. Extend source and destination,
    // insert element and then truncate the result.
    MVT ExtVecVT = (VecVT == MVT::v8i1 ?  MVT::v8i64 : MVT::v16i32);
    MVT ExtEltVT = (VecVT == MVT::v8i1 ?  MVT::i64 : MVT::i32);
    SDValue ExtOp = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, ExtVecVT,
      DAG.getNode(ISD::ZERO_EXTEND, dl, ExtVecVT, Vec),
      DAG.getNode(ISD::ZERO_EXTEND, dl, ExtEltVT, Elt), Idx);
    return DAG.getNode(ISD::TRUNCATE, dl, VecVT, ExtOp);
  }

  unsigned IdxVal = cast<ConstantSDNode>(Idx)->getZExtValue();
  SDValue EltInVec = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VecVT, Elt);
  if (Vec.getOpcode() == ISD::UNDEF)
    return DAG.getNode(X86ISD::VSHLI, dl, VecVT, EltInVec,
                       DAG.getConstant(IdxVal, MVT::i8));
  const TargetRegisterClass* rc = getRegClassFor(VecVT);
  unsigned MaxSift = rc->getSize()*8 - 1;
  EltInVec = DAG.getNode(X86ISD::VSHLI, dl, VecVT, EltInVec,
                    DAG.getConstant(MaxSift, MVT::i8));
  EltInVec = DAG.getNode(X86ISD::VSRLI, dl, VecVT, EltInVec,
                    DAG.getConstant(MaxSift - IdxVal, MVT::i8));
  return DAG.getNode(ISD::OR, dl, VecVT, Vec, EltInVec);
}

SDValue X86TargetLowering::LowerINSERT_VECTOR_ELT(SDValue Op,
                                                  SelectionDAG &DAG) const {
  MVT VT = Op.getSimpleValueType();
  MVT EltVT = VT.getVectorElementType();

  if (EltVT == MVT::i1)
    return InsertBitToMaskVector(Op, DAG);

  SDLoc dl(Op);
  SDValue N0 = Op.getOperand(0);
  SDValue N1 = Op.getOperand(1);
  SDValue N2 = Op.getOperand(2);
  if (!isa<ConstantSDNode>(N2))
    return SDValue();
  auto *N2C = cast<ConstantSDNode>(N2);
  unsigned IdxVal = N2C->getZExtValue();

  // If the vector is wider than 128 bits, extract the 128-bit subvector, insert
  // into that, and then insert the subvector back into the result.
  if (VT.is256BitVector() || VT.is512BitVector()) {
    // Get the desired 128-bit vector half.
    SDValue V = Extract128BitVector(N0, IdxVal, DAG, dl);

    // Insert the element into the desired half.
    unsigned NumEltsIn128 = 128 / EltVT.getSizeInBits();
    unsigned IdxIn128 = IdxVal - (IdxVal / NumEltsIn128) * NumEltsIn128;

    V = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, V.getValueType(), V, N1,
                    DAG.getConstant(IdxIn128, MVT::i32));

    // Insert the changed part back to the 256-bit vector
    return Insert128BitVector(N0, V, IdxVal, DAG, dl);
  }
  assert(VT.is128BitVector() && "Only 128-bit vector types should be left!");

  if (Subtarget->hasSSE41()) {
    if (EltVT.getSizeInBits() == 8 || EltVT.getSizeInBits() == 16) {
      unsigned Opc;
      if (VT == MVT::v8i16) {
        Opc = X86ISD::PINSRW;
      } else {
        assert(VT == MVT::v16i8);
        Opc = X86ISD::PINSRB;
      }

      // Transform it so it match pinsr{b,w} which expects a GR32 as its second
      // argument.
      if (N1.getValueType() != MVT::i32)
        N1 = DAG.getNode(ISD::ANY_EXTEND, dl, MVT::i32, N1);
      if (N2.getValueType() != MVT::i32)
        N2 = DAG.getIntPtrConstant(IdxVal);
      return DAG.getNode(Opc, dl, VT, N0, N1, N2);
    }

    if (EltVT == MVT::f32) {
      // Bits [7:6] of the constant are the source select.  This will always be
      //  zero here.  The DAG Combiner may combine an extract_elt index into
      //  these
      //  bits.  For example (insert (extract, 3), 2) could be matched by
      //  putting
      //  the '3' into bits [7:6] of X86ISD::INSERTPS.
      // Bits [5:4] of the constant are the destination select.  This is the
      //  value of the incoming immediate.
      // Bits [3:0] of the constant are the zero mask.  The DAG Combiner may
      //   combine either bitwise AND or insert of float 0.0 to set these bits.
      N2 = DAG.getIntPtrConstant(IdxVal << 4);
      // Create this as a scalar to vector..
      N1 = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, MVT::v4f32, N1);
      return DAG.getNode(X86ISD::INSERTPS, dl, VT, N0, N1, N2);
    }

    if (EltVT == MVT::i32 || EltVT == MVT::i64) {
      // PINSR* works with constant index.
      return Op;
    }
  }

  if (EltVT == MVT::i8)
    return SDValue();

  if (EltVT.getSizeInBits() == 16) {
    // Transform it so it match pinsrw which expects a 16-bit value in a GR32
    // as its second argument.
    if (N1.getValueType() != MVT::i32)
      N1 = DAG.getNode(ISD::ANY_EXTEND, dl, MVT::i32, N1);
    if (N2.getValueType() != MVT::i32)
      N2 = DAG.getIntPtrConstant(IdxVal);
    return DAG.getNode(X86ISD::PINSRW, dl, VT, N0, N1, N2);
  }
  return SDValue();
}

static SDValue LowerSCALAR_TO_VECTOR(SDValue Op, SelectionDAG &DAG) {
  SDLoc dl(Op);
  MVT OpVT = Op.getSimpleValueType();

  // If this is a 256-bit vector result, first insert into a 128-bit
  // vector and then insert into the 256-bit vector.
  if (!OpVT.is128BitVector()) {
    // Insert into a 128-bit vector.
    unsigned SizeFactor = OpVT.getSizeInBits()/128;
    MVT VT128 = MVT::getVectorVT(OpVT.getVectorElementType(),
                                 OpVT.getVectorNumElements() / SizeFactor);

    Op = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT128, Op.getOperand(0));

    // Insert the 128-bit vector.
    return Insert128BitVector(DAG.getUNDEF(OpVT), Op, 0, DAG, dl);
  }

  if (OpVT == MVT::v1i64 &&
      Op.getOperand(0).getValueType() == MVT::i64)
    return DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, MVT::v1i64, Op.getOperand(0));

  SDValue AnyExt = DAG.getNode(ISD::ANY_EXTEND, dl, MVT::i32, Op.getOperand(0));
  assert(OpVT.is128BitVector() && "Expected an SSE type!");
  return DAG.getNode(ISD::BITCAST, dl, OpVT,
                     DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, MVT::v4i32,AnyExt));
}

// Lower a node with an EXTRACT_SUBVECTOR opcode.  This may result in
// a simple subregister reference or explicit instructions to grab
// upper bits of a vector.
static SDValue LowerEXTRACT_SUBVECTOR(SDValue Op, const X86Subtarget *Subtarget,
                                      SelectionDAG &DAG) {
  SDLoc dl(Op);
  SDValue In =  Op.getOperand(0);
  SDValue Idx = Op.getOperand(1);
  unsigned IdxVal = cast<ConstantSDNode>(Idx)->getZExtValue();
  MVT ResVT   = Op.getSimpleValueType();
  MVT InVT    = In.getSimpleValueType();

  if (Subtarget->hasFp256()) {
    if (ResVT.is128BitVector() &&
        (InVT.is256BitVector() || InVT.is512BitVector()) &&
        isa<ConstantSDNode>(Idx)) {
      return Extract128BitVector(In, IdxVal, DAG, dl);
    }
    if (ResVT.is256BitVector() && InVT.is512BitVector() &&
        isa<ConstantSDNode>(Idx)) {
      return Extract256BitVector(In, IdxVal, DAG, dl);
    }
  }
  return SDValue();
}

// Lower a node with an INSERT_SUBVECTOR opcode.  This may result in a
// simple superregister reference or explicit instructions to insert
// the upper bits of a vector.
static SDValue LowerINSERT_SUBVECTOR(SDValue Op, const X86Subtarget *Subtarget,
                                     SelectionDAG &DAG) {
  if (!Subtarget->hasAVX())
    return SDValue();

  SDLoc dl(Op);
  SDValue Vec = Op.getOperand(0);
  SDValue SubVec = Op.getOperand(1);
  SDValue Idx = Op.getOperand(2);

  if (!isa<ConstantSDNode>(Idx))
    return SDValue();

  unsigned IdxVal = cast<ConstantSDNode>(Idx)->getZExtValue();
  MVT OpVT = Op.getSimpleValueType();
  MVT SubVecVT = SubVec.getSimpleValueType();

  // Fold two 16-byte subvector loads into one 32-byte load:
  // (insert_subvector (insert_subvector undef, (load addr), 0),
  //                   (load addr + 16), Elts/2)
  // --> load32 addr
  if ((IdxVal == OpVT.getVectorNumElements() / 2) &&
      Vec.getOpcode() == ISD::INSERT_SUBVECTOR &&
      OpVT.is256BitVector() && SubVecVT.is128BitVector() &&
      !Subtarget->isUnalignedMem32Slow()) {
    SDValue SubVec2 = Vec.getOperand(1);
    if (auto *Idx2 = dyn_cast<ConstantSDNode>(Vec.getOperand(2))) {
      if (Idx2->getZExtValue() == 0) {
        SDValue Ops[] = { SubVec2, SubVec };
        SDValue LD = EltsFromConsecutiveLoads(OpVT, Ops, dl, DAG, false);
        if (LD.getNode())
          return LD;
      }
    }
  }

  if ((OpVT.is256BitVector() || OpVT.is512BitVector()) &&
      SubVecVT.is128BitVector())
    return Insert128BitVector(Vec, SubVec, IdxVal, DAG, dl);

  if (OpVT.is512BitVector() && SubVecVT.is256BitVector())
    return Insert256BitVector(Vec, SubVec, IdxVal, DAG, dl);

  return SDValue();
}

// ConstantPool, JumpTable, GlobalAddress, and ExternalSymbol are lowered as
// their target countpart wrapped in the X86ISD::Wrapper node. Suppose N is
// one of the above mentioned nodes. It has to be wrapped because otherwise
// Select(N) returns N. So the raw TargetGlobalAddress nodes, etc. can only
// be used to form addressing mode. These wrapped nodes will be selected
// into MOV32ri.
SDValue
X86TargetLowering::LowerConstantPool(SDValue Op, SelectionDAG &DAG) const {
  ConstantPoolSDNode *CP = cast<ConstantPoolSDNode>(Op);

  // In PIC mode (unless we're in RIPRel PIC mode) we add an offset to the
  // global base reg.
  unsigned char OpFlag = 0;
  unsigned WrapperKind = X86ISD::Wrapper;
  CodeModel::Model M = DAG.getTarget().getCodeModel();

  if (Subtarget->isPICStyleRIPRel() &&
      (M == CodeModel::Small || M == CodeModel::Kernel))
    WrapperKind = X86ISD::WrapperRIP;
  else if (Subtarget->isPICStyleGOT())
    OpFlag = X86II::MO_GOTOFF;
  else if (Subtarget->isPICStyleStubPIC())
    OpFlag = X86II::MO_PIC_BASE_OFFSET;

  SDValue Result = DAG.getTargetConstantPool(CP->getConstVal(), getPointerTy(),
                                             CP->getAlignment(),
                                             CP->getOffset(), OpFlag);
  SDLoc DL(CP);
  Result = DAG.getNode(WrapperKind, DL, getPointerTy(), Result);
  // With PIC, the address is actually $g + Offset.
  if (OpFlag) {
    Result = DAG.getNode(ISD::ADD, DL, getPointerTy(),
                         DAG.getNode(X86ISD::GlobalBaseReg,
                                     SDLoc(), getPointerTy()),
                         Result);
  }

  return Result;
}

SDValue X86TargetLowering::LowerJumpTable(SDValue Op, SelectionDAG &DAG) const {
  JumpTableSDNode *JT = cast<JumpTableSDNode>(Op);

  // In PIC mode (unless we're in RIPRel PIC mode) we add an offset to the
  // global base reg.
  unsigned char OpFlag = 0;
  unsigned WrapperKind = X86ISD::Wrapper;
  CodeModel::Model M = DAG.getTarget().getCodeModel();

  if (Subtarget->isPICStyleRIPRel() &&
      (M == CodeModel::Small || M == CodeModel::Kernel))
    WrapperKind = X86ISD::WrapperRIP;
  else if (Subtarget->isPICStyleGOT())
    OpFlag = X86II::MO_GOTOFF;
  else if (Subtarget->isPICStyleStubPIC())
    OpFlag = X86II::MO_PIC_BASE_OFFSET;

  SDValue Result = DAG.getTargetJumpTable(JT->getIndex(), getPointerTy(),
                                          OpFlag);
  SDLoc DL(JT);
  Result = DAG.getNode(WrapperKind, DL, getPointerTy(), Result);

  // With PIC, the address is actually $g + Offset.
  if (OpFlag)
    Result = DAG.getNode(ISD::ADD, DL, getPointerTy(),
                         DAG.getNode(X86ISD::GlobalBaseReg,
                                     SDLoc(), getPointerTy()),
                         Result);

  return Result;
}

SDValue
X86TargetLowering::LowerExternalSymbol(SDValue Op, SelectionDAG &DAG) const {
  const char *Sym = cast<ExternalSymbolSDNode>(Op)->getSymbol();

  // In PIC mode (unless we're in RIPRel PIC mode) we add an offset to the
  // global base reg.
  unsigned char OpFlag = 0;
  unsigned WrapperKind = X86ISD::Wrapper;
  CodeModel::Model M = DAG.getTarget().getCodeModel();

  if (Subtarget->isPICStyleRIPRel() &&
      (M == CodeModel::Small || M == CodeModel::Kernel)) {
    if (Subtarget->isTargetDarwin() || Subtarget->isTargetELF())
      OpFlag = X86II::MO_GOTPCREL;
    WrapperKind = X86ISD::WrapperRIP;
  } else if (Subtarget->isPICStyleGOT()) {
    OpFlag = X86II::MO_GOT;
  } else if (Subtarget->isPICStyleStubPIC()) {
    OpFlag = X86II::MO_DARWIN_NONLAZY_PIC_BASE;
  } else if (Subtarget->isPICStyleStubNoDynamic()) {
    OpFlag = X86II::MO_DARWIN_NONLAZY;
  }

  SDValue Result = DAG.getTargetExternalSymbol(Sym, getPointerTy(), OpFlag);

  SDLoc DL(Op);
  Result = DAG.getNode(WrapperKind, DL, getPointerTy(), Result);

  // With PIC, the address is actually $g + Offset.
  if (DAG.getTarget().getRelocationModel() == Reloc::PIC_ &&
      !Subtarget->is64Bit()) {
    Result = DAG.getNode(ISD::ADD, DL, getPointerTy(),
                         DAG.getNode(X86ISD::GlobalBaseReg,
                                     SDLoc(), getPointerTy()),
                         Result);
  }

  // For symbols that require a load from a stub to get the address, emit the
  // load.
  if (isGlobalStubReference(OpFlag))
    Result = DAG.getLoad(getPointerTy(), DL, DAG.getEntryNode(), Result,
                         MachinePointerInfo::getGOT(), false, false, false, 0);

  return Result;
}

SDValue
X86TargetLowering::LowerBlockAddress(SDValue Op, SelectionDAG &DAG) const {
  // Create the TargetBlockAddressAddress node.
  unsigned char OpFlags =
    Subtarget->ClassifyBlockAddressReference();
  CodeModel::Model M = DAG.getTarget().getCodeModel();
  const BlockAddress *BA = cast<BlockAddressSDNode>(Op)->getBlockAddress();
  int64_t Offset = cast<BlockAddressSDNode>(Op)->getOffset();
  SDLoc dl(Op);
  SDValue Result = DAG.getTargetBlockAddress(BA, getPointerTy(), Offset,
                                             OpFlags);

  if (Subtarget->isPICStyleRIPRel() &&
      (M == CodeModel::Small || M == CodeModel::Kernel))
    Result = DAG.getNode(X86ISD::WrapperRIP, dl, getPointerTy(), Result);
  else
    Result = DAG.getNode(X86ISD::Wrapper, dl, getPointerTy(), Result);

  // With PIC, the address is actually $g + Offset.
  if (isGlobalRelativeToPICBase(OpFlags)) {
    Result = DAG.getNode(ISD::ADD, dl, getPointerTy(),
                         DAG.getNode(X86ISD::GlobalBaseReg, dl, getPointerTy()),
                         Result);
  }

  return Result;
}

SDValue
X86TargetLowering::LowerGlobalAddress(const GlobalValue *GV, SDLoc dl,
                                      int64_t Offset, SelectionDAG &DAG) const {
  // Create the TargetGlobalAddress node, folding in the constant
  // offset if it is legal.
  unsigned char OpFlags =
      Subtarget->ClassifyGlobalReference(GV, DAG.getTarget());
  CodeModel::Model M = DAG.getTarget().getCodeModel();
  SDValue Result;
  if (OpFlags == X86II::MO_NO_FLAG &&
      X86::isOffsetSuitableForCodeModel(Offset, M)) {
    // A direct static reference to a global.
    Result = DAG.getTargetGlobalAddress(GV, dl, getPointerTy(), Offset);
    Offset = 0;
  } else {
    Result = DAG.getTargetGlobalAddress(GV, dl, getPointerTy(), 0, OpFlags);
  }

  if (Subtarget->isPICStyleRIPRel() &&
      (M == CodeModel::Small || M == CodeModel::Kernel))
    Result = DAG.getNode(X86ISD::WrapperRIP, dl, getPointerTy(), Result);
  else
    Result = DAG.getNode(X86ISD::Wrapper, dl, getPointerTy(), Result);

  // With PIC, the address is actually $g + Offset.
  if (isGlobalRelativeToPICBase(OpFlags)) {
    Result = DAG.getNode(ISD::ADD, dl, getPointerTy(),
                         DAG.getNode(X86ISD::GlobalBaseReg, dl, getPointerTy()),
                         Result);
  }

  // For globals that require a load from a stub to get the address, emit the
  // load.
  if (isGlobalStubReference(OpFlags))
    Result = DAG.getLoad(getPointerTy(), dl, DAG.getEntryNode(), Result,
                         MachinePointerInfo::getGOT(), false, false, false, 0);

  // If there was a non-zero offset that we didn't fold, create an explicit
  // addition for it.
  if (Offset != 0)
    Result = DAG.getNode(ISD::ADD, dl, getPointerTy(), Result,
                         DAG.getConstant(Offset, getPointerTy()));

  return Result;
}

SDValue
X86TargetLowering::LowerGlobalAddress(SDValue Op, SelectionDAG &DAG) const {
  const GlobalValue *GV = cast<GlobalAddressSDNode>(Op)->getGlobal();
  int64_t Offset = cast<GlobalAddressSDNode>(Op)->getOffset();
  return LowerGlobalAddress(GV, SDLoc(Op), Offset, DAG);
}

static SDValue
GetTLSADDR(SelectionDAG &DAG, SDValue Chain, GlobalAddressSDNode *GA,
           SDValue *InFlag, const EVT PtrVT, unsigned ReturnReg,
           unsigned char OperandFlags, bool LocalDynamic = false) {
  MachineFrameInfo *MFI = DAG.getMachineFunction().getFrameInfo();
  SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue);
  SDLoc dl(GA);
  SDValue TGA = DAG.getTargetGlobalAddress(GA->getGlobal(), dl,
                                           GA->getValueType(0),
                                           GA->getOffset(),
                                           OperandFlags);

  X86ISD::NodeType CallType = LocalDynamic ? X86ISD::TLSBASEADDR
                                           : X86ISD::TLSADDR;

  if (InFlag) {
    SDValue Ops[] = { Chain,  TGA, *InFlag };
    Chain = DAG.getNode(CallType, dl, NodeTys, Ops);
  } else {
    SDValue Ops[]  = { Chain, TGA };
    Chain = DAG.getNode(CallType, dl, NodeTys, Ops);
  }

  // TLSADDR will be codegen'ed as call. Inform MFI that function has calls.
  MFI->setAdjustsStack(true);
  MFI->setHasCalls(true);

  SDValue Flag = Chain.getValue(1);
  return DAG.getCopyFromReg(Chain, dl, ReturnReg, PtrVT, Flag);
}

// Lower ISD::GlobalTLSAddress using the "general dynamic" model, 32 bit
static SDValue
LowerToTLSGeneralDynamicModel32(GlobalAddressSDNode *GA, SelectionDAG &DAG,
                                const EVT PtrVT) {
  SDValue InFlag;
  SDLoc dl(GA);  // ? function entry point might be better
  SDValue Chain = DAG.getCopyToReg(DAG.getEntryNode(), dl, X86::EBX,
                                   DAG.getNode(X86ISD::GlobalBaseReg,
                                               SDLoc(), PtrVT), InFlag);
  InFlag = Chain.getValue(1);

  return GetTLSADDR(DAG, Chain, GA, &InFlag, PtrVT, X86::EAX, X86II::MO_TLSGD);
}

// Lower ISD::GlobalTLSAddress using the "general dynamic" model, 64 bit
static SDValue
LowerToTLSGeneralDynamicModel64(GlobalAddressSDNode *GA, SelectionDAG &DAG,
                                const EVT PtrVT) {
  return GetTLSADDR(DAG, DAG.getEntryNode(), GA, nullptr, PtrVT,
                    X86::RAX, X86II::MO_TLSGD);
}

static SDValue LowerToTLSLocalDynamicModel(GlobalAddressSDNode *GA,
                                           SelectionDAG &DAG,
                                           const EVT PtrVT,
                                           bool is64Bit) {
  SDLoc dl(GA);

  // Get the start address of the TLS block for this module.
  X86MachineFunctionInfo* MFI = DAG.getMachineFunction()
      .getInfo<X86MachineFunctionInfo>();
  MFI->incNumLocalDynamicTLSAccesses();

  SDValue Base;
  if (is64Bit) {
    Base = GetTLSADDR(DAG, DAG.getEntryNode(), GA, nullptr, PtrVT, X86::RAX,
                      X86II::MO_TLSLD, /*LocalDynamic=*/true);
  } else {
    SDValue InFlag;
    SDValue Chain = DAG.getCopyToReg(DAG.getEntryNode(), dl, X86::EBX,
        DAG.getNode(X86ISD::GlobalBaseReg, SDLoc(), PtrVT), InFlag);
    InFlag = Chain.getValue(1);
    Base = GetTLSADDR(DAG, Chain, GA, &InFlag, PtrVT, X86::EAX,
                      X86II::MO_TLSLDM, /*LocalDynamic=*/true);
  }

  // Note: the CleanupLocalDynamicTLSPass will remove redundant computations
  // of Base.

  // Build x@dtpoff.
  unsigned char OperandFlags = X86II::MO_DTPOFF;
  unsigned WrapperKind = X86ISD::Wrapper;
  SDValue TGA = DAG.getTargetGlobalAddress(GA->getGlobal(), dl,
                                           GA->getValueType(0),
                                           GA->getOffset(), OperandFlags);
  SDValue Offset = DAG.getNode(WrapperKind, dl, PtrVT, TGA);

  // Add x@dtpoff with the base.
  return DAG.getNode(ISD::ADD, dl, PtrVT, Offset, Base);
}

// Lower ISD::GlobalTLSAddress using the "initial exec" or "local exec" model.
static SDValue LowerToTLSExecModel(GlobalAddressSDNode *GA, SelectionDAG &DAG,
                                   const EVT PtrVT, TLSModel::Model model,
                                   bool is64Bit, bool isPIC) {
  SDLoc dl(GA);

  // Get the Thread Pointer, which is %gs:0 (32-bit) or %fs:0 (64-bit).
  Value *Ptr = Constant::getNullValue(Type::getInt8PtrTy(*DAG.getContext(),
                                                         is64Bit ? 257 : 256));

  SDValue ThreadPointer =
      DAG.getLoad(PtrVT, dl, DAG.getEntryNode(), DAG.getIntPtrConstant(0),
                  MachinePointerInfo(Ptr), false, false, false, 0);

  unsigned char OperandFlags = 0;
  // Most TLS accesses are not RIP relative, even on x86-64.  One exception is
  // initialexec.
  unsigned WrapperKind = X86ISD::Wrapper;
  if (model == TLSModel::LocalExec) {
    OperandFlags = is64Bit ? X86II::MO_TPOFF : X86II::MO_NTPOFF;
  } else if (model == TLSModel::InitialExec) {
    if (is64Bit) {
      OperandFlags = X86II::MO_GOTTPOFF;
      WrapperKind = X86ISD::WrapperRIP;
    } else {
      OperandFlags = isPIC ? X86II::MO_GOTNTPOFF : X86II::MO_INDNTPOFF;
    }
  } else {
    llvm_unreachable("Unexpected model");
  }

  // emit "addl x@ntpoff,%eax" (local exec)
  // or "addl x@indntpoff,%eax" (initial exec)
  // or "addl x@gotntpoff(%ebx) ,%eax" (initial exec, 32-bit pic)
  SDValue TGA =
      DAG.getTargetGlobalAddress(GA->getGlobal(), dl, GA->getValueType(0),
                                 GA->getOffset(), OperandFlags);
  SDValue Offset = DAG.getNode(WrapperKind, dl, PtrVT, TGA);

  if (model == TLSModel::InitialExec) {
    if (isPIC && !is64Bit) {
      Offset = DAG.getNode(ISD::ADD, dl, PtrVT,
                           DAG.getNode(X86ISD::GlobalBaseReg, SDLoc(), PtrVT),
                           Offset);
    }

    Offset = DAG.getLoad(PtrVT, dl, DAG.getEntryNode(), Offset,
                         MachinePointerInfo::getGOT(), false, false, false, 0);
  }

  // The address of the thread local variable is the add of the thread
  // pointer with the offset of the variable.
  return DAG.getNode(ISD::ADD, dl, PtrVT, ThreadPointer, Offset);
}

SDValue
X86TargetLowering::LowerGlobalTLSAddress(SDValue Op, SelectionDAG &DAG) const {

  GlobalAddressSDNode *GA = cast<GlobalAddressSDNode>(Op);
  const GlobalValue *GV = GA->getGlobal();

  if (Subtarget->isTargetELF()) {
    TLSModel::Model model = DAG.getTarget().getTLSModel(GV);

    switch (model) {
      case TLSModel::GeneralDynamic:
        if (Subtarget->is64Bit())
          return LowerToTLSGeneralDynamicModel64(GA, DAG, getPointerTy());
        return LowerToTLSGeneralDynamicModel32(GA, DAG, getPointerTy());
      case TLSModel::LocalDynamic:
        return LowerToTLSLocalDynamicModel(GA, DAG, getPointerTy(),
                                           Subtarget->is64Bit());
      case TLSModel::InitialExec:
      case TLSModel::LocalExec:
        return LowerToTLSExecModel(
            GA, DAG, getPointerTy(), model, Subtarget->is64Bit(),
            DAG.getTarget().getRelocationModel() == Reloc::PIC_);
    }
    llvm_unreachable("Unknown TLS model.");
  }

  if (Subtarget->isTargetDarwin()) {
    // Darwin only has one model of TLS.  Lower to that.
    unsigned char OpFlag = 0;
    unsigned WrapperKind = Subtarget->isPICStyleRIPRel() ?
                           X86ISD::WrapperRIP : X86ISD::Wrapper;

    // In PIC mode (unless we're in RIPRel PIC mode) we add an offset to the
    // global base reg.
    bool PIC32 = (DAG.getTarget().getRelocationModel() == Reloc::PIC_) &&
                 !Subtarget->is64Bit();
    if (PIC32)
      OpFlag = X86II::MO_TLVP_PIC_BASE;
    else
      OpFlag = X86II::MO_TLVP;
    SDLoc DL(Op);
    SDValue Result = DAG.getTargetGlobalAddress(GA->getGlobal(), DL,
                                                GA->getValueType(0),
                                                GA->getOffset(), OpFlag);
    SDValue Offset = DAG.getNode(WrapperKind, DL, getPointerTy(), Result);

    // With PIC32, the address is actually $g + Offset.
    if (PIC32)
      Offset = DAG.getNode(ISD::ADD, DL, getPointerTy(),
                           DAG.getNode(X86ISD::GlobalBaseReg,
                                       SDLoc(), getPointerTy()),
                           Offset);

    // Lowering the machine isd will make sure everything is in the right
    // location.
    SDValue Chain = DAG.getEntryNode();
    SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue);
    SDValue Args[] = { Chain, Offset };
    Chain = DAG.getNode(X86ISD::TLSCALL, DL, NodeTys, Args);

    // TLSCALL will be codegen'ed as call. Inform MFI that function has calls.
    MachineFrameInfo *MFI = DAG.getMachineFunction().getFrameInfo();
    MFI->setAdjustsStack(true);

    // And our return value (tls address) is in the standard call return value
    // location.
    unsigned Reg = Subtarget->is64Bit() ? X86::RAX : X86::EAX;
    return DAG.getCopyFromReg(Chain, DL, Reg, getPointerTy(),
                              Chain.getValue(1));
  }

  if (Subtarget->isTargetKnownWindowsMSVC() ||
      Subtarget->isTargetWindowsGNU()) {
    // Just use the implicit TLS architecture
    // Need to generate someting similar to:
    //   mov     rdx, qword [gs:abs 58H]; Load pointer to ThreadLocalStorage
    //                                  ; from TEB
    //   mov     ecx, dword [rel _tls_index]: Load index (from C runtime)
    //   mov     rcx, qword [rdx+rcx*8]
    //   mov     eax, .tls$:tlsvar
    //   [rax+rcx] contains the address
    // Windows 64bit: gs:0x58
    // Windows 32bit: fs:__tls_array

    SDLoc dl(GA);
    SDValue Chain = DAG.getEntryNode();

    // Get the Thread Pointer, which is %fs:__tls_array (32-bit) or
    // %gs:0x58 (64-bit). On MinGW, __tls_array is not available, so directly
    // use its literal value of 0x2C.
    Value *Ptr = Constant::getNullValue(Subtarget->is64Bit()
                                        ? Type::getInt8PtrTy(*DAG.getContext(),
                                                             256)
                                        : Type::getInt32PtrTy(*DAG.getContext(),
                                                              257));

    SDValue TlsArray =
        Subtarget->is64Bit()
            ? DAG.getIntPtrConstant(0x58)
            : (Subtarget->isTargetWindowsGNU()
                   ? DAG.getIntPtrConstant(0x2C)
                   : DAG.getExternalSymbol("_tls_array", getPointerTy()));

    SDValue ThreadPointer =
        DAG.getLoad(getPointerTy(), dl, Chain, TlsArray,
                    MachinePointerInfo(Ptr), false, false, false, 0);

    // Load the _tls_index variable
    SDValue IDX = DAG.getExternalSymbol("_tls_index", getPointerTy());
    if (Subtarget->is64Bit())
      IDX = DAG.getExtLoad(ISD::ZEXTLOAD, dl, getPointerTy(), Chain,
                           IDX, MachinePointerInfo(), MVT::i32,
                           false, false, false, 0);
    else
      IDX = DAG.getLoad(getPointerTy(), dl, Chain, IDX, MachinePointerInfo(),
                        false, false, false, 0);

    SDValue Scale = DAG.getConstant(Log2_64_Ceil(TD->getPointerSize()),
                                    getPointerTy());
    IDX = DAG.getNode(ISD::SHL, dl, getPointerTy(), IDX, Scale);

    SDValue res = DAG.getNode(ISD::ADD, dl, getPointerTy(), ThreadPointer, IDX);
    res = DAG.getLoad(getPointerTy(), dl, Chain, res, MachinePointerInfo(),
                      false, false, false, 0);

    // Get the offset of start of .tls section
    SDValue TGA = DAG.getTargetGlobalAddress(GA->getGlobal(), dl,
                                             GA->getValueType(0),
                                             GA->getOffset(), X86II::MO_SECREL);
    SDValue Offset = DAG.getNode(X86ISD::Wrapper, dl, getPointerTy(), TGA);

    // The address of the thread local variable is the add of the thread
    // pointer with the offset of the variable.
    return DAG.getNode(ISD::ADD, dl, getPointerTy(), res, Offset);
  }

  llvm_unreachable("TLS not implemented for this target.");
}

/// LowerShiftParts - Lower SRA_PARTS and friends, which return two i32 values
/// and take a 2 x i32 value to shift plus a shift amount.
static SDValue LowerShiftParts(SDValue Op, SelectionDAG &DAG) {
  assert(Op.getNumOperands() == 3 && "Not a double-shift!");
  MVT VT = Op.getSimpleValueType();
  unsigned VTBits = VT.getSizeInBits();
  SDLoc dl(Op);
  bool isSRA = Op.getOpcode() == ISD::SRA_PARTS;
  SDValue ShOpLo = Op.getOperand(0);
  SDValue ShOpHi = Op.getOperand(1);
  SDValue ShAmt  = Op.getOperand(2);
  // X86ISD::SHLD and X86ISD::SHRD have defined overflow behavior but the
  // generic ISD nodes haven't. Insert an AND to be safe, it's optimized away
  // during isel.
  SDValue SafeShAmt = DAG.getNode(ISD::AND, dl, MVT::i8, ShAmt,
                                  DAG.getConstant(VTBits - 1, MVT::i8));
  SDValue Tmp1 = isSRA ? DAG.getNode(ISD::SRA, dl, VT, ShOpHi,
                                     DAG.getConstant(VTBits - 1, MVT::i8))
                       : DAG.getConstant(0, VT);

  SDValue Tmp2, Tmp3;
  if (Op.getOpcode() == ISD::SHL_PARTS) {
    Tmp2 = DAG.getNode(X86ISD::SHLD, dl, VT, ShOpHi, ShOpLo, ShAmt);
    Tmp3 = DAG.getNode(ISD::SHL, dl, VT, ShOpLo, SafeShAmt);
  } else {
    Tmp2 = DAG.getNode(X86ISD::SHRD, dl, VT, ShOpLo, ShOpHi, ShAmt);
    Tmp3 = DAG.getNode(isSRA ? ISD::SRA : ISD::SRL, dl, VT, ShOpHi, SafeShAmt);
  }

  // If the shift amount is larger or equal than the width of a part we can't
  // rely on the results of shld/shrd. Insert a test and select the appropriate
  // values for large shift amounts.
  SDValue AndNode = DAG.getNode(ISD::AND, dl, MVT::i8, ShAmt,
                                DAG.getConstant(VTBits, MVT::i8));
  SDValue Cond = DAG.getNode(X86ISD::CMP, dl, MVT::i32,
                             AndNode, DAG.getConstant(0, MVT::i8));

  SDValue Hi, Lo;
  SDValue CC = DAG.getConstant(X86::COND_NE, MVT::i8);
  SDValue Ops0[4] = { Tmp2, Tmp3, CC, Cond };
  SDValue Ops1[4] = { Tmp3, Tmp1, CC, Cond };

  if (Op.getOpcode() == ISD::SHL_PARTS) {
    Hi = DAG.getNode(X86ISD::CMOV, dl, VT, Ops0);
    Lo = DAG.getNode(X86ISD::CMOV, dl, VT, Ops1);
  } else {
    Lo = DAG.getNode(X86ISD::CMOV, dl, VT, Ops0);
    Hi = DAG.getNode(X86ISD::CMOV, dl, VT, Ops1);
  }

  SDValue Ops[2] = { Lo, Hi };
  return DAG.getMergeValues(Ops, dl);
}

SDValue X86TargetLowering::LowerSINT_TO_FP(SDValue Op,
                                           SelectionDAG &DAG) const {
  MVT SrcVT = Op.getOperand(0).getSimpleValueType();
  SDLoc dl(Op);

  if (SrcVT.isVector()) {
    if (SrcVT.getVectorElementType() == MVT::i1) {
      MVT IntegerVT = MVT::getVectorVT(MVT::i32, SrcVT.getVectorNumElements());
      return DAG.getNode(ISD::SINT_TO_FP, dl, Op.getValueType(),
                         DAG.getNode(ISD::SIGN_EXTEND, dl, IntegerVT,
                                     Op.getOperand(0)));
    }
    return SDValue();
  }

  assert(SrcVT <= MVT::i64 && SrcVT >= MVT::i16 &&
         "Unknown SINT_TO_FP to lower!");

  // These are really Legal; return the operand so the caller accepts it as
  // Legal.
  if (SrcVT == MVT::i32 && isScalarFPTypeInSSEReg(Op.getValueType()))
    return Op;
  if (SrcVT == MVT::i64 && isScalarFPTypeInSSEReg(Op.getValueType()) &&
      Subtarget->is64Bit()) {
    return Op;
  }

  unsigned Size = SrcVT.getSizeInBits()/8;
  MachineFunction &MF = DAG.getMachineFunction();
  int SSFI = MF.getFrameInfo()->CreateStackObject(Size, Size, false);
  SDValue StackSlot = DAG.getFrameIndex(SSFI, getPointerTy());
  SDValue Chain = DAG.getStore(DAG.getEntryNode(), dl, Op.getOperand(0),
                               StackSlot,
                               MachinePointerInfo::getFixedStack(SSFI),
                               false, false, 0);
  return BuildFILD(Op, SrcVT, Chain, StackSlot, DAG);
}

SDValue X86TargetLowering::BuildFILD(SDValue Op, EVT SrcVT, SDValue Chain,
                                     SDValue StackSlot,
                                     SelectionDAG &DAG) const {
  // Build the FILD
  SDLoc DL(Op);
  SDVTList Tys;
  bool useSSE = isScalarFPTypeInSSEReg(Op.getValueType());
  if (useSSE)
    Tys = DAG.getVTList(MVT::f64, MVT::Other, MVT::Glue);
  else
    Tys = DAG.getVTList(Op.getValueType(), MVT::Other);

  unsigned ByteSize = SrcVT.getSizeInBits()/8;

  FrameIndexSDNode *FI = dyn_cast<FrameIndexSDNode>(StackSlot);
  MachineMemOperand *MMO;
  if (FI) {
    int SSFI = FI->getIndex();
    MMO =
      DAG.getMachineFunction()
      .getMachineMemOperand(MachinePointerInfo::getFixedStack(SSFI),
                            MachineMemOperand::MOLoad, ByteSize, ByteSize);
  } else {
    MMO = cast<LoadSDNode>(StackSlot)->getMemOperand();
    StackSlot = StackSlot.getOperand(1);
  }
  SDValue Ops[] = { Chain, StackSlot, DAG.getValueType(SrcVT) };
  SDValue Result = DAG.getMemIntrinsicNode(useSSE ? X86ISD::FILD_FLAG :
                                           X86ISD::FILD, DL,
                                           Tys, Ops, SrcVT, MMO);

  if (useSSE) {
    Chain = Result.getValue(1);
    SDValue InFlag = Result.getValue(2);

    // FIXME: Currently the FST is flagged to the FILD_FLAG. This
    // shouldn't be necessary except that RFP cannot be live across
    // multiple blocks. When stackifier is fixed, they can be uncoupled.
    MachineFunction &MF = DAG.getMachineFunction();
    unsigned SSFISize = Op.getValueType().getSizeInBits()/8;
    int SSFI = MF.getFrameInfo()->CreateStackObject(SSFISize, SSFISize, false);
    SDValue StackSlot = DAG.getFrameIndex(SSFI, getPointerTy());
    Tys = DAG.getVTList(MVT::Other);
    SDValue Ops[] = {
      Chain, Result, StackSlot, DAG.getValueType(Op.getValueType()), InFlag
    };
    MachineMemOperand *MMO =
      DAG.getMachineFunction()
      .getMachineMemOperand(MachinePointerInfo::getFixedStack(SSFI),
                            MachineMemOperand::MOStore, SSFISize, SSFISize);

    Chain = DAG.getMemIntrinsicNode(X86ISD::FST, DL, Tys,
                                    Ops, Op.getValueType(), MMO);
    Result = DAG.getLoad(Op.getValueType(), DL, Chain, StackSlot,
                         MachinePointerInfo::getFixedStack(SSFI),
                         false, false, false, 0);
  }

  return Result;
}

// LowerUINT_TO_FP_i64 - 64-bit unsigned integer to double expansion.
SDValue X86TargetLowering::LowerUINT_TO_FP_i64(SDValue Op,
                                               SelectionDAG &DAG) const {
  // This algorithm is not obvious. Here it is what we're trying to output:
  /*
     movq       %rax,  %xmm0
     punpckldq  (c0),  %xmm0  // c0: (uint4){ 0x43300000U, 0x45300000U, 0U, 0U }
     subpd      (c1),  %xmm0  // c1: (double2){ 0x1.0p52, 0x1.0p52 * 0x1.0p32 }
     #ifdef __SSE3__
       haddpd   %xmm0, %xmm0
     #else
       pshufd   $0x4e, %xmm0, %xmm1
       addpd    %xmm1, %xmm0
     #endif
  */

  SDLoc dl(Op);
  LLVMContext *Context = DAG.getContext();

  // Build some magic constants.
  static const uint32_t CV0[] = { 0x43300000, 0x45300000, 0, 0 };
  Constant *C0 = ConstantDataVector::get(*Context, CV0);
  SDValue CPIdx0 = DAG.getConstantPool(C0, getPointerTy(), 16);

  SmallVector<Constant*,2> CV1;
  CV1.push_back(
    ConstantFP::get(*Context, APFloat(APFloat::IEEEdouble,
                                      APInt(64, 0x4330000000000000ULL))));
  CV1.push_back(
    ConstantFP::get(*Context, APFloat(APFloat::IEEEdouble,
                                      APInt(64, 0x4530000000000000ULL))));
  Constant *C1 = ConstantVector::get(CV1);
  SDValue CPIdx1 = DAG.getConstantPool(C1, getPointerTy(), 16);

  // Load the 64-bit value into an XMM register.
  SDValue XR1 = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, MVT::v2i64,
                            Op.getOperand(0));
  SDValue CLod0 = DAG.getLoad(MVT::v4i32, dl, DAG.getEntryNode(), CPIdx0,
                              MachinePointerInfo::getConstantPool(),
                              false, false, false, 16);
  SDValue Unpck1 = getUnpackl(DAG, dl, MVT::v4i32,
                              DAG.getNode(ISD::BITCAST, dl, MVT::v4i32, XR1),
                              CLod0);

  SDValue CLod1 = DAG.getLoad(MVT::v2f64, dl, CLod0.getValue(1), CPIdx1,
                              MachinePointerInfo::getConstantPool(),
                              false, false, false, 16);
  SDValue XR2F = DAG.getNode(ISD::BITCAST, dl, MVT::v2f64, Unpck1);
  SDValue Sub = DAG.getNode(ISD::FSUB, dl, MVT::v2f64, XR2F, CLod1);
  SDValue Result;

  if (Subtarget->hasSSE3()) {
    // FIXME: The 'haddpd' instruction may be slower than 'movhlps + addsd'.
    Result = DAG.getNode(X86ISD::FHADD, dl, MVT::v2f64, Sub, Sub);
  } else {
    SDValue S2F = DAG.getNode(ISD::BITCAST, dl, MVT::v4i32, Sub);
    SDValue Shuffle = getTargetShuffleNode(X86ISD::PSHUFD, dl, MVT::v4i32,
                                           S2F, 0x4E, DAG);
    Result = DAG.getNode(ISD::FADD, dl, MVT::v2f64,
                         DAG.getNode(ISD::BITCAST, dl, MVT::v2f64, Shuffle),
                         Sub);
  }

  return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, MVT::f64, Result,
                     DAG.getIntPtrConstant(0));
}

// LowerUINT_TO_FP_i32 - 32-bit unsigned integer to float expansion.
SDValue X86TargetLowering::LowerUINT_TO_FP_i32(SDValue Op,
                                               SelectionDAG &DAG) const {
  SDLoc dl(Op);
  // FP constant to bias correct the final result.
  SDValue Bias = DAG.getConstantFP(BitsToDouble(0x4330000000000000ULL),
                                   MVT::f64);

  // Load the 32-bit value into an XMM register.
  SDValue Load = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, MVT::v4i32,
                             Op.getOperand(0));

  // Zero out the upper parts of the register.
  Load = getShuffleVectorZeroOrUndef(Load, 0, true, Subtarget, DAG);

  Load = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, MVT::f64,
                     DAG.getNode(ISD::BITCAST, dl, MVT::v2f64, Load),
                     DAG.getIntPtrConstant(0));

  // Or the load with the bias.
  SDValue Or = DAG.getNode(ISD::OR, dl, MVT::v2i64,
                           DAG.getNode(ISD::BITCAST, dl, MVT::v2i64,
                                       DAG.getNode(ISD::SCALAR_TO_VECTOR, dl,
                                                   MVT::v2f64, Load)),
                           DAG.getNode(ISD::BITCAST, dl, MVT::v2i64,
                                       DAG.getNode(ISD::SCALAR_TO_VECTOR, dl,
                                                   MVT::v2f64, Bias)));
  Or = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, MVT::f64,
                   DAG.getNode(ISD::BITCAST, dl, MVT::v2f64, Or),
                   DAG.getIntPtrConstant(0));

  // Subtract the bias.
  SDValue Sub = DAG.getNode(ISD::FSUB, dl, MVT::f64, Or, Bias);

  // Handle final rounding.
  EVT DestVT = Op.getValueType();

  if (DestVT.bitsLT(MVT::f64))
    return DAG.getNode(ISD::FP_ROUND, dl, DestVT, Sub,
                       DAG.getIntPtrConstant(0));
  if (DestVT.bitsGT(MVT::f64))
    return DAG.getNode(ISD::FP_EXTEND, dl, DestVT, Sub);

  // Handle final rounding.
  return Sub;
}

static SDValue lowerUINT_TO_FP_vXi32(SDValue Op, SelectionDAG &DAG,
                                     const X86Subtarget &Subtarget) {
  // The algorithm is the following:
  // #ifdef __SSE4_1__
  //     uint4 lo = _mm_blend_epi16( v, (uint4) 0x4b000000, 0xaa);
  //     uint4 hi = _mm_blend_epi16( _mm_srli_epi32(v,16),
  //                                 (uint4) 0x53000000, 0xaa);
  // #else
  //     uint4 lo = (v & (uint4) 0xffff) | (uint4) 0x4b000000;
  //     uint4 hi = (v >> 16) | (uint4) 0x53000000;
  // #endif
  //     float4 fhi = (float4) hi - (0x1.0p39f + 0x1.0p23f);
  //     return (float4) lo + fhi;

  SDLoc DL(Op);
  SDValue V = Op->getOperand(0);
  EVT VecIntVT = V.getValueType();
  bool Is128 = VecIntVT == MVT::v4i32;
  EVT VecFloatVT = Is128 ? MVT::v4f32 : MVT::v8f32;
  // If we convert to something else than the supported type, e.g., to v4f64,
  // abort early.
  if (VecFloatVT != Op->getValueType(0))
    return SDValue();

  unsigned NumElts = VecIntVT.getVectorNumElements();
  assert((VecIntVT == MVT::v4i32 || VecIntVT == MVT::v8i32) &&
         "Unsupported custom type");
  assert(NumElts <= 8 && "The size of the constant array must be fixed");

  // In the #idef/#else code, we have in common:
  // - The vector of constants:
  // -- 0x4b000000
  // -- 0x53000000
  // - A shift:
  // -- v >> 16

  // Create the splat vector for 0x4b000000.
  SDValue CstLow = DAG.getConstant(0x4b000000, MVT::i32);
  SDValue CstLowArray[] = {CstLow, CstLow, CstLow, CstLow,
                           CstLow, CstLow, CstLow, CstLow};
  SDValue VecCstLow = DAG.getNode(ISD::BUILD_VECTOR, DL, VecIntVT,
                                  makeArrayRef(&CstLowArray[0], NumElts));
  // Create the splat vector for 0x53000000.
  SDValue CstHigh = DAG.getConstant(0x53000000, MVT::i32);
  SDValue CstHighArray[] = {CstHigh, CstHigh, CstHigh, CstHigh,
                            CstHigh, CstHigh, CstHigh, CstHigh};
  SDValue VecCstHigh = DAG.getNode(ISD::BUILD_VECTOR, DL, VecIntVT,
                                   makeArrayRef(&CstHighArray[0], NumElts));

  // Create the right shift.
  SDValue CstShift = DAG.getConstant(16, MVT::i32);
  SDValue CstShiftArray[] = {CstShift, CstShift, CstShift, CstShift,
                             CstShift, CstShift, CstShift, CstShift};
  SDValue VecCstShift = DAG.getNode(ISD::BUILD_VECTOR, DL, VecIntVT,
                                    makeArrayRef(&CstShiftArray[0], NumElts));
  SDValue HighShift = DAG.getNode(ISD::SRL, DL, VecIntVT, V, VecCstShift);

  SDValue Low, High;
  if (Subtarget.hasSSE41()) {
    EVT VecI16VT = Is128 ? MVT::v8i16 : MVT::v16i16;
    //     uint4 lo = _mm_blend_epi16( v, (uint4) 0x4b000000, 0xaa);
    SDValue VecCstLowBitcast =
        DAG.getNode(ISD::BITCAST, DL, VecI16VT, VecCstLow);
    SDValue VecBitcast = DAG.getNode(ISD::BITCAST, DL, VecI16VT, V);
    // Low will be bitcasted right away, so do not bother bitcasting back to its
    // original type.
    Low = DAG.getNode(X86ISD::BLENDI, DL, VecI16VT, VecBitcast,
                      VecCstLowBitcast, DAG.getConstant(0xaa, MVT::i32));
    //     uint4 hi = _mm_blend_epi16( _mm_srli_epi32(v,16),
    //                                 (uint4) 0x53000000, 0xaa);
    SDValue VecCstHighBitcast =
        DAG.getNode(ISD::BITCAST, DL, VecI16VT, VecCstHigh);
    SDValue VecShiftBitcast =
        DAG.getNode(ISD::BITCAST, DL, VecI16VT, HighShift);
    // High will be bitcasted right away, so do not bother bitcasting back to
    // its original type.
    High = DAG.getNode(X86ISD::BLENDI, DL, VecI16VT, VecShiftBitcast,
                       VecCstHighBitcast, DAG.getConstant(0xaa, MVT::i32));
  } else {
    SDValue CstMask = DAG.getConstant(0xffff, MVT::i32);
    SDValue VecCstMask = DAG.getNode(ISD::BUILD_VECTOR, DL, VecIntVT, CstMask,
                                     CstMask, CstMask, CstMask);
    //     uint4 lo = (v & (uint4) 0xffff) | (uint4) 0x4b000000;
    SDValue LowAnd = DAG.getNode(ISD::AND, DL, VecIntVT, V, VecCstMask);
    Low = DAG.getNode(ISD::OR, DL, VecIntVT, LowAnd, VecCstLow);

    //     uint4 hi = (v >> 16) | (uint4) 0x53000000;
    High = DAG.getNode(ISD::OR, DL, VecIntVT, HighShift, VecCstHigh);
  }

  // Create the vector constant for -(0x1.0p39f + 0x1.0p23f).
  SDValue CstFAdd = DAG.getConstantFP(
      APFloat(APFloat::IEEEsingle, APInt(32, 0xD3000080)), MVT::f32);
  SDValue CstFAddArray[] = {CstFAdd, CstFAdd, CstFAdd, CstFAdd,
                            CstFAdd, CstFAdd, CstFAdd, CstFAdd};
  SDValue VecCstFAdd = DAG.getNode(ISD::BUILD_VECTOR, DL, VecFloatVT,
                                   makeArrayRef(&CstFAddArray[0], NumElts));

  //     float4 fhi = (float4) hi - (0x1.0p39f + 0x1.0p23f);
  SDValue HighBitcast = DAG.getNode(ISD::BITCAST, DL, VecFloatVT, High);
  SDValue FHigh =
      DAG.getNode(ISD::FADD, DL, VecFloatVT, HighBitcast, VecCstFAdd);
  //     return (float4) lo + fhi;
  SDValue LowBitcast = DAG.getNode(ISD::BITCAST, DL, VecFloatVT, Low);
  return DAG.getNode(ISD::FADD, DL, VecFloatVT, LowBitcast, FHigh);
}

SDValue X86TargetLowering::lowerUINT_TO_FP_vec(SDValue Op,
                                               SelectionDAG &DAG) const {
  SDValue N0 = Op.getOperand(0);
  MVT SVT = N0.getSimpleValueType();
  SDLoc dl(Op);

  switch (SVT.SimpleTy) {
  default:
    llvm_unreachable("Custom UINT_TO_FP is not supported!");
  case MVT::v4i8:
  case MVT::v4i16:
  case MVT::v8i8:
  case MVT::v8i16: {
    MVT NVT = MVT::getVectorVT(MVT::i32, SVT.getVectorNumElements());
    return DAG.getNode(ISD::SINT_TO_FP, dl, Op.getValueType(),
                       DAG.getNode(ISD::ZERO_EXTEND, dl, NVT, N0));
  }
  case MVT::v4i32:
  case MVT::v8i32:
    return lowerUINT_TO_FP_vXi32(Op, DAG, *Subtarget);
  }
  llvm_unreachable(nullptr);
}

SDValue X86TargetLowering::LowerUINT_TO_FP(SDValue Op,
                                           SelectionDAG &DAG) const {
  SDValue N0 = Op.getOperand(0);
  SDLoc dl(Op);

  if (Op.getValueType().isVector())
    return lowerUINT_TO_FP_vec(Op, DAG);

  // Since UINT_TO_FP is legal (it's marked custom), dag combiner won't
  // optimize it to a SINT_TO_FP when the sign bit is known zero. Perform
  // the optimization here.
  if (DAG.SignBitIsZero(N0))
    return DAG.getNode(ISD::SINT_TO_FP, dl, Op.getValueType(), N0);

  MVT SrcVT = N0.getSimpleValueType();
  MVT DstVT = Op.getSimpleValueType();
  if (SrcVT == MVT::i64 && DstVT == MVT::f64 && X86ScalarSSEf64)
    return LowerUINT_TO_FP_i64(Op, DAG);
  if (SrcVT == MVT::i32 && X86ScalarSSEf64)
    return LowerUINT_TO_FP_i32(Op, DAG);
  if (Subtarget->is64Bit() && SrcVT == MVT::i64 && DstVT == MVT::f32)
    return SDValue();

  // Make a 64-bit buffer, and use it to build an FILD.
  SDValue StackSlot = DAG.CreateStackTemporary(MVT::i64);
  if (SrcVT == MVT::i32) {
    SDValue WordOff = DAG.getConstant(4, getPointerTy());
    SDValue OffsetSlot = DAG.getNode(ISD::ADD, dl,
                                     getPointerTy(), StackSlot, WordOff);
    SDValue Store1 = DAG.getStore(DAG.getEntryNode(), dl, Op.getOperand(0),
                                  StackSlot, MachinePointerInfo(),
                                  false, false, 0);
    SDValue Store2 = DAG.getStore(Store1, dl, DAG.getConstant(0, MVT::i32),
                                  OffsetSlot, MachinePointerInfo(),
                                  false, false, 0);
    SDValue Fild = BuildFILD(Op, MVT::i64, Store2, StackSlot, DAG);
    return Fild;
  }

  assert(SrcVT == MVT::i64 && "Unexpected type in UINT_TO_FP");
  SDValue Store = DAG.getStore(DAG.getEntryNode(), dl, Op.getOperand(0),
                               StackSlot, MachinePointerInfo(),
                               false, false, 0);
  // For i64 source, we need to add the appropriate power of 2 if the input
  // was negative.  This is the same as the optimization in
  // DAGTypeLegalizer::ExpandIntOp_UNIT_TO_FP, and for it to be safe here,
  // we must be careful to do the computation in x87 extended precision, not
  // in SSE. (The generic code can't know it's OK to do this, or how to.)
  int SSFI = cast<FrameIndexSDNode>(StackSlot)->getIndex();
  MachineMemOperand *MMO =
    DAG.getMachineFunction()
    .getMachineMemOperand(MachinePointerInfo::getFixedStack(SSFI),
                          MachineMemOperand::MOLoad, 8, 8);

  SDVTList Tys = DAG.getVTList(MVT::f80, MVT::Other);
  SDValue Ops[] = { Store, StackSlot, DAG.getValueType(MVT::i64) };
  SDValue Fild = DAG.getMemIntrinsicNode(X86ISD::FILD, dl, Tys, Ops,
                                         MVT::i64, MMO);

  APInt FF(32, 0x5F800000ULL);

  // Check whether the sign bit is set.
  SDValue SignSet = DAG.getSetCC(dl,
                                 getSetCCResultType(*DAG.getContext(), MVT::i64),
                                 Op.getOperand(0), DAG.getConstant(0, MVT::i64),
                                 ISD::SETLT);

  // Build a 64 bit pair (0, FF) in the constant pool, with FF in the lo bits.
  SDValue FudgePtr = DAG.getConstantPool(
                             ConstantInt::get(*DAG.getContext(), FF.zext(64)),
                                         getPointerTy());

  // Get a pointer to FF if the sign bit was set, or to 0 otherwise.
  SDValue Zero = DAG.getIntPtrConstant(0);
  SDValue Four = DAG.getIntPtrConstant(4);
  SDValue Offset = DAG.getNode(ISD::SELECT, dl, Zero.getValueType(), SignSet,
                               Zero, Four);
  FudgePtr = DAG.getNode(ISD::ADD, dl, getPointerTy(), FudgePtr, Offset);

  // Load the value out, extending it from f32 to f80.
  // FIXME: Avoid the extend by constructing the right constant pool?
  SDValue Fudge = DAG.getExtLoad(ISD::EXTLOAD, dl, MVT::f80, DAG.getEntryNode(),
                                 FudgePtr, MachinePointerInfo::getConstantPool(),
                                 MVT::f32, false, false, false, 4);
  // Extend everything to 80 bits to force it to be done on x87.
  SDValue Add = DAG.getNode(ISD::FADD, dl, MVT::f80, Fild, Fudge);
  return DAG.getNode(ISD::FP_ROUND, dl, DstVT, Add, DAG.getIntPtrConstant(0));
}

std::pair<SDValue,SDValue>
X86TargetLowering:: FP_TO_INTHelper(SDValue Op, SelectionDAG &DAG,
                                    bool IsSigned, bool IsReplace) const {
  SDLoc DL(Op);

  EVT DstTy = Op.getValueType();

  if (!IsSigned && !isIntegerTypeFTOL(DstTy)) {
    assert(DstTy == MVT::i32 && "Unexpected FP_TO_UINT");
    DstTy = MVT::i64;
  }

  assert(DstTy.getSimpleVT() <= MVT::i64 &&
         DstTy.getSimpleVT() >= MVT::i16 &&
         "Unknown FP_TO_INT to lower!");

  // These are really Legal.
  if (DstTy == MVT::i32 &&
      isScalarFPTypeInSSEReg(Op.getOperand(0).getValueType()))
    return std::make_pair(SDValue(), SDValue());
  if (Subtarget->is64Bit() &&
      DstTy == MVT::i64 &&
      isScalarFPTypeInSSEReg(Op.getOperand(0).getValueType()))
    return std::make_pair(SDValue(), SDValue());

  // We lower FP->int64 either into FISTP64 followed by a load from a temporary
  // stack slot, or into the FTOL runtime function.
  MachineFunction &MF = DAG.getMachineFunction();
  unsigned MemSize = DstTy.getSizeInBits()/8;
  int SSFI = MF.getFrameInfo()->CreateStackObject(MemSize, MemSize, false);
  SDValue StackSlot = DAG.getFrameIndex(SSFI, getPointerTy());

  unsigned Opc;
  if (!IsSigned && isIntegerTypeFTOL(DstTy))
    Opc = X86ISD::WIN_FTOL;
  else
    switch (DstTy.getSimpleVT().SimpleTy) {
    default: llvm_unreachable("Invalid FP_TO_SINT to lower!");
    case MVT::i16: Opc = X86ISD::FP_TO_INT16_IN_MEM; break;
    case MVT::i32: Opc = X86ISD::FP_TO_INT32_IN_MEM; break;
    case MVT::i64: Opc = X86ISD::FP_TO_INT64_IN_MEM; break;
    }

  SDValue Chain = DAG.getEntryNode();
  SDValue Value = Op.getOperand(0);
  EVT TheVT = Op.getOperand(0).getValueType();
  // FIXME This causes a redundant load/store if the SSE-class value is already
  // in memory, such as if it is on the callstack.
  if (isScalarFPTypeInSSEReg(TheVT)) {
    assert(DstTy == MVT::i64 && "Invalid FP_TO_SINT to lower!");
    Chain = DAG.getStore(Chain, DL, Value, StackSlot,
                         MachinePointerInfo::getFixedStack(SSFI),
                         false, false, 0);
    SDVTList Tys = DAG.getVTList(Op.getOperand(0).getValueType(), MVT::Other);
    SDValue Ops[] = {
      Chain, StackSlot, DAG.getValueType(TheVT)
    };

    MachineMemOperand *MMO =
      MF.getMachineMemOperand(MachinePointerInfo::getFixedStack(SSFI),
                              MachineMemOperand::MOLoad, MemSize, MemSize);
    Value = DAG.getMemIntrinsicNode(X86ISD::FLD, DL, Tys, Ops, DstTy, MMO);
    Chain = Value.getValue(1);
    SSFI = MF.getFrameInfo()->CreateStackObject(MemSize, MemSize, false);
    StackSlot = DAG.getFrameIndex(SSFI, getPointerTy());
  }

  MachineMemOperand *MMO =
    MF.getMachineMemOperand(MachinePointerInfo::getFixedStack(SSFI),
                            MachineMemOperand::MOStore, MemSize, MemSize);

  if (Opc != X86ISD::WIN_FTOL) {
    // Build the FP_TO_INT*_IN_MEM
    SDValue Ops[] = { Chain, Value, StackSlot };
    SDValue FIST = DAG.getMemIntrinsicNode(Opc, DL, DAG.getVTList(MVT::Other),
                                           Ops, DstTy, MMO);
    return std::make_pair(FIST, StackSlot);
  } else {
    SDValue ftol = DAG.getNode(X86ISD::WIN_FTOL, DL,
      DAG.getVTList(MVT::Other, MVT::Glue),
      Chain, Value);
    SDValue eax = DAG.getCopyFromReg(ftol, DL, X86::EAX,
      MVT::i32, ftol.getValue(1));
    SDValue edx = DAG.getCopyFromReg(eax.getValue(1), DL, X86::EDX,
      MVT::i32, eax.getValue(2));
    SDValue Ops[] = { eax, edx };
    SDValue pair = IsReplace
      ? DAG.getNode(ISD::BUILD_PAIR, DL, MVT::i64, Ops)
      : DAG.getMergeValues(Ops, DL);
    return std::make_pair(pair, SDValue());
  }
}

static SDValue LowerAVXExtend(SDValue Op, SelectionDAG &DAG,
                              const X86Subtarget *Subtarget) {
  MVT VT = Op->getSimpleValueType(0);
  SDValue In = Op->getOperand(0);
  MVT InVT = In.getSimpleValueType();
  SDLoc dl(Op);

  // Optimize vectors in AVX mode:
  //
  //   v8i16 -> v8i32
  //   Use vpunpcklwd for 4 lower elements  v8i16 -> v4i32.
  //   Use vpunpckhwd for 4 upper elements  v8i16 -> v4i32.
  //   Concat upper and lower parts.
  //
  //   v4i32 -> v4i64
  //   Use vpunpckldq for 4 lower elements  v4i32 -> v2i64.
  //   Use vpunpckhdq for 4 upper elements  v4i32 -> v2i64.
  //   Concat upper and lower parts.
  //

  if (((VT != MVT::v16i16) || (InVT != MVT::v16i8)) &&
      ((VT != MVT::v8i32) || (InVT != MVT::v8i16)) &&
      ((VT != MVT::v4i64) || (InVT != MVT::v4i32)))
    return SDValue();

  if (Subtarget->hasInt256())
    return DAG.getNode(X86ISD::VZEXT, dl, VT, In);

  SDValue ZeroVec = getZeroVector(InVT, Subtarget, DAG, dl);
  SDValue Undef = DAG.getUNDEF(InVT);
  bool NeedZero = Op.getOpcode() == ISD::ZERO_EXTEND;
  SDValue OpLo = getUnpackl(DAG, dl, InVT, In, NeedZero ? ZeroVec : Undef);
  SDValue OpHi = getUnpackh(DAG, dl, InVT, In, NeedZero ? ZeroVec : Undef);

  MVT HVT = MVT::getVectorVT(VT.getVectorElementType(),
                             VT.getVectorNumElements()/2);

  OpLo = DAG.getNode(ISD::BITCAST, dl, HVT, OpLo);
  OpHi = DAG.getNode(ISD::BITCAST, dl, HVT, OpHi);

  return DAG.getNode(ISD::CONCAT_VECTORS, dl, VT, OpLo, OpHi);
}

static  SDValue LowerZERO_EXTEND_AVX512(SDValue Op,
                                        SelectionDAG &DAG) {
  MVT VT = Op->getSimpleValueType(0);
  SDValue In = Op->getOperand(0);
  MVT InVT = In.getSimpleValueType();
  SDLoc DL(Op);
  unsigned int NumElts = VT.getVectorNumElements();
  if (NumElts != 8 && NumElts != 16)
    return SDValue();

  if (VT.is512BitVector() && InVT.getVectorElementType() != MVT::i1)
    return DAG.getNode(X86ISD::VZEXT, DL, VT, In);

  EVT ExtVT = (NumElts == 8)? MVT::v8i64 : MVT::v16i32;
  const TargetLowering &TLI = DAG.getTargetLoweringInfo();
  // Now we have only mask extension
  assert(InVT.getVectorElementType() == MVT::i1);
  SDValue Cst = DAG.getTargetConstant(1, ExtVT.getScalarType());
  const Constant *C = (dyn_cast<ConstantSDNode>(Cst))->getConstantIntValue();
  SDValue CP = DAG.getConstantPool(C, TLI.getPointerTy());
  unsigned Alignment = cast<ConstantPoolSDNode>(CP)->getAlignment();
  SDValue Ld = DAG.getLoad(Cst.getValueType(), DL, DAG.getEntryNode(), CP,
                           MachinePointerInfo::getConstantPool(),
                           false, false, false, Alignment);

  SDValue Brcst = DAG.getNode(X86ISD::VBROADCASTM, DL, ExtVT, In, Ld);
  if (VT.is512BitVector())
    return Brcst;
  return DAG.getNode(X86ISD::VTRUNC, DL, VT, Brcst);
}

static SDValue LowerANY_EXTEND(SDValue Op, const X86Subtarget *Subtarget,
                               SelectionDAG &DAG) {
  if (Subtarget->hasFp256()) {
    SDValue Res = LowerAVXExtend(Op, DAG, Subtarget);
    if (Res.getNode())
      return Res;
  }

  return SDValue();
}

static SDValue LowerZERO_EXTEND(SDValue Op, const X86Subtarget *Subtarget,
                                SelectionDAG &DAG) {
  SDLoc DL(Op);
  MVT VT = Op.getSimpleValueType();
  SDValue In = Op.getOperand(0);
  MVT SVT = In.getSimpleValueType();

  if (VT.is512BitVector() || SVT.getVectorElementType() == MVT::i1)
    return LowerZERO_EXTEND_AVX512(Op, DAG);

  if (Subtarget->hasFp256()) {
    SDValue Res = LowerAVXExtend(Op, DAG, Subtarget);
    if (Res.getNode())
      return Res;
  }

  assert(!VT.is256BitVector() || !SVT.is128BitVector() ||
         VT.getVectorNumElements() != SVT.getVectorNumElements());
  return SDValue();
}

SDValue X86TargetLowering::LowerTRUNCATE(SDValue Op, SelectionDAG &DAG) const {
  SDLoc DL(Op);
  MVT VT = Op.getSimpleValueType();
  SDValue In = Op.getOperand(0);
  MVT InVT = In.getSimpleValueType();

  if (VT == MVT::i1) {
    assert((InVT.isInteger() && (InVT.getSizeInBits() <= 64)) &&
           "Invalid scalar TRUNCATE operation");
    if (InVT.getSizeInBits() >= 32)
      return SDValue();
    In = DAG.getNode(ISD::ANY_EXTEND, DL, MVT::i32, In);
    return DAG.getNode(ISD::TRUNCATE, DL, VT, In);
  }
  assert(VT.getVectorNumElements() == InVT.getVectorNumElements() &&
         "Invalid TRUNCATE operation");

  if (InVT.is512BitVector() || VT.getVectorElementType() == MVT::i1) {
    if (VT.getVectorElementType().getSizeInBits() >=8)
      return DAG.getNode(X86ISD::VTRUNC, DL, VT, In);

    assert(VT.getVectorElementType() == MVT::i1 && "Unexpected vector type");
    unsigned NumElts = InVT.getVectorNumElements();
    assert ((NumElts == 8 || NumElts == 16) && "Unexpected vector type");
    if (InVT.getSizeInBits() < 512) {
      MVT ExtVT = (NumElts == 16)? MVT::v16i32 : MVT::v8i64;
      In = DAG.getNode(ISD::SIGN_EXTEND, DL, ExtVT, In);
      InVT = ExtVT;
    }

    SDValue Cst = DAG.getTargetConstant(1, InVT.getVectorElementType());
    const Constant *C = (dyn_cast<ConstantSDNode>(Cst))->getConstantIntValue();
    SDValue CP = DAG.getConstantPool(C, getPointerTy());
    unsigned Alignment = cast<ConstantPoolSDNode>(CP)->getAlignment();
    SDValue Ld = DAG.getLoad(Cst.getValueType(), DL, DAG.getEntryNode(), CP,
                           MachinePointerInfo::getConstantPool(),
                           false, false, false, Alignment);
    SDValue OneV = DAG.getNode(X86ISD::VBROADCAST, DL, InVT, Ld);
    SDValue And = DAG.getNode(ISD::AND, DL, InVT, OneV, In);
    return DAG.getNode(X86ISD::TESTM, DL, VT, And, And);
  }

  if ((VT == MVT::v4i32) && (InVT == MVT::v4i64)) {
    // On AVX2, v4i64 -> v4i32 becomes VPERMD.
    if (Subtarget->hasInt256()) {
      static const int ShufMask[] = {0, 2, 4, 6, -1, -1, -1, -1};
      In = DAG.getNode(ISD::BITCAST, DL, MVT::v8i32, In);
      In = DAG.getVectorShuffle(MVT::v8i32, DL, In, DAG.getUNDEF(MVT::v8i32),
                                ShufMask);
      return DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, VT, In,
                         DAG.getIntPtrConstant(0));
    }

    SDValue OpLo = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, MVT::v2i64, In,
                               DAG.getIntPtrConstant(0));
    SDValue OpHi = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, MVT::v2i64, In,
                               DAG.getIntPtrConstant(2));
    OpLo = DAG.getNode(ISD::BITCAST, DL, MVT::v4i32, OpLo);
    OpHi = DAG.getNode(ISD::BITCAST, DL, MVT::v4i32, OpHi);
    static const int ShufMask[] = {0, 2, 4, 6};
    return DAG.getVectorShuffle(VT, DL, OpLo, OpHi, ShufMask);
  }

  if ((VT == MVT::v8i16) && (InVT == MVT::v8i32)) {
    // On AVX2, v8i32 -> v8i16 becomed PSHUFB.
    if (Subtarget->hasInt256()) {
      In = DAG.getNode(ISD::BITCAST, DL, MVT::v32i8, In);

      SmallVector<SDValue,32> pshufbMask;
      for (unsigned i = 0; i < 2; ++i) {
        pshufbMask.push_back(DAG.getConstant(0x0, MVT::i8));
        pshufbMask.push_back(DAG.getConstant(0x1, MVT::i8));
        pshufbMask.push_back(DAG.getConstant(0x4, MVT::i8));
        pshufbMask.push_back(DAG.getConstant(0x5, MVT::i8));
        pshufbMask.push_back(DAG.getConstant(0x8, MVT::i8));
        pshufbMask.push_back(DAG.getConstant(0x9, MVT::i8));
        pshufbMask.push_back(DAG.getConstant(0xc, MVT::i8));
        pshufbMask.push_back(DAG.getConstant(0xd, MVT::i8));
        for (unsigned j = 0; j < 8; ++j)
          pshufbMask.push_back(DAG.getConstant(0x80, MVT::i8));
      }
      SDValue BV = DAG.getNode(ISD::BUILD_VECTOR, DL, MVT::v32i8, pshufbMask);
      In = DAG.getNode(X86ISD::PSHUFB, DL, MVT::v32i8, In, BV);
      In = DAG.getNode(ISD::BITCAST, DL, MVT::v4i64, In);

      static const int ShufMask[] = {0,  2,  -1,  -1};
      In = DAG.getVectorShuffle(MVT::v4i64, DL,  In, DAG.getUNDEF(MVT::v4i64),
                                &ShufMask[0]);
      In = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, MVT::v2i64, In,
                       DAG.getIntPtrConstant(0));
      return DAG.getNode(ISD::BITCAST, DL, VT, In);
    }

    SDValue OpLo = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, MVT::v4i32, In,
                               DAG.getIntPtrConstant(0));

    SDValue OpHi = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, MVT::v4i32, In,
                               DAG.getIntPtrConstant(4));

    OpLo = DAG.getNode(ISD::BITCAST, DL, MVT::v16i8, OpLo);
    OpHi = DAG.getNode(ISD::BITCAST, DL, MVT::v16i8, OpHi);

    // The PSHUFB mask:
    static const int ShufMask1[] = {0,  1,  4,  5,  8,  9, 12, 13,
                                   -1, -1, -1, -1, -1, -1, -1, -1};

    SDValue Undef = DAG.getUNDEF(MVT::v16i8);
    OpLo = DAG.getVectorShuffle(MVT::v16i8, DL, OpLo, Undef, ShufMask1);
    OpHi = DAG.getVectorShuffle(MVT::v16i8, DL, OpHi, Undef, ShufMask1);

    OpLo = DAG.getNode(ISD::BITCAST, DL, MVT::v4i32, OpLo);
    OpHi = DAG.getNode(ISD::BITCAST, DL, MVT::v4i32, OpHi);

    // The MOVLHPS Mask:
    static const int ShufMask2[] = {0, 1, 4, 5};
    SDValue res = DAG.getVectorShuffle(MVT::v4i32, DL, OpLo, OpHi, ShufMask2);
    return DAG.getNode(ISD::BITCAST, DL, MVT::v8i16, res);
  }

  // Handle truncation of V256 to V128 using shuffles.
  if (!VT.is128BitVector() || !InVT.is256BitVector())
    return SDValue();

  assert(Subtarget->hasFp256() && "256-bit vector without AVX!");

  unsigned NumElems = VT.getVectorNumElements();
  MVT NVT = MVT::getVectorVT(VT.getVectorElementType(), NumElems * 2);

  SmallVector<int, 16> MaskVec(NumElems * 2, -1);
  // Prepare truncation shuffle mask
  for (unsigned i = 0; i != NumElems; ++i)
    MaskVec[i] = i * 2;
  SDValue V = DAG.getVectorShuffle(NVT, DL,
                                   DAG.getNode(ISD::BITCAST, DL, NVT, In),
                                   DAG.getUNDEF(NVT), &MaskVec[0]);
  return DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, VT, V,
                     DAG.getIntPtrConstant(0));
}

SDValue X86TargetLowering::LowerFP_TO_SINT(SDValue Op,
                                           SelectionDAG &DAG) const {
  assert(!Op.getSimpleValueType().isVector());

  std::pair<SDValue,SDValue> Vals = FP_TO_INTHelper(Op, DAG,
    /*IsSigned=*/ true, /*IsReplace=*/ false);
  SDValue FIST = Vals.first, StackSlot = Vals.second;
  // If FP_TO_INTHelper failed, the node is actually supposed to be Legal.
  if (!FIST.getNode()) return Op;

  if (StackSlot.getNode())
    // Load the result.
    return DAG.getLoad(Op.getValueType(), SDLoc(Op),
                       FIST, StackSlot, MachinePointerInfo(),
                       false, false, false, 0);

  // The node is the result.
  return FIST;
}

SDValue X86TargetLowering::LowerFP_TO_UINT(SDValue Op,
                                           SelectionDAG &DAG) const {
  std::pair<SDValue,SDValue> Vals = FP_TO_INTHelper(Op, DAG,
    /*IsSigned=*/ false, /*IsReplace=*/ false);
  SDValue FIST = Vals.first, StackSlot = Vals.second;
  assert(FIST.getNode() && "Unexpected failure");

  if (StackSlot.getNode())
    // Load the result.
    return DAG.getLoad(Op.getValueType(), SDLoc(Op),
                       FIST, StackSlot, MachinePointerInfo(),
                       false, false, false, 0);

  // The node is the result.
  return FIST;
}

static SDValue LowerFP_EXTEND(SDValue Op, SelectionDAG &DAG) {
  SDLoc DL(Op);
  MVT VT = Op.getSimpleValueType();
  SDValue In = Op.getOperand(0);
  MVT SVT = In.getSimpleValueType();

  assert(SVT == MVT::v2f32 && "Only customize MVT::v2f32 type legalization!");

  return DAG.getNode(X86ISD::VFPEXT, DL, VT,
                     DAG.getNode(ISD::CONCAT_VECTORS, DL, MVT::v4f32,
                                 In, DAG.getUNDEF(SVT)));
}

/// The only differences between FABS and FNEG are the mask and the logic op.
/// FNEG also has a folding opportunity for FNEG(FABS(x)).
static SDValue LowerFABSorFNEG(SDValue Op, SelectionDAG &DAG) {
  assert((Op.getOpcode() == ISD::FABS || Op.getOpcode() == ISD::FNEG) &&
         "Wrong opcode for lowering FABS or FNEG.");

  bool IsFABS = (Op.getOpcode() == ISD::FABS);

  // If this is a FABS and it has an FNEG user, bail out to fold the combination
  // into an FNABS. We'll lower the FABS after that if it is still in use.
  if (IsFABS)
    for (SDNode *User : Op->uses())
      if (User->getOpcode() == ISD::FNEG)
        return Op;

  SDValue Op0 = Op.getOperand(0);
  bool IsFNABS = !IsFABS && (Op0.getOpcode() == ISD::FABS);

  SDLoc dl(Op);
  MVT VT = Op.getSimpleValueType();
  // Assume scalar op for initialization; update for vector if needed.
  // Note that there are no scalar bitwise logical SSE/AVX instructions, so we
  // generate a 16-byte vector constant and logic op even for the scalar case.
  // Using a 16-byte mask allows folding the load of the mask with
  // the logic op, so it can save (~4 bytes) on code size.
  MVT EltVT = VT;
  unsigned NumElts = VT == MVT::f64 ? 2 : 4;
  // FIXME: Use function attribute "OptimizeForSize" and/or CodeGenOpt::Level to
  // decide if we should generate a 16-byte constant mask when we only need 4 or
  // 8 bytes for the scalar case.
  if (VT.isVector()) {
    EltVT = VT.getVectorElementType();
    NumElts = VT.getVectorNumElements();
  }

  unsigned EltBits = EltVT.getSizeInBits();
  LLVMContext *Context = DAG.getContext();
  // For FABS, mask is 0x7f...; for FNEG, mask is 0x80...
  APInt MaskElt =
    IsFABS ? APInt::getSignedMaxValue(EltBits) : APInt::getSignBit(EltBits);
  Constant *C = ConstantInt::get(*Context, MaskElt);
  C = ConstantVector::getSplat(NumElts, C);
  const TargetLowering &TLI = DAG.getTargetLoweringInfo();
  SDValue CPIdx = DAG.getConstantPool(C, TLI.getPointerTy());
  unsigned Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlignment();
  SDValue Mask = DAG.getLoad(VT, dl, DAG.getEntryNode(), CPIdx,
                             MachinePointerInfo::getConstantPool(),
                             false, false, false, Alignment);

  if (VT.isVector()) {
    // For a vector, cast operands to a vector type, perform the logic op,
    // and cast the result back to the original value type.
    MVT VecVT = MVT::getVectorVT(MVT::i64, VT.getSizeInBits() / 64);
    SDValue MaskCasted = DAG.getNode(ISD::BITCAST, dl, VecVT, Mask);
    SDValue Operand = IsFNABS ?
      DAG.getNode(ISD::BITCAST, dl, VecVT, Op0.getOperand(0)) :
      DAG.getNode(ISD::BITCAST, dl, VecVT, Op0);
    unsigned BitOp = IsFABS ? ISD::AND : IsFNABS ? ISD::OR : ISD::XOR;
    return DAG.getNode(ISD::BITCAST, dl, VT,
                       DAG.getNode(BitOp, dl, VecVT, Operand, MaskCasted));
  }

  // If not vector, then scalar.
  unsigned BitOp = IsFABS ? X86ISD::FAND : IsFNABS ? X86ISD::FOR : X86ISD::FXOR;
  SDValue Operand = IsFNABS ? Op0.getOperand(0) : Op0;
  return DAG.getNode(BitOp, dl, VT, Operand, Mask);
}

static SDValue LowerFCOPYSIGN(SDValue Op, SelectionDAG &DAG) {
  const TargetLowering &TLI = DAG.getTargetLoweringInfo();
  LLVMContext *Context = DAG.getContext();
  SDValue Op0 = Op.getOperand(0);
  SDValue Op1 = Op.getOperand(1);
  SDLoc dl(Op);
  MVT VT = Op.getSimpleValueType();
  MVT SrcVT = Op1.getSimpleValueType();

  // If second operand is smaller, extend it first.
  if (SrcVT.bitsLT(VT)) {
    Op1 = DAG.getNode(ISD::FP_EXTEND, dl, VT, Op1);
    SrcVT = VT;
  }
  // And if it is bigger, shrink it first.
  if (SrcVT.bitsGT(VT)) {
    Op1 = DAG.getNode(ISD::FP_ROUND, dl, VT, Op1, DAG.getIntPtrConstant(1));
    SrcVT = VT;
  }

  // At this point the operands and the result should have the same
  // type, and that won't be f80 since that is not custom lowered.

  const fltSemantics &Sem =
      VT == MVT::f64 ? APFloat::IEEEdouble : APFloat::IEEEsingle;
  const unsigned SizeInBits = VT.getSizeInBits();

  SmallVector<Constant *, 4> CV(
      VT == MVT::f64 ? 2 : 4,
      ConstantFP::get(*Context, APFloat(Sem, APInt(SizeInBits, 0))));

  // First, clear all bits but the sign bit from the second operand (sign).
  CV[0] = ConstantFP::get(*Context,
                          APFloat(Sem, APInt::getHighBitsSet(SizeInBits, 1)));
  Constant *C = ConstantVector::get(CV);
  SDValue CPIdx = DAG.getConstantPool(C, TLI.getPointerTy(), 16);
  SDValue Mask1 = DAG.getLoad(SrcVT, dl, DAG.getEntryNode(), CPIdx,
                              MachinePointerInfo::getConstantPool(),
                              false, false, false, 16);
  SDValue SignBit = DAG.getNode(X86ISD::FAND, dl, SrcVT, Op1, Mask1);

  // Next, clear the sign bit from the first operand (magnitude).
  // If it's a constant, we can clear it here.
  if (ConstantFPSDNode *Op0CN = dyn_cast<ConstantFPSDNode>(Op0)) {
    APFloat APF = Op0CN->getValueAPF();
    // If the magnitude is a positive zero, the sign bit alone is enough.
    if (APF.isPosZero())
      return SignBit;
    APF.clearSign();
    CV[0] = ConstantFP::get(*Context, APF);
  } else {
    CV[0] = ConstantFP::get(
        *Context,
        APFloat(Sem, APInt::getLowBitsSet(SizeInBits, SizeInBits - 1)));
  }
  C = ConstantVector::get(CV);
  CPIdx = DAG.getConstantPool(C, TLI.getPointerTy(), 16);
  SDValue Val = DAG.getLoad(VT, dl, DAG.getEntryNode(), CPIdx,
                            MachinePointerInfo::getConstantPool(),
                            false, false, false, 16);
  // If the magnitude operand wasn't a constant, we need to AND out the sign.
  if (!isa<ConstantFPSDNode>(Op0))
    Val = DAG.getNode(X86ISD::FAND, dl, VT, Op0, Val);

  // OR the magnitude value with the sign bit.
  return DAG.getNode(X86ISD::FOR, dl, VT, Val, SignBit);
}

static SDValue LowerFGETSIGN(SDValue Op, SelectionDAG &DAG) {
  SDValue N0 = Op.getOperand(0);
  SDLoc dl(Op);
  MVT VT = Op.getSimpleValueType();

  // Lower ISD::FGETSIGN to (AND (X86ISD::FGETSIGNx86 ...) 1).
  SDValue xFGETSIGN = DAG.getNode(X86ISD::FGETSIGNx86, dl, VT, N0,
                                  DAG.getConstant(1, VT));
  return DAG.getNode(ISD::AND, dl, VT, xFGETSIGN, DAG.getConstant(1, VT));
}

// Check whether an OR'd tree is PTEST-able.
static SDValue LowerVectorAllZeroTest(SDValue Op, const X86Subtarget *Subtarget,
                                      SelectionDAG &DAG) {
  assert(Op.getOpcode() == ISD::OR && "Only check OR'd tree.");

  if (!Subtarget->hasSSE41())
    return SDValue();

  if (!Op->hasOneUse())
    return SDValue();

  SDNode *N = Op.getNode();
  SDLoc DL(N);

  SmallVector<SDValue, 8> Opnds;
  DenseMap<SDValue, unsigned> VecInMap;
  SmallVector<SDValue, 8> VecIns;
  EVT VT = MVT::Other;

  // Recognize a special case where a vector is casted into wide integer to
  // test all 0s.
  Opnds.push_back(N->getOperand(0));
  Opnds.push_back(N->getOperand(1));

  for (unsigned Slot = 0, e = Opnds.size(); Slot < e; ++Slot) {
    SmallVectorImpl<SDValue>::const_iterator I = Opnds.begin() + Slot;
    // BFS traverse all OR'd operands.
    if (I->getOpcode() == ISD::OR) {
      Opnds.push_back(I->getOperand(0));
      Opnds.push_back(I->getOperand(1));
      // Re-evaluate the number of nodes to be traversed.
      e += 2; // 2 more nodes (LHS and RHS) are pushed.
      continue;
    }

    // Quit if a non-EXTRACT_VECTOR_ELT
    if (I->getOpcode() != ISD::EXTRACT_VECTOR_ELT)
      return SDValue();

    // Quit if without a constant index.
    SDValue Idx = I->getOperand(1);
    if (!isa<ConstantSDNode>(Idx))
      return SDValue();

    SDValue ExtractedFromVec = I->getOperand(0);
    DenseMap<SDValue, unsigned>::iterator M = VecInMap.find(ExtractedFromVec);
    if (M == VecInMap.end()) {
      VT = ExtractedFromVec.getValueType();
      // Quit if not 128/256-bit vector.
      if (!VT.is128BitVector() && !VT.is256BitVector())
        return SDValue();
      // Quit if not the same type.
      if (VecInMap.begin() != VecInMap.end() &&
          VT != VecInMap.begin()->first.getValueType())
        return SDValue();
      M = VecInMap.insert(std::make_pair(ExtractedFromVec, 0)).first;
      VecIns.push_back(ExtractedFromVec);
    }
    M->second |= 1U << cast<ConstantSDNode>(Idx)->getZExtValue();
  }

  assert((VT.is128BitVector() || VT.is256BitVector()) &&
         "Not extracted from 128-/256-bit vector.");

  unsigned FullMask = (1U << VT.getVectorNumElements()) - 1U;

  for (DenseMap<SDValue, unsigned>::const_iterator
        I = VecInMap.begin(), E = VecInMap.end(); I != E; ++I) {
    // Quit if not all elements are used.
    if (I->second != FullMask)
      return SDValue();
  }

  EVT TestVT = VT.is128BitVector() ? MVT::v2i64 : MVT::v4i64;

  // Cast all vectors into TestVT for PTEST.
  for (unsigned i = 0, e = VecIns.size(); i < e; ++i)
    VecIns[i] = DAG.getNode(ISD::BITCAST, DL, TestVT, VecIns[i]);

  // If more than one full vectors are evaluated, OR them first before PTEST.
  for (unsigned Slot = 0, e = VecIns.size(); e - Slot > 1; Slot += 2, e += 1) {
    // Each iteration will OR 2 nodes and append the result until there is only
    // 1 node left, i.e. the final OR'd value of all vectors.
    SDValue LHS = VecIns[Slot];
    SDValue RHS = VecIns[Slot + 1];
    VecIns.push_back(DAG.getNode(ISD::OR, DL, TestVT, LHS, RHS));
  }

  return DAG.getNode(X86ISD::PTEST, DL, MVT::i32,
                     VecIns.back(), VecIns.back());
}

/// \brief return true if \c Op has a use that doesn't just read flags.
static bool hasNonFlagsUse(SDValue Op) {
  for (SDNode::use_iterator UI = Op->use_begin(), UE = Op->use_end(); UI != UE;
       ++UI) {
    SDNode *User = *UI;
    unsigned UOpNo = UI.getOperandNo();
    if (User->getOpcode() == ISD::TRUNCATE && User->hasOneUse()) {
      // Look pass truncate.
      UOpNo = User->use_begin().getOperandNo();
      User = *User->use_begin();
    }

    if (User->getOpcode() != ISD::BRCOND && User->getOpcode() != ISD::SETCC &&
        !(User->getOpcode() == ISD::SELECT && UOpNo == 0))
      return true;
  }
  return false;
}

/// Emit nodes that will be selected as "test Op0,Op0", or something
/// equivalent.
SDValue X86TargetLowering::EmitTest(SDValue Op, unsigned X86CC, SDLoc dl,
                                    SelectionDAG &DAG) const {
  if (Op.getValueType() == MVT::i1) {
    SDValue ExtOp = DAG.getNode(ISD::ZERO_EXTEND, dl, MVT::i8, Op);
    return DAG.getNode(X86ISD::CMP, dl, MVT::i32, ExtOp,
                       DAG.getConstant(0, MVT::i8));
  }
  // CF and OF aren't always set the way we want. Determine which
  // of these we need.
  bool NeedCF = false;
  bool NeedOF = false;
  switch (X86CC) {
  default: break;
  case X86::COND_A: case X86::COND_AE:
  case X86::COND_B: case X86::COND_BE:
    NeedCF = true;
    break;
  case X86::COND_G: case X86::COND_GE:
  case X86::COND_L: case X86::COND_LE:
  case X86::COND_O: case X86::COND_NO: {
    // Check if we really need to set the
    // Overflow flag. If NoSignedWrap is present
    // that is not actually needed.
    switch (Op->getOpcode()) {
    case ISD::ADD:
    case ISD::SUB:
    case ISD::MUL:
    case ISD::SHL: {
      const BinaryWithFlagsSDNode *BinNode =
          cast<BinaryWithFlagsSDNode>(Op.getNode());
      if (BinNode->hasNoSignedWrap())
        break;
    }
    default:
      NeedOF = true;
      break;
    }
    break;
  }
  }
  // See if we can use the EFLAGS value from the operand instead of
  // doing a separate TEST. TEST always sets OF and CF to 0, so unless
  // we prove that the arithmetic won't overflow, we can't use OF or CF.
  if (Op.getResNo() != 0 || NeedOF || NeedCF) {
    // Emit a CMP with 0, which is the TEST pattern.
    //if (Op.getValueType() == MVT::i1)
    //  return DAG.getNode(X86ISD::CMP, dl, MVT::i1, Op,
    //                     DAG.getConstant(0, MVT::i1));
    return DAG.getNode(X86ISD::CMP, dl, MVT::i32, Op,
                       DAG.getConstant(0, Op.getValueType()));
  }
  unsigned Opcode = 0;
  unsigned NumOperands = 0;

  // Truncate operations may prevent the merge of the SETCC instruction
  // and the arithmetic instruction before it. Attempt to truncate the operands
  // of the arithmetic instruction and use a reduced bit-width instruction.
  bool NeedTruncation = false;
  SDValue ArithOp = Op;
  if (Op->getOpcode() == ISD::TRUNCATE && Op->hasOneUse()) {
    SDValue Arith = Op->getOperand(0);
    // Both the trunc and the arithmetic op need to have one user each.
    if (Arith->hasOneUse())
      switch (Arith.getOpcode()) {
        default: break;
        case ISD::ADD:
        case ISD::SUB:
        case ISD::AND:
        case ISD::OR:
        case ISD::XOR: {
          NeedTruncation = true;
          ArithOp = Arith;
        }
      }
  }

  // NOTICE: In the code below we use ArithOp to hold the arithmetic operation
  // which may be the result of a CAST.  We use the variable 'Op', which is the
  // non-casted variable when we check for possible users.
  switch (ArithOp.getOpcode()) {
  case ISD::ADD:
    // Due to an isel shortcoming, be conservative if this add is likely to be
    // selected as part of a load-modify-store instruction. When the root node
    // in a match is a store, isel doesn't know how to remap non-chain non-flag
    // uses of other nodes in the match, such as the ADD in this case. This
    // leads to the ADD being left around and reselected, with the result being
    // two adds in the output.  Alas, even if none our users are stores, that
    // doesn't prove we're O.K.  Ergo, if we have any parents that aren't
    // CopyToReg or SETCC, eschew INC/DEC.  A better fix seems to require
    // climbing the DAG back to the root, and it doesn't seem to be worth the
    // effort.
    for (SDNode::use_iterator UI = Op.getNode()->use_begin(),
         UE = Op.getNode()->use_end(); UI != UE; ++UI)
      if (UI->getOpcode() != ISD::CopyToReg &&
          UI->getOpcode() != ISD::SETCC &&
          UI->getOpcode() != ISD::STORE)
        goto default_case;

    if (ConstantSDNode *C =
        dyn_cast<ConstantSDNode>(ArithOp.getNode()->getOperand(1))) {
      // An add of one will be selected as an INC.
      if (C->getAPIntValue() == 1 && !Subtarget->slowIncDec()) {
        Opcode = X86ISD::INC;
        NumOperands = 1;
        break;
      }

      // An add of negative one (subtract of one) will be selected as a DEC.
      if (C->getAPIntValue().isAllOnesValue() && !Subtarget->slowIncDec()) {
        Opcode = X86ISD::DEC;
        NumOperands = 1;
        break;
      }
    }

    // Otherwise use a regular EFLAGS-setting add.
    Opcode = X86ISD::ADD;
    NumOperands = 2;
    break;
  case ISD::SHL:
  case ISD::SRL:
    // If we have a constant logical shift that's only used in a comparison
    // against zero turn it into an equivalent AND. This allows turning it into
    // a TEST instruction later.
    if ((X86CC == X86::COND_E || X86CC == X86::COND_NE) && Op->hasOneUse() &&
        isa<ConstantSDNode>(Op->getOperand(1)) && !hasNonFlagsUse(Op)) {
      EVT VT = Op.getValueType();
      unsigned BitWidth = VT.getSizeInBits();
      unsigned ShAmt = Op->getConstantOperandVal(1);
      if (ShAmt >= BitWidth) // Avoid undefined shifts.
        break;
      APInt Mask = ArithOp.getOpcode() == ISD::SRL
                       ? APInt::getHighBitsSet(BitWidth, BitWidth - ShAmt)
                       : APInt::getLowBitsSet(BitWidth, BitWidth - ShAmt);
      if (!Mask.isSignedIntN(32)) // Avoid large immediates.
        break;
      SDValue New = DAG.getNode(ISD::AND, dl, VT, Op->getOperand(0),
                                DAG.getConstant(Mask, VT));
      DAG.ReplaceAllUsesWith(Op, New);
      Op = New;
    }
    break;

  case ISD::AND:
    // If the primary and result isn't used, don't bother using X86ISD::AND,
    // because a TEST instruction will be better.
    if (!hasNonFlagsUse(Op))
      break;
    // FALL THROUGH
  case ISD::SUB:
  case ISD::OR:
  case ISD::XOR:
    // Due to the ISEL shortcoming noted above, be conservative if this op is
    // likely to be selected as part of a load-modify-store instruction.
    for (SDNode::use_iterator UI = Op.getNode()->use_begin(),
           UE = Op.getNode()->use_end(); UI != UE; ++UI)
      if (UI->getOpcode() == ISD::STORE)
        goto default_case;

    // Otherwise use a regular EFLAGS-setting instruction.
    switch (ArithOp.getOpcode()) {
    default: llvm_unreachable("unexpected operator!");
    case ISD::SUB: Opcode = X86ISD::SUB; break;
    case ISD::XOR: Opcode = X86ISD::XOR; break;
    case ISD::AND: Opcode = X86ISD::AND; break;
    case ISD::OR: {
      if (!NeedTruncation && (X86CC == X86::COND_E || X86CC == X86::COND_NE)) {
        SDValue EFLAGS = LowerVectorAllZeroTest(Op, Subtarget, DAG);
        if (EFLAGS.getNode())
          return EFLAGS;
      }
      Opcode = X86ISD::OR;
      break;
    }
    }

    NumOperands = 2;
    break;
  case X86ISD::ADD:
  case X86ISD::SUB:
  case X86ISD::INC:
  case X86ISD::DEC:
  case X86ISD::OR:
  case X86ISD::XOR:
  case X86ISD::AND:
    return SDValue(Op.getNode(), 1);
  default:
  default_case:
    break;
  }

  // If we found that truncation is beneficial, perform the truncation and
  // update 'Op'.
  if (NeedTruncation) {
    EVT VT = Op.getValueType();
    SDValue WideVal = Op->getOperand(0);
    EVT WideVT = WideVal.getValueType();
    unsigned ConvertedOp = 0;
    // Use a target machine opcode to prevent further DAGCombine
    // optimizations that may separate the arithmetic operations
    // from the setcc node.
    switch (WideVal.getOpcode()) {
      default: break;
      case ISD::ADD: ConvertedOp = X86ISD::ADD; break;
      case ISD::SUB: ConvertedOp = X86ISD::SUB; break;
      case ISD::AND: ConvertedOp = X86ISD::AND; break;
      case ISD::OR:  ConvertedOp = X86ISD::OR;  break;
      case ISD::XOR: ConvertedOp = X86ISD::XOR; break;
    }

    if (ConvertedOp) {
      const TargetLowering &TLI = DAG.getTargetLoweringInfo();
      if (TLI.isOperationLegal(WideVal.getOpcode(), WideVT)) {
        SDValue V0 = DAG.getNode(ISD::TRUNCATE, dl, VT, WideVal.getOperand(0));
        SDValue V1 = DAG.getNode(ISD::TRUNCATE, dl, VT, WideVal.getOperand(1));
        Op = DAG.getNode(ConvertedOp, dl, VT, V0, V1);
      }
    }
  }

  if (Opcode == 0)
    // Emit a CMP with 0, which is the TEST pattern.
    return DAG.getNode(X86ISD::CMP, dl, MVT::i32, Op,
                       DAG.getConstant(0, Op.getValueType()));

  SDVTList VTs = DAG.getVTList(Op.getValueType(), MVT::i32);
  SmallVector<SDValue, 4> Ops(Op->op_begin(), Op->op_begin() + NumOperands);

  SDValue New = DAG.getNode(Opcode, dl, VTs, Ops);
  DAG.ReplaceAllUsesWith(Op, New);
  return SDValue(New.getNode(), 1);
}

/// Emit nodes that will be selected as "cmp Op0,Op1", or something
/// equivalent.
SDValue X86TargetLowering::EmitCmp(SDValue Op0, SDValue Op1, unsigned X86CC,
                                   SDLoc dl, SelectionDAG &DAG) const {
  if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op1)) {
    if (C->getAPIntValue() == 0)
      return EmitTest(Op0, X86CC, dl, DAG);

     if (Op0.getValueType() == MVT::i1)
       llvm_unreachable("Unexpected comparison operation for MVT::i1 operands");
  }

  if ((Op0.getValueType() == MVT::i8 || Op0.getValueType() == MVT::i16 ||
       Op0.getValueType() == MVT::i32 || Op0.getValueType() == MVT::i64)) {
    // Do the comparison at i32 if it's smaller, besides the Atom case.
    // This avoids subregister aliasing issues. Keep the smaller reference
    // if we're optimizing for size, however, as that'll allow better folding
    // of memory operations.
    if (Op0.getValueType() != MVT::i32 && Op0.getValueType() != MVT::i64 &&
        !DAG.getMachineFunction().getFunction()->hasFnAttribute(
            Attribute::MinSize) &&
        !Subtarget->isAtom()) {
      unsigned ExtendOp =
          isX86CCUnsigned(X86CC) ? ISD::ZERO_EXTEND : ISD::SIGN_EXTEND;
      Op0 = DAG.getNode(ExtendOp, dl, MVT::i32, Op0);
      Op1 = DAG.getNode(ExtendOp, dl, MVT::i32, Op1);
    }
    // Use SUB instead of CMP to enable CSE between SUB and CMP.
    SDVTList VTs = DAG.getVTList(Op0.getValueType(), MVT::i32);
    SDValue Sub = DAG.getNode(X86ISD::SUB, dl, VTs,
                              Op0, Op1);
    return SDValue(Sub.getNode(), 1);
  }
  return DAG.getNode(X86ISD::CMP, dl, MVT::i32, Op0, Op1);
}

/// Convert a comparison if required by the subtarget.
SDValue X86TargetLowering::ConvertCmpIfNecessary(SDValue Cmp,
                                                 SelectionDAG &DAG) const {
  // If the subtarget does not support the FUCOMI instruction, floating-point
  // comparisons have to be converted.
  if (Subtarget->hasCMov() ||
      Cmp.getOpcode() != X86ISD::CMP ||
      !Cmp.getOperand(0).getValueType().isFloatingPoint() ||
      !Cmp.getOperand(1).getValueType().isFloatingPoint())
    return Cmp;

  // The instruction selector will select an FUCOM instruction instead of
  // FUCOMI, which writes the comparison result to FPSW instead of EFLAGS. Hence
  // build an SDNode sequence that transfers the result from FPSW into EFLAGS:
  // (X86sahf (trunc (srl (X86fp_stsw (trunc (X86cmp ...)), 8))))
  SDLoc dl(Cmp);
  SDValue TruncFPSW = DAG.getNode(ISD::TRUNCATE, dl, MVT::i16, Cmp);
  SDValue FNStSW = DAG.getNode(X86ISD::FNSTSW16r, dl, MVT::i16, TruncFPSW);
  SDValue Srl = DAG.getNode(ISD::SRL, dl, MVT::i16, FNStSW,
                            DAG.getConstant(8, MVT::i8));
  SDValue TruncSrl = DAG.getNode(ISD::TRUNCATE, dl, MVT::i8, Srl);
  return DAG.getNode(X86ISD::SAHF, dl, MVT::i32, TruncSrl);
}

/// The minimum architected relative accuracy is 2^-12. We need one
/// Newton-Raphson step to have a good float result (24 bits of precision).
SDValue X86TargetLowering::getRsqrtEstimate(SDValue Op,
                                            DAGCombinerInfo &DCI,
                                            unsigned &RefinementSteps,
                                            bool &UseOneConstNR) const {
  // FIXME: We should use instruction latency models to calculate the cost of
  // each potential sequence, but this is very hard to do reliably because
  // at least Intel's Core* chips have variable timing based on the number of
  // significant digits in the divisor and/or sqrt operand.
  if (!Subtarget->useSqrtEst())
    return SDValue();

  EVT VT = Op.getValueType();

  // SSE1 has rsqrtss and rsqrtps.
  // TODO: Add support for AVX512 (v16f32).
  // It is likely not profitable to do this for f64 because a double-precision
  // rsqrt estimate with refinement on x86 prior to FMA requires at least 16
  // instructions: convert to single, rsqrtss, convert back to double, refine
  // (3 steps = at least 13 insts). If an 'rsqrtsd' variant was added to the ISA
  // along with FMA, this could be a throughput win.
  if ((Subtarget->hasSSE1() && (VT == MVT::f32 || VT == MVT::v4f32)) ||
      (Subtarget->hasAVX() && VT == MVT::v8f32)) {
    RefinementSteps = 1;
    UseOneConstNR = false;
    return DCI.DAG.getNode(X86ISD::FRSQRT, SDLoc(Op), VT, Op);
  }
  return SDValue();
}

/// The minimum architected relative accuracy is 2^-12. We need one
/// Newton-Raphson step to have a good float result (24 bits of precision).
SDValue X86TargetLowering::getRecipEstimate(SDValue Op,
                                            DAGCombinerInfo &DCI,
                                            unsigned &RefinementSteps) const {
  // FIXME: We should use instruction latency models to calculate the cost of
  // each potential sequence, but this is very hard to do reliably because
  // at least Intel's Core* chips have variable timing based on the number of
  // significant digits in the divisor.
  if (!Subtarget->useReciprocalEst())
    return SDValue();

  EVT VT = Op.getValueType();

  // SSE1 has rcpss and rcpps. AVX adds a 256-bit variant for rcpps.
  // TODO: Add support for AVX512 (v16f32).
  // It is likely not profitable to do this for f64 because a double-precision
  // reciprocal estimate with refinement on x86 prior to FMA requires
  // 15 instructions: convert to single, rcpss, convert back to double, refine
  // (3 steps = 12 insts). If an 'rcpsd' variant was added to the ISA
  // along with FMA, this could be a throughput win.
  if ((Subtarget->hasSSE1() && (VT == MVT::f32 || VT == MVT::v4f32)) ||
      (Subtarget->hasAVX() && VT == MVT::v8f32)) {
    RefinementSteps = ReciprocalEstimateRefinementSteps;
    return DCI.DAG.getNode(X86ISD::FRCP, SDLoc(Op), VT, Op);
  }
  return SDValue();
}

static bool isAllOnes(SDValue V) {
  ConstantSDNode *C = dyn_cast<ConstantSDNode>(V);
  return C && C->isAllOnesValue();
}

/// LowerToBT - Result of 'and' is compared against zero. Turn it into a BT node
/// if it's possible.
SDValue X86TargetLowering::LowerToBT(SDValue And, ISD::CondCode CC,
                                     SDLoc dl, SelectionDAG &DAG) const {
  SDValue Op0 = And.getOperand(0);
  SDValue Op1 = And.getOperand(1);
  if (Op0.getOpcode() == ISD::TRUNCATE)
    Op0 = Op0.getOperand(0);
  if (Op1.getOpcode() == ISD::TRUNCATE)
    Op1 = Op1.getOperand(0);

  SDValue LHS, RHS;
  if (Op1.getOpcode() == ISD::SHL)
    std::swap(Op0, Op1);
  if (Op0.getOpcode() == ISD::SHL) {
    if (ConstantSDNode *And00C = dyn_cast<ConstantSDNode>(Op0.getOperand(0)))
      if (And00C->getZExtValue() == 1) {
        // If we looked past a truncate, check that it's only truncating away
        // known zeros.
        unsigned BitWidth = Op0.getValueSizeInBits();
        unsigned AndBitWidth = And.getValueSizeInBits();
        if (BitWidth > AndBitWidth) {
          APInt Zeros, Ones;
          DAG.computeKnownBits(Op0, Zeros, Ones);
          if (Zeros.countLeadingOnes() < BitWidth - AndBitWidth)
            return SDValue();
        }
        LHS = Op1;
        RHS = Op0.getOperand(1);
      }
  } else if (Op1.getOpcode() == ISD::Constant) {
    ConstantSDNode *AndRHS = cast<ConstantSDNode>(Op1);
    uint64_t AndRHSVal = AndRHS->getZExtValue();
    SDValue AndLHS = Op0;

    if (AndRHSVal == 1 && AndLHS.getOpcode() == ISD::SRL) {
      LHS = AndLHS.getOperand(0);
      RHS = AndLHS.getOperand(1);
    }

    // Use BT if the immediate can't be encoded in a TEST instruction.
    if (!isUInt<32>(AndRHSVal) && isPowerOf2_64(AndRHSVal)) {
      LHS = AndLHS;
      RHS = DAG.getConstant(Log2_64_Ceil(AndRHSVal), LHS.getValueType());
    }
  }

  if (LHS.getNode()) {
    // If LHS is i8, promote it to i32 with any_extend.  There is no i8 BT
    // instruction.  Since the shift amount is in-range-or-undefined, we know
    // that doing a bittest on the i32 value is ok.  We extend to i32 because
    // the encoding for the i16 version is larger than the i32 version.
    // Also promote i16 to i32 for performance / code size reason.
    if (LHS.getValueType() == MVT::i8 ||
        LHS.getValueType() == MVT::i16)
      LHS = DAG.getNode(ISD::ANY_EXTEND, dl, MVT::i32, LHS);

    // If the operand types disagree, extend the shift amount to match.  Since
    // BT ignores high bits (like shifts) we can use anyextend.
    if (LHS.getValueType() != RHS.getValueType())
      RHS = DAG.getNode(ISD::ANY_EXTEND, dl, LHS.getValueType(), RHS);

    SDValue BT = DAG.getNode(X86ISD::BT, dl, MVT::i32, LHS, RHS);
    X86::CondCode Cond = CC == ISD::SETEQ ? X86::COND_AE : X86::COND_B;
    return DAG.getNode(X86ISD::SETCC, dl, MVT::i8,
                       DAG.getConstant(Cond, MVT::i8), BT);
  }

  return SDValue();
}

/// \brief - Turns an ISD::CondCode into a value suitable for SSE floating point
/// mask CMPs.
static int translateX86FSETCC(ISD::CondCode SetCCOpcode, SDValue &Op0,
                              SDValue &Op1) {
  unsigned SSECC;
  bool Swap = false;

  // SSE Condition code mapping:
  //  0 - EQ
  //  1 - LT
  //  2 - LE
  //  3 - UNORD
  //  4 - NEQ
  //  5 - NLT
  //  6 - NLE
  //  7 - ORD
  switch (SetCCOpcode) {
  default: llvm_unreachable("Unexpected SETCC condition");
  case ISD::SETOEQ:
  case ISD::SETEQ:  SSECC = 0; break;
  case ISD::SETOGT:
  case ISD::SETGT:  Swap = true; // Fallthrough
  case ISD::SETLT:
  case ISD::SETOLT: SSECC = 1; break;
  case ISD::SETOGE:
  case ISD::SETGE:  Swap = true; // Fallthrough
  case ISD::SETLE:
  case ISD::SETOLE: SSECC = 2; break;
  case ISD::SETUO:  SSECC = 3; break;
  case ISD::SETUNE:
  case ISD::SETNE:  SSECC = 4; break;
  case ISD::SETULE: Swap = true; // Fallthrough
  case ISD::SETUGE: SSECC = 5; break;
  case ISD::SETULT: Swap = true; // Fallthrough
  case ISD::SETUGT: SSECC = 6; break;
  case ISD::SETO:   SSECC = 7; break;
  case ISD::SETUEQ:
  case ISD::SETONE: SSECC = 8; break;
  }
  if (Swap)
    std::swap(Op0, Op1);

  return SSECC;
}

// Lower256IntVSETCC - Break a VSETCC 256-bit integer VSETCC into two new 128
// ones, and then concatenate the result back.
static SDValue Lower256IntVSETCC(SDValue Op, SelectionDAG &DAG) {
  MVT VT = Op.getSimpleValueType();

  assert(VT.is256BitVector() && Op.getOpcode() == ISD::SETCC &&
         "Unsupported value type for operation");

  unsigned NumElems = VT.getVectorNumElements();
  SDLoc dl(Op);
  SDValue CC = Op.getOperand(2);

  // Extract the LHS vectors
  SDValue LHS = Op.getOperand(0);
  SDValue LHS1 = Extract128BitVector(LHS, 0, DAG, dl);
  SDValue LHS2 = Extract128BitVector(LHS, NumElems/2, DAG, dl);

  // Extract the RHS vectors
  SDValue RHS = Op.getOperand(1);
  SDValue RHS1 = Extract128BitVector(RHS, 0, DAG, dl);
  SDValue RHS2 = Extract128BitVector(RHS, NumElems/2, DAG, dl);

  // Issue the operation on the smaller types and concatenate the result back
  MVT EltVT = VT.getVectorElementType();
  MVT NewVT = MVT::getVectorVT(EltVT, NumElems/2);
  return DAG.getNode(ISD::CONCAT_VECTORS, dl, VT,
                     DAG.getNode(Op.getOpcode(), dl, NewVT, LHS1, RHS1, CC),
                     DAG.getNode(Op.getOpcode(), dl, NewVT, LHS2, RHS2, CC));
}

static SDValue LowerIntVSETCC_AVX512(SDValue Op, SelectionDAG &DAG,
                                     const X86Subtarget *Subtarget) {
  SDValue Op0 = Op.getOperand(0);
  SDValue Op1 = Op.getOperand(1);
  SDValue CC = Op.getOperand(2);
  MVT VT = Op.getSimpleValueType();
  SDLoc dl(Op);

  assert(Op0.getValueType().getVectorElementType().getSizeInBits() >= 8 &&
         Op.getValueType().getScalarType() == MVT::i1 &&
         "Cannot set masked compare for this operation");

  ISD::CondCode SetCCOpcode = cast<CondCodeSDNode>(CC)->get();
  unsigned  Opc = 0;
  bool Unsigned = false;
  bool Swap = false;
  unsigned SSECC;
  switch (SetCCOpcode) {
  default: llvm_unreachable("Unexpected SETCC condition");
  case ISD::SETNE:  SSECC = 4; break;
  case ISD::SETEQ:  Opc = X86ISD::PCMPEQM; break;
  case ISD::SETUGT: SSECC = 6; Unsigned = true; break;
  case ISD::SETLT:  Swap = true; //fall-through
  case ISD::SETGT:  Opc = X86ISD::PCMPGTM; break;
  case ISD::SETULT: SSECC = 1; Unsigned = true; break;
  case ISD::SETUGE: SSECC = 5; Unsigned = true; break; //NLT
  case ISD::SETGE:  Swap = true; SSECC = 2; break; // LE + swap
  case ISD::SETULE: Unsigned = true; //fall-through
  case ISD::SETLE:  SSECC = 2; break;
  }

  if (Swap)
    std::swap(Op0, Op1);
  if (Opc)
    return DAG.getNode(Opc, dl, VT, Op0, Op1);
  Opc = Unsigned ? X86ISD::CMPMU: X86ISD::CMPM;
  return DAG.getNode(Opc, dl, VT, Op0, Op1,
                     DAG.getConstant(SSECC, MVT::i8));
}

/// \brief Try to turn a VSETULT into a VSETULE by modifying its second
/// operand \p Op1.  If non-trivial (for example because it's not constant)
/// return an empty value.
static SDValue ChangeVSETULTtoVSETULE(SDLoc dl, SDValue Op1, SelectionDAG &DAG)
{
  BuildVectorSDNode *BV = dyn_cast<BuildVectorSDNode>(Op1.getNode());
  if (!BV)
    return SDValue();

  MVT VT = Op1.getSimpleValueType();
  MVT EVT = VT.getVectorElementType();
  unsigned n = VT.getVectorNumElements();
  SmallVector<SDValue, 8> ULTOp1;

  for (unsigned i = 0; i < n; ++i) {
    ConstantSDNode *Elt = dyn_cast<ConstantSDNode>(BV->getOperand(i));
    if (!Elt || Elt->isOpaque() || Elt->getValueType(0) != EVT)
      return SDValue();

    // Avoid underflow.
    APInt Val = Elt->getAPIntValue();
    if (Val == 0)
      return SDValue();

    ULTOp1.push_back(DAG.getConstant(Val - 1, EVT));
  }

  return DAG.getNode(ISD::BUILD_VECTOR, dl, VT, ULTOp1);
}

static SDValue LowerVSETCC(SDValue Op, const X86Subtarget *Subtarget,
                           SelectionDAG &DAG) {
  SDValue Op0 = Op.getOperand(0);
  SDValue Op1 = Op.getOperand(1);
  SDValue CC = Op.getOperand(2);
  MVT VT = Op.getSimpleValueType();
  ISD::CondCode SetCCOpcode = cast<CondCodeSDNode>(CC)->get();
  bool isFP = Op.getOperand(1).getSimpleValueType().isFloatingPoint();
  SDLoc dl(Op);

  if (isFP) {
#ifndef NDEBUG
    MVT EltVT = Op0.getSimpleValueType().getVectorElementType();
    assert(EltVT == MVT::f32 || EltVT == MVT::f64);
#endif

    unsigned SSECC = translateX86FSETCC(SetCCOpcode, Op0, Op1);
    unsigned Opc = X86ISD::CMPP;
    if (Subtarget->hasAVX512() && VT.getVectorElementType() == MVT::i1) {
      assert(VT.getVectorNumElements() <= 16);
      Opc = X86ISD::CMPM;
    }
    // In the two special cases we can't handle, emit two comparisons.
    if (SSECC == 8) {
      unsigned CC0, CC1;
      unsigned CombineOpc;
      if (SetCCOpcode == ISD::SETUEQ) {
        CC0 = 3; CC1 = 0; CombineOpc = ISD::OR;
      } else {
        assert(SetCCOpcode == ISD::SETONE);
        CC0 = 7; CC1 = 4; CombineOpc = ISD::AND;
      }

      SDValue Cmp0 = DAG.getNode(Opc, dl, VT, Op0, Op1,
                                 DAG.getConstant(CC0, MVT::i8));
      SDValue Cmp1 = DAG.getNode(Opc, dl, VT, Op0, Op1,
                                 DAG.getConstant(CC1, MVT::i8));
      return DAG.getNode(CombineOpc, dl, VT, Cmp0, Cmp1);
    }
    // Handle all other FP comparisons here.
    return DAG.getNode(Opc, dl, VT, Op0, Op1,
                       DAG.getConstant(SSECC, MVT::i8));
  }

  // Break 256-bit integer vector compare into smaller ones.
  if (VT.is256BitVector() && !Subtarget->hasInt256())
    return Lower256IntVSETCC(Op, DAG);

  bool MaskResult = (VT.getVectorElementType() == MVT::i1);
  EVT OpVT = Op1.getValueType();
  if (Subtarget->hasAVX512()) {
    if (Op1.getValueType().is512BitVector() ||
        (Subtarget->hasBWI() && Subtarget->hasVLX()) ||
        (MaskResult && OpVT.getVectorElementType().getSizeInBits() >= 32))
      return LowerIntVSETCC_AVX512(Op, DAG, Subtarget);

    // In AVX-512 architecture setcc returns mask with i1 elements,
    // But there is no compare instruction for i8 and i16 elements in KNL.
    // We are not talking about 512-bit operands in this case, these
    // types are illegal.
    if (MaskResult &&
        (OpVT.getVectorElementType().getSizeInBits() < 32 &&
         OpVT.getVectorElementType().getSizeInBits() >= 8))
      return DAG.getNode(ISD::TRUNCATE, dl, VT,
                         DAG.getNode(ISD::SETCC, dl, OpVT, Op0, Op1, CC));
  }

  // We are handling one of the integer comparisons here.  Since SSE only has
  // GT and EQ comparisons for integer, swapping operands and multiple
  // operations may be required for some comparisons.
  unsigned Opc;
  bool Swap = false, Invert = false, FlipSigns = false, MinMax = false;
  bool Subus = false;

  switch (SetCCOpcode) {
  default: llvm_unreachable("Unexpected SETCC condition");
  case ISD::SETNE:  Invert = true;
  case ISD::SETEQ:  Opc = X86ISD::PCMPEQ; break;
  case ISD::SETLT:  Swap = true;
  case ISD::SETGT:  Opc = X86ISD::PCMPGT; break;
  case ISD::SETGE:  Swap = true;
  case ISD::SETLE:  Opc = X86ISD::PCMPGT;
                    Invert = true; break;
  case ISD::SETULT: Swap = true;
  case ISD::SETUGT: Opc = X86ISD::PCMPGT;
                    FlipSigns = true; break;
  case ISD::SETUGE: Swap = true;
  case ISD::SETULE: Opc = X86ISD::PCMPGT;
                    FlipSigns = true; Invert = true; break;
  }

  // Special case: Use min/max operations for SETULE/SETUGE
  MVT VET = VT.getVectorElementType();
  bool hasMinMax =
       (Subtarget->hasSSE41() && (VET >= MVT::i8 && VET <= MVT::i32))
    || (Subtarget->hasSSE2()  && (VET == MVT::i8));

  if (hasMinMax) {
    switch (SetCCOpcode) {
    default: break;
    case ISD::SETULE: Opc = X86ISD::UMIN; MinMax = true; break;
    case ISD::SETUGE: Opc = X86ISD::UMAX; MinMax = true; break;
    }

    if (MinMax) { Swap = false; Invert = false; FlipSigns = false; }
  }

  bool hasSubus = Subtarget->hasSSE2() && (VET == MVT::i8 || VET == MVT::i16);
  if (!MinMax && hasSubus) {
    // As another special case, use PSUBUS[BW] when it's profitable. E.g. for
    // Op0 u<= Op1:
    //   t = psubus Op0, Op1
    //   pcmpeq t, <0..0>
    switch (SetCCOpcode) {
    default: break;
    case ISD::SETULT: {
      // If the comparison is against a constant we can turn this into a
      // setule.  With psubus, setule does not require a swap.  This is
      // beneficial because the constant in the register is no longer
      // destructed as the destination so it can be hoisted out of a loop.
      // Only do this pre-AVX since vpcmp* is no longer destructive.
      if (Subtarget->hasAVX())
        break;
      SDValue ULEOp1 = ChangeVSETULTtoVSETULE(dl, Op1, DAG);
      if (ULEOp1.getNode()) {
        Op1 = ULEOp1;
        Subus = true; Invert = false; Swap = false;
      }
      break;
    }
    // Psubus is better than flip-sign because it requires no inversion.
    case ISD::SETUGE: Subus = true; Invert = false; Swap = true;  break;
    case ISD::SETULE: Subus = true; Invert = false; Swap = false; break;
    }

    if (Subus) {
      Opc = X86ISD::SUBUS;
      FlipSigns = false;
    }
  }

  if (Swap)
    std::swap(Op0, Op1);

  // Check that the operation in question is available (most are plain SSE2,
  // but PCMPGTQ and PCMPEQQ have different requirements).
  if (VT == MVT::v2i64) {
    if (Opc == X86ISD::PCMPGT && !Subtarget->hasSSE42()) {
      assert(Subtarget->hasSSE2() && "Don't know how to lower!");

      // First cast everything to the right type.
      Op0 = DAG.getNode(ISD::BITCAST, dl, MVT::v4i32, Op0);
      Op1 = DAG.getNode(ISD::BITCAST, dl, MVT::v4i32, Op1);

      // Since SSE has no unsigned integer comparisons, we need to flip the sign
      // bits of the inputs before performing those operations. The lower
      // compare is always unsigned.
      SDValue SB;
      if (FlipSigns) {
        SB = DAG.getConstant(0x80000000U, MVT::v4i32);
      } else {
        SDValue Sign = DAG.getConstant(0x80000000U, MVT::i32);
        SDValue Zero = DAG.getConstant(0x00000000U, MVT::i32);
        SB = DAG.getNode(ISD::BUILD_VECTOR, dl, MVT::v4i32,
                         Sign, Zero, Sign, Zero);
      }
      Op0 = DAG.getNode(ISD::XOR, dl, MVT::v4i32, Op0, SB);
      Op1 = DAG.getNode(ISD::XOR, dl, MVT::v4i32, Op1, SB);

      // Emulate PCMPGTQ with (hi1 > hi2) | ((hi1 == hi2) & (lo1 > lo2))
      SDValue GT = DAG.getNode(X86ISD::PCMPGT, dl, MVT::v4i32, Op0, Op1);
      SDValue EQ = DAG.getNode(X86ISD::PCMPEQ, dl, MVT::v4i32, Op0, Op1);

      // Create masks for only the low parts/high parts of the 64 bit integers.
      static const int MaskHi[] = { 1, 1, 3, 3 };
      static const int MaskLo[] = { 0, 0, 2, 2 };
      SDValue EQHi = DAG.getVectorShuffle(MVT::v4i32, dl, EQ, EQ, MaskHi);
      SDValue GTLo = DAG.getVectorShuffle(MVT::v4i32, dl, GT, GT, MaskLo);
      SDValue GTHi = DAG.getVectorShuffle(MVT::v4i32, dl, GT, GT, MaskHi);

      SDValue Result = DAG.getNode(ISD::AND, dl, MVT::v4i32, EQHi, GTLo);
      Result = DAG.getNode(ISD::OR, dl, MVT::v4i32, Result, GTHi);

      if (Invert)
        Result = DAG.getNOT(dl, Result, MVT::v4i32);

      return DAG.getNode(ISD::BITCAST, dl, VT, Result);
    }

    if (Opc == X86ISD::PCMPEQ && !Subtarget->hasSSE41()) {
      // If pcmpeqq is missing but pcmpeqd is available synthesize pcmpeqq with
      // pcmpeqd + pshufd + pand.
      assert(Subtarget->hasSSE2() && !FlipSigns && "Don't know how to lower!");

      // First cast everything to the right type.
      Op0 = DAG.getNode(ISD::BITCAST, dl, MVT::v4i32, Op0);
      Op1 = DAG.getNode(ISD::BITCAST, dl, MVT::v4i32, Op1);

      // Do the compare.
      SDValue Result = DAG.getNode(Opc, dl, MVT::v4i32, Op0, Op1);

      // Make sure the lower and upper halves are both all-ones.
      static const int Mask[] = { 1, 0, 3, 2 };
      SDValue Shuf = DAG.getVectorShuffle(MVT::v4i32, dl, Result, Result, Mask);
      Result = DAG.getNode(ISD::AND, dl, MVT::v4i32, Result, Shuf);

      if (Invert)
        Result = DAG.getNOT(dl, Result, MVT::v4i32);

      return DAG.getNode(ISD::BITCAST, dl, VT, Result);
    }
  }

  // Since SSE has no unsigned integer comparisons, we need to flip the sign
  // bits of the inputs before performing those operations.
  if (FlipSigns) {
    EVT EltVT = VT.getVectorElementType();
    SDValue SB = DAG.getConstant(APInt::getSignBit(EltVT.getSizeInBits()), VT);
    Op0 = DAG.getNode(ISD::XOR, dl, VT, Op0, SB);
    Op1 = DAG.getNode(ISD::XOR, dl, VT, Op1, SB);
  }

  SDValue Result = DAG.getNode(Opc, dl, VT, Op0, Op1);

  // If the logical-not of the result is required, perform that now.
  if (Invert)
    Result = DAG.getNOT(dl, Result, VT);

  if (MinMax)
    Result = DAG.getNode(X86ISD::PCMPEQ, dl, VT, Op0, Result);

  if (Subus)
    Result = DAG.getNode(X86ISD::PCMPEQ, dl, VT, Result,
                         getZeroVector(VT, Subtarget, DAG, dl));

  return Result;
}

SDValue X86TargetLowering::LowerSETCC(SDValue Op, SelectionDAG &DAG) const {

  MVT VT = Op.getSimpleValueType();

  if (VT.isVector()) return LowerVSETCC(Op, Subtarget, DAG);

  assert(((!Subtarget->hasAVX512() && VT == MVT::i8) || (VT == MVT::i1))
         && "SetCC type must be 8-bit or 1-bit integer");
  SDValue Op0 = Op.getOperand(0);
  SDValue Op1 = Op.getOperand(1);
  SDLoc dl(Op);
  ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(2))->get();

  // Optimize to BT if possible.
  // Lower (X & (1 << N)) == 0 to BT(X, N).
  // Lower ((X >>u N) & 1) != 0 to BT(X, N).
  // Lower ((X >>s N) & 1) != 0 to BT(X, N).
  if (Op0.getOpcode() == ISD::AND && Op0.hasOneUse() &&
      Op1.getOpcode() == ISD::Constant &&
      cast<ConstantSDNode>(Op1)->isNullValue() &&
      (CC == ISD::SETEQ || CC == ISD::SETNE)) {
    SDValue NewSetCC = LowerToBT(Op0, CC, dl, DAG);
    if (NewSetCC.getNode()) {
      if (VT == MVT::i1)
        return DAG.getNode(ISD::TRUNCATE, dl, MVT::i1, NewSetCC);
      return NewSetCC;
    }
  }

  // Look for X == 0, X == 1, X != 0, or X != 1.  We can simplify some forms of
  // these.
  if (Op1.getOpcode() == ISD::Constant &&
      (cast<ConstantSDNode>(Op1)->getZExtValue() == 1 ||
       cast<ConstantSDNode>(Op1)->isNullValue()) &&
      (CC == ISD::SETEQ || CC == ISD::SETNE)) {

    // If the input is a setcc, then reuse the input setcc or use a new one with
    // the inverted condition.
    if (Op0.getOpcode() == X86ISD::SETCC) {
      X86::CondCode CCode = (X86::CondCode)Op0.getConstantOperandVal(0);
      bool Invert = (CC == ISD::SETNE) ^
        cast<ConstantSDNode>(Op1)->isNullValue();
      if (!Invert)
        return Op0;

      CCode = X86::GetOppositeBranchCondition(CCode);
      SDValue SetCC = DAG.getNode(X86ISD::SETCC, dl, MVT::i8,
                                  DAG.getConstant(CCode, MVT::i8),
                                  Op0.getOperand(1));
      if (VT == MVT::i1)
        return DAG.getNode(ISD::TRUNCATE, dl, MVT::i1, SetCC);
      return SetCC;
    }
  }
  if ((Op0.getValueType() == MVT::i1) && (Op1.getOpcode() == ISD::Constant) &&
      (cast<ConstantSDNode>(Op1)->getZExtValue() == 1) &&
      (CC == ISD::SETEQ || CC == ISD::SETNE)) {

    ISD::CondCode NewCC = ISD::getSetCCInverse(CC, true);
    return DAG.getSetCC(dl, VT, Op0, DAG.getConstant(0, MVT::i1), NewCC);
  }

  bool isFP = Op1.getSimpleValueType().isFloatingPoint();
  unsigned X86CC = TranslateX86CC(CC, isFP, Op0, Op1, DAG);
  if (X86CC == X86::COND_INVALID)
    return SDValue();

  SDValue EFLAGS = EmitCmp(Op0, Op1, X86CC, dl, DAG);
  EFLAGS = ConvertCmpIfNecessary(EFLAGS, DAG);
  SDValue SetCC = DAG.getNode(X86ISD::SETCC, dl, MVT::i8,
                              DAG.getConstant(X86CC, MVT::i8), EFLAGS);
  if (VT == MVT::i1)
    return DAG.getNode(ISD::TRUNCATE, dl, MVT::i1, SetCC);
  return SetCC;
}

// isX86LogicalCmp - Return true if opcode is a X86 logical comparison.
static bool isX86LogicalCmp(SDValue Op) {
  unsigned Opc = Op.getNode()->getOpcode();
  if (Opc == X86ISD::CMP || Opc == X86ISD::COMI || Opc == X86ISD::UCOMI ||
      Opc == X86ISD::SAHF)
    return true;
  if (Op.getResNo() == 1 &&
      (Opc == X86ISD::ADD ||
       Opc == X86ISD::SUB ||
       Opc == X86ISD::ADC ||
       Opc == X86ISD::SBB ||
       Opc == X86ISD::SMUL ||
       Opc == X86ISD::UMUL ||
       Opc == X86ISD::INC ||
       Opc == X86ISD::DEC ||
       Opc == X86ISD::OR ||
       Opc == X86ISD::XOR ||
       Opc == X86ISD::AND))
    return true;

  if (Op.getResNo() == 2 && Opc == X86ISD::UMUL)
    return true;

  return false;
}

static bool isTruncWithZeroHighBitsInput(SDValue V, SelectionDAG &DAG) {
  if (V.getOpcode() != ISD::TRUNCATE)
    return false;

  SDValue VOp0 = V.getOperand(0);
  unsigned InBits = VOp0.getValueSizeInBits();
  unsigned Bits = V.getValueSizeInBits();
  return DAG.MaskedValueIsZero(VOp0, APInt::getHighBitsSet(InBits,InBits-Bits));
}

SDValue X86TargetLowering::LowerSELECT(SDValue Op, SelectionDAG &DAG) const {
  bool addTest = true;
  SDValue Cond  = Op.getOperand(0);
  SDValue Op1 = Op.getOperand(1);
  SDValue Op2 = Op.getOperand(2);
  SDLoc DL(Op);
  EVT VT = Op1.getValueType();
  SDValue CC;

  // Lower fp selects into a CMP/AND/ANDN/OR sequence when the necessary SSE ops
  // are available. Otherwise fp cmovs get lowered into a less efficient branch
  // sequence later on.
  if (Cond.getOpcode() == ISD::SETCC &&
      ((Subtarget->hasSSE2() && (VT == MVT::f32 || VT == MVT::f64)) ||
       (Subtarget->hasSSE1() && VT == MVT::f32)) &&
      VT == Cond.getOperand(0).getValueType() && Cond->hasOneUse()) {
    SDValue CondOp0 = Cond.getOperand(0), CondOp1 = Cond.getOperand(1);
    int SSECC = translateX86FSETCC(
        cast<CondCodeSDNode>(Cond.getOperand(2))->get(), CondOp0, CondOp1);

    if (SSECC != 8) {
      if (Subtarget->hasAVX512()) {
        SDValue Cmp = DAG.getNode(X86ISD::FSETCC, DL, MVT::i1, CondOp0, CondOp1,
                                  DAG.getConstant(SSECC, MVT::i8));
        return DAG.getNode(X86ISD::SELECT, DL, VT, Cmp, Op1, Op2);
      }
      SDValue Cmp = DAG.getNode(X86ISD::FSETCC, DL, VT, CondOp0, CondOp1,
                                DAG.getConstant(SSECC, MVT::i8));
      SDValue AndN = DAG.getNode(X86ISD::FANDN, DL, VT, Cmp, Op2);
      SDValue And = DAG.getNode(X86ISD::FAND, DL, VT, Cmp, Op1);
      return DAG.getNode(X86ISD::FOR, DL, VT, AndN, And);
    }
  }

  if (Cond.getOpcode() == ISD::SETCC) {
    SDValue NewCond = LowerSETCC(Cond, DAG);
    if (NewCond.getNode())
      Cond = NewCond;
  }

  // (select (x == 0), -1, y) -> (sign_bit (x - 1)) | y
  // (select (x == 0), y, -1) -> ~(sign_bit (x - 1)) | y
  // (select (x != 0), y, -1) -> (sign_bit (x - 1)) | y
  // (select (x != 0), -1, y) -> ~(sign_bit (x - 1)) | y
  if (Cond.getOpcode() == X86ISD::SETCC &&
      Cond.getOperand(1).getOpcode() == X86ISD::CMP &&
      isZero(Cond.getOperand(1).getOperand(1))) {
    SDValue Cmp = Cond.getOperand(1);

    unsigned CondCode =cast<ConstantSDNode>(Cond.getOperand(0))->getZExtValue();

    if ((isAllOnes(Op1) || isAllOnes(Op2)) &&
        (CondCode == X86::COND_E || CondCode == X86::COND_NE)) {
      SDValue Y = isAllOnes(Op2) ? Op1 : Op2;

      SDValue CmpOp0 = Cmp.getOperand(0);
      // Apply further optimizations for special cases
      // (select (x != 0), -1, 0) -> neg & sbb
      // (select (x == 0), 0, -1) -> neg & sbb
      if (ConstantSDNode *YC = dyn_cast<ConstantSDNode>(Y))
        if (YC->isNullValue() &&
            (isAllOnes(Op1) == (CondCode == X86::COND_NE))) {
          SDVTList VTs = DAG.getVTList(CmpOp0.getValueType(), MVT::i32);
          SDValue Neg = DAG.getNode(X86ISD::SUB, DL, VTs,
                                    DAG.getConstant(0, CmpOp0.getValueType()),
                                    CmpOp0);
          SDValue Res = DAG.getNode(X86ISD::SETCC_CARRY, DL, Op.getValueType(),
                                    DAG.getConstant(X86::COND_B, MVT::i8),
                                    SDValue(Neg.getNode(), 1));
          return Res;
        }

      Cmp = DAG.getNode(X86ISD::CMP, DL, MVT::i32,
                        CmpOp0, DAG.getConstant(1, CmpOp0.getValueType()));
      Cmp = ConvertCmpIfNecessary(Cmp, DAG);

      SDValue Res =   // Res = 0 or -1.
        DAG.getNode(X86ISD::SETCC_CARRY, DL, Op.getValueType(),
                    DAG.getConstant(X86::COND_B, MVT::i8), Cmp);

      if (isAllOnes(Op1) != (CondCode == X86::COND_E))
        Res = DAG.getNOT(DL, Res, Res.getValueType());

      ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(Op2);
      if (!N2C || !N2C->isNullValue())
        Res = DAG.getNode(ISD::OR, DL, Res.getValueType(), Res, Y);
      return Res;
    }
  }

  // Look past (and (setcc_carry (cmp ...)), 1).
  if (Cond.getOpcode() == ISD::AND &&
      Cond.getOperand(0).getOpcode() == X86ISD::SETCC_CARRY) {
    ConstantSDNode *C = dyn_cast<ConstantSDNode>(Cond.getOperand(1));
    if (C && C->getAPIntValue() == 1)
      Cond = Cond.getOperand(0);
  }

  // If condition flag is set by a X86ISD::CMP, then use it as the condition
  // setting operand in place of the X86ISD::SETCC.
  unsigned CondOpcode = Cond.getOpcode();
  if (CondOpcode == X86ISD::SETCC ||
      CondOpcode == X86ISD::SETCC_CARRY) {
    CC = Cond.getOperand(0);

    SDValue Cmp = Cond.getOperand(1);
    unsigned Opc = Cmp.getOpcode();
    MVT VT = Op.getSimpleValueType();

    bool IllegalFPCMov = false;
    if (VT.isFloatingPoint() && !VT.isVector() &&
        !isScalarFPTypeInSSEReg(VT))  // FPStack?
      IllegalFPCMov = !hasFPCMov(cast<ConstantSDNode>(CC)->getSExtValue());

    if ((isX86LogicalCmp(Cmp) && !IllegalFPCMov) ||
        Opc == X86ISD::BT) { // FIXME
      Cond = Cmp;
      addTest = false;
    }
  } else if (CondOpcode == ISD::USUBO || CondOpcode == ISD::SSUBO ||
             CondOpcode == ISD::UADDO || CondOpcode == ISD::SADDO ||
             ((CondOpcode == ISD::UMULO || CondOpcode == ISD::SMULO) &&
              Cond.getOperand(0).getValueType() != MVT::i8)) {
    SDValue LHS = Cond.getOperand(0);
    SDValue RHS = Cond.getOperand(1);
    unsigned X86Opcode;
    unsigned X86Cond;
    SDVTList VTs;
    switch (CondOpcode) {
    case ISD::UADDO: X86Opcode = X86ISD::ADD; X86Cond = X86::COND_B; break;
    case ISD::SADDO: X86Opcode = X86ISD::ADD; X86Cond = X86::COND_O; break;
    case ISD::USUBO: X86Opcode = X86ISD::SUB; X86Cond = X86::COND_B; break;
    case ISD::SSUBO: X86Opcode = X86ISD::SUB; X86Cond = X86::COND_O; break;
    case ISD::UMULO: X86Opcode = X86ISD::UMUL; X86Cond = X86::COND_O; break;
    case ISD::SMULO: X86Opcode = X86ISD::SMUL; X86Cond = X86::COND_O; break;
    default: llvm_unreachable("unexpected overflowing operator");
    }
    if (CondOpcode == ISD::UMULO)
      VTs = DAG.getVTList(LHS.getValueType(), LHS.getValueType(),
                          MVT::i32);
    else
      VTs = DAG.getVTList(LHS.getValueType(), MVT::i32);

    SDValue X86Op = DAG.getNode(X86Opcode, DL, VTs, LHS, RHS);

    if (CondOpcode == ISD::UMULO)
      Cond = X86Op.getValue(2);
    else
      Cond = X86Op.getValue(1);

    CC = DAG.getConstant(X86Cond, MVT::i8);
    addTest = false;
  }

  if (addTest) {
    // Look pass the truncate if the high bits are known zero.
    if (isTruncWithZeroHighBitsInput(Cond, DAG))
        Cond = Cond.getOperand(0);

    // We know the result of AND is compared against zero. Try to match
    // it to BT.
    if (Cond.getOpcode() == ISD::AND && Cond.hasOneUse()) {
      SDValue NewSetCC = LowerToBT(Cond, ISD::SETNE, DL, DAG);
      if (NewSetCC.getNode()) {
        CC = NewSetCC.getOperand(0);
        Cond = NewSetCC.getOperand(1);
        addTest = false;
      }
    }
  }

  if (addTest) {
    CC = DAG.getConstant(X86::COND_NE, MVT::i8);
    Cond = EmitTest(Cond, X86::COND_NE, DL, DAG);
  }

  // a <  b ? -1 :  0 -> RES = ~setcc_carry
  // a <  b ?  0 : -1 -> RES = setcc_carry
  // a >= b ? -1 :  0 -> RES = setcc_carry
  // a >= b ?  0 : -1 -> RES = ~setcc_carry
  if (Cond.getOpcode() == X86ISD::SUB) {
    Cond = ConvertCmpIfNecessary(Cond, DAG);
    unsigned CondCode = cast<ConstantSDNode>(CC)->getZExtValue();

    if ((CondCode == X86::COND_AE || CondCode == X86::COND_B) &&
        (isAllOnes(Op1) || isAllOnes(Op2)) && (isZero(Op1) || isZero(Op2))) {
      SDValue Res = DAG.getNode(X86ISD::SETCC_CARRY, DL, Op.getValueType(),
                                DAG.getConstant(X86::COND_B, MVT::i8), Cond);
      if (isAllOnes(Op1) != (CondCode == X86::COND_B))
        return DAG.getNOT(DL, Res, Res.getValueType());
      return Res;
    }
  }

  // X86 doesn't have an i8 cmov. If both operands are the result of a truncate
  // widen the cmov and push the truncate through. This avoids introducing a new
  // branch during isel and doesn't add any extensions.
  if (Op.getValueType() == MVT::i8 &&
      Op1.getOpcode() == ISD::TRUNCATE && Op2.getOpcode() == ISD::TRUNCATE) {
    SDValue T1 = Op1.getOperand(0), T2 = Op2.getOperand(0);
    if (T1.getValueType() == T2.getValueType() &&
        // Blacklist CopyFromReg to avoid partial register stalls.
        T1.getOpcode() != ISD::CopyFromReg && T2.getOpcode()!=ISD::CopyFromReg){
      SDVTList VTs = DAG.getVTList(T1.getValueType(), MVT::Glue);
      SDValue Cmov = DAG.getNode(X86ISD::CMOV, DL, VTs, T2, T1, CC, Cond);
      return DAG.getNode(ISD::TRUNCATE, DL, Op.getValueType(), Cmov);
    }
  }

  // X86ISD::CMOV means set the result (which is operand 1) to the RHS if
  // condition is true.
  SDVTList VTs = DAG.getVTList(Op.getValueType(), MVT::Glue);
  SDValue Ops[] = { Op2, Op1, CC, Cond };
  return DAG.getNode(X86ISD::CMOV, DL, VTs, Ops);
}

static SDValue LowerSIGN_EXTEND_AVX512(SDValue Op, const X86Subtarget *Subtarget,
                                       SelectionDAG &DAG) {
  MVT VT = Op->getSimpleValueType(0);
  SDValue In = Op->getOperand(0);
  MVT InVT = In.getSimpleValueType();
  MVT VTElt = VT.getVectorElementType();
  MVT InVTElt = InVT.getVectorElementType();
  SDLoc dl(Op);

  // SKX processor
  if ((InVTElt == MVT::i1) &&
      (((Subtarget->hasBWI() && Subtarget->hasVLX() &&
        VT.getSizeInBits() <= 256 && VTElt.getSizeInBits() <= 16)) ||

       ((Subtarget->hasBWI() && VT.is512BitVector() &&
        VTElt.getSizeInBits() <= 16)) ||

       ((Subtarget->hasDQI() && Subtarget->hasVLX() &&
        VT.getSizeInBits() <= 256 && VTElt.getSizeInBits() >= 32)) ||

       ((Subtarget->hasDQI() && VT.is512BitVector() &&
        VTElt.getSizeInBits() >= 32))))
    return DAG.getNode(X86ISD::VSEXT, dl, VT, In);

  unsigned int NumElts = VT.getVectorNumElements();

  if (NumElts != 8 && NumElts != 16)
    return SDValue();

  if (VT.is512BitVector() && InVT.getVectorElementType() != MVT::i1) {
    if (In.getOpcode() == X86ISD::VSEXT || In.getOpcode() == X86ISD::VZEXT)
      return DAG.getNode(In.getOpcode(), dl, VT, In.getOperand(0));
    return DAG.getNode(X86ISD::VSEXT, dl, VT, In);
  }

  const TargetLowering &TLI = DAG.getTargetLoweringInfo();
  assert (InVT.getVectorElementType() == MVT::i1 && "Unexpected vector type");

  MVT ExtVT = (NumElts == 8) ? MVT::v8i64 : MVT::v16i32;
  Constant *C = ConstantInt::get(*DAG.getContext(),
    APInt::getAllOnesValue(ExtVT.getScalarType().getSizeInBits()));

  SDValue CP = DAG.getConstantPool(C, TLI.getPointerTy());
  unsigned Alignment = cast<ConstantPoolSDNode>(CP)->getAlignment();
  SDValue Ld = DAG.getLoad(ExtVT.getScalarType(), dl, DAG.getEntryNode(), CP,
                          MachinePointerInfo::getConstantPool(),
                          false, false, false, Alignment);
  SDValue Brcst = DAG.getNode(X86ISD::VBROADCASTM, dl, ExtVT, In, Ld);
  if (VT.is512BitVector())
    return Brcst;
  return DAG.getNode(X86ISD::VTRUNC, dl, VT, Brcst);
}

static SDValue LowerSIGN_EXTEND(SDValue Op, const X86Subtarget *Subtarget,
                                SelectionDAG &DAG) {
  MVT VT = Op->getSimpleValueType(0);
  SDValue In = Op->getOperand(0);
  MVT InVT = In.getSimpleValueType();
  SDLoc dl(Op);

  if (VT.is512BitVector() || InVT.getVectorElementType() == MVT::i1)
    return LowerSIGN_EXTEND_AVX512(Op, Subtarget, DAG);

  if ((VT != MVT::v4i64 || InVT != MVT::v4i32) &&
      (VT != MVT::v8i32 || InVT != MVT::v8i16) &&
      (VT != MVT::v16i16 || InVT != MVT::v16i8))
    return SDValue();

  if (Subtarget->hasInt256())
    return DAG.getNode(X86ISD::VSEXT, dl, VT, In);

  // Optimize vectors in AVX mode
  // Sign extend  v8i16 to v8i32 and
  //              v4i32 to v4i64
  //
  // Divide input vector into two parts
  // for v4i32 the shuffle mask will be { 0, 1, -1, -1} {2, 3, -1, -1}
  // use vpmovsx instruction to extend v4i32 -> v2i64; v8i16 -> v4i32
  // concat the vectors to original VT

  unsigned NumElems = InVT.getVectorNumElements();
  SDValue Undef = DAG.getUNDEF(InVT);

  SmallVector<int,8> ShufMask1(NumElems, -1);
  for (unsigned i = 0; i != NumElems/2; ++i)
    ShufMask1[i] = i;

  SDValue OpLo = DAG.getVectorShuffle(InVT, dl, In, Undef, &ShufMask1[0]);

  SmallVector<int,8> ShufMask2(NumElems, -1);
  for (unsigned i = 0; i != NumElems/2; ++i)
    ShufMask2[i] = i + NumElems/2;

  SDValue OpHi = DAG.getVectorShuffle(InVT, dl, In, Undef, &ShufMask2[0]);

  MVT HalfVT = MVT::getVectorVT(VT.getScalarType(),
                                VT.getVectorNumElements()/2);

  OpLo = DAG.getNode(X86ISD::VSEXT, dl, HalfVT, OpLo);
  OpHi = DAG.getNode(X86ISD::VSEXT, dl, HalfVT, OpHi);

  return DAG.getNode(ISD::CONCAT_VECTORS, dl, VT, OpLo, OpHi);
}

// Lower vector extended loads using a shuffle. If SSSE3 is not available we
// may emit an illegal shuffle but the expansion is still better than scalar
// code. We generate X86ISD::VSEXT for SEXTLOADs if it's available, otherwise
// we'll emit a shuffle and a arithmetic shift.
// FIXME: Is the expansion actually better than scalar code? It doesn't seem so.
// TODO: It is possible to support ZExt by zeroing the undef values during
// the shuffle phase or after the shuffle.
static SDValue LowerExtendedLoad(SDValue Op, const X86Subtarget *Subtarget,
                                 SelectionDAG &DAG) {
  MVT RegVT = Op.getSimpleValueType();
  assert(RegVT.isVector() && "We only custom lower vector sext loads.");
  assert(RegVT.isInteger() &&
         "We only custom lower integer vector sext loads.");

  // Nothing useful we can do without SSE2 shuffles.
  assert(Subtarget->hasSSE2() && "We only custom lower sext loads with SSE2.");

  LoadSDNode *Ld = cast<LoadSDNode>(Op.getNode());
  SDLoc dl(Ld);
  EVT MemVT = Ld->getMemoryVT();
  const TargetLowering &TLI = DAG.getTargetLoweringInfo();
  unsigned RegSz = RegVT.getSizeInBits();

  ISD::LoadExtType Ext = Ld->getExtensionType();

  assert((Ext == ISD::EXTLOAD || Ext == ISD::SEXTLOAD)
         && "Only anyext and sext are currently implemented.");
  assert(MemVT != RegVT && "Cannot extend to the same type");
  assert(MemVT.isVector() && "Must load a vector from memory");

  unsigned NumElems = RegVT.getVectorNumElements();
  unsigned MemSz = MemVT.getSizeInBits();
  assert(RegSz > MemSz && "Register size must be greater than the mem size");

  if (Ext == ISD::SEXTLOAD && RegSz == 256 && !Subtarget->hasInt256()) {
    // The only way in which we have a legal 256-bit vector result but not the
    // integer 256-bit operations needed to directly lower a sextload is if we
    // have AVX1 but not AVX2. In that case, we can always emit a sextload to
    // a 128-bit vector and a normal sign_extend to 256-bits that should get
    // correctly legalized. We do this late to allow the canonical form of
    // sextload to persist throughout the rest of the DAG combiner -- it wants
    // to fold together any extensions it can, and so will fuse a sign_extend
    // of an sextload into a sextload targeting a wider value.
    SDValue Load;
    if (MemSz == 128) {
      // Just switch this to a normal load.
      assert(TLI.isTypeLegal(MemVT) && "If the memory type is a 128-bit type, "
                                       "it must be a legal 128-bit vector "
                                       "type!");
      Load = DAG.getLoad(MemVT, dl, Ld->getChain(), Ld->getBasePtr(),
                  Ld->getPointerInfo(), Ld->isVolatile(), Ld->isNonTemporal(),
                  Ld->isInvariant(), Ld->getAlignment());
    } else {
      assert(MemSz < 128 &&
             "Can't extend a type wider than 128 bits to a 256 bit vector!");
      // Do an sext load to a 128-bit vector type. We want to use the same
      // number of elements, but elements half as wide. This will end up being
      // recursively lowered by this routine, but will succeed as we definitely
      // have all the necessary features if we're using AVX1.
      EVT HalfEltVT =
          EVT::getIntegerVT(*DAG.getContext(), RegVT.getScalarSizeInBits() / 2);
      EVT HalfVecVT = EVT::getVectorVT(*DAG.getContext(), HalfEltVT, NumElems);
      Load =
          DAG.getExtLoad(Ext, dl, HalfVecVT, Ld->getChain(), Ld->getBasePtr(),
                         Ld->getPointerInfo(), MemVT, Ld->isVolatile(),
                         Ld->isNonTemporal(), Ld->isInvariant(),
                         Ld->getAlignment());
    }

    // Replace chain users with the new chain.
    assert(Load->getNumValues() == 2 && "Loads must carry a chain!");
    DAG.ReplaceAllUsesOfValueWith(SDValue(Ld, 1), Load.getValue(1));

    // Finally, do a normal sign-extend to the desired register.
    return DAG.getSExtOrTrunc(Load, dl, RegVT);
  }

  // All sizes must be a power of two.
  assert(isPowerOf2_32(RegSz * MemSz * NumElems) &&
         "Non-power-of-two elements are not custom lowered!");

  // Attempt to load the original value using scalar loads.
  // Find the largest scalar type that divides the total loaded size.
  MVT SclrLoadTy = MVT::i8;
  for (MVT Tp : MVT::integer_valuetypes()) {
    if (TLI.isTypeLegal(Tp) && ((MemSz % Tp.getSizeInBits()) == 0)) {
      SclrLoadTy = Tp;
    }
  }

  // On 32bit systems, we can't save 64bit integers. Try bitcasting to F64.
  if (TLI.isTypeLegal(MVT::f64) && SclrLoadTy.getSizeInBits() < 64 &&
      (64 <= MemSz))
    SclrLoadTy = MVT::f64;

  // Calculate the number of scalar loads that we need to perform
  // in order to load our vector from memory.
  unsigned NumLoads = MemSz / SclrLoadTy.getSizeInBits();

  assert((Ext != ISD::SEXTLOAD || NumLoads == 1) &&
         "Can only lower sext loads with a single scalar load!");

  unsigned loadRegZize = RegSz;
  if (Ext == ISD::SEXTLOAD && RegSz == 256)
    loadRegZize /= 2;

  // Represent our vector as a sequence of elements which are the
  // largest scalar that we can load.
  EVT LoadUnitVecVT = EVT::getVectorVT(
      *DAG.getContext(), SclrLoadTy, loadRegZize / SclrLoadTy.getSizeInBits());

  // Represent the data using the same element type that is stored in
  // memory. In practice, we ''widen'' MemVT.
  EVT WideVecVT =
      EVT::getVectorVT(*DAG.getContext(), MemVT.getScalarType(),
                       loadRegZize / MemVT.getScalarType().getSizeInBits());

  assert(WideVecVT.getSizeInBits() == LoadUnitVecVT.getSizeInBits() &&
         "Invalid vector type");

  // We can't shuffle using an illegal type.
  assert(TLI.isTypeLegal(WideVecVT) &&
         "We only lower types that form legal widened vector types");

  SmallVector<SDValue, 8> Chains;
  SDValue Ptr = Ld->getBasePtr();
  SDValue Increment =
      DAG.getConstant(SclrLoadTy.getSizeInBits() / 8, TLI.getPointerTy());
  SDValue Res = DAG.getUNDEF(LoadUnitVecVT);

  for (unsigned i = 0; i < NumLoads; ++i) {
    // Perform a single load.
    SDValue ScalarLoad =
        DAG.getLoad(SclrLoadTy, dl, Ld->getChain(), Ptr, Ld->getPointerInfo(),
                    Ld->isVolatile(), Ld->isNonTemporal(), Ld->isInvariant(),
                    Ld->getAlignment());
    Chains.push_back(ScalarLoad.getValue(1));
    // Create the first element type using SCALAR_TO_VECTOR in order to avoid
    // another round of DAGCombining.
    if (i == 0)
      Res = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, LoadUnitVecVT, ScalarLoad);
    else
      Res = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, LoadUnitVecVT, Res,
                        ScalarLoad, DAG.getIntPtrConstant(i));

    Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr, Increment);
  }

  SDValue TF = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Chains);

  // Bitcast the loaded value to a vector of the original element type, in
  // the size of the target vector type.
  SDValue SlicedVec = DAG.getNode(ISD::BITCAST, dl, WideVecVT, Res);
  unsigned SizeRatio = RegSz / MemSz;

  if (Ext == ISD::SEXTLOAD) {
    // If we have SSE4.1, we can directly emit a VSEXT node.
    if (Subtarget->hasSSE41()) {
      SDValue Sext = DAG.getNode(X86ISD::VSEXT, dl, RegVT, SlicedVec);
      DAG.ReplaceAllUsesOfValueWith(SDValue(Ld, 1), TF);
      return Sext;
    }

    // Otherwise we'll shuffle the small elements in the high bits of the
    // larger type and perform an arithmetic shift. If the shift is not legal
    // it's better to scalarize.
    assert(TLI.isOperationLegalOrCustom(ISD::SRA, RegVT) &&
           "We can't implement a sext load without an arithmetic right shift!");

    // Redistribute the loaded elements into the different locations.
    SmallVector<int, 16> ShuffleVec(NumElems * SizeRatio, -1);
    for (unsigned i = 0; i != NumElems; ++i)
      ShuffleVec[i * SizeRatio + SizeRatio - 1] = i;

    SDValue Shuff = DAG.getVectorShuffle(
        WideVecVT, dl, SlicedVec, DAG.getUNDEF(WideVecVT), &ShuffleVec[0]);

    Shuff = DAG.getNode(ISD::BITCAST, dl, RegVT, Shuff);

    // Build the arithmetic shift.
    unsigned Amt = RegVT.getVectorElementType().getSizeInBits() -
                   MemVT.getVectorElementType().getSizeInBits();
    Shuff =
        DAG.getNode(ISD::SRA, dl, RegVT, Shuff, DAG.getConstant(Amt, RegVT));

    DAG.ReplaceAllUsesOfValueWith(SDValue(Ld, 1), TF);
    return Shuff;
  }

  // Redistribute the loaded elements into the different locations.
  SmallVector<int, 16> ShuffleVec(NumElems * SizeRatio, -1);
  for (unsigned i = 0; i != NumElems; ++i)
    ShuffleVec[i * SizeRatio] = i;

  SDValue Shuff = DAG.getVectorShuffle(WideVecVT, dl, SlicedVec,
                                       DAG.getUNDEF(WideVecVT), &ShuffleVec[0]);

  // Bitcast to the requested type.
  Shuff = DAG.getNode(ISD::BITCAST, dl, RegVT, Shuff);
  DAG.ReplaceAllUsesOfValueWith(SDValue(Ld, 1), TF);
  return Shuff;
}

// isAndOrOfSingleUseSetCCs - Return true if node is an ISD::AND or
// ISD::OR of two X86ISD::SETCC nodes each of which has no other use apart
// from the AND / OR.
static bool isAndOrOfSetCCs(SDValue Op, unsigned &Opc) {
  Opc = Op.getOpcode();
  if (Opc != ISD::OR && Opc != ISD::AND)
    return false;
  return (Op.getOperand(0).getOpcode() == X86ISD::SETCC &&
          Op.getOperand(0).hasOneUse() &&
          Op.getOperand(1).getOpcode() == X86ISD::SETCC &&
          Op.getOperand(1).hasOneUse());
}

// isXor1OfSetCC - Return true if node is an ISD::XOR of a X86ISD::SETCC and
// 1 and that the SETCC node has a single use.
static bool isXor1OfSetCC(SDValue Op) {
  if (Op.getOpcode() != ISD::XOR)
    return false;
  ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(Op.getOperand(1));
  if (N1C && N1C->getAPIntValue() == 1) {
    return Op.getOperand(0).getOpcode() == X86ISD::SETCC &&
      Op.getOperand(0).hasOneUse();
  }
  return false;
}

SDValue X86TargetLowering::LowerBRCOND(SDValue Op, SelectionDAG &DAG) const {
  bool addTest = true;
  SDValue Chain = Op.getOperand(0);
  SDValue Cond  = Op.getOperand(1);
  SDValue Dest  = Op.getOperand(2);
  SDLoc dl(Op);
  SDValue CC;
  bool Inverted = false;

  if (Cond.getOpcode() == ISD::SETCC) {
    // Check for setcc([su]{add,sub,mul}o == 0).
    if (cast<CondCodeSDNode>(Cond.getOperand(2))->get() == ISD::SETEQ &&
        isa<ConstantSDNode>(Cond.getOperand(1)) &&
        cast<ConstantSDNode>(Cond.getOperand(1))->isNullValue() &&
        Cond.getOperand(0).getResNo() == 1 &&
        (Cond.getOperand(0).getOpcode() == ISD::SADDO ||
         Cond.getOperand(0).getOpcode() == ISD::UADDO ||
         Cond.getOperand(0).getOpcode() == ISD::SSUBO ||
         Cond.getOperand(0).getOpcode() == ISD::USUBO ||
         Cond.getOperand(0).getOpcode() == ISD::SMULO ||
         Cond.getOperand(0).getOpcode() == ISD::UMULO)) {
      Inverted = true;
      Cond = Cond.getOperand(0);
    } else {
      SDValue NewCond = LowerSETCC(Cond, DAG);
      if (NewCond.getNode())
        Cond = NewCond;
    }
  }
#if 0
  // FIXME: LowerXALUO doesn't handle these!!
  else if (Cond.getOpcode() == X86ISD::ADD  ||
           Cond.getOpcode() == X86ISD::SUB  ||
           Cond.getOpcode() == X86ISD::SMUL ||
           Cond.getOpcode() == X86ISD::UMUL)
    Cond = LowerXALUO(Cond, DAG);
#endif

  // Look pass (and (setcc_carry (cmp ...)), 1).
  if (Cond.getOpcode() == ISD::AND &&
      Cond.getOperand(0).getOpcode() == X86ISD::SETCC_CARRY) {
    ConstantSDNode *C = dyn_cast<ConstantSDNode>(Cond.getOperand(1));
    if (C && C->getAPIntValue() == 1)
      Cond = Cond.getOperand(0);
  }

  // If condition flag is set by a X86ISD::CMP, then use it as the condition
  // setting operand in place of the X86ISD::SETCC.
  unsigned CondOpcode = Cond.getOpcode();
  if (CondOpcode == X86ISD::SETCC ||
      CondOpcode == X86ISD::SETCC_CARRY) {
    CC = Cond.getOperand(0);

    SDValue Cmp = Cond.getOperand(1);
    unsigned Opc = Cmp.getOpcode();
    // FIXME: WHY THE SPECIAL CASING OF LogicalCmp??
    if (isX86LogicalCmp(Cmp) || Opc == X86ISD::BT) {
      Cond = Cmp;
      addTest = false;
    } else {
      switch (cast<ConstantSDNode>(CC)->getZExtValue()) {
      default: break;
      case X86::COND_O:
      case X86::COND_B:
        // These can only come from an arithmetic instruction with overflow,
        // e.g. SADDO, UADDO.
        Cond = Cond.getNode()->getOperand(1);
        addTest = false;
        break;
      }
    }
  }
  CondOpcode = Cond.getOpcode();
  if (CondOpcode == ISD::UADDO || CondOpcode == ISD::SADDO ||
      CondOpcode == ISD::USUBO || CondOpcode == ISD::SSUBO ||
      ((CondOpcode == ISD::UMULO || CondOpcode == ISD::SMULO) &&
       Cond.getOperand(0).getValueType() != MVT::i8)) {
    SDValue LHS = Cond.getOperand(0);
    SDValue RHS = Cond.getOperand(1);
    unsigned X86Opcode;
    unsigned X86Cond;
    SDVTList VTs;
    // Keep this in sync with LowerXALUO, otherwise we might create redundant
    // instructions that can't be removed afterwards (i.e. X86ISD::ADD and
    // X86ISD::INC).
    switch (CondOpcode) {
    case ISD::UADDO: X86Opcode = X86ISD::ADD; X86Cond = X86::COND_B; break;
    case ISD::SADDO:
      if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(RHS))
        if (C->isOne()) {
          X86Opcode = X86ISD::INC; X86Cond = X86::COND_O;
          break;
        }
      X86Opcode = X86ISD::ADD; X86Cond = X86::COND_O; break;
    case ISD::USUBO: X86Opcode = X86ISD::SUB; X86Cond = X86::COND_B; break;
    case ISD::SSUBO:
      if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(RHS))
        if (C->isOne()) {
          X86Opcode = X86ISD::DEC; X86Cond = X86::COND_O;
          break;
        }
      X86Opcode = X86ISD::SUB; X86Cond = X86::COND_O; break;
    case ISD::UMULO: X86Opcode = X86ISD::UMUL; X86Cond = X86::COND_O; break;
    case ISD::SMULO: X86Opcode = X86ISD::SMUL; X86Cond = X86::COND_O; break;
    default: llvm_unreachable("unexpected overflowing operator");
    }
    if (Inverted)
      X86Cond = X86::GetOppositeBranchCondition((X86::CondCode)X86Cond);
    if (CondOpcode == ISD::UMULO)
      VTs = DAG.getVTList(LHS.getValueType(), LHS.getValueType(),
                          MVT::i32);
    else
      VTs = DAG.getVTList(LHS.getValueType(), MVT::i32);

    SDValue X86Op = DAG.getNode(X86Opcode, dl, VTs, LHS, RHS);

    if (CondOpcode == ISD::UMULO)
      Cond = X86Op.getValue(2);
    else
      Cond = X86Op.getValue(1);

    CC = DAG.getConstant(X86Cond, MVT::i8);
    addTest = false;
  } else {
    unsigned CondOpc;
    if (Cond.hasOneUse() && isAndOrOfSetCCs(Cond, CondOpc)) {
      SDValue Cmp = Cond.getOperand(0).getOperand(1);
      if (CondOpc == ISD::OR) {
        // Also, recognize the pattern generated by an FCMP_UNE. We can emit
        // two branches instead of an explicit OR instruction with a
        // separate test.
        if (Cmp == Cond.getOperand(1).getOperand(1) &&
            isX86LogicalCmp(Cmp)) {
          CC = Cond.getOperand(0).getOperand(0);
          Chain = DAG.getNode(X86ISD::BRCOND, dl, Op.getValueType(),
                              Chain, Dest, CC, Cmp);
          CC = Cond.getOperand(1).getOperand(0);
          Cond = Cmp;
          addTest = false;
        }
      } else { // ISD::AND
        // Also, recognize the pattern generated by an FCMP_OEQ. We can emit
        // two branches instead of an explicit AND instruction with a
        // separate test. However, we only do this if this block doesn't
        // have a fall-through edge, because this requires an explicit
        // jmp when the condition is false.
        if (Cmp == Cond.getOperand(1).getOperand(1) &&
            isX86LogicalCmp(Cmp) &&
            Op.getNode()->hasOneUse()) {
          X86::CondCode CCode =
            (X86::CondCode)Cond.getOperand(0).getConstantOperandVal(0);
          CCode = X86::GetOppositeBranchCondition(CCode);
          CC = DAG.getConstant(CCode, MVT::i8);
          SDNode *User = *Op.getNode()->use_begin();
          // Look for an unconditional branch following this conditional branch.
          // We need this because we need to reverse the successors in order
          // to implement FCMP_OEQ.
          if (User->getOpcode() == ISD::BR) {
            SDValue FalseBB = User->getOperand(1);
            SDNode *NewBR =
              DAG.UpdateNodeOperands(User, User->getOperand(0), Dest);
            assert(NewBR == User);
            (void)NewBR;
            Dest = FalseBB;

            Chain = DAG.getNode(X86ISD::BRCOND, dl, Op.getValueType(),
                                Chain, Dest, CC, Cmp);
            X86::CondCode CCode =
              (X86::CondCode)Cond.getOperand(1).getConstantOperandVal(0);
            CCode = X86::GetOppositeBranchCondition(CCode);
            CC = DAG.getConstant(CCode, MVT::i8);
            Cond = Cmp;
            addTest = false;
          }
        }
      }
    } else if (Cond.hasOneUse() && isXor1OfSetCC(Cond)) {
      // Recognize for xorb (setcc), 1 patterns. The xor inverts the condition.
      // It should be transformed during dag combiner except when the condition
      // is set by a arithmetics with overflow node.
      X86::CondCode CCode =
        (X86::CondCode)Cond.getOperand(0).getConstantOperandVal(0);
      CCode = X86::GetOppositeBranchCondition(CCode);
      CC = DAG.getConstant(CCode, MVT::i8);
      Cond = Cond.getOperand(0).getOperand(1);
      addTest = false;
    } else if (Cond.getOpcode() == ISD::SETCC &&
               cast<CondCodeSDNode>(Cond.getOperand(2))->get() == ISD::SETOEQ) {
      // For FCMP_OEQ, we can emit
      // two branches instead of an explicit AND instruction with a
      // separate test. However, we only do this if this block doesn't
      // have a fall-through edge, because this requires an explicit
      // jmp when the condition is false.
      if (Op.getNode()->hasOneUse()) {
        SDNode *User = *Op.getNode()->use_begin();
        // Look for an unconditional branch following this conditional branch.
        // We need this because we need to reverse the successors in order
        // to implement FCMP_OEQ.
        if (User->getOpcode() == ISD::BR) {
          SDValue FalseBB = User->getOperand(1);
          SDNode *NewBR =
            DAG.UpdateNodeOperands(User, User->getOperand(0), Dest);
          assert(NewBR == User);
          (void)NewBR;
          Dest = FalseBB;

          SDValue Cmp = DAG.getNode(X86ISD::CMP, dl, MVT::i32,
                                    Cond.getOperand(0), Cond.getOperand(1));
          Cmp = ConvertCmpIfNecessary(Cmp, DAG);
          CC = DAG.getConstant(X86::COND_NE, MVT::i8);
          Chain = DAG.getNode(X86ISD::BRCOND, dl, Op.getValueType(),
                              Chain, Dest, CC, Cmp);
          CC = DAG.getConstant(X86::COND_P, MVT::i8);
          Cond = Cmp;
          addTest = false;
        }
      }
    } else if (Cond.getOpcode() == ISD::SETCC &&
               cast<CondCodeSDNode>(Cond.getOperand(2))->get() == ISD::SETUNE) {
      // For FCMP_UNE, we can emit
      // two branches instead of an explicit AND instruction with a
      // separate test. However, we only do this if this block doesn't
      // have a fall-through edge, because this requires an explicit
      // jmp when the condition is false.
      if (Op.getNode()->hasOneUse()) {
        SDNode *User = *Op.getNode()->use_begin();
        // Look for an unconditional branch following this conditional branch.
        // We need this because we need to reverse the successors in order
        // to implement FCMP_UNE.
        if (User->getOpcode() == ISD::BR) {
          SDValue FalseBB = User->getOperand(1);
          SDNode *NewBR =
            DAG.UpdateNodeOperands(User, User->getOperand(0), Dest);
          assert(NewBR == User);
          (void)NewBR;

          SDValue Cmp = DAG.getNode(X86ISD::CMP, dl, MVT::i32,
                                    Cond.getOperand(0), Cond.getOperand(1));
          Cmp = ConvertCmpIfNecessary(Cmp, DAG);
          CC = DAG.getConstant(X86::COND_NE, MVT::i8);
          Chain = DAG.getNode(X86ISD::BRCOND, dl, Op.getValueType(),
                              Chain, Dest, CC, Cmp);
          CC = DAG.getConstant(X86::COND_NP, MVT::i8);
          Cond = Cmp;
          addTest = false;
          Dest = FalseBB;
        }
      }
    }
  }

  if (addTest) {
    // Look pass the truncate if the high bits are known zero.
    if (isTruncWithZeroHighBitsInput(Cond, DAG))
        Cond = Cond.getOperand(0);

    // We know the result of AND is compared against zero. Try to match
    // it to BT.
    if (Cond.getOpcode() == ISD::AND && Cond.hasOneUse()) {
      SDValue NewSetCC = LowerToBT(Cond, ISD::SETNE, dl, DAG);
      if (NewSetCC.getNode()) {
        CC = NewSetCC.getOperand(0);
        Cond = NewSetCC.getOperand(1);
        addTest = false;
      }
    }
  }

  if (addTest) {
    X86::CondCode X86Cond = Inverted ? X86::COND_E : X86::COND_NE;
    CC = DAG.getConstant(X86Cond, MVT::i8);
    Cond = EmitTest(Cond, X86Cond, dl, DAG);
  }
  Cond = ConvertCmpIfNecessary(Cond, DAG);
  return DAG.getNode(X86ISD::BRCOND, dl, Op.getValueType(),
                     Chain, Dest, CC, Cond);
}

// Lower dynamic stack allocation to _alloca call for Cygwin/Mingw targets.
// Calls to _alloca are needed to probe the stack when allocating more than 4k
// bytes in one go. Touching the stack at 4K increments is necessary to ensure
// that the guard pages used by the OS virtual memory manager are allocated in
// correct sequence.
SDValue
X86TargetLowering::LowerDYNAMIC_STACKALLOC(SDValue Op,
                                           SelectionDAG &DAG) const {
  MachineFunction &MF = DAG.getMachineFunction();
  bool SplitStack = MF.shouldSplitStack();
  bool Lower = (Subtarget->isOSWindows() && !Subtarget->isTargetMachO()) ||
               SplitStack;
  SDLoc dl(Op);

  if (!Lower) {
    const TargetLowering &TLI = DAG.getTargetLoweringInfo();
    SDNode* Node = Op.getNode();

    unsigned SPReg = TLI.getStackPointerRegisterToSaveRestore();
    assert(SPReg && "Target cannot require DYNAMIC_STACKALLOC expansion and"
        " not tell us which reg is the stack pointer!");
    EVT VT = Node->getValueType(0);
    SDValue Tmp1 = SDValue(Node, 0);
    SDValue Tmp2 = SDValue(Node, 1);
    SDValue Tmp3 = Node->getOperand(2);
    SDValue Chain = Tmp1.getOperand(0);

    // Chain the dynamic stack allocation so that it doesn't modify the stack
    // pointer when other instructions are using the stack.
    Chain = DAG.getCALLSEQ_START(Chain, DAG.getIntPtrConstant(0, true),
        SDLoc(Node));

    SDValue Size = Tmp2.getOperand(1);
    SDValue SP = DAG.getCopyFromReg(Chain, dl, SPReg, VT);
    Chain = SP.getValue(1);
    unsigned Align = cast<ConstantSDNode>(Tmp3)->getZExtValue();
    const TargetFrameLowering &TFI = *Subtarget->getFrameLowering();
    unsigned StackAlign = TFI.getStackAlignment();
    Tmp1 = DAG.getNode(ISD::SUB, dl, VT, SP, Size); // Value
    if (Align > StackAlign)
      Tmp1 = DAG.getNode(ISD::AND, dl, VT, Tmp1,
          DAG.getConstant(-(uint64_t)Align, VT));
    Chain = DAG.getCopyToReg(Chain, dl, SPReg, Tmp1); // Output chain

    Tmp2 = DAG.getCALLSEQ_END(Chain, DAG.getIntPtrConstant(0, true),
        DAG.getIntPtrConstant(0, true), SDValue(),
        SDLoc(Node));

    SDValue Ops[2] = { Tmp1, Tmp2 };
    return DAG.getMergeValues(Ops, dl);
  }

  // Get the inputs.
  SDValue Chain = Op.getOperand(0);
  SDValue Size  = Op.getOperand(1);
  unsigned Align = cast<ConstantSDNode>(Op.getOperand(2))->getZExtValue();
  EVT VT = Op.getNode()->getValueType(0);

  bool Is64Bit = Subtarget->is64Bit();
  EVT SPTy = getPointerTy();

  if (SplitStack) {
    MachineRegisterInfo &MRI = MF.getRegInfo();

    if (Is64Bit) {
      // The 64 bit implementation of segmented stacks needs to clobber both r10
      // r11. This makes it impossible to use it along with nested parameters.
      const Function *F = MF.getFunction();

      for (Function::const_arg_iterator I = F->arg_begin(), E = F->arg_end();
           I != E; ++I)
        if (I->hasNestAttr())
          report_fatal_error("Cannot use segmented stacks with functions that "
                             "have nested arguments.");
    }

    const TargetRegisterClass *AddrRegClass =
      getRegClassFor(getPointerTy());
    unsigned Vreg = MRI.createVirtualRegister(AddrRegClass);
    Chain = DAG.getCopyToReg(Chain, dl, Vreg, Size);
    SDValue Value = DAG.getNode(X86ISD::SEG_ALLOCA, dl, SPTy, Chain,
                                DAG.getRegister(Vreg, SPTy));
    SDValue Ops1[2] = { Value, Chain };
    return DAG.getMergeValues(Ops1, dl);
  } else {
    SDValue Flag;
    const unsigned Reg = (Subtarget->isTarget64BitLP64() ? X86::RAX : X86::EAX);

    Chain = DAG.getCopyToReg(Chain, dl, Reg, Size, Flag);
    Flag = Chain.getValue(1);
    SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue);

    Chain = DAG.getNode(X86ISD::WIN_ALLOCA, dl, NodeTys, Chain, Flag);

    const X86RegisterInfo *RegInfo = Subtarget->getRegisterInfo();
    unsigned SPReg = RegInfo->getStackRegister();
    SDValue SP = DAG.getCopyFromReg(Chain, dl, SPReg, SPTy);
    Chain = SP.getValue(1);

    if (Align) {
      SP = DAG.getNode(ISD::AND, dl, VT, SP.getValue(0),
                       DAG.getConstant(-(uint64_t)Align, VT));
      Chain = DAG.getCopyToReg(Chain, dl, SPReg, SP);
    }

    SDValue Ops1[2] = { SP, Chain };
    return DAG.getMergeValues(Ops1, dl);
  }
}

SDValue X86TargetLowering::LowerVASTART(SDValue Op, SelectionDAG &DAG) const {
  MachineFunction &MF = DAG.getMachineFunction();
  X86MachineFunctionInfo *FuncInfo = MF.getInfo<X86MachineFunctionInfo>();

  const Value *SV = cast<SrcValueSDNode>(Op.getOperand(2))->getValue();
  SDLoc DL(Op);

  if (!Subtarget->is64Bit() || Subtarget->isTargetWin64()) {
    // vastart just stores the address of the VarArgsFrameIndex slot into the
    // memory location argument.
    SDValue FR = DAG.getFrameIndex(FuncInfo->getVarArgsFrameIndex(),
                                   getPointerTy());
    return DAG.getStore(Op.getOperand(0), DL, FR, Op.getOperand(1),
                        MachinePointerInfo(SV), false, false, 0);
  }

  // __va_list_tag:
  //   gp_offset         (0 - 6 * 8)
  //   fp_offset         (48 - 48 + 8 * 16)
  //   overflow_arg_area (point to parameters coming in memory).
  //   reg_save_area
  SmallVector<SDValue, 8> MemOps;
  SDValue FIN = Op.getOperand(1);
  // Store gp_offset
  SDValue Store = DAG.getStore(Op.getOperand(0), DL,
                               DAG.getConstant(FuncInfo->getVarArgsGPOffset(),
                                               MVT::i32),
                               FIN, MachinePointerInfo(SV), false, false, 0);
  MemOps.push_back(Store);

  // Store fp_offset
  FIN = DAG.getNode(ISD::ADD, DL, getPointerTy(),
                    FIN, DAG.getIntPtrConstant(4));
  Store = DAG.getStore(Op.getOperand(0), DL,
                       DAG.getConstant(FuncInfo->getVarArgsFPOffset(),
                                       MVT::i32),
                       FIN, MachinePointerInfo(SV, 4), false, false, 0);
  MemOps.push_back(Store);

  // Store ptr to overflow_arg_area
  FIN = DAG.getNode(ISD::ADD, DL, getPointerTy(),
                    FIN, DAG.getIntPtrConstant(4));
  SDValue OVFIN = DAG.getFrameIndex(FuncInfo->getVarArgsFrameIndex(),
                                    getPointerTy());
  Store = DAG.getStore(Op.getOperand(0), DL, OVFIN, FIN,
                       MachinePointerInfo(SV, 8),
                       false, false, 0);
  MemOps.push_back(Store);

  // Store ptr to reg_save_area.
  FIN = DAG.getNode(ISD::ADD, DL, getPointerTy(),
                    FIN, DAG.getIntPtrConstant(8));
  SDValue RSFIN = DAG.getFrameIndex(FuncInfo->getRegSaveFrameIndex(),
                                    getPointerTy());
  Store = DAG.getStore(Op.getOperand(0), DL, RSFIN, FIN,
                       MachinePointerInfo(SV, 16), false, false, 0);
  MemOps.push_back(Store);
  return DAG.getNode(ISD::TokenFactor, DL, MVT::Other, MemOps);
}

SDValue X86TargetLowering::LowerVAARG(SDValue Op, SelectionDAG &DAG) const {
  assert(Subtarget->is64Bit() &&
         "LowerVAARG only handles 64-bit va_arg!");
  assert((Subtarget->isTargetLinux() ||
          Subtarget->isTargetDarwin()) &&
          "Unhandled target in LowerVAARG");
  assert(Op.getNode()->getNumOperands() == 4);
  SDValue Chain = Op.getOperand(0);
  SDValue SrcPtr = Op.getOperand(1);
  const Value *SV = cast<SrcValueSDNode>(Op.getOperand(2))->getValue();
  unsigned Align = Op.getConstantOperandVal(3);
  SDLoc dl(Op);

  EVT ArgVT = Op.getNode()->getValueType(0);
  Type *ArgTy = ArgVT.getTypeForEVT(*DAG.getContext());
  uint32_t ArgSize = getDataLayout()->getTypeAllocSize(ArgTy);
  uint8_t ArgMode;

  // Decide which area this value should be read from.
  // TODO: Implement the AMD64 ABI in its entirety. This simple
  // selection mechanism works only for the basic types.
  if (ArgVT == MVT::f80) {
    llvm_unreachable("va_arg for f80 not yet implemented");
  } else if (ArgVT.isFloatingPoint() && ArgSize <= 16 /*bytes*/) {
    ArgMode = 2;  // Argument passed in XMM register. Use fp_offset.
  } else if (ArgVT.isInteger() && ArgSize <= 32 /*bytes*/) {
    ArgMode = 1;  // Argument passed in GPR64 register(s). Use gp_offset.
  } else {
    llvm_unreachable("Unhandled argument type in LowerVAARG");
  }

  if (ArgMode == 2) {
    // Sanity Check: Make sure using fp_offset makes sense.
    assert(!DAG.getTarget().Options.UseSoftFloat &&
           !(DAG.getMachineFunction().getFunction()->hasFnAttribute(
               Attribute::NoImplicitFloat)) &&
           Subtarget->hasSSE1());
  }

  // Insert VAARG_64 node into the DAG
  // VAARG_64 returns two values: Variable Argument Address, Chain
  SmallVector<SDValue, 11> InstOps;
  InstOps.push_back(Chain);
  InstOps.push_back(SrcPtr);
  InstOps.push_back(DAG.getConstant(ArgSize, MVT::i32));
  InstOps.push_back(DAG.getConstant(ArgMode, MVT::i8));
  InstOps.push_back(DAG.getConstant(Align, MVT::i32));
  SDVTList VTs = DAG.getVTList(getPointerTy(), MVT::Other);
  SDValue VAARG = DAG.getMemIntrinsicNode(X86ISD::VAARG_64, dl,
                                          VTs, InstOps, MVT::i64,
                                          MachinePointerInfo(SV),
                                          /*Align=*/0,
                                          /*Volatile=*/false,
                                          /*ReadMem=*/true,
                                          /*WriteMem=*/true);
  Chain = VAARG.getValue(1);

  // Load the next argument and return it
  return DAG.getLoad(ArgVT, dl,
                     Chain,
                     VAARG,
                     MachinePointerInfo(),
                     false, false, false, 0);
}

static SDValue LowerVACOPY(SDValue Op, const X86Subtarget *Subtarget,
                           SelectionDAG &DAG) {
  // X86-64 va_list is a struct { i32, i32, i8*, i8* }.
  assert(Subtarget->is64Bit() && "This code only handles 64-bit va_copy!");
  SDValue Chain = Op.getOperand(0);
  SDValue DstPtr = Op.getOperand(1);
  SDValue SrcPtr = Op.getOperand(2);
  const Value *DstSV = cast<SrcValueSDNode>(Op.getOperand(3))->getValue();
  const Value *SrcSV = cast<SrcValueSDNode>(Op.getOperand(4))->getValue();
  SDLoc DL(Op);

  return DAG.getMemcpy(Chain, DL, DstPtr, SrcPtr,
                       DAG.getIntPtrConstant(24), 8, /*isVolatile*/false,
                       false,
                       MachinePointerInfo(DstSV), MachinePointerInfo(SrcSV));
}

// getTargetVShiftByConstNode - Handle vector element shifts where the shift
// amount is a constant. Takes immediate version of shift as input.
static SDValue getTargetVShiftByConstNode(unsigned Opc, SDLoc dl, MVT VT,
                                          SDValue SrcOp, uint64_t ShiftAmt,
                                          SelectionDAG &DAG) {
  MVT ElementType = VT.getVectorElementType();

  // Fold this packed shift into its first operand if ShiftAmt is 0.
  if (ShiftAmt == 0)
    return SrcOp;

  // Check for ShiftAmt >= element width
  if (ShiftAmt >= ElementType.getSizeInBits()) {
    if (Opc == X86ISD::VSRAI)
      ShiftAmt = ElementType.getSizeInBits() - 1;
    else
      return DAG.getConstant(0, VT);
  }

  assert((Opc == X86ISD::VSHLI || Opc == X86ISD::VSRLI || Opc == X86ISD::VSRAI)
         && "Unknown target vector shift-by-constant node");

  // Fold this packed vector shift into a build vector if SrcOp is a
  // vector of Constants or UNDEFs, and SrcOp valuetype is the same as VT.
  if (VT == SrcOp.getSimpleValueType() &&
      ISD::isBuildVectorOfConstantSDNodes(SrcOp.getNode())) {
    SmallVector<SDValue, 8> Elts;
    unsigned NumElts = SrcOp->getNumOperands();
    ConstantSDNode *ND;

    switch(Opc) {
    default: llvm_unreachable(nullptr);
    case X86ISD::VSHLI:
      for (unsigned i=0; i!=NumElts; ++i) {
        SDValue CurrentOp = SrcOp->getOperand(i);
        if (CurrentOp->getOpcode() == ISD::UNDEF) {
          Elts.push_back(CurrentOp);
          continue;
        }
        ND = cast<ConstantSDNode>(CurrentOp);
        const APInt &C = ND->getAPIntValue();
        Elts.push_back(DAG.getConstant(C.shl(ShiftAmt), ElementType));
      }
      break;
    case X86ISD::VSRLI:
      for (unsigned i=0; i!=NumElts; ++i) {
        SDValue CurrentOp = SrcOp->getOperand(i);
        if (CurrentOp->getOpcode() == ISD::UNDEF) {
          Elts.push_back(CurrentOp);
          continue;
        }
        ND = cast<ConstantSDNode>(CurrentOp);
        const APInt &C = ND->getAPIntValue();
        Elts.push_back(DAG.getConstant(C.lshr(ShiftAmt), ElementType));
      }
      break;
    case X86ISD::VSRAI:
      for (unsigned i=0; i!=NumElts; ++i) {
        SDValue CurrentOp = SrcOp->getOperand(i);
        if (CurrentOp->getOpcode() == ISD::UNDEF) {
          Elts.push_back(CurrentOp);
          continue;
        }
        ND = cast<ConstantSDNode>(CurrentOp);
        const APInt &C = ND->getAPIntValue();
        Elts.push_back(DAG.getConstant(C.ashr(ShiftAmt), ElementType));
      }
      break;
    }

    return DAG.getNode(ISD::BUILD_VECTOR, dl, VT, Elts);
  }

  return DAG.getNode(Opc, dl, VT, SrcOp, DAG.getConstant(ShiftAmt, MVT::i8));
}

// getTargetVShiftNode - Handle vector element shifts where the shift amount
// may or may not be a constant. Takes immediate version of shift as input.
static SDValue getTargetVShiftNode(unsigned Opc, SDLoc dl, MVT VT,
                                   SDValue SrcOp, SDValue ShAmt,
                                   SelectionDAG &DAG) {
  MVT SVT = ShAmt.getSimpleValueType();
  assert((SVT == MVT::i32 || SVT == MVT::i64) && "Unexpected value type!");

  // Catch shift-by-constant.
  if (ConstantSDNode *CShAmt = dyn_cast<ConstantSDNode>(ShAmt))
    return getTargetVShiftByConstNode(Opc, dl, VT, SrcOp,
                                      CShAmt->getZExtValue(), DAG);

  // Change opcode to non-immediate version
  switch (Opc) {
    default: llvm_unreachable("Unknown target vector shift node");
    case X86ISD::VSHLI: Opc = X86ISD::VSHL; break;
    case X86ISD::VSRLI: Opc = X86ISD::VSRL; break;
    case X86ISD::VSRAI: Opc = X86ISD::VSRA; break;
  }

  const X86Subtarget &Subtarget =
      static_cast<const X86Subtarget &>(DAG.getSubtarget());
  if (Subtarget.hasSSE41() && ShAmt.getOpcode() == ISD::ZERO_EXTEND &&
      ShAmt.getOperand(0).getSimpleValueType() == MVT::i16) {
    // Let the shuffle legalizer expand this shift amount node.
    SDValue Op0 = ShAmt.getOperand(0);
    Op0 = DAG.getNode(ISD::SCALAR_TO_VECTOR, SDLoc(Op0), MVT::v8i16, Op0);
    ShAmt = getShuffleVectorZeroOrUndef(Op0, 0, true, &Subtarget, DAG);
  } else {
    // Need to build a vector containing shift amount.
    // SSE/AVX packed shifts only use the lower 64-bit of the shift count.
    SmallVector<SDValue, 4> ShOps;
    ShOps.push_back(ShAmt);
    if (SVT == MVT::i32) {
      ShOps.push_back(DAG.getConstant(0, SVT));
      ShOps.push_back(DAG.getUNDEF(SVT));
    }
    ShOps.push_back(DAG.getUNDEF(SVT));

    MVT BVT = SVT == MVT::i32 ? MVT::v4i32 : MVT::v2i64;
    ShAmt = DAG.getNode(ISD::BUILD_VECTOR, dl, BVT, ShOps);
  }

  // The return type has to be a 128-bit type with the same element
  // type as the input type.
  MVT EltVT = VT.getVectorElementType();
  EVT ShVT = MVT::getVectorVT(EltVT, 128/EltVT.getSizeInBits());

  ShAmt = DAG.getNode(ISD::BITCAST, dl, ShVT, ShAmt);
  return DAG.getNode(Opc, dl, VT, SrcOp, ShAmt);
}

/// \brief Return (and \p Op, \p Mask) for compare instructions or
/// (vselect \p Mask, \p Op, \p PreservedSrc) for others along with the
/// necessary casting for \p Mask when lowering masking intrinsics.
static SDValue getVectorMaskingNode(SDValue Op, SDValue Mask,
                                    SDValue PreservedSrc,
                                    const X86Subtarget *Subtarget,
                                    SelectionDAG &DAG) {
    EVT VT = Op.getValueType();
    EVT MaskVT = EVT::getVectorVT(*DAG.getContext(),
                                  MVT::i1, VT.getVectorNumElements());
    EVT BitcastVT = EVT::getVectorVT(*DAG.getContext(), MVT::i1,
                                     Mask.getValueType().getSizeInBits());
    SDLoc dl(Op);

    assert(MaskVT.isSimple() && "invalid mask type");

    if (isAllOnes(Mask))
      return Op;

    // In case when MaskVT equals v2i1 or v4i1, low 2 or 4 elements
    // are extracted by EXTRACT_SUBVECTOR.
    SDValue VMask = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, MaskVT,
                              DAG.getNode(ISD::BITCAST, dl, BitcastVT, Mask),
                              DAG.getIntPtrConstant(0));

    switch (Op.getOpcode()) {
      default: break;
      case X86ISD::PCMPEQM:
      case X86ISD::PCMPGTM:
      case X86ISD::CMPM:
      case X86ISD::CMPMU:
        return DAG.getNode(ISD::AND, dl, VT, Op, VMask);
    }
    if (PreservedSrc.getOpcode() == ISD::UNDEF)
      PreservedSrc = getZeroVector(VT, Subtarget, DAG, dl);
    return DAG.getNode(ISD::VSELECT, dl, VT, VMask, Op, PreservedSrc);
}

/// \brief Creates an SDNode for a predicated scalar operation.
/// \returns (X86vselect \p Mask, \p Op, \p PreservedSrc).
/// The mask is comming as MVT::i8 and it should be truncated
/// to MVT::i1 while lowering masking intrinsics.
/// The main difference between ScalarMaskingNode and VectorMaskingNode is using
/// "X86select" instead of "vselect". We just can't create the "vselect" node for
/// a scalar instruction.
static SDValue getScalarMaskingNode(SDValue Op, SDValue Mask,
                                    SDValue PreservedSrc,
                                    const X86Subtarget *Subtarget,
                                    SelectionDAG &DAG) {
    if (isAllOnes(Mask))
      return Op;

    EVT VT = Op.getValueType();
    SDLoc dl(Op);
    // The mask should be of type MVT::i1
    SDValue IMask = DAG.getNode(ISD::TRUNCATE, dl, MVT::i1, Mask);

    if (PreservedSrc.getOpcode() == ISD::UNDEF)
      PreservedSrc = getZeroVector(VT, Subtarget, DAG, dl);
    return DAG.getNode(X86ISD::SELECT, dl, VT, IMask, Op, PreservedSrc);
}

static SDValue LowerINTRINSIC_WO_CHAIN(SDValue Op, const X86Subtarget *Subtarget,
                                       SelectionDAG &DAG) {
  SDLoc dl(Op);
  unsigned IntNo = cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue();
  EVT VT = Op.getValueType();
  const IntrinsicData* IntrData = getIntrinsicWithoutChain(IntNo);
  if (IntrData) {
    switch(IntrData->Type) {
    case INTR_TYPE_1OP:
      return DAG.getNode(IntrData->Opc0, dl, Op.getValueType(), Op.getOperand(1));
    case INTR_TYPE_2OP:
      return DAG.getNode(IntrData->Opc0, dl, Op.getValueType(), Op.getOperand(1),
        Op.getOperand(2));
    case INTR_TYPE_3OP:
      return DAG.getNode(IntrData->Opc0, dl, Op.getValueType(), Op.getOperand(1),
        Op.getOperand(2), Op.getOperand(3));
    case INTR_TYPE_1OP_MASK_RM: {
      SDValue Src = Op.getOperand(1);
      SDValue Src0 = Op.getOperand(2);
      SDValue Mask = Op.getOperand(3);
      SDValue RoundingMode = Op.getOperand(4);
      return getVectorMaskingNode(DAG.getNode(IntrData->Opc0, dl, VT, Src,
                                              RoundingMode),
                                  Mask, Src0, Subtarget, DAG);
    }
    case INTR_TYPE_SCALAR_MASK_RM: {
      SDValue Src1 = Op.getOperand(1);
      SDValue Src2 = Op.getOperand(2);
      SDValue Src0 = Op.getOperand(3);
      SDValue Mask = Op.getOperand(4);
      // There are 2 kinds of intrinsics in this group:
      // (1) With supress-all-exceptions (sae) - 6 operands
      // (2) With rounding mode and sae - 7 operands.
      if (Op.getNumOperands() == 6) {
        SDValue Sae  = Op.getOperand(5);
        return getScalarMaskingNode(DAG.getNode(IntrData->Opc0, dl, VT, Src1, Src2,
                                                Sae),
                                    Mask, Src0, Subtarget, DAG);
      }
      assert(Op.getNumOperands() == 7 && "Unexpected intrinsic form");
      SDValue RoundingMode  = Op.getOperand(5);
      SDValue Sae  = Op.getOperand(6);
      return getScalarMaskingNode(DAG.getNode(IntrData->Opc0, dl, VT, Src1, Src2,
                                              RoundingMode, Sae),
                                  Mask, Src0, Subtarget, DAG);
    }
    case INTR_TYPE_2OP_MASK: {
      SDValue Src1 = Op.getOperand(1);
      SDValue Src2 = Op.getOperand(2);
      SDValue PassThru = Op.getOperand(3);
      SDValue Mask = Op.getOperand(4);
      // We specify 2 possible opcodes for intrinsics with rounding modes.
      // First, we check if the intrinsic may have non-default rounding mode,
      // (IntrData->Opc1 != 0), then we check the rounding mode operand.
      unsigned IntrWithRoundingModeOpcode = IntrData->Opc1;
      if (IntrWithRoundingModeOpcode != 0) {
        SDValue Rnd = Op.getOperand(5);
        unsigned Round = cast<ConstantSDNode>(Rnd)->getZExtValue();
        if (Round != X86::STATIC_ROUNDING::CUR_DIRECTION) {
          return getVectorMaskingNode(DAG.getNode(IntrWithRoundingModeOpcode,
                                      dl, Op.getValueType(),
                                      Src1, Src2, Rnd),
                                      Mask, PassThru, Subtarget, DAG);
        }
      }
      return getVectorMaskingNode(DAG.getNode(IntrData->Opc0, dl, VT,
                                              Src1,Src2),
                                  Mask, PassThru, Subtarget, DAG);
    }
    case FMA_OP_MASK: {
      SDValue Src1 = Op.getOperand(1);
      SDValue Src2 = Op.getOperand(2);
      SDValue Src3 = Op.getOperand(3);
      SDValue Mask = Op.getOperand(4);
      // We specify 2 possible opcodes for intrinsics with rounding modes.
      // First, we check if the intrinsic may have non-default rounding mode,
      // (IntrData->Opc1 != 0), then we check the rounding mode operand.
      unsigned IntrWithRoundingModeOpcode = IntrData->Opc1;
      if (IntrWithRoundingModeOpcode != 0) {
        SDValue Rnd = Op.getOperand(5);
        if (cast<ConstantSDNode>(Rnd)->getZExtValue() !=
            X86::STATIC_ROUNDING::CUR_DIRECTION)
          return getVectorMaskingNode(DAG.getNode(IntrWithRoundingModeOpcode,
                                                  dl, Op.getValueType(),
                                                  Src1, Src2, Src3, Rnd),
                                      Mask, Src1, Subtarget, DAG);
      }
      return getVectorMaskingNode(DAG.getNode(IntrData->Opc0,
                                              dl, Op.getValueType(),
                                              Src1, Src2, Src3),
                                  Mask, Src1, Subtarget, DAG);
    }
    case CMP_MASK:
    case CMP_MASK_CC: {
      // Comparison intrinsics with masks.
      // Example of transformation:
      // (i8 (int_x86_avx512_mask_pcmpeq_q_128
      //             (v2i64 %a), (v2i64 %b), (i8 %mask))) ->
      // (i8 (bitcast
      //   (v8i1 (insert_subvector undef,
      //           (v2i1 (and (PCMPEQM %a, %b),
      //                      (extract_subvector
      //                         (v8i1 (bitcast %mask)), 0))), 0))))
      EVT VT = Op.getOperand(1).getValueType();
      EVT MaskVT = EVT::getVectorVT(*DAG.getContext(), MVT::i1,
                                    VT.getVectorNumElements());
      SDValue Mask = Op.getOperand((IntrData->Type == CMP_MASK_CC) ? 4 : 3);
      EVT BitcastVT = EVT::getVectorVT(*DAG.getContext(), MVT::i1,
                                       Mask.getValueType().getSizeInBits());
      SDValue Cmp;
      if (IntrData->Type == CMP_MASK_CC) {
        Cmp = DAG.getNode(IntrData->Opc0, dl, MaskVT, Op.getOperand(1),
                    Op.getOperand(2), Op.getOperand(3));
      } else {
        assert(IntrData->Type == CMP_MASK && "Unexpected intrinsic type!");
        Cmp = DAG.getNode(IntrData->Opc0, dl, MaskVT, Op.getOperand(1),
                    Op.getOperand(2));
      }
      SDValue CmpMask = getVectorMaskingNode(Cmp, Mask,
                                             DAG.getTargetConstant(0, MaskVT),
                                             Subtarget, DAG);
      SDValue Res = DAG.getNode(ISD::INSERT_SUBVECTOR, dl, BitcastVT,
                                DAG.getUNDEF(BitcastVT), CmpMask,
                                DAG.getIntPtrConstant(0));
      return DAG.getNode(ISD::BITCAST, dl, Op.getValueType(), Res);
    }
    case COMI: { // Comparison intrinsics
      ISD::CondCode CC = (ISD::CondCode)IntrData->Opc1;
      SDValue LHS = Op.getOperand(1);
      SDValue RHS = Op.getOperand(2);
      unsigned X86CC = TranslateX86CC(CC, true, LHS, RHS, DAG);
      assert(X86CC != X86::COND_INVALID && "Unexpected illegal condition!");
      SDValue Cond = DAG.getNode(IntrData->Opc0, dl, MVT::i32, LHS, RHS);
      SDValue SetCC = DAG.getNode(X86ISD::SETCC, dl, MVT::i8,
                                  DAG.getConstant(X86CC, MVT::i8), Cond);
      return DAG.getNode(ISD::ZERO_EXTEND, dl, MVT::i32, SetCC);
    }
    case VSHIFT:
      return getTargetVShiftNode(IntrData->Opc0, dl, Op.getSimpleValueType(),
                                 Op.getOperand(1), Op.getOperand(2), DAG);
    case VSHIFT_MASK:
      return getVectorMaskingNode(getTargetVShiftNode(IntrData->Opc0, dl,
                                                      Op.getSimpleValueType(),
                                                      Op.getOperand(1),
                                                      Op.getOperand(2), DAG),
                                  Op.getOperand(4), Op.getOperand(3), Subtarget,
                                  DAG);
    case COMPRESS_EXPAND_IN_REG: {
      SDValue Mask = Op.getOperand(3);
      SDValue DataToCompress = Op.getOperand(1);
      SDValue PassThru = Op.getOperand(2);
      if (isAllOnes(Mask)) // return data as is
        return Op.getOperand(1);
      EVT VT = Op.getValueType();
      EVT MaskVT = EVT::getVectorVT(*DAG.getContext(), MVT::i1,
                                    VT.getVectorNumElements());
      EVT BitcastVT = EVT::getVectorVT(*DAG.getContext(), MVT::i1,
                                       Mask.getValueType().getSizeInBits());
      SDLoc dl(Op);
      SDValue VMask = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, MaskVT,
                                  DAG.getNode(ISD::BITCAST, dl, BitcastVT, Mask),
                                  DAG.getIntPtrConstant(0));

      return DAG.getNode(IntrData->Opc0, dl, VT, VMask, DataToCompress,
                         PassThru);
    }
    case BLEND: {
      SDValue Mask = Op.getOperand(3);
      EVT VT = Op.getValueType();
      EVT MaskVT = EVT::getVectorVT(*DAG.getContext(), MVT::i1,
                                    VT.getVectorNumElements());
      EVT BitcastVT = EVT::getVectorVT(*DAG.getContext(), MVT::i1,
                                       Mask.getValueType().getSizeInBits());
      SDLoc dl(Op);
      SDValue VMask = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, MaskVT,
                                  DAG.getNode(ISD::BITCAST, dl, BitcastVT, Mask),
                                  DAG.getIntPtrConstant(0));
      return DAG.getNode(IntrData->Opc0, dl, VT, VMask, Op.getOperand(1),
                         Op.getOperand(2));
    }
    default:
      break;
    }
  }

  switch (IntNo) {
  default: return SDValue();    // Don't custom lower most intrinsics.

  case Intrinsic::x86_avx512_mask_valign_q_512:
  case Intrinsic::x86_avx512_mask_valign_d_512:
    // Vector source operands are swapped.
    return getVectorMaskingNode(DAG.getNode(X86ISD::VALIGN, dl,
                                            Op.getValueType(), Op.getOperand(2),
                                            Op.getOperand(1),
                                            Op.getOperand(3)),
                                Op.getOperand(5), Op.getOperand(4),
                                Subtarget, DAG);

  // ptest and testp intrinsics. The intrinsic these come from are designed to
  // return an integer value, not just an instruction so lower it to the ptest
  // or testp pattern and a setcc for the result.
  case Intrinsic::x86_sse41_ptestz:
  case Intrinsic::x86_sse41_ptestc:
  case Intrinsic::x86_sse41_ptestnzc:
  case Intrinsic::x86_avx_ptestz_256:
  case Intrinsic::x86_avx_ptestc_256:
  case Intrinsic::x86_avx_ptestnzc_256:
  case Intrinsic::x86_avx_vtestz_ps:
  case Intrinsic::x86_avx_vtestc_ps:
  case Intrinsic::x86_avx_vtestnzc_ps:
  case Intrinsic::x86_avx_vtestz_pd:
  case Intrinsic::x86_avx_vtestc_pd:
  case Intrinsic::x86_avx_vtestnzc_pd:
  case Intrinsic::x86_avx_vtestz_ps_256:
  case Intrinsic::x86_avx_vtestc_ps_256:
  case Intrinsic::x86_avx_vtestnzc_ps_256:
  case Intrinsic::x86_avx_vtestz_pd_256:
  case Intrinsic::x86_avx_vtestc_pd_256:
  case Intrinsic::x86_avx_vtestnzc_pd_256: {
    bool IsTestPacked = false;
    unsigned X86CC;
    switch (IntNo) {
    default: llvm_unreachable("Bad fallthrough in Intrinsic lowering.");
    case Intrinsic::x86_avx_vtestz_ps:
    case Intrinsic::x86_avx_vtestz_pd:
    case Intrinsic::x86_avx_vtestz_ps_256:
    case Intrinsic::x86_avx_vtestz_pd_256:
      IsTestPacked = true; // Fallthrough
    case Intrinsic::x86_sse41_ptestz:
    case Intrinsic::x86_avx_ptestz_256:
      // ZF = 1
      X86CC = X86::COND_E;
      break;
    case Intrinsic::x86_avx_vtestc_ps:
    case Intrinsic::x86_avx_vtestc_pd:
    case Intrinsic::x86_avx_vtestc_ps_256:
    case Intrinsic::x86_avx_vtestc_pd_256:
      IsTestPacked = true; // Fallthrough
    case Intrinsic::x86_sse41_ptestc:
    case Intrinsic::x86_avx_ptestc_256:
      // CF = 1
      X86CC = X86::COND_B;
      break;
    case Intrinsic::x86_avx_vtestnzc_ps:
    case Intrinsic::x86_avx_vtestnzc_pd:
    case Intrinsic::x86_avx_vtestnzc_ps_256:
    case Intrinsic::x86_avx_vtestnzc_pd_256:
      IsTestPacked = true; // Fallthrough
    case Intrinsic::x86_sse41_ptestnzc:
    case Intrinsic::x86_avx_ptestnzc_256:
      // ZF and CF = 0
      X86CC = X86::COND_A;
      break;
    }

    SDValue LHS = Op.getOperand(1);
    SDValue RHS = Op.getOperand(2);
    unsigned TestOpc = IsTestPacked ? X86ISD::TESTP : X86ISD::PTEST;
    SDValue Test = DAG.getNode(TestOpc, dl, MVT::i32, LHS, RHS);
    SDValue CC = DAG.getConstant(X86CC, MVT::i8);
    SDValue SetCC = DAG.getNode(X86ISD::SETCC, dl, MVT::i8, CC, Test);
    return DAG.getNode(ISD::ZERO_EXTEND, dl, MVT::i32, SetCC);
  }
  case Intrinsic::x86_avx512_kortestz_w:
  case Intrinsic::x86_avx512_kortestc_w: {
    unsigned X86CC = (IntNo == Intrinsic::x86_avx512_kortestz_w)? X86::COND_E: X86::COND_B;
    SDValue LHS = DAG.getNode(ISD::BITCAST, dl, MVT::v16i1, Op.getOperand(1));
    SDValue RHS = DAG.getNode(ISD::BITCAST, dl, MVT::v16i1, Op.getOperand(2));
    SDValue CC = DAG.getConstant(X86CC, MVT::i8);
    SDValue Test = DAG.getNode(X86ISD::KORTEST, dl, MVT::i32, LHS, RHS);
    SDValue SetCC = DAG.getNode(X86ISD::SETCC, dl, MVT::i1, CC, Test);
    return DAG.getNode(ISD::ZERO_EXTEND, dl, MVT::i32, SetCC);
  }

  case Intrinsic::x86_sse42_pcmpistria128:
  case Intrinsic::x86_sse42_pcmpestria128:
  case Intrinsic::x86_sse42_pcmpistric128:
  case Intrinsic::x86_sse42_pcmpestric128:
  case Intrinsic::x86_sse42_pcmpistrio128:
  case Intrinsic::x86_sse42_pcmpestrio128:
  case Intrinsic::x86_sse42_pcmpistris128:
  case Intrinsic::x86_sse42_pcmpestris128:
  case Intrinsic::x86_sse42_pcmpistriz128:
  case Intrinsic::x86_sse42_pcmpestriz128: {
    unsigned Opcode;
    unsigned X86CC;
    switch (IntNo) {
    default: llvm_unreachable("Impossible intrinsic");  // Can't reach here.
    case Intrinsic::x86_sse42_pcmpistria128:
      Opcode = X86ISD::PCMPISTRI;
      X86CC = X86::COND_A;
      break;
    case Intrinsic::x86_sse42_pcmpestria128:
      Opcode = X86ISD::PCMPESTRI;
      X86CC = X86::COND_A;
      break;
    case Intrinsic::x86_sse42_pcmpistric128:
      Opcode = X86ISD::PCMPISTRI;
      X86CC = X86::COND_B;
      break;
    case Intrinsic::x86_sse42_pcmpestric128:
      Opcode = X86ISD::PCMPESTRI;
      X86CC = X86::COND_B;
      break;
    case Intrinsic::x86_sse42_pcmpistrio128:
      Opcode = X86ISD::PCMPISTRI;
      X86CC = X86::COND_O;
      break;
    case Intrinsic::x86_sse42_pcmpestrio128:
      Opcode = X86ISD::PCMPESTRI;
      X86CC = X86::COND_O;
      break;
    case Intrinsic::x86_sse42_pcmpistris128:
      Opcode = X86ISD::PCMPISTRI;
      X86CC = X86::COND_S;
      break;
    case Intrinsic::x86_sse42_pcmpestris128:
      Opcode = X86ISD::PCMPESTRI;
      X86CC = X86::COND_S;
      break;
    case Intrinsic::x86_sse42_pcmpistriz128:
      Opcode = X86ISD::PCMPISTRI;
      X86CC = X86::COND_E;
      break;
    case Intrinsic::x86_sse42_pcmpestriz128:
      Opcode = X86ISD::PCMPESTRI;
      X86CC = X86::COND_E;
      break;
    }
    SmallVector<SDValue, 5> NewOps(Op->op_begin()+1, Op->op_end());
    SDVTList VTs = DAG.getVTList(Op.getValueType(), MVT::i32);
    SDValue PCMP = DAG.getNode(Opcode, dl, VTs, NewOps);
    SDValue SetCC = DAG.getNode(X86ISD::SETCC, dl, MVT::i8,
                                DAG.getConstant(X86CC, MVT::i8),
                                SDValue(PCMP.getNode(), 1));
    return DAG.getNode(ISD::ZERO_EXTEND, dl, MVT::i32, SetCC);
  }

  case Intrinsic::x86_sse42_pcmpistri128:
  case Intrinsic::x86_sse42_pcmpestri128: {
    unsigned Opcode;
    if (IntNo == Intrinsic::x86_sse42_pcmpistri128)
      Opcode = X86ISD::PCMPISTRI;
    else
      Opcode = X86ISD::PCMPESTRI;

    SmallVector<SDValue, 5> NewOps(Op->op_begin()+1, Op->op_end());
    SDVTList VTs = DAG.getVTList(Op.getValueType(), MVT::i32);
    return DAG.getNode(Opcode, dl, VTs, NewOps);
  }
  }
}

static SDValue getGatherNode(unsigned Opc, SDValue Op, SelectionDAG &DAG,
                              SDValue Src, SDValue Mask, SDValue Base,
                              SDValue Index, SDValue ScaleOp, SDValue Chain,
                              const X86Subtarget * Subtarget) {
  SDLoc dl(Op);
  ConstantSDNode *C = dyn_cast<ConstantSDNode>(ScaleOp);
  assert(C && "Invalid scale type");
  SDValue Scale = DAG.getTargetConstant(C->getZExtValue(), MVT::i8);
  EVT MaskVT = MVT::getVectorVT(MVT::i1,
                             Index.getSimpleValueType().getVectorNumElements());
  SDValue MaskInReg;
  ConstantSDNode *MaskC = dyn_cast<ConstantSDNode>(Mask);
  if (MaskC)
    MaskInReg = DAG.getTargetConstant(MaskC->getSExtValue(), MaskVT);
  else
    MaskInReg = DAG.getNode(ISD::BITCAST, dl, MaskVT, Mask);
  SDVTList VTs = DAG.getVTList(Op.getValueType(), MaskVT, MVT::Other);
  SDValue Disp = DAG.getTargetConstant(0, MVT::i32);
  SDValue Segment = DAG.getRegister(0, MVT::i32);
  if (Src.getOpcode() == ISD::UNDEF)
    Src = getZeroVector(Op.getValueType(), Subtarget, DAG, dl);
  SDValue Ops[] = {Src, MaskInReg, Base, Scale, Index, Disp, Segment, Chain};
  SDNode *Res = DAG.getMachineNode(Opc, dl, VTs, Ops);
  SDValue RetOps[] = { SDValue(Res, 0), SDValue(Res, 2) };
  return DAG.getMergeValues(RetOps, dl);
}

static SDValue getScatterNode(unsigned Opc, SDValue Op, SelectionDAG &DAG,
                               SDValue Src, SDValue Mask, SDValue Base,
                               SDValue Index, SDValue ScaleOp, SDValue Chain) {
  SDLoc dl(Op);
  ConstantSDNode *C = dyn_cast<ConstantSDNode>(ScaleOp);
  assert(C && "Invalid scale type");
  SDValue Scale = DAG.getTargetConstant(C->getZExtValue(), MVT::i8);
  SDValue Disp = DAG.getTargetConstant(0, MVT::i32);
  SDValue Segment = DAG.getRegister(0, MVT::i32);
  EVT MaskVT = MVT::getVectorVT(MVT::i1,
                             Index.getSimpleValueType().getVectorNumElements());
  SDValue MaskInReg;
  ConstantSDNode *MaskC = dyn_cast<ConstantSDNode>(Mask);
  if (MaskC)
    MaskInReg = DAG.getTargetConstant(MaskC->getSExtValue(), MaskVT);
  else
    MaskInReg = DAG.getNode(ISD::BITCAST, dl, MaskVT, Mask);
  SDVTList VTs = DAG.getVTList(MaskVT, MVT::Other);
  SDValue Ops[] = {Base, Scale, Index, Disp, Segment, MaskInReg, Src, Chain};
  SDNode *Res = DAG.getMachineNode(Opc, dl, VTs, Ops);
  return SDValue(Res, 1);
}

static SDValue getPrefetchNode(unsigned Opc, SDValue Op, SelectionDAG &DAG,
                               SDValue Mask, SDValue Base, SDValue Index,
                               SDValue ScaleOp, SDValue Chain) {
  SDLoc dl(Op);
  ConstantSDNode *C = dyn_cast<ConstantSDNode>(ScaleOp);
  assert(C && "Invalid scale type");
  SDValue Scale = DAG.getTargetConstant(C->getZExtValue(), MVT::i8);
  SDValue Disp = DAG.getTargetConstant(0, MVT::i32);
  SDValue Segment = DAG.getRegister(0, MVT::i32);
  EVT MaskVT =
    MVT::getVectorVT(MVT::i1, Index.getSimpleValueType().getVectorNumElements());
  SDValue MaskInReg;
  ConstantSDNode *MaskC = dyn_cast<ConstantSDNode>(Mask);
  if (MaskC)
    MaskInReg = DAG.getTargetConstant(MaskC->getSExtValue(), MaskVT);
  else
    MaskInReg = DAG.getNode(ISD::BITCAST, dl, MaskVT, Mask);
  //SDVTList VTs = DAG.getVTList(MVT::Other);
  SDValue Ops[] = {MaskInReg, Base, Scale, Index, Disp, Segment, Chain};
  SDNode *Res = DAG.getMachineNode(Opc, dl, MVT::Other, Ops);
  return SDValue(Res, 0);
}

// getReadPerformanceCounter - Handles the lowering of builtin intrinsics that
// read performance monitor counters (x86_rdpmc).
static void getReadPerformanceCounter(SDNode *N, SDLoc DL,
                              SelectionDAG &DAG, const X86Subtarget *Subtarget,
                              SmallVectorImpl<SDValue> &Results) {
  assert(N->getNumOperands() == 3 && "Unexpected number of operands!");
  SDVTList Tys = DAG.getVTList(MVT::Other, MVT::Glue);
  SDValue LO, HI;

  // The ECX register is used to select the index of the performance counter
  // to read.
  SDValue Chain = DAG.getCopyToReg(N->getOperand(0), DL, X86::ECX,
                                   N->getOperand(2));
  SDValue rd = DAG.getNode(X86ISD::RDPMC_DAG, DL, Tys, Chain);

  // Reads the content of a 64-bit performance counter and returns it in the
  // registers EDX:EAX.
  if (Subtarget->is64Bit()) {
    LO = DAG.getCopyFromReg(rd, DL, X86::RAX, MVT::i64, rd.getValue(1));
    HI = DAG.getCopyFromReg(LO.getValue(1), DL, X86::RDX, MVT::i64,
                            LO.getValue(2));
  } else {
    LO = DAG.getCopyFromReg(rd, DL, X86::EAX, MVT::i32, rd.getValue(1));
    HI = DAG.getCopyFromReg(LO.getValue(1), DL, X86::EDX, MVT::i32,
                            LO.getValue(2));
  }
  Chain = HI.getValue(1);

  if (Subtarget->is64Bit()) {
    // The EAX register is loaded with the low-order 32 bits. The EDX register
    // is loaded with the supported high-order bits of the counter.
    SDValue Tmp = DAG.getNode(ISD::SHL, DL, MVT::i64, HI,
                              DAG.getConstant(32, MVT::i8));
    Results.push_back(DAG.getNode(ISD::OR, DL, MVT::i64, LO, Tmp));
    Results.push_back(Chain);
    return;
  }

  // Use a buildpair to merge the two 32-bit values into a 64-bit one.
  SDValue Ops[] = { LO, HI };
  SDValue Pair = DAG.getNode(ISD::BUILD_PAIR, DL, MVT::i64, Ops);
  Results.push_back(Pair);
  Results.push_back(Chain);
}

// getReadTimeStampCounter - Handles the lowering of builtin intrinsics that
// read the time stamp counter (x86_rdtsc and x86_rdtscp). This function is
// also used to custom lower READCYCLECOUNTER nodes.
static void getReadTimeStampCounter(SDNode *N, SDLoc DL, unsigned Opcode,
                              SelectionDAG &DAG, const X86Subtarget *Subtarget,
                              SmallVectorImpl<SDValue> &Results) {
  SDVTList Tys = DAG.getVTList(MVT::Other, MVT::Glue);
  SDValue rd = DAG.getNode(Opcode, DL, Tys, N->getOperand(0));
  SDValue LO, HI;

  // The processor's time-stamp counter (a 64-bit MSR) is stored into the
  // EDX:EAX registers. EDX is loaded with the high-order 32 bits of the MSR
  // and the EAX register is loaded with the low-order 32 bits.
  if (Subtarget->is64Bit()) {
    LO = DAG.getCopyFromReg(rd, DL, X86::RAX, MVT::i64, rd.getValue(1));
    HI = DAG.getCopyFromReg(LO.getValue(1), DL, X86::RDX, MVT::i64,
                            LO.getValue(2));
  } else {
    LO = DAG.getCopyFromReg(rd, DL, X86::EAX, MVT::i32, rd.getValue(1));
    HI = DAG.getCopyFromReg(LO.getValue(1), DL, X86::EDX, MVT::i32,
                            LO.getValue(2));
  }
  SDValue Chain = HI.getValue(1);

  if (Opcode == X86ISD::RDTSCP_DAG) {
    assert(N->getNumOperands() == 3 && "Unexpected number of operands!");

    // Instruction RDTSCP loads the IA32:TSC_AUX_MSR (address C000_0103H) into
    // the ECX register. Add 'ecx' explicitly to the chain.
    SDValue ecx = DAG.getCopyFromReg(Chain, DL, X86::ECX, MVT::i32,
                                     HI.getValue(2));
    // Explicitly store the content of ECX at the location passed in input
    // to the 'rdtscp' intrinsic.
    Chain = DAG.getStore(ecx.getValue(1), DL, ecx, N->getOperand(2),
                         MachinePointerInfo(), false, false, 0);
  }

  if (Subtarget->is64Bit()) {
    // The EDX register is loaded with the high-order 32 bits of the MSR, and
    // the EAX register is loaded with the low-order 32 bits.
    SDValue Tmp = DAG.getNode(ISD::SHL, DL, MVT::i64, HI,
                              DAG.getConstant(32, MVT::i8));
    Results.push_back(DAG.getNode(ISD::OR, DL, MVT::i64, LO, Tmp));
    Results.push_back(Chain);
    return;
  }

  // Use a buildpair to merge the two 32-bit values into a 64-bit one.
  SDValue Ops[] = { LO, HI };
  SDValue Pair = DAG.getNode(ISD::BUILD_PAIR, DL, MVT::i64, Ops);
  Results.push_back(Pair);
  Results.push_back(Chain);
}

static SDValue LowerREADCYCLECOUNTER(SDValue Op, const X86Subtarget *Subtarget,
                                     SelectionDAG &DAG) {
  SmallVector<SDValue, 2> Results;
  SDLoc DL(Op);
  getReadTimeStampCounter(Op.getNode(), DL, X86ISD::RDTSC_DAG, DAG, Subtarget,
                          Results);
  return DAG.getMergeValues(Results, DL);
}


static SDValue LowerINTRINSIC_W_CHAIN(SDValue Op, const X86Subtarget *Subtarget,
                                      SelectionDAG &DAG) {
  unsigned IntNo = cast<ConstantSDNode>(Op.getOperand(1))->getZExtValue();

  const IntrinsicData* IntrData = getIntrinsicWithChain(IntNo);
  if (!IntrData)
    return SDValue();

  SDLoc dl(Op);
  switch(IntrData->Type) {
  default:
    llvm_unreachable("Unknown Intrinsic Type");
    break;
  case RDSEED:
  case RDRAND: {
    // Emit the node with the right value type.
    SDVTList VTs = DAG.getVTList(Op->getValueType(0), MVT::Glue, MVT::Other);
    SDValue Result = DAG.getNode(IntrData->Opc0, dl, VTs, Op.getOperand(0));

    // If the value returned by RDRAND/RDSEED was valid (CF=1), return 1.
    // Otherwise return the value from Rand, which is always 0, casted to i32.
    SDValue Ops[] = { DAG.getZExtOrTrunc(Result, dl, Op->getValueType(1)),
                      DAG.getConstant(1, Op->getValueType(1)),
                      DAG.getConstant(X86::COND_B, MVT::i32),
                      SDValue(Result.getNode(), 1) };
    SDValue isValid = DAG.getNode(X86ISD::CMOV, dl,
                                  DAG.getVTList(Op->getValueType(1), MVT::Glue),
                                  Ops);

    // Return { result, isValid, chain }.
    return DAG.getNode(ISD::MERGE_VALUES, dl, Op->getVTList(), Result, isValid,
                       SDValue(Result.getNode(), 2));
  }
  case GATHER: {
  //gather(v1, mask, index, base, scale);
    SDValue Chain = Op.getOperand(0);
    SDValue Src   = Op.getOperand(2);
    SDValue Base  = Op.getOperand(3);
    SDValue Index = Op.getOperand(4);
    SDValue Mask  = Op.getOperand(5);
    SDValue Scale = Op.getOperand(6);
    return getGatherNode(IntrData->Opc0, Op, DAG, Src, Mask, Base, Index, Scale, Chain,
                          Subtarget);
  }
  case SCATTER: {
  //scatter(base, mask, index, v1, scale);
    SDValue Chain = Op.getOperand(0);
    SDValue Base  = Op.getOperand(2);
    SDValue Mask  = Op.getOperand(3);
    SDValue Index = Op.getOperand(4);
    SDValue Src   = Op.getOperand(5);
    SDValue Scale = Op.getOperand(6);
    return getScatterNode(IntrData->Opc0, Op, DAG, Src, Mask, Base, Index, Scale, Chain);
  }
  case PREFETCH: {
    SDValue Hint = Op.getOperand(6);
    unsigned HintVal;
    if (dyn_cast<ConstantSDNode> (Hint) == nullptr ||
        (HintVal = dyn_cast<ConstantSDNode> (Hint)->getZExtValue()) > 1)
      llvm_unreachable("Wrong prefetch hint in intrinsic: should be 0 or 1");
    unsigned Opcode = (HintVal ? IntrData->Opc1 : IntrData->Opc0);
    SDValue Chain = Op.getOperand(0);
    SDValue Mask  = Op.getOperand(2);
    SDValue Index = Op.getOperand(3);
    SDValue Base  = Op.getOperand(4);
    SDValue Scale = Op.getOperand(5);
    return getPrefetchNode(Opcode, Op, DAG, Mask, Base, Index, Scale, Chain);
  }
  // Read Time Stamp Counter (RDTSC) and Processor ID (RDTSCP).
  case RDTSC: {
    SmallVector<SDValue, 2> Results;
    getReadTimeStampCounter(Op.getNode(), dl, IntrData->Opc0, DAG, Subtarget, Results);
    return DAG.getMergeValues(Results, dl);
  }
  // Read Performance Monitoring Counters.
  case RDPMC: {
    SmallVector<SDValue, 2> Results;
    getReadPerformanceCounter(Op.getNode(), dl, DAG, Subtarget, Results);
    return DAG.getMergeValues(Results, dl);
  }
  // XTEST intrinsics.
  case XTEST: {
    SDVTList VTs = DAG.getVTList(Op->getValueType(0), MVT::Other);
    SDValue InTrans = DAG.getNode(IntrData->Opc0, dl, VTs, Op.getOperand(0));
    SDValue SetCC = DAG.getNode(X86ISD::SETCC, dl, MVT::i8,
                                DAG.getConstant(X86::COND_NE, MVT::i8),
                                InTrans);
    SDValue Ret = DAG.getNode(ISD::ZERO_EXTEND, dl, Op->getValueType(0), SetCC);
    return DAG.getNode(ISD::MERGE_VALUES, dl, Op->getVTList(),
                       Ret, SDValue(InTrans.getNode(), 1));
  }
  // ADC/ADCX/SBB
  case ADX: {
    SmallVector<SDValue, 2> Results;
    SDVTList CFVTs = DAG.getVTList(Op->getValueType(0), MVT::Other);
    SDVTList VTs = DAG.getVTList(Op.getOperand(3)->getValueType(0), MVT::Other);
    SDValue GenCF = DAG.getNode(X86ISD::ADD, dl, CFVTs, Op.getOperand(2),
                                DAG.getConstant(-1, MVT::i8));
    SDValue Res = DAG.getNode(IntrData->Opc0, dl, VTs, Op.getOperand(3),
                              Op.getOperand(4), GenCF.getValue(1));
    SDValue Store = DAG.getStore(Op.getOperand(0), dl, Res.getValue(0),
                                 Op.getOperand(5), MachinePointerInfo(),
                                 false, false, 0);
    SDValue SetCC = DAG.getNode(X86ISD::SETCC, dl, MVT::i8,
                                DAG.getConstant(X86::COND_B, MVT::i8),
                                Res.getValue(1));
    Results.push_back(SetCC);
    Results.push_back(Store);
    return DAG.getMergeValues(Results, dl);
  }
  case COMPRESS_TO_MEM: {
    SDLoc dl(Op);
    SDValue Mask = Op.getOperand(4);
    SDValue DataToCompress = Op.getOperand(3);
    SDValue Addr = Op.getOperand(2);
    SDValue Chain = Op.getOperand(0);

    if (isAllOnes(Mask)) // return just a store
      return DAG.getStore(Chain, dl, DataToCompress, Addr,
                          MachinePointerInfo(), false, false, 0);

    EVT VT = DataToCompress.getValueType();
    EVT MaskVT = EVT::getVectorVT(*DAG.getContext(), MVT::i1,
                                  VT.getVectorNumElements());
    EVT BitcastVT = EVT::getVectorVT(*DAG.getContext(), MVT::i1,
                                     Mask.getValueType().getSizeInBits());
    SDValue VMask = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, MaskVT,
                                DAG.getNode(ISD::BITCAST, dl, BitcastVT, Mask),
                                DAG.getIntPtrConstant(0));

    SDValue Compressed =  DAG.getNode(IntrData->Opc0, dl, VT, VMask,
                                      DataToCompress, DAG.getUNDEF(VT));
    return DAG.getStore(Chain, dl, Compressed, Addr,
                        MachinePointerInfo(), false, false, 0);
  }
  case EXPAND_FROM_MEM: {
    SDLoc dl(Op);
    SDValue Mask = Op.getOperand(4);
    SDValue PathThru = Op.getOperand(3);
    SDValue Addr = Op.getOperand(2);
    SDValue Chain = Op.getOperand(0);
    EVT VT = Op.getValueType();

    if (isAllOnes(Mask)) // return just a load
      return DAG.getLoad(VT, dl, Chain, Addr, MachinePointerInfo(), false, false,
                         false, 0);
    EVT MaskVT = EVT::getVectorVT(*DAG.getContext(), MVT::i1,
                                  VT.getVectorNumElements());
    EVT BitcastVT = EVT::getVectorVT(*DAG.getContext(), MVT::i1,
                                     Mask.getValueType().getSizeInBits());
    SDValue VMask = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, MaskVT,
                                DAG.getNode(ISD::BITCAST, dl, BitcastVT, Mask),
                                DAG.getIntPtrConstant(0));

    SDValue DataToExpand = DAG.getLoad(VT, dl, Chain, Addr, MachinePointerInfo(),
                                   false, false, false, 0);

    SmallVector<SDValue, 2> Results;
    Results.push_back(DAG.getNode(IntrData->Opc0, dl, VT, VMask, DataToExpand,
                                  PathThru));
    Results.push_back(Chain);
    return DAG.getMergeValues(Results, dl);
  }
  }
}

SDValue X86TargetLowering::LowerRETURNADDR(SDValue Op,
                                           SelectionDAG &DAG) const {
  MachineFrameInfo *MFI = DAG.getMachineFunction().getFrameInfo();
  MFI->setReturnAddressIsTaken(true);

  if (verifyReturnAddressArgumentIsConstant(Op, DAG))
    return SDValue();

  unsigned Depth = cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue();
  SDLoc dl(Op);
  EVT PtrVT = getPointerTy();

  if (Depth > 0) {
    SDValue FrameAddr = LowerFRAMEADDR(Op, DAG);
    const X86RegisterInfo *RegInfo = Subtarget->getRegisterInfo();
    SDValue Offset = DAG.getConstant(RegInfo->getSlotSize(), PtrVT);
    return DAG.getLoad(PtrVT, dl, DAG.getEntryNode(),
                       DAG.getNode(ISD::ADD, dl, PtrVT,
                                   FrameAddr, Offset),
                       MachinePointerInfo(), false, false, false, 0);
  }

  // Just load the return address.
  SDValue RetAddrFI = getReturnAddressFrameIndex(DAG);
  return DAG.getLoad(PtrVT, dl, DAG.getEntryNode(),
                     RetAddrFI, MachinePointerInfo(), false, false, false, 0);
}

SDValue X86TargetLowering::LowerFRAMEADDR(SDValue Op, SelectionDAG &DAG) const {
  MachineFunction &MF = DAG.getMachineFunction();
  MachineFrameInfo *MFI = MF.getFrameInfo();
  X86MachineFunctionInfo *FuncInfo = MF.getInfo<X86MachineFunctionInfo>();
  const X86RegisterInfo *RegInfo = Subtarget->getRegisterInfo();
  EVT VT = Op.getValueType();

  MFI->setFrameAddressIsTaken(true);

  if (MF.getTarget().getMCAsmInfo()->usesWindowsCFI()) {
    // Depth > 0 makes no sense on targets which use Windows unwind codes.  It
    // is not possible to crawl up the stack without looking at the unwind codes
    // simultaneously.
    int FrameAddrIndex = FuncInfo->getFAIndex();
    if (!FrameAddrIndex) {
      // Set up a frame object for the return address.
      unsigned SlotSize = RegInfo->getSlotSize();
      FrameAddrIndex = MF.getFrameInfo()->CreateFixedObject(
          SlotSize, /*Offset=*/INT64_MIN, /*IsImmutable=*/false);
      FuncInfo->setFAIndex(FrameAddrIndex);
    }
    return DAG.getFrameIndex(FrameAddrIndex, VT);
  }

  unsigned FrameReg =
      RegInfo->getPtrSizedFrameRegister(DAG.getMachineFunction());
  SDLoc dl(Op);  // FIXME probably not meaningful
  unsigned Depth = cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue();
  assert(((FrameReg == X86::RBP && VT == MVT::i64) ||
          (FrameReg == X86::EBP && VT == MVT::i32)) &&
         "Invalid Frame Register!");
  SDValue FrameAddr = DAG.getCopyFromReg(DAG.getEntryNode(), dl, FrameReg, VT);
  while (Depth--)
    FrameAddr = DAG.getLoad(VT, dl, DAG.getEntryNode(), FrameAddr,
                            MachinePointerInfo(),
                            false, false, false, 0);
  return FrameAddr;
}

// FIXME? Maybe this could be a TableGen attribute on some registers and
// this table could be generated automatically from RegInfo.
unsigned X86TargetLowering::getRegisterByName(const char* RegName,
                                              EVT VT) const {
  unsigned Reg = StringSwitch<unsigned>(RegName)
                       .Case("esp", X86::ESP)
                       .Case("rsp", X86::RSP)
                       .Default(0);
  if (Reg)
    return Reg;
  report_fatal_error("Invalid register name global variable");
}

SDValue X86TargetLowering::LowerFRAME_TO_ARGS_OFFSET(SDValue Op,
                                                     SelectionDAG &DAG) const {
  const X86RegisterInfo *RegInfo = Subtarget->getRegisterInfo();
  return DAG.getIntPtrConstant(2 * RegInfo->getSlotSize());
}

SDValue X86TargetLowering::LowerEH_RETURN(SDValue Op, SelectionDAG &DAG) const {
  SDValue Chain     = Op.getOperand(0);
  SDValue Offset    = Op.getOperand(1);
  SDValue Handler   = Op.getOperand(2);
  SDLoc dl      (Op);

  EVT PtrVT = getPointerTy();
  const X86RegisterInfo *RegInfo = Subtarget->getRegisterInfo();
  unsigned FrameReg = RegInfo->getFrameRegister(DAG.getMachineFunction());
  assert(((FrameReg == X86::RBP && PtrVT == MVT::i64) ||
          (FrameReg == X86::EBP && PtrVT == MVT::i32)) &&
         "Invalid Frame Register!");
  SDValue Frame = DAG.getCopyFromReg(DAG.getEntryNode(), dl, FrameReg, PtrVT);
  unsigned StoreAddrReg = (PtrVT == MVT::i64) ? X86::RCX : X86::ECX;

  SDValue StoreAddr = DAG.getNode(ISD::ADD, dl, PtrVT, Frame,
                                 DAG.getIntPtrConstant(RegInfo->getSlotSize()));
  StoreAddr = DAG.getNode(ISD::ADD, dl, PtrVT, StoreAddr, Offset);
  Chain = DAG.getStore(Chain, dl, Handler, StoreAddr, MachinePointerInfo(),
                       false, false, 0);
  Chain = DAG.getCopyToReg(Chain, dl, StoreAddrReg, StoreAddr);

  return DAG.getNode(X86ISD::EH_RETURN, dl, MVT::Other, Chain,
                     DAG.getRegister(StoreAddrReg, PtrVT));
}

SDValue X86TargetLowering::lowerEH_SJLJ_SETJMP(SDValue Op,
                                               SelectionDAG &DAG) const {
  SDLoc DL(Op);
  return DAG.getNode(X86ISD::EH_SJLJ_SETJMP, DL,
                     DAG.getVTList(MVT::i32, MVT::Other),
                     Op.getOperand(0), Op.getOperand(1));
}

SDValue X86TargetLowering::lowerEH_SJLJ_LONGJMP(SDValue Op,
                                                SelectionDAG &DAG) const {
  SDLoc DL(Op);
  return DAG.getNode(X86ISD::EH_SJLJ_LONGJMP, DL, MVT::Other,
                     Op.getOperand(0), Op.getOperand(1));
}

static SDValue LowerADJUST_TRAMPOLINE(SDValue Op, SelectionDAG &DAG) {
  return Op.getOperand(0);
}

SDValue X86TargetLowering::LowerINIT_TRAMPOLINE(SDValue Op,
                                                SelectionDAG &DAG) const {
  SDValue Root = Op.getOperand(0);
  SDValue Trmp = Op.getOperand(1); // trampoline
  SDValue FPtr = Op.getOperand(2); // nested function
  SDValue Nest = Op.getOperand(3); // 'nest' parameter value
  SDLoc dl (Op);

  const Value *TrmpAddr = cast<SrcValueSDNode>(Op.getOperand(4))->getValue();
  const TargetRegisterInfo *TRI = Subtarget->getRegisterInfo();

  if (Subtarget->is64Bit()) {
    SDValue OutChains[6];

    // Large code-model.
    const unsigned char JMP64r  = 0xFF; // 64-bit jmp through register opcode.
    const unsigned char MOV64ri = 0xB8; // X86::MOV64ri opcode.

    const unsigned char N86R10 = TRI->getEncodingValue(X86::R10) & 0x7;
    const unsigned char N86R11 = TRI->getEncodingValue(X86::R11) & 0x7;

    const unsigned char REX_WB = 0x40 | 0x08 | 0x01; // REX prefix

    // Load the pointer to the nested function into R11.
    unsigned OpCode = ((MOV64ri | N86R11) << 8) | REX_WB; // movabsq r11
    SDValue Addr = Trmp;
    OutChains[0] = DAG.getStore(Root, dl, DAG.getConstant(OpCode, MVT::i16),
                                Addr, MachinePointerInfo(TrmpAddr),
                                false, false, 0);

    Addr = DAG.getNode(ISD::ADD, dl, MVT::i64, Trmp,
                       DAG.getConstant(2, MVT::i64));
    OutChains[1] = DAG.getStore(Root, dl, FPtr, Addr,
                                MachinePointerInfo(TrmpAddr, 2),
                                false, false, 2);

    // Load the 'nest' parameter value into R10.
    // R10 is specified in X86CallingConv.td
    OpCode = ((MOV64ri | N86R10) << 8) | REX_WB; // movabsq r10
    Addr = DAG.getNode(ISD::ADD, dl, MVT::i64, Trmp,
                       DAG.getConstant(10, MVT::i64));
    OutChains[2] = DAG.getStore(Root, dl, DAG.getConstant(OpCode, MVT::i16),
                                Addr, MachinePointerInfo(TrmpAddr, 10),
                                false, false, 0);

    Addr = DAG.getNode(ISD::ADD, dl, MVT::i64, Trmp,
                       DAG.getConstant(12, MVT::i64));
    OutChains[3] = DAG.getStore(Root, dl, Nest, Addr,
                                MachinePointerInfo(TrmpAddr, 12),
                                false, false, 2);

    // Jump to the nested function.
    OpCode = (JMP64r << 8) | REX_WB; // jmpq *...
    Addr = DAG.getNode(ISD::ADD, dl, MVT::i64, Trmp,
                       DAG.getConstant(20, MVT::i64));
    OutChains[4] = DAG.getStore(Root, dl, DAG.getConstant(OpCode, MVT::i16),
                                Addr, MachinePointerInfo(TrmpAddr, 20),
                                false, false, 0);

    unsigned char ModRM = N86R11 | (4 << 3) | (3 << 6); // ...r11
    Addr = DAG.getNode(ISD::ADD, dl, MVT::i64, Trmp,
                       DAG.getConstant(22, MVT::i64));
    OutChains[5] = DAG.getStore(Root, dl, DAG.getConstant(ModRM, MVT::i8), Addr,
                                MachinePointerInfo(TrmpAddr, 22),
                                false, false, 0);

    return DAG.getNode(ISD::TokenFactor, dl, MVT::Other, OutChains);
  } else {
    const Function *Func =
      cast<Function>(cast<SrcValueSDNode>(Op.getOperand(5))->getValue());
    CallingConv::ID CC = Func->getCallingConv();
    unsigned NestReg;

    switch (CC) {
    default:
      llvm_unreachable("Unsupported calling convention");
    case CallingConv::C:
    case CallingConv::X86_StdCall: {
      // Pass 'nest' parameter in ECX.
      // Must be kept in sync with X86CallingConv.td
      NestReg = X86::ECX;

      // Check that ECX wasn't needed by an 'inreg' parameter.
      FunctionType *FTy = Func->getFunctionType();
      const AttributeSet &Attrs = Func->getAttributes();

      if (!Attrs.isEmpty() && !Func->isVarArg()) {
        unsigned InRegCount = 0;
        unsigned Idx = 1;

        for (FunctionType::param_iterator I = FTy->param_begin(),
             E = FTy->param_end(); I != E; ++I, ++Idx)
          if (Attrs.hasAttribute(Idx, Attribute::InReg))
            // FIXME: should only count parameters that are lowered to integers.
            InRegCount += (TD->getTypeSizeInBits(*I) + 31) / 32;

        if (InRegCount > 2) {
          report_fatal_error("Nest register in use - reduce number of inreg"
                             " parameters!");
        }
      }
      break;
    }
    case CallingConv::X86_FastCall:
    case CallingConv::X86_ThisCall:
    case CallingConv::Fast:
      // Pass 'nest' parameter in EAX.
      // Must be kept in sync with X86CallingConv.td
      NestReg = X86::EAX;
      break;
    }

    SDValue OutChains[4];
    SDValue Addr, Disp;

    Addr = DAG.getNode(ISD::ADD, dl, MVT::i32, Trmp,
                       DAG.getConstant(10, MVT::i32));
    Disp = DAG.getNode(ISD::SUB, dl, MVT::i32, FPtr, Addr);

    // This is storing the opcode for MOV32ri.
    const unsigned char MOV32ri = 0xB8; // X86::MOV32ri's opcode byte.
    const unsigned char N86Reg = TRI->getEncodingValue(NestReg) & 0x7;
    OutChains[0] = DAG.getStore(Root, dl,
                                DAG.getConstant(MOV32ri|N86Reg, MVT::i8),
                                Trmp, MachinePointerInfo(TrmpAddr),
                                false, false, 0);

    Addr = DAG.getNode(ISD::ADD, dl, MVT::i32, Trmp,
                       DAG.getConstant(1, MVT::i32));
    OutChains[1] = DAG.getStore(Root, dl, Nest, Addr,
                                MachinePointerInfo(TrmpAddr, 1),
                                false, false, 1);

    const unsigned char JMP = 0xE9; // jmp <32bit dst> opcode.
    Addr = DAG.getNode(ISD::ADD, dl, MVT::i32, Trmp,
                       DAG.getConstant(5, MVT::i32));
    OutChains[2] = DAG.getStore(Root, dl, DAG.getConstant(JMP, MVT::i8), Addr,
                                MachinePointerInfo(TrmpAddr, 5),
                                false, false, 1);

    Addr = DAG.getNode(ISD::ADD, dl, MVT::i32, Trmp,
                       DAG.getConstant(6, MVT::i32));
    OutChains[3] = DAG.getStore(Root, dl, Disp, Addr,
                                MachinePointerInfo(TrmpAddr, 6),
                                false, false, 1);

    return DAG.getNode(ISD::TokenFactor, dl, MVT::Other, OutChains);
  }
}

SDValue X86TargetLowering::LowerFLT_ROUNDS_(SDValue Op,
                                            SelectionDAG &DAG) const {
  /*
   The rounding mode is in bits 11:10 of FPSR, and has the following
   settings:
     00 Round to nearest
     01 Round to -inf
     10 Round to +inf
     11 Round to 0

  FLT_ROUNDS, on the other hand, expects the following:
    -1 Undefined
     0 Round to 0
     1 Round to nearest
     2 Round to +inf
     3 Round to -inf

  To perform the conversion, we do:
    (((((FPSR & 0x800) >> 11) | ((FPSR & 0x400) >> 9)) + 1) & 3)
  */

  MachineFunction &MF = DAG.getMachineFunction();
  const TargetFrameLowering &TFI = *Subtarget->getFrameLowering();
  unsigned StackAlignment = TFI.getStackAlignment();
  MVT VT = Op.getSimpleValueType();
  SDLoc DL(Op);

  // Save FP Control Word to stack slot
  int SSFI = MF.getFrameInfo()->CreateStackObject(2, StackAlignment, false);
  SDValue StackSlot = DAG.getFrameIndex(SSFI, getPointerTy());

  MachineMemOperand *MMO =
   MF.getMachineMemOperand(MachinePointerInfo::getFixedStack(SSFI),
                           MachineMemOperand::MOStore, 2, 2);

  SDValue Ops[] = { DAG.getEntryNode(), StackSlot };
  SDValue Chain = DAG.getMemIntrinsicNode(X86ISD::FNSTCW16m, DL,
                                          DAG.getVTList(MVT::Other),
                                          Ops, MVT::i16, MMO);

  // Load FP Control Word from stack slot
  SDValue CWD = DAG.getLoad(MVT::i16, DL, Chain, StackSlot,
                            MachinePointerInfo(), false, false, false, 0);

  // Transform as necessary
  SDValue CWD1 =
    DAG.getNode(ISD::SRL, DL, MVT::i16,
                DAG.getNode(ISD::AND, DL, MVT::i16,
                            CWD, DAG.getConstant(0x800, MVT::i16)),
                DAG.getConstant(11, MVT::i8));
  SDValue CWD2 =
    DAG.getNode(ISD::SRL, DL, MVT::i16,
                DAG.getNode(ISD::AND, DL, MVT::i16,
                            CWD, DAG.getConstant(0x400, MVT::i16)),
                DAG.getConstant(9, MVT::i8));

  SDValue RetVal =
    DAG.getNode(ISD::AND, DL, MVT::i16,
                DAG.getNode(ISD::ADD, DL, MVT::i16,
                            DAG.getNode(ISD::OR, DL, MVT::i16, CWD1, CWD2),
                            DAG.getConstant(1, MVT::i16)),
                DAG.getConstant(3, MVT::i16));

  return DAG.getNode((VT.getSizeInBits() < 16 ?
                      ISD::TRUNCATE : ISD::ZERO_EXTEND), DL, VT, RetVal);
}

static SDValue LowerCTLZ(SDValue Op, SelectionDAG &DAG) {
  MVT VT = Op.getSimpleValueType();
  EVT OpVT = VT;
  unsigned NumBits = VT.getSizeInBits();
  SDLoc dl(Op);

  Op = Op.getOperand(0);
  if (VT == MVT::i8) {
    // Zero extend to i32 since there is not an i8 bsr.
    OpVT = MVT::i32;
    Op = DAG.getNode(ISD::ZERO_EXTEND, dl, OpVT, Op);
  }

  // Issue a bsr (scan bits in reverse) which also sets EFLAGS.
  SDVTList VTs = DAG.getVTList(OpVT, MVT::i32);
  Op = DAG.getNode(X86ISD::BSR, dl, VTs, Op);

  // If src is zero (i.e. bsr sets ZF), returns NumBits.
  SDValue Ops[] = {
    Op,
    DAG.getConstant(NumBits+NumBits-1, OpVT),
    DAG.getConstant(X86::COND_E, MVT::i8),
    Op.getValue(1)
  };
  Op = DAG.getNode(X86ISD::CMOV, dl, OpVT, Ops);

  // Finally xor with NumBits-1.
  Op = DAG.getNode(ISD::XOR, dl, OpVT, Op, DAG.getConstant(NumBits-1, OpVT));

  if (VT == MVT::i8)
    Op = DAG.getNode(ISD::TRUNCATE, dl, MVT::i8, Op);
  return Op;
}

static SDValue LowerCTLZ_ZERO_UNDEF(SDValue Op, SelectionDAG &DAG) {
  MVT VT = Op.getSimpleValueType();
  EVT OpVT = VT;
  unsigned NumBits = VT.getSizeInBits();
  SDLoc dl(Op);

  Op = Op.getOperand(0);
  if (VT == MVT::i8) {
    // Zero extend to i32 since there is not an i8 bsr.
    OpVT = MVT::i32;
    Op = DAG.getNode(ISD::ZERO_EXTEND, dl, OpVT, Op);
  }

  // Issue a bsr (scan bits in reverse).
  SDVTList VTs = DAG.getVTList(OpVT, MVT::i32);
  Op = DAG.getNode(X86ISD::BSR, dl, VTs, Op);

  // And xor with NumBits-1.
  Op = DAG.getNode(ISD::XOR, dl, OpVT, Op, DAG.getConstant(NumBits-1, OpVT));

  if (VT == MVT::i8)
    Op = DAG.getNode(ISD::TRUNCATE, dl, MVT::i8, Op);
  return Op;
}

static SDValue LowerCTTZ(SDValue Op, SelectionDAG &DAG) {
  MVT VT = Op.getSimpleValueType();
  unsigned NumBits = VT.getSizeInBits();
  SDLoc dl(Op);
  Op = Op.getOperand(0);

  // Issue a bsf (scan bits forward) which also sets EFLAGS.
  SDVTList VTs = DAG.getVTList(VT, MVT::i32);
  Op = DAG.getNode(X86ISD::BSF, dl, VTs, Op);

  // If src is zero (i.e. bsf sets ZF), returns NumBits.
  SDValue Ops[] = {
    Op,
    DAG.getConstant(NumBits, VT),
    DAG.getConstant(X86::COND_E, MVT::i8),
    Op.getValue(1)
  };
  return DAG.getNode(X86ISD::CMOV, dl, VT, Ops);
}

// Lower256IntArith - Break a 256-bit integer operation into two new 128-bit
// ones, and then concatenate the result back.
static SDValue Lower256IntArith(SDValue Op, SelectionDAG &DAG) {
  MVT VT = Op.getSimpleValueType();

  assert(VT.is256BitVector() && VT.isInteger() &&
         "Unsupported value type for operation");

  unsigned NumElems = VT.getVectorNumElements();
  SDLoc dl(Op);

  // Extract the LHS vectors
  SDValue LHS = Op.getOperand(0);
  SDValue LHS1 = Extract128BitVector(LHS, 0, DAG, dl);
  SDValue LHS2 = Extract128BitVector(LHS, NumElems/2, DAG, dl);

  // Extract the RHS vectors
  SDValue RHS = Op.getOperand(1);
  SDValue RHS1 = Extract128BitVector(RHS, 0, DAG, dl);
  SDValue RHS2 = Extract128BitVector(RHS, NumElems/2, DAG, dl);

  MVT EltVT = VT.getVectorElementType();
  MVT NewVT = MVT::getVectorVT(EltVT, NumElems/2);

  return DAG.getNode(ISD::CONCAT_VECTORS, dl, VT,
                     DAG.getNode(Op.getOpcode(), dl, NewVT, LHS1, RHS1),
                     DAG.getNode(Op.getOpcode(), dl, NewVT, LHS2, RHS2));
}

static SDValue LowerADD(SDValue Op, SelectionDAG &DAG) {
  assert(Op.getSimpleValueType().is256BitVector() &&
         Op.getSimpleValueType().isInteger() &&
         "Only handle AVX 256-bit vector integer operation");
  return Lower256IntArith(Op, DAG);
}

static SDValue LowerSUB(SDValue Op, SelectionDAG &DAG) {
  assert(Op.getSimpleValueType().is256BitVector() &&
         Op.getSimpleValueType().isInteger() &&
         "Only handle AVX 256-bit vector integer operation");
  return Lower256IntArith(Op, DAG);
}

static SDValue LowerMUL(SDValue Op, const X86Subtarget *Subtarget,
                        SelectionDAG &DAG) {
  SDLoc dl(Op);
  MVT VT = Op.getSimpleValueType();

  // Decompose 256-bit ops into smaller 128-bit ops.
  if (VT.is256BitVector() && !Subtarget->hasInt256())
    return Lower256IntArith(Op, DAG);

  SDValue A = Op.getOperand(0);
  SDValue B = Op.getOperand(1);

  // Lower v4i32 mul as 2x shuffle, 2x pmuludq, 2x shuffle.
  if (VT == MVT::v4i32) {
    assert(Subtarget->hasSSE2() && !Subtarget->hasSSE41() &&
           "Should not custom lower when pmuldq is available!");

    // Extract the odd parts.
    static const int UnpackMask[] = { 1, -1, 3, -1 };
    SDValue Aodds = DAG.getVectorShuffle(VT, dl, A, A, UnpackMask);
    SDValue Bodds = DAG.getVectorShuffle(VT, dl, B, B, UnpackMask);

    // Multiply the even parts.
    SDValue Evens = DAG.getNode(X86ISD::PMULUDQ, dl, MVT::v2i64, A, B);
    // Now multiply odd parts.
    SDValue Odds = DAG.getNode(X86ISD::PMULUDQ, dl, MVT::v2i64, Aodds, Bodds);

    Evens = DAG.getNode(ISD::BITCAST, dl, VT, Evens);
    Odds = DAG.getNode(ISD::BITCAST, dl, VT, Odds);

    // Merge the two vectors back together with a shuffle. This expands into 2
    // shuffles.
    static const int ShufMask[] = { 0, 4, 2, 6 };
    return DAG.getVectorShuffle(VT, dl, Evens, Odds, ShufMask);
  }

  assert((VT == MVT::v2i64 || VT == MVT::v4i64 || VT == MVT::v8i64) &&
         "Only know how to lower V2I64/V4I64/V8I64 multiply");

  //  Ahi = psrlqi(a, 32);
  //  Bhi = psrlqi(b, 32);
  //
  //  AloBlo = pmuludq(a, b);
  //  AloBhi = pmuludq(a, Bhi);
  //  AhiBlo = pmuludq(Ahi, b);

  //  AloBhi = psllqi(AloBhi, 32);
  //  AhiBlo = psllqi(AhiBlo, 32);
  //  return AloBlo + AloBhi + AhiBlo;

  SDValue Ahi = getTargetVShiftByConstNode(X86ISD::VSRLI, dl, VT, A, 32, DAG);
  SDValue Bhi = getTargetVShiftByConstNode(X86ISD::VSRLI, dl, VT, B, 32, DAG);

  // Bit cast to 32-bit vectors for MULUDQ
  EVT MulVT = (VT == MVT::v2i64) ? MVT::v4i32 :
                                  (VT == MVT::v4i64) ? MVT::v8i32 : MVT::v16i32;
  A = DAG.getNode(ISD::BITCAST, dl, MulVT, A);
  B = DAG.getNode(ISD::BITCAST, dl, MulVT, B);
  Ahi = DAG.getNode(ISD::BITCAST, dl, MulVT, Ahi);
  Bhi = DAG.getNode(ISD::BITCAST, dl, MulVT, Bhi);

  SDValue AloBlo = DAG.getNode(X86ISD::PMULUDQ, dl, VT, A, B);
  SDValue AloBhi = DAG.getNode(X86ISD::PMULUDQ, dl, VT, A, Bhi);
  SDValue AhiBlo = DAG.getNode(X86ISD::PMULUDQ, dl, VT, Ahi, B);

  AloBhi = getTargetVShiftByConstNode(X86ISD::VSHLI, dl, VT, AloBhi, 32, DAG);
  AhiBlo = getTargetVShiftByConstNode(X86ISD::VSHLI, dl, VT, AhiBlo, 32, DAG);

  SDValue Res = DAG.getNode(ISD::ADD, dl, VT, AloBlo, AloBhi);
  return DAG.getNode(ISD::ADD, dl, VT, Res, AhiBlo);
}

SDValue X86TargetLowering::LowerWin64_i128OP(SDValue Op, SelectionDAG &DAG) const {
  assert(Subtarget->isTargetWin64() && "Unexpected target");
  EVT VT = Op.getValueType();
  assert(VT.isInteger() && VT.getSizeInBits() == 128 &&
         "Unexpected return type for lowering");

  RTLIB::Libcall LC;
  bool isSigned;
  switch (Op->getOpcode()) {
  default: llvm_unreachable("Unexpected request for libcall!");
  case ISD::SDIV:      isSigned = true;  LC = RTLIB::SDIV_I128;    break;
  case ISD::UDIV:      isSigned = false; LC = RTLIB::UDIV_I128;    break;
  case ISD::SREM:      isSigned = true;  LC = RTLIB::SREM_I128;    break;
  case ISD::UREM:      isSigned = false; LC = RTLIB::UREM_I128;    break;
  case ISD::SDIVREM:   isSigned = true;  LC = RTLIB::SDIVREM_I128; break;
  case ISD::UDIVREM:   isSigned = false; LC = RTLIB::UDIVREM_I128; break;
  }

  SDLoc dl(Op);
  SDValue InChain = DAG.getEntryNode();

  TargetLowering::ArgListTy Args;
  TargetLowering::ArgListEntry Entry;
  for (unsigned i = 0, e = Op->getNumOperands(); i != e; ++i) {
    EVT ArgVT = Op->getOperand(i).getValueType();
    assert(ArgVT.isInteger() && ArgVT.getSizeInBits() == 128 &&
           "Unexpected argument type for lowering");
    SDValue StackPtr = DAG.CreateStackTemporary(ArgVT, 16);
    Entry.Node = StackPtr;
    InChain = DAG.getStore(InChain, dl, Op->getOperand(i), StackPtr, MachinePointerInfo(),
                           false, false, 16);
    Type *ArgTy = ArgVT.getTypeForEVT(*DAG.getContext());
    Entry.Ty = PointerType::get(ArgTy,0);
    Entry.isSExt = false;
    Entry.isZExt = false;
    Args.push_back(Entry);
  }

  SDValue Callee = DAG.getExternalSymbol(getLibcallName(LC),
                                         getPointerTy());

  TargetLowering::CallLoweringInfo CLI(DAG);
  CLI.setDebugLoc(dl).setChain(InChain)
    .setCallee(getLibcallCallingConv(LC),
               static_cast<EVT>(MVT::v2i64).getTypeForEVT(*DAG.getContext()),
               Callee, std::move(Args), 0)
    .setInRegister().setSExtResult(isSigned).setZExtResult(!isSigned);

  std::pair<SDValue, SDValue> CallInfo = LowerCallTo(CLI);
  return DAG.getNode(ISD::BITCAST, dl, VT, CallInfo.first);
}

static SDValue LowerMUL_LOHI(SDValue Op, const X86Subtarget *Subtarget,
                             SelectionDAG &DAG) {
  SDValue Op0 = Op.getOperand(0), Op1 = Op.getOperand(1);
  EVT VT = Op0.getValueType();
  SDLoc dl(Op);

  assert((VT == MVT::v4i32 && Subtarget->hasSSE2()) ||
         (VT == MVT::v8i32 && Subtarget->hasInt256()));

  // PMULxD operations multiply each even value (starting at 0) of LHS with
  // the related value of RHS and produce a widen result.
  // E.g., PMULUDQ <4 x i32> <a|b|c|d>, <4 x i32> <e|f|g|h>
  // => <2 x i64> <ae|cg>
  //
  // In other word, to have all the results, we need to perform two PMULxD:
  // 1. one with the even values.
  // 2. one with the odd values.
  // To achieve #2, with need to place the odd values at an even position.
  //
  // Place the odd value at an even position (basically, shift all values 1
  // step to the left):
  const int Mask[] = {1, -1, 3, -1, 5, -1, 7, -1};
  // <a|b|c|d> => <b|undef|d|undef>
  SDValue Odd0 = DAG.getVectorShuffle(VT, dl, Op0, Op0, Mask);
  // <e|f|g|h> => <f|undef|h|undef>
  SDValue Odd1 = DAG.getVectorShuffle(VT, dl, Op1, Op1, Mask);

  // Emit two multiplies, one for the lower 2 ints and one for the higher 2
  // ints.
  MVT MulVT = VT == MVT::v4i32 ? MVT::v2i64 : MVT::v4i64;
  bool IsSigned = Op->getOpcode() == ISD::SMUL_LOHI;
  unsigned Opcode =
      (!IsSigned || !Subtarget->hasSSE41()) ? X86ISD::PMULUDQ : X86ISD::PMULDQ;
  // PMULUDQ <4 x i32> <a|b|c|d>, <4 x i32> <e|f|g|h>
  // => <2 x i64> <ae|cg>
  SDValue Mul1 = DAG.getNode(ISD::BITCAST, dl, VT,
                             DAG.getNode(Opcode, dl, MulVT, Op0, Op1));
  // PMULUDQ <4 x i32> <b|undef|d|undef>, <4 x i32> <f|undef|h|undef>
  // => <2 x i64> <bf|dh>
  SDValue Mul2 = DAG.getNode(ISD::BITCAST, dl, VT,
                             DAG.getNode(Opcode, dl, MulVT, Odd0, Odd1));

  // Shuffle it back into the right order.
  SDValue Highs, Lows;
  if (VT == MVT::v8i32) {
    const int HighMask[] = {1, 9, 3, 11, 5, 13, 7, 15};
    Highs = DAG.getVectorShuffle(VT, dl, Mul1, Mul2, HighMask);
    const int LowMask[] = {0, 8, 2, 10, 4, 12, 6, 14};
    Lows = DAG.getVectorShuffle(VT, dl, Mul1, Mul2, LowMask);
  } else {
    const int HighMask[] = {1, 5, 3, 7};
    Highs = DAG.getVectorShuffle(VT, dl, Mul1, Mul2, HighMask);
    const int LowMask[] = {0, 4, 2, 6};
    Lows = DAG.getVectorShuffle(VT, dl, Mul1, Mul2, LowMask);
  }

  // If we have a signed multiply but no PMULDQ fix up the high parts of a
  // unsigned multiply.
  if (IsSigned && !Subtarget->hasSSE41()) {
    SDValue ShAmt =
        DAG.getConstant(31, DAG.getTargetLoweringInfo().getShiftAmountTy(VT));
    SDValue T1 = DAG.getNode(ISD::AND, dl, VT,
                             DAG.getNode(ISD::SRA, dl, VT, Op0, ShAmt), Op1);
    SDValue T2 = DAG.getNode(ISD::AND, dl, VT,
                             DAG.getNode(ISD::SRA, dl, VT, Op1, ShAmt), Op0);

    SDValue Fixup = DAG.getNode(ISD::ADD, dl, VT, T1, T2);
    Highs = DAG.getNode(ISD::SUB, dl, VT, Highs, Fixup);
  }

  // The first result of MUL_LOHI is actually the low value, followed by the
  // high value.
  SDValue Ops[] = {Lows, Highs};
  return DAG.getMergeValues(Ops, dl);
}

static SDValue LowerScalarImmediateShift(SDValue Op, SelectionDAG &DAG,
                                         const X86Subtarget *Subtarget) {
  MVT VT = Op.getSimpleValueType();
  SDLoc dl(Op);
  SDValue R = Op.getOperand(0);
  SDValue Amt = Op.getOperand(1);

  // Optimize shl/srl/sra with constant shift amount.
  if (auto *BVAmt = dyn_cast<BuildVectorSDNode>(Amt)) {
    if (auto *ShiftConst = BVAmt->getConstantSplatNode()) {
      uint64_t ShiftAmt = ShiftConst->getZExtValue();

      if (VT == MVT::v2i64 || VT == MVT::v4i32 || VT == MVT::v8i16 ||
          (Subtarget->hasInt256() &&
           (VT == MVT::v4i64 || VT == MVT::v8i32 || VT == MVT::v16i16)) ||
          (Subtarget->hasAVX512() &&
           (VT == MVT::v8i64 || VT == MVT::v16i32))) {
        if (Op.getOpcode() == ISD::SHL)
          return getTargetVShiftByConstNode(X86ISD::VSHLI, dl, VT, R, ShiftAmt,
                                            DAG);
        if (Op.getOpcode() == ISD::SRL)
          return getTargetVShiftByConstNode(X86ISD::VSRLI, dl, VT, R, ShiftAmt,
                                            DAG);
        if (Op.getOpcode() == ISD::SRA && VT != MVT::v2i64 && VT != MVT::v4i64)
          return getTargetVShiftByConstNode(X86ISD::VSRAI, dl, VT, R, ShiftAmt,
                                            DAG);
      }

      if (VT == MVT::v16i8) {
        if (Op.getOpcode() == ISD::SHL) {
          // Make a large shift.
          SDValue SHL = getTargetVShiftByConstNode(X86ISD::VSHLI, dl,
                                                   MVT::v8i16, R, ShiftAmt,
                                                   DAG);
          SHL = DAG.getNode(ISD::BITCAST, dl, VT, SHL);
          // Zero out the rightmost bits.
          SmallVector<SDValue, 16> V(16,
                                     DAG.getConstant(uint8_t(-1U << ShiftAmt),
                                                     MVT::i8));
          return DAG.getNode(ISD::AND, dl, VT, SHL,
                             DAG.getNode(ISD::BUILD_VECTOR, dl, VT, V));
        }
        if (Op.getOpcode() == ISD::SRL) {
          // Make a large shift.
          SDValue SRL = getTargetVShiftByConstNode(X86ISD::VSRLI, dl,
                                                   MVT::v8i16, R, ShiftAmt,
                                                   DAG);
          SRL = DAG.getNode(ISD::BITCAST, dl, VT, SRL);
          // Zero out the leftmost bits.
          SmallVector<SDValue, 16> V(16,
                                     DAG.getConstant(uint8_t(-1U) >> ShiftAmt,
                                                     MVT::i8));
          return DAG.getNode(ISD::AND, dl, VT, SRL,
                             DAG.getNode(ISD::BUILD_VECTOR, dl, VT, V));
        }
        if (Op.getOpcode() == ISD::SRA) {
          if (ShiftAmt == 7) {
            // R s>> 7  ===  R s< 0
            SDValue Zeros = getZeroVector(VT, Subtarget, DAG, dl);
            return DAG.getNode(X86ISD::PCMPGT, dl, VT, Zeros, R);
          }

          // R s>> a === ((R u>> a) ^ m) - m
          SDValue Res = DAG.getNode(ISD::SRL, dl, VT, R, Amt);
          SmallVector<SDValue, 16> V(16, DAG.getConstant(128 >> ShiftAmt,
                                                         MVT::i8));
          SDValue Mask = DAG.getNode(ISD::BUILD_VECTOR, dl, VT, V);
          Res = DAG.getNode(ISD::XOR, dl, VT, Res, Mask);
          Res = DAG.getNode(ISD::SUB, dl, VT, Res, Mask);
          return Res;
        }
        llvm_unreachable("Unknown shift opcode.");
      }

      if (Subtarget->hasInt256() && VT == MVT::v32i8) {
        if (Op.getOpcode() == ISD::SHL) {
          // Make a large shift.
          SDValue SHL = getTargetVShiftByConstNode(X86ISD::VSHLI, dl,
                                                   MVT::v16i16, R, ShiftAmt,
                                                   DAG);
          SHL = DAG.getNode(ISD::BITCAST, dl, VT, SHL);
          // Zero out the rightmost bits.
          SmallVector<SDValue, 32> V(32,
                                     DAG.getConstant(uint8_t(-1U << ShiftAmt),
                                                     MVT::i8));
          return DAG.getNode(ISD::AND, dl, VT, SHL,
                             DAG.getNode(ISD::BUILD_VECTOR, dl, VT, V));
        }
        if (Op.getOpcode() == ISD::SRL) {
          // Make a large shift.
          SDValue SRL = getTargetVShiftByConstNode(X86ISD::VSRLI, dl,
                                                   MVT::v16i16, R, ShiftAmt,
                                                   DAG);
          SRL = DAG.getNode(ISD::BITCAST, dl, VT, SRL);
          // Zero out the leftmost bits.
          SmallVector<SDValue, 32> V(32,
                                     DAG.getConstant(uint8_t(-1U) >> ShiftAmt,
                                                     MVT::i8));
          return DAG.getNode(ISD::AND, dl, VT, SRL,
                             DAG.getNode(ISD::BUILD_VECTOR, dl, VT, V));
        }
        if (Op.getOpcode() == ISD::SRA) {
          if (ShiftAmt == 7) {
            // R s>> 7  ===  R s< 0
            SDValue Zeros = getZeroVector(VT, Subtarget, DAG, dl);
            return DAG.getNode(X86ISD::PCMPGT, dl, VT, Zeros, R);
          }

          // R s>> a === ((R u>> a) ^ m) - m
          SDValue Res = DAG.getNode(ISD::SRL, dl, VT, R, Amt);
          SmallVector<SDValue, 32> V(32, DAG.getConstant(128 >> ShiftAmt,
                                                         MVT::i8));
          SDValue Mask = DAG.getNode(ISD::BUILD_VECTOR, dl, VT, V);
          Res = DAG.getNode(ISD::XOR, dl, VT, Res, Mask);
          Res = DAG.getNode(ISD::SUB, dl, VT, Res, Mask);
          return Res;
        }
        llvm_unreachable("Unknown shift opcode.");
      }
    }
  }

  // Special case in 32-bit mode, where i64 is expanded into high and low parts.
  if (!Subtarget->is64Bit() &&
      (VT == MVT::v2i64 || (Subtarget->hasInt256() && VT == MVT::v4i64)) &&
      Amt.getOpcode() == ISD::BITCAST &&
      Amt.getOperand(0).getOpcode() == ISD::BUILD_VECTOR) {
    Amt = Amt.getOperand(0);
    unsigned Ratio = Amt.getSimpleValueType().getVectorNumElements() /
                     VT.getVectorNumElements();
    unsigned RatioInLog2 = Log2_32_Ceil(Ratio);
    uint64_t ShiftAmt = 0;
    for (unsigned i = 0; i != Ratio; ++i) {
      ConstantSDNode *C = dyn_cast<ConstantSDNode>(Amt.getOperand(i));
      if (!C)
        return SDValue();
      // 6 == Log2(64)
      ShiftAmt |= C->getZExtValue() << (i * (1 << (6 - RatioInLog2)));
    }
    // Check remaining shift amounts.
    for (unsigned i = Ratio; i != Amt.getNumOperands(); i += Ratio) {
      uint64_t ShAmt = 0;
      for (unsigned j = 0; j != Ratio; ++j) {
        ConstantSDNode *C =
          dyn_cast<ConstantSDNode>(Amt.getOperand(i + j));
        if (!C)
          return SDValue();
        // 6 == Log2(64)
        ShAmt |= C->getZExtValue() << (j * (1 << (6 - RatioInLog2)));
      }
      if (ShAmt != ShiftAmt)
        return SDValue();
    }
    switch (Op.getOpcode()) {
    default:
      llvm_unreachable("Unknown shift opcode!");
    case ISD::SHL:
      return getTargetVShiftByConstNode(X86ISD::VSHLI, dl, VT, R, ShiftAmt,
                                        DAG);
    case ISD::SRL:
      return getTargetVShiftByConstNode(X86ISD::VSRLI, dl, VT, R, ShiftAmt,
                                        DAG);
    case ISD::SRA:
      return getTargetVShiftByConstNode(X86ISD::VSRAI, dl, VT, R, ShiftAmt,
                                        DAG);
    }
  }

  return SDValue();
}

static SDValue LowerScalarVariableShift(SDValue Op, SelectionDAG &DAG,
                                        const X86Subtarget* Subtarget) {
  MVT VT = Op.getSimpleValueType();
  SDLoc dl(Op);
  SDValue R = Op.getOperand(0);
  SDValue Amt = Op.getOperand(1);

  if ((VT == MVT::v2i64 && Op.getOpcode() != ISD::SRA) ||
      VT == MVT::v4i32 || VT == MVT::v8i16 ||
      (Subtarget->hasInt256() &&
       ((VT == MVT::v4i64 && Op.getOpcode() != ISD::SRA) ||
        VT == MVT::v8i32 || VT == MVT::v16i16)) ||
       (Subtarget->hasAVX512() && (VT == MVT::v8i64 || VT == MVT::v16i32))) {
    SDValue BaseShAmt;
    EVT EltVT = VT.getVectorElementType();

    if (BuildVectorSDNode *BV = dyn_cast<BuildVectorSDNode>(Amt)) {
      // Check if this build_vector node is doing a splat.
      // If so, then set BaseShAmt equal to the splat value.
      BaseShAmt = BV->getSplatValue();
      if (BaseShAmt && BaseShAmt.getOpcode() == ISD::UNDEF)
        BaseShAmt = SDValue();
    } else {
      if (Amt.getOpcode() == ISD::EXTRACT_SUBVECTOR)
        Amt = Amt.getOperand(0);

      ShuffleVectorSDNode *SVN = dyn_cast<ShuffleVectorSDNode>(Amt);
      if (SVN && SVN->isSplat()) {
        unsigned SplatIdx = (unsigned)SVN->getSplatIndex();
        SDValue InVec = Amt.getOperand(0);
        if (InVec.getOpcode() == ISD::BUILD_VECTOR) {
          assert((SplatIdx < InVec.getValueType().getVectorNumElements()) &&
                 "Unexpected shuffle index found!");
          BaseShAmt = InVec.getOperand(SplatIdx);
        } else if (InVec.getOpcode() == ISD::INSERT_VECTOR_ELT) {
           if (ConstantSDNode *C =
               dyn_cast<ConstantSDNode>(InVec.getOperand(2))) {
             if (C->getZExtValue() == SplatIdx)
               BaseShAmt = InVec.getOperand(1);
           }
        }

        if (!BaseShAmt)
          // Avoid introducing an extract element from a shuffle.
          BaseShAmt = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, EltVT, InVec,
                                    DAG.getIntPtrConstant(SplatIdx));
      }
    }

    if (BaseShAmt.getNode()) {
      assert(EltVT.bitsLE(MVT::i64) && "Unexpected element type!");
      if (EltVT != MVT::i64 && EltVT.bitsGT(MVT::i32))
        BaseShAmt = DAG.getNode(ISD::ZERO_EXTEND, dl, MVT::i64, BaseShAmt);
      else if (EltVT.bitsLT(MVT::i32))
        BaseShAmt = DAG.getNode(ISD::ZERO_EXTEND, dl, MVT::i32, BaseShAmt);

      switch (Op.getOpcode()) {
      default:
        llvm_unreachable("Unknown shift opcode!");
      case ISD::SHL:
        switch (VT.SimpleTy) {
        default: return SDValue();
        case MVT::v2i64:
        case MVT::v4i32:
        case MVT::v8i16:
        case MVT::v4i64:
        case MVT::v8i32:
        case MVT::v16i16:
        case MVT::v16i32:
        case MVT::v8i64:
          return getTargetVShiftNode(X86ISD::VSHLI, dl, VT, R, BaseShAmt, DAG);
        }
      case ISD::SRA:
        switch (VT.SimpleTy) {
        default: return SDValue();
        case MVT::v4i32:
        case MVT::v8i16:
        case MVT::v8i32:
        case MVT::v16i16:
        case MVT::v16i32:
        case MVT::v8i64:
          return getTargetVShiftNode(X86ISD::VSRAI, dl, VT, R, BaseShAmt, DAG);
        }
      case ISD::SRL:
        switch (VT.SimpleTy) {
        default: return SDValue();
        case MVT::v2i64:
        case MVT::v4i32:
        case MVT::v8i16:
        case MVT::v4i64:
        case MVT::v8i32:
        case MVT::v16i16:
        case MVT::v16i32:
        case MVT::v8i64:
          return getTargetVShiftNode(X86ISD::VSRLI, dl, VT, R, BaseShAmt, DAG);
        }
      }
    }
  }

  // Special case in 32-bit mode, where i64 is expanded into high and low parts.
  if (!Subtarget->is64Bit() &&
      (VT == MVT::v2i64 || (Subtarget->hasInt256() && VT == MVT::v4i64) ||
      (Subtarget->hasAVX512() && VT == MVT::v8i64)) &&
      Amt.getOpcode() == ISD::BITCAST &&
      Amt.getOperand(0).getOpcode() == ISD::BUILD_VECTOR) {
    Amt = Amt.getOperand(0);
    unsigned Ratio = Amt.getSimpleValueType().getVectorNumElements() /
                     VT.getVectorNumElements();
    std::vector<SDValue> Vals(Ratio);
    for (unsigned i = 0; i != Ratio; ++i)
      Vals[i] = Amt.getOperand(i);
    for (unsigned i = Ratio; i != Amt.getNumOperands(); i += Ratio) {
      for (unsigned j = 0; j != Ratio; ++j)
        if (Vals[j] != Amt.getOperand(i + j))
          return SDValue();
    }
    switch (Op.getOpcode()) {
    default:
      llvm_unreachable("Unknown shift opcode!");
    case ISD::SHL:
      return DAG.getNode(X86ISD::VSHL, dl, VT, R, Op.getOperand(1));
    case ISD::SRL:
      return DAG.getNode(X86ISD::VSRL, dl, VT, R, Op.getOperand(1));
    case ISD::SRA:
      return DAG.getNode(X86ISD::VSRA, dl, VT, R, Op.getOperand(1));
    }
  }

  return SDValue();
}

static SDValue LowerShift(SDValue Op, const X86Subtarget* Subtarget,
                          SelectionDAG &DAG) {
  MVT VT = Op.getSimpleValueType();
  SDLoc dl(Op);
  SDValue R = Op.getOperand(0);
  SDValue Amt = Op.getOperand(1);
  SDValue V;

  assert(VT.isVector() && "Custom lowering only for vector shifts!");
  assert(Subtarget->hasSSE2() && "Only custom lower when we have SSE2!");

  V = LowerScalarImmediateShift(Op, DAG, Subtarget);
  if (V.getNode())
    return V;

  V = LowerScalarVariableShift(Op, DAG, Subtarget);
  if (V.getNode())
      return V;

  if (Subtarget->hasAVX512() && (VT == MVT::v16i32 || VT == MVT::v8i64))
    return Op;
  // AVX2 has VPSLLV/VPSRAV/VPSRLV.
  if (Subtarget->hasInt256()) {
    if (Op.getOpcode() == ISD::SRL &&
        (VT == MVT::v2i64 || VT == MVT::v4i32 ||
         VT == MVT::v4i64 || VT == MVT::v8i32))
      return Op;
    if (Op.getOpcode() == ISD::SHL &&
        (VT == MVT::v2i64 || VT == MVT::v4i32 ||
         VT == MVT::v4i64 || VT == MVT::v8i32))
      return Op;
    if (Op.getOpcode() == ISD::SRA && (VT == MVT::v4i32 || VT == MVT::v8i32))
      return Op;
  }

  // If possible, lower this packed shift into a vector multiply instead of
  // expanding it into a sequence of scalar shifts.
  // Do this only if the vector shift count is a constant build_vector.
  if (Op.getOpcode() == ISD::SHL &&
      (VT == MVT::v8i16 || VT == MVT::v4i32 ||
       (Subtarget->hasInt256() && VT == MVT::v16i16)) &&
      ISD::isBuildVectorOfConstantSDNodes(Amt.getNode())) {
    SmallVector<SDValue, 8> Elts;
    EVT SVT = VT.getScalarType();
    unsigned SVTBits = SVT.getSizeInBits();
    const APInt &One = APInt(SVTBits, 1);
    unsigned NumElems = VT.getVectorNumElements();

    for (unsigned i=0; i !=NumElems; ++i) {
      SDValue Op = Amt->getOperand(i);
      if (Op->getOpcode() == ISD::UNDEF) {
        Elts.push_back(Op);
        continue;
      }

      ConstantSDNode *ND = cast<ConstantSDNode>(Op);
      const APInt &C = APInt(SVTBits, ND->getAPIntValue().getZExtValue());
      uint64_t ShAmt = C.getZExtValue();
      if (ShAmt >= SVTBits) {
        Elts.push_back(DAG.getUNDEF(SVT));
        continue;
      }
      Elts.push_back(DAG.getConstant(One.shl(ShAmt), SVT));
    }
    SDValue BV = DAG.getNode(ISD::BUILD_VECTOR, dl, VT, Elts);
    return DAG.getNode(ISD::MUL, dl, VT, R, BV);
  }

  // Lower SHL with variable shift amount.
  if (VT == MVT::v4i32 && Op->getOpcode() == ISD::SHL) {
    Op = DAG.getNode(ISD::SHL, dl, VT, Amt, DAG.getConstant(23, VT));

    Op = DAG.getNode(ISD::ADD, dl, VT, Op, DAG.getConstant(0x3f800000U, VT));
    Op = DAG.getNode(ISD::BITCAST, dl, MVT::v4f32, Op);
    Op = DAG.getNode(ISD::FP_TO_SINT, dl, VT, Op);
    return DAG.getNode(ISD::MUL, dl, VT, Op, R);
  }

  // If possible, lower this shift as a sequence of two shifts by
  // constant plus a MOVSS/MOVSD instead of scalarizing it.
  // Example:
  //   (v4i32 (srl A, (build_vector < X, Y, Y, Y>)))
  //
  // Could be rewritten as:
  //   (v4i32 (MOVSS (srl A, <Y,Y,Y,Y>), (srl A, <X,X,X,X>)))
  //
  // The advantage is that the two shifts from the example would be
  // lowered as X86ISD::VSRLI nodes. This would be cheaper than scalarizing
  // the vector shift into four scalar shifts plus four pairs of vector
  // insert/extract.
  if ((VT == MVT::v8i16 || VT == MVT::v4i32) &&
      ISD::isBuildVectorOfConstantSDNodes(Amt.getNode())) {
    unsigned TargetOpcode = X86ISD::MOVSS;
    bool CanBeSimplified;
    // The splat value for the first packed shift (the 'X' from the example).
    SDValue Amt1 = Amt->getOperand(0);
    // The splat value for the second packed shift (the 'Y' from the example).
    SDValue Amt2 = (VT == MVT::v4i32) ? Amt->getOperand(1) :
                                        Amt->getOperand(2);

    // See if it is possible to replace this node with a sequence of
    // two shifts followed by a MOVSS/MOVSD
    if (VT == MVT::v4i32) {
      // Check if it is legal to use a MOVSS.
      CanBeSimplified = Amt2 == Amt->getOperand(2) &&
                        Amt2 == Amt->getOperand(3);
      if (!CanBeSimplified) {
        // Otherwise, check if we can still simplify this node using a MOVSD.
        CanBeSimplified = Amt1 == Amt->getOperand(1) &&
                          Amt->getOperand(2) == Amt->getOperand(3);
        TargetOpcode = X86ISD::MOVSD;
        Amt2 = Amt->getOperand(2);
      }
    } else {
      // Do similar checks for the case where the machine value type
      // is MVT::v8i16.
      CanBeSimplified = Amt1 == Amt->getOperand(1);
      for (unsigned i=3; i != 8 && CanBeSimplified; ++i)
        CanBeSimplified = Amt2 == Amt->getOperand(i);

      if (!CanBeSimplified) {
        TargetOpcode = X86ISD::MOVSD;
        CanBeSimplified = true;
        Amt2 = Amt->getOperand(4);
        for (unsigned i=0; i != 4 && CanBeSimplified; ++i)
          CanBeSimplified = Amt1 == Amt->getOperand(i);
        for (unsigned j=4; j != 8 && CanBeSimplified; ++j)
          CanBeSimplified = Amt2 == Amt->getOperand(j);
      }
    }

    if (CanBeSimplified && isa<ConstantSDNode>(Amt1) &&
        isa<ConstantSDNode>(Amt2)) {
      // Replace this node with two shifts followed by a MOVSS/MOVSD.
      EVT CastVT = MVT::v4i32;
      SDValue Splat1 =
        DAG.getConstant(cast<ConstantSDNode>(Amt1)->getAPIntValue(), VT);
      SDValue Shift1 = DAG.getNode(Op->getOpcode(), dl, VT, R, Splat1);
      SDValue Splat2 =
        DAG.getConstant(cast<ConstantSDNode>(Amt2)->getAPIntValue(), VT);
      SDValue Shift2 = DAG.getNode(Op->getOpcode(), dl, VT, R, Splat2);
      if (TargetOpcode == X86ISD::MOVSD)
        CastVT = MVT::v2i64;
      SDValue BitCast1 = DAG.getNode(ISD::BITCAST, dl, CastVT, Shift1);
      SDValue BitCast2 = DAG.getNode(ISD::BITCAST, dl, CastVT, Shift2);
      SDValue Result = getTargetShuffleNode(TargetOpcode, dl, CastVT, BitCast2,
                                            BitCast1, DAG);
      return DAG.getNode(ISD::BITCAST, dl, VT, Result);
    }
  }

  if (VT == MVT::v16i8 && Op->getOpcode() == ISD::SHL) {
    assert(Subtarget->hasSSE2() && "Need SSE2 for pslli/pcmpeq.");

    // a = a << 5;
    Op = DAG.getNode(ISD::SHL, dl, VT, Amt, DAG.getConstant(5, VT));
    Op = DAG.getNode(ISD::BITCAST, dl, VT, Op);

    // Turn 'a' into a mask suitable for VSELECT
    SDValue VSelM = DAG.getConstant(0x80, VT);
    SDValue OpVSel = DAG.getNode(ISD::AND, dl, VT, VSelM, Op);
    OpVSel = DAG.getNode(X86ISD::PCMPEQ, dl, VT, OpVSel, VSelM);

    SDValue CM1 = DAG.getConstant(0x0f, VT);
    SDValue CM2 = DAG.getConstant(0x3f, VT);

    // r = VSELECT(r, psllw(r & (char16)15, 4), a);
    SDValue M = DAG.getNode(ISD::AND, dl, VT, R, CM1);
    M = getTargetVShiftByConstNode(X86ISD::VSHLI, dl, MVT::v8i16, M, 4, DAG);
    M = DAG.getNode(ISD::BITCAST, dl, VT, M);
    R = DAG.getNode(ISD::VSELECT, dl, VT, OpVSel, M, R);

    // a += a
    Op = DAG.getNode(ISD::ADD, dl, VT, Op, Op);
    OpVSel = DAG.getNode(ISD::AND, dl, VT, VSelM, Op);
    OpVSel = DAG.getNode(X86ISD::PCMPEQ, dl, VT, OpVSel, VSelM);

    // r = VSELECT(r, psllw(r & (char16)63, 2), a);
    M = DAG.getNode(ISD::AND, dl, VT, R, CM2);
    M = getTargetVShiftByConstNode(X86ISD::VSHLI, dl, MVT::v8i16, M, 2, DAG);
    M = DAG.getNode(ISD::BITCAST, dl, VT, M);
    R = DAG.getNode(ISD::VSELECT, dl, VT, OpVSel, M, R);

    // a += a
    Op = DAG.getNode(ISD::ADD, dl, VT, Op, Op);
    OpVSel = DAG.getNode(ISD::AND, dl, VT, VSelM, Op);
    OpVSel = DAG.getNode(X86ISD::PCMPEQ, dl, VT, OpVSel, VSelM);

    // return VSELECT(r, r+r, a);
    R = DAG.getNode(ISD::VSELECT, dl, VT, OpVSel,
                    DAG.getNode(ISD::ADD, dl, VT, R, R), R);
    return R;
  }

  // It's worth extending once and using the v8i32 shifts for 16-bit types, but
  // the extra overheads to get from v16i8 to v8i32 make the existing SSE
  // solution better.
  if (Subtarget->hasInt256() && VT == MVT::v8i16) {
    MVT NewVT = VT == MVT::v8i16 ? MVT::v8i32 : MVT::v16i16;
    unsigned ExtOpc =
        Op.getOpcode() == ISD::SRA ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND;
    R = DAG.getNode(ExtOpc, dl, NewVT, R);
    Amt = DAG.getNode(ISD::ANY_EXTEND, dl, NewVT, Amt);
    return DAG.getNode(ISD::TRUNCATE, dl, VT,
                       DAG.getNode(Op.getOpcode(), dl, NewVT, R, Amt));
    }

  // Decompose 256-bit shifts into smaller 128-bit shifts.
  if (VT.is256BitVector()) {
    unsigned NumElems = VT.getVectorNumElements();
    MVT EltVT = VT.getVectorElementType();
    EVT NewVT = MVT::getVectorVT(EltVT, NumElems/2);

    // Extract the two vectors
    SDValue V1 = Extract128BitVector(R, 0, DAG, dl);
    SDValue V2 = Extract128BitVector(R, NumElems/2, DAG, dl);

    // Recreate the shift amount vectors
    SDValue Amt1, Amt2;
    if (Amt.getOpcode() == ISD::BUILD_VECTOR) {
      // Constant shift amount
      SmallVector<SDValue, 4> Amt1Csts;
      SmallVector<SDValue, 4> Amt2Csts;
      for (unsigned i = 0; i != NumElems/2; ++i)
        Amt1Csts.push_back(Amt->getOperand(i));
      for (unsigned i = NumElems/2; i != NumElems; ++i)
        Amt2Csts.push_back(Amt->getOperand(i));

      Amt1 = DAG.getNode(ISD::BUILD_VECTOR, dl, NewVT, Amt1Csts);
      Amt2 = DAG.getNode(ISD::BUILD_VECTOR, dl, NewVT, Amt2Csts);
    } else {
      // Variable shift amount
      Amt1 = Extract128BitVector(Amt, 0, DAG, dl);
      Amt2 = Extract128BitVector(Amt, NumElems/2, DAG, dl);
    }

    // Issue new vector shifts for the smaller types
    V1 = DAG.getNode(Op.getOpcode(), dl, NewVT, V1, Amt1);
    V2 = DAG.getNode(Op.getOpcode(), dl, NewVT, V2, Amt2);

    // Concatenate the result back
    return DAG.getNode(ISD::CONCAT_VECTORS, dl, VT, V1, V2);
  }

  return SDValue();
}

static SDValue LowerXALUO(SDValue Op, SelectionDAG &DAG) {
  // Lower the "add/sub/mul with overflow" instruction into a regular ins plus
  // a "setcc" instruction that checks the overflow flag. The "brcond" lowering
  // looks for this combo and may remove the "setcc" instruction if the "setcc"
  // has only one use.
  SDNode *N = Op.getNode();
  SDValue LHS = N->getOperand(0);
  SDValue RHS = N->getOperand(1);
  unsigned BaseOp = 0;
  unsigned Cond = 0;
  SDLoc DL(Op);
  switch (Op.getOpcode()) {
  default: llvm_unreachable("Unknown ovf instruction!");
  case ISD::SADDO:
    // A subtract of one will be selected as a INC. Note that INC doesn't
    // set CF, so we can't do this for UADDO.
    if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(RHS))
      if (C->isOne()) {
        BaseOp = X86ISD::INC;
        Cond = X86::COND_O;
        break;
      }
    BaseOp = X86ISD::ADD;
    Cond = X86::COND_O;
    break;
  case ISD::UADDO:
    BaseOp = X86ISD::ADD;
    Cond = X86::COND_B;
    break;
  case ISD::SSUBO:
    // A subtract of one will be selected as a DEC. Note that DEC doesn't
    // set CF, so we can't do this for USUBO.
    if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(RHS))
      if (C->isOne()) {
        BaseOp = X86ISD::DEC;
        Cond = X86::COND_O;
        break;
      }
    BaseOp = X86ISD::SUB;
    Cond = X86::COND_O;
    break;
  case ISD::USUBO:
    BaseOp = X86ISD::SUB;
    Cond = X86::COND_B;
    break;
  case ISD::SMULO:
    BaseOp = N->getValueType(0) == MVT::i8 ? X86ISD::SMUL8 : X86ISD::SMUL;
    Cond = X86::COND_O;
    break;
  case ISD::UMULO: { // i64, i8 = umulo lhs, rhs --> i64, i64, i32 umul lhs,rhs
    if (N->getValueType(0) == MVT::i8) {
      BaseOp = X86ISD::UMUL8;
      Cond = X86::COND_O;
      break;
    }
    SDVTList VTs = DAG.getVTList(N->getValueType(0), N->getValueType(0),
                                 MVT::i32);
    SDValue Sum = DAG.getNode(X86ISD::UMUL, DL, VTs, LHS, RHS);

    SDValue SetCC =
      DAG.getNode(X86ISD::SETCC, DL, MVT::i8,
                  DAG.getConstant(X86::COND_O, MVT::i32),
                  SDValue(Sum.getNode(), 2));

    return DAG.getNode(ISD::MERGE_VALUES, DL, N->getVTList(), Sum, SetCC);
  }
  }

  // Also sets EFLAGS.
  SDVTList VTs = DAG.getVTList(N->getValueType(0), MVT::i32);
  SDValue Sum = DAG.getNode(BaseOp, DL, VTs, LHS, RHS);

  SDValue SetCC =
    DAG.getNode(X86ISD::SETCC, DL, N->getValueType(1),
                DAG.getConstant(Cond, MVT::i32),
                SDValue(Sum.getNode(), 1));

  return DAG.getNode(ISD::MERGE_VALUES, DL, N->getVTList(), Sum, SetCC);
}

// Sign extension of the low part of vector elements. This may be used either
// when sign extend instructions are not available or if the vector element
// sizes already match the sign-extended size. If the vector elements are in
// their pre-extended size and sign extend instructions are available, that will
// be handled by LowerSIGN_EXTEND.
SDValue X86TargetLowering::LowerSIGN_EXTEND_INREG(SDValue Op,
                                                  SelectionDAG &DAG) const {
  SDLoc dl(Op);
  EVT ExtraVT = cast<VTSDNode>(Op.getOperand(1))->getVT();
  MVT VT = Op.getSimpleValueType();

  if (!Subtarget->hasSSE2() || !VT.isVector())
    return SDValue();

  unsigned BitsDiff = VT.getScalarType().getSizeInBits() -
                      ExtraVT.getScalarType().getSizeInBits();

  switch (VT.SimpleTy) {
    default: return SDValue();
    case MVT::v8i32:
    case MVT::v16i16:
      if (!Subtarget->hasFp256())
        return SDValue();
      if (!Subtarget->hasInt256()) {
        // needs to be split
        unsigned NumElems = VT.getVectorNumElements();

        // Extract the LHS vectors
        SDValue LHS = Op.getOperand(0);
        SDValue LHS1 = Extract128BitVector(LHS, 0, DAG, dl);
        SDValue LHS2 = Extract128BitVector(LHS, NumElems/2, DAG, dl);

        MVT EltVT = VT.getVectorElementType();
        EVT NewVT = MVT::getVectorVT(EltVT, NumElems/2);

        EVT ExtraEltVT = ExtraVT.getVectorElementType();
        unsigned ExtraNumElems = ExtraVT.getVectorNumElements();
        ExtraVT = EVT::getVectorVT(*DAG.getContext(), ExtraEltVT,
                                   ExtraNumElems/2);
        SDValue Extra = DAG.getValueType(ExtraVT);

        LHS1 = DAG.getNode(Op.getOpcode(), dl, NewVT, LHS1, Extra);
        LHS2 = DAG.getNode(Op.getOpcode(), dl, NewVT, LHS2, Extra);

        return DAG.getNode(ISD::CONCAT_VECTORS, dl, VT, LHS1, LHS2);
      }
      // fall through
    case MVT::v4i32:
    case MVT::v8i16: {
      SDValue Op0 = Op.getOperand(0);

      // This is a sign extension of some low part of vector elements without
      // changing the size of the vector elements themselves:
      // Shift-Left + Shift-Right-Algebraic.
      SDValue Shl = getTargetVShiftByConstNode(X86ISD::VSHLI, dl, VT, Op0,
                                               BitsDiff, DAG);
      return getTargetVShiftByConstNode(X86ISD::VSRAI, dl, VT, Shl, BitsDiff,
                                        DAG);
    }
  }
}

/// Returns true if the operand type is exactly twice the native width, and
/// the corresponding cmpxchg8b or cmpxchg16b instruction is available.
/// Used to know whether to use cmpxchg8/16b when expanding atomic operations
/// (otherwise we leave them alone to become __sync_fetch_and_... calls).
bool X86TargetLowering::needsCmpXchgNb(const Type *MemType) const {
  unsigned OpWidth = MemType->getPrimitiveSizeInBits();

  if (OpWidth == 64)
    return !Subtarget->is64Bit(); // FIXME this should be Subtarget.hasCmpxchg8b
  else if (OpWidth == 128)
    return Subtarget->hasCmpxchg16b();
  else
    return false;
}

bool X86TargetLowering::shouldExpandAtomicStoreInIR(StoreInst *SI) const {
  return needsCmpXchgNb(SI->getValueOperand()->getType());
}

// Note: this turns large loads into lock cmpxchg8b/16b.
// FIXME: On 32 bits x86, fild/movq might be faster than lock cmpxchg8b.
bool X86TargetLowering::shouldExpandAtomicLoadInIR(LoadInst *LI) const {
  auto PTy = cast<PointerType>(LI->getPointerOperand()->getType());
  return needsCmpXchgNb(PTy->getElementType());
}

bool X86TargetLowering::shouldExpandAtomicRMWInIR(AtomicRMWInst *AI) const {
  unsigned NativeWidth = Subtarget->is64Bit() ? 64 : 32;
  const Type *MemType = AI->getType();

  // If the operand is too big, we must see if cmpxchg8/16b is available
  // and default to library calls otherwise.
  if (MemType->getPrimitiveSizeInBits() > NativeWidth)
    return needsCmpXchgNb(MemType);

  AtomicRMWInst::BinOp Op = AI->getOperation();
  switch (Op) {
  default:
    llvm_unreachable("Unknown atomic operation");
  case AtomicRMWInst::Xchg:
  case AtomicRMWInst::Add:
  case AtomicRMWInst::Sub:
    // It's better to use xadd, xsub or xchg for these in all cases.
    return false;
  case AtomicRMWInst::Or:
  case AtomicRMWInst::And:
  case AtomicRMWInst::Xor:
    // If the atomicrmw's result isn't actually used, we can just add a "lock"
    // prefix to a normal instruction for these operations.
    return !AI->use_empty();
  case AtomicRMWInst::Nand:
  case AtomicRMWInst::Max:
  case AtomicRMWInst::Min:
  case AtomicRMWInst::UMax:
  case AtomicRMWInst::UMin:
    // These always require a non-trivial set of data operations on x86. We must
    // use a cmpxchg loop.
    return true;
  }
}

static bool hasMFENCE(const X86Subtarget& Subtarget) {
  // Use mfence if we have SSE2 or we're on x86-64 (even if we asked for
  // no-sse2). There isn't any reason to disable it if the target processor
  // supports it.
  return Subtarget.hasSSE2() || Subtarget.is64Bit();
}

LoadInst *
X86TargetLowering::lowerIdempotentRMWIntoFencedLoad(AtomicRMWInst *AI) const {
  unsigned NativeWidth = Subtarget->is64Bit() ? 64 : 32;
  const Type *MemType = AI->getType();
  // Accesses larger than the native width are turned into cmpxchg/libcalls, so
  // there is no benefit in turning such RMWs into loads, and it is actually
  // harmful as it introduces a mfence.
  if (MemType->getPrimitiveSizeInBits() > NativeWidth)
    return nullptr;

  auto Builder = IRBuilder<>(AI);
  Module *M = Builder.GetInsertBlock()->getParent()->getParent();
  auto SynchScope = AI->getSynchScope();
  // We must restrict the ordering to avoid generating loads with Release or
  // ReleaseAcquire orderings.
  auto Order = AtomicCmpXchgInst::getStrongestFailureOrdering(AI->getOrdering());
  auto Ptr = AI->getPointerOperand();

  // Before the load we need a fence. Here is an example lifted from
  // http://www.hpl.hp.com/techreports/2012/HPL-2012-68.pdf showing why a fence
  // is required:
  // Thread 0:
  //   x.store(1, relaxed);
  //   r1 = y.fetch_add(0, release);
  // Thread 1:
  //   y.fetch_add(42, acquire);
  //   r2 = x.load(relaxed);
  // r1 = r2 = 0 is impossible, but becomes possible if the idempotent rmw is
  // lowered to just a load without a fence. A mfence flushes the store buffer,
  // making the optimization clearly correct.
  // FIXME: it is required if isAtLeastRelease(Order) but it is not clear
  // otherwise, we might be able to be more agressive on relaxed idempotent
  // rmw. In practice, they do not look useful, so we don't try to be
  // especially clever.
  if (SynchScope == SingleThread) {
    // FIXME: we could just insert an X86ISD::MEMBARRIER here, except we are at
    // the IR level, so we must wrap it in an intrinsic.
    return nullptr;
  } else if (hasMFENCE(*Subtarget)) {
    Function *MFence = llvm::Intrinsic::getDeclaration(M,
            Intrinsic::x86_sse2_mfence);
    Builder.CreateCall(MFence);
  } else {
    // FIXME: it might make sense to use a locked operation here but on a
    // different cache-line to prevent cache-line bouncing. In practice it
    // is probably a small win, and x86 processors without mfence are rare
    // enough that we do not bother.
    return nullptr;
  }

  // Finally we can emit the atomic load.
  LoadInst *Loaded = Builder.CreateAlignedLoad(Ptr,
          AI->getType()->getPrimitiveSizeInBits());
  Loaded->setAtomic(Order, SynchScope);
  AI->replaceAllUsesWith(Loaded);
  AI->eraseFromParent();
  return Loaded;
}

static SDValue LowerATOMIC_FENCE(SDValue Op, const X86Subtarget *Subtarget,
                                 SelectionDAG &DAG) {
  SDLoc dl(Op);
  AtomicOrdering FenceOrdering = static_cast<AtomicOrdering>(
    cast<ConstantSDNode>(Op.getOperand(1))->getZExtValue());
  SynchronizationScope FenceScope = static_cast<SynchronizationScope>(
    cast<ConstantSDNode>(Op.getOperand(2))->getZExtValue());

  // The only fence that needs an instruction is a sequentially-consistent
  // cross-thread fence.
  if (FenceOrdering == SequentiallyConsistent && FenceScope == CrossThread) {
    if (hasMFENCE(*Subtarget))
      return DAG.getNode(X86ISD::MFENCE, dl, MVT::Other, Op.getOperand(0));

    SDValue Chain = Op.getOperand(0);
    SDValue Zero = DAG.getConstant(0, MVT::i32);
    SDValue Ops[] = {
      DAG.getRegister(X86::ESP, MVT::i32), // Base
      DAG.getTargetConstant(1, MVT::i8),   // Scale
      DAG.getRegister(0, MVT::i32),        // Index
      DAG.getTargetConstant(0, MVT::i32),  // Disp
      DAG.getRegister(0, MVT::i32),        // Segment.
      Zero,
      Chain
    };
    SDNode *Res = DAG.getMachineNode(X86::OR32mrLocked, dl, MVT::Other, Ops);
    return SDValue(Res, 0);
  }

  // MEMBARRIER is a compiler barrier; it codegens to a no-op.
  return DAG.getNode(X86ISD::MEMBARRIER, dl, MVT::Other, Op.getOperand(0));
}

static SDValue LowerCMP_SWAP(SDValue Op, const X86Subtarget *Subtarget,
                             SelectionDAG &DAG) {
  MVT T = Op.getSimpleValueType();
  SDLoc DL(Op);
  unsigned Reg = 0;
  unsigned size = 0;
  switch(T.SimpleTy) {
  default: llvm_unreachable("Invalid value type!");
  case MVT::i8:  Reg = X86::AL;  size = 1; break;
  case MVT::i16: Reg = X86::AX;  size = 2; break;
  case MVT::i32: Reg = X86::EAX; size = 4; break;
  case MVT::i64:
    assert(Subtarget->is64Bit() && "Node not type legal!");
    Reg = X86::RAX; size = 8;
    break;
  }
  SDValue cpIn = DAG.getCopyToReg(Op.getOperand(0), DL, Reg,
                                  Op.getOperand(2), SDValue());
  SDValue Ops[] = { cpIn.getValue(0),
                    Op.getOperand(1),
                    Op.getOperand(3),
                    DAG.getTargetConstant(size, MVT::i8),
                    cpIn.getValue(1) };
  SDVTList Tys = DAG.getVTList(MVT::Other, MVT::Glue);
  MachineMemOperand *MMO = cast<AtomicSDNode>(Op)->getMemOperand();
  SDValue Result = DAG.getMemIntrinsicNode(X86ISD::LCMPXCHG_DAG, DL, Tys,
                                           Ops, T, MMO);

  SDValue cpOut =
    DAG.getCopyFromReg(Result.getValue(0), DL, Reg, T, Result.getValue(1));
  SDValue EFLAGS = DAG.getCopyFromReg(cpOut.getValue(1), DL, X86::EFLAGS,
                                      MVT::i32, cpOut.getValue(2));
  SDValue Success = DAG.getNode(X86ISD::SETCC, DL, Op->getValueType(1),
                                DAG.getConstant(X86::COND_E, MVT::i8), EFLAGS);

  DAG.ReplaceAllUsesOfValueWith(Op.getValue(0), cpOut);
  DAG.ReplaceAllUsesOfValueWith(Op.getValue(1), Success);
  DAG.ReplaceAllUsesOfValueWith(Op.getValue(2), EFLAGS.getValue(1));
  return SDValue();
}

static SDValue LowerBITCAST(SDValue Op, const X86Subtarget *Subtarget,
                            SelectionDAG &DAG) {
  MVT SrcVT = Op.getOperand(0).getSimpleValueType();
  MVT DstVT = Op.getSimpleValueType();

  if (SrcVT == MVT::v2i32 || SrcVT == MVT::v4i16 || SrcVT == MVT::v8i8) {
    assert(Subtarget->hasSSE2() && "Requires at least SSE2!");
    if (DstVT != MVT::f64)
      // This conversion needs to be expanded.
      return SDValue();

    SDValue InVec = Op->getOperand(0);
    SDLoc dl(Op);
    unsigned NumElts = SrcVT.getVectorNumElements();
    EVT SVT = SrcVT.getVectorElementType();

    // Widen the vector in input in the case of MVT::v2i32.
    // Example: from MVT::v2i32 to MVT::v4i32.
    SmallVector<SDValue, 16> Elts;
    for (unsigned i = 0, e = NumElts; i != e; ++i)
      Elts.push_back(DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, SVT, InVec,
                                 DAG.getIntPtrConstant(i)));

    // Explicitly mark the extra elements as Undef.
    Elts.append(NumElts, DAG.getUNDEF(SVT));

    EVT NewVT = EVT::getVectorVT(*DAG.getContext(), SVT, NumElts * 2);
    SDValue BV = DAG.getNode(ISD::BUILD_VECTOR, dl, NewVT, Elts);
    SDValue ToV2F64 = DAG.getNode(ISD::BITCAST, dl, MVT::v2f64, BV);
    return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, MVT::f64, ToV2F64,
                       DAG.getIntPtrConstant(0));
  }

  assert(Subtarget->is64Bit() && !Subtarget->hasSSE2() &&
         Subtarget->hasMMX() && "Unexpected custom BITCAST");
  assert((DstVT == MVT::i64 ||
          (DstVT.isVector() && DstVT.getSizeInBits()==64)) &&
         "Unexpected custom BITCAST");
  // i64 <=> MMX conversions are Legal.
  if (SrcVT==MVT::i64 && DstVT.isVector())
    return Op;
  if (DstVT==MVT::i64 && SrcVT.isVector())
    return Op;
  // MMX <=> MMX conversions are Legal.
  if (SrcVT.isVector() && DstVT.isVector())
    return Op;
  // All other conversions need to be expanded.
  return SDValue();
}

static SDValue LowerCTPOP(SDValue Op, const X86Subtarget *Subtarget,
                          SelectionDAG &DAG) {
  SDNode *Node = Op.getNode();
  SDLoc dl(Node);

  Op = Op.getOperand(0);
  EVT VT = Op.getValueType();
  assert((VT.is128BitVector() || VT.is256BitVector()) &&
         "CTPOP lowering only implemented for 128/256-bit wide vector types");

  unsigned NumElts = VT.getVectorNumElements();
  EVT EltVT = VT.getVectorElementType();
  unsigned Len = EltVT.getSizeInBits();

  // This is the vectorized version of the "best" algorithm from
  // http://graphics.stanford.edu/~seander/bithacks.html#CountBitsSetParallel
  // with a minor tweak to use a series of adds + shifts instead of vector
  // multiplications. Implemented for the v2i64, v4i64, v4i32, v8i32 types:
  //
  //  v2i64, v4i64, v4i32 => Only profitable w/ popcnt disabled
  //  v8i32 => Always profitable
  //
  // FIXME: There a couple of possible improvements:
  //
  // 1) Support for i8 and i16 vectors (needs measurements if popcnt enabled).
  // 2) Use strategies from http://wm.ite.pl/articles/sse-popcount.html
  //
  assert(EltVT.isInteger() && (Len == 32 || Len == 64) && Len % 8 == 0 &&
         "CTPOP not implemented for this vector element type.");

  // X86 canonicalize ANDs to vXi64, generate the appropriate bitcasts to avoid
  // extra legalization.
  bool NeedsBitcast = EltVT == MVT::i32;
  MVT BitcastVT = VT.is256BitVector() ? MVT::v4i64 : MVT::v2i64;

  SDValue Cst55 = DAG.getConstant(APInt::getSplat(Len, APInt(8, 0x55)), EltVT);
  SDValue Cst33 = DAG.getConstant(APInt::getSplat(Len, APInt(8, 0x33)), EltVT);
  SDValue Cst0F = DAG.getConstant(APInt::getSplat(Len, APInt(8, 0x0F)), EltVT);

  // v = v - ((v >> 1) & 0x55555555...)
  SmallVector<SDValue, 8> Ones(NumElts, DAG.getConstant(1, EltVT));
  SDValue OnesV = DAG.getNode(ISD::BUILD_VECTOR, dl, VT, Ones);
  SDValue Srl = DAG.getNode(ISD::SRL, dl, VT, Op, OnesV);
  if (NeedsBitcast)
    Srl = DAG.getNode(ISD::BITCAST, dl, BitcastVT, Srl);

  SmallVector<SDValue, 8> Mask55(NumElts, Cst55);
  SDValue M55 = DAG.getNode(ISD::BUILD_VECTOR, dl, VT, Mask55);
  if (NeedsBitcast)
    M55 = DAG.getNode(ISD::BITCAST, dl, BitcastVT, M55);

  SDValue And = DAG.getNode(ISD::AND, dl, Srl.getValueType(), Srl, M55);
  if (VT != And.getValueType())
    And = DAG.getNode(ISD::BITCAST, dl, VT, And);
  SDValue Sub = DAG.getNode(ISD::SUB, dl, VT, Op, And);

  // v = (v & 0x33333333...) + ((v >> 2) & 0x33333333...)
  SmallVector<SDValue, 8> Mask33(NumElts, Cst33);
  SDValue M33 = DAG.getNode(ISD::BUILD_VECTOR, dl, VT, Mask33);
  SmallVector<SDValue, 8> Twos(NumElts, DAG.getConstant(2, EltVT));
  SDValue TwosV = DAG.getNode(ISD::BUILD_VECTOR, dl, VT, Twos);

  Srl = DAG.getNode(ISD::SRL, dl, VT, Sub, TwosV);
  if (NeedsBitcast) {
    Srl = DAG.getNode(ISD::BITCAST, dl, BitcastVT, Srl);
    M33 = DAG.getNode(ISD::BITCAST, dl, BitcastVT, M33);
    Sub = DAG.getNode(ISD::BITCAST, dl, BitcastVT, Sub);
  }

  SDValue AndRHS = DAG.getNode(ISD::AND, dl, M33.getValueType(), Srl, M33);
  SDValue AndLHS = DAG.getNode(ISD::AND, dl, M33.getValueType(), Sub, M33);
  if (VT != AndRHS.getValueType()) {
    AndRHS = DAG.getNode(ISD::BITCAST, dl, VT, AndRHS);
    AndLHS = DAG.getNode(ISD::BITCAST, dl, VT, AndLHS);
  }
  SDValue Add = DAG.getNode(ISD::ADD, dl, VT, AndLHS, AndRHS);

  // v = (v + (v >> 4)) & 0x0F0F0F0F...
  SmallVector<SDValue, 8> Fours(NumElts, DAG.getConstant(4, EltVT));
  SDValue FoursV = DAG.getNode(ISD::BUILD_VECTOR, dl, VT, Fours);
  Srl = DAG.getNode(ISD::SRL, dl, VT, Add, FoursV);
  Add = DAG.getNode(ISD::ADD, dl, VT, Add, Srl);

  SmallVector<SDValue, 8> Mask0F(NumElts, Cst0F);
  SDValue M0F = DAG.getNode(ISD::BUILD_VECTOR, dl, VT, Mask0F);
  if (NeedsBitcast) {
    Add = DAG.getNode(ISD::BITCAST, dl, BitcastVT, Add);
    M0F = DAG.getNode(ISD::BITCAST, dl, BitcastVT, M0F);
  }
  And = DAG.getNode(ISD::AND, dl, M0F.getValueType(), Add, M0F);
  if (VT != And.getValueType())
    And = DAG.getNode(ISD::BITCAST, dl, VT, And);

  // The algorithm mentioned above uses:
  //    v = (v * 0x01010101...) >> (Len - 8)
  //
  // Change it to use vector adds + vector shifts which yield faster results on
  // Haswell than using vector integer multiplication.
  //
  // For i32 elements:
  //    v = v + (v >> 8)
  //    v = v + (v >> 16)
  //
  // For i64 elements:
  //    v = v + (v >> 8)
  //    v = v + (v >> 16)
  //    v = v + (v >> 32)
  //
  Add = And;
  SmallVector<SDValue, 8> Csts;
  for (unsigned i = 8; i <= Len/2; i *= 2) {
    Csts.assign(NumElts, DAG.getConstant(i, EltVT));
    SDValue CstsV = DAG.getNode(ISD::BUILD_VECTOR, dl, VT, Csts);
    Srl = DAG.getNode(ISD::SRL, dl, VT, Add, CstsV);
    Add = DAG.getNode(ISD::ADD, dl, VT, Add, Srl);
    Csts.clear();
  }

  // The result is on the least significant 6-bits on i32 and 7-bits on i64.
  SDValue Cst3F = DAG.getConstant(APInt(Len, Len == 32 ? 0x3F : 0x7F), EltVT);
  SmallVector<SDValue, 8> Cst3FV(NumElts, Cst3F);
  SDValue M3F = DAG.getNode(ISD::BUILD_VECTOR, dl, VT, Cst3FV);
  if (NeedsBitcast) {
    Add = DAG.getNode(ISD::BITCAST, dl, BitcastVT, Add);
    M3F = DAG.getNode(ISD::BITCAST, dl, BitcastVT, M3F);
  }
  And = DAG.getNode(ISD::AND, dl, M3F.getValueType(), Add, M3F);
  if (VT != And.getValueType())
    And = DAG.getNode(ISD::BITCAST, dl, VT, And);

  return And;
}

static SDValue LowerLOAD_SUB(SDValue Op, SelectionDAG &DAG) {
  SDNode *Node = Op.getNode();
  SDLoc dl(Node);
  EVT T = Node->getValueType(0);
  SDValue negOp = DAG.getNode(ISD::SUB, dl, T,
                              DAG.getConstant(0, T), Node->getOperand(2));
  return DAG.getAtomic(ISD::ATOMIC_LOAD_ADD, dl,
                       cast<AtomicSDNode>(Node)->getMemoryVT(),
                       Node->getOperand(0),
                       Node->getOperand(1), negOp,
                       cast<AtomicSDNode>(Node)->getMemOperand(),
                       cast<AtomicSDNode>(Node)->getOrdering(),
                       cast<AtomicSDNode>(Node)->getSynchScope());
}

static SDValue LowerATOMIC_STORE(SDValue Op, SelectionDAG &DAG) {
  SDNode *Node = Op.getNode();
  SDLoc dl(Node);
  EVT VT = cast<AtomicSDNode>(Node)->getMemoryVT();

  // Convert seq_cst store -> xchg
  // Convert wide store -> swap (-> cmpxchg8b/cmpxchg16b)
  // FIXME: On 32-bit, store -> fist or movq would be more efficient
  //        (The only way to get a 16-byte store is cmpxchg16b)
  // FIXME: 16-byte ATOMIC_SWAP isn't actually hooked up at the moment.
  if (cast<AtomicSDNode>(Node)->getOrdering() == SequentiallyConsistent ||
      !DAG.getTargetLoweringInfo().isTypeLegal(VT)) {
    SDValue Swap = DAG.getAtomic(ISD::ATOMIC_SWAP, dl,
                                 cast<AtomicSDNode>(Node)->getMemoryVT(),
                                 Node->getOperand(0),
                                 Node->getOperand(1), Node->getOperand(2),
                                 cast<AtomicSDNode>(Node)->getMemOperand(),
                                 cast<AtomicSDNode>(Node)->getOrdering(),
                                 cast<AtomicSDNode>(Node)->getSynchScope());
    return Swap.getValue(1);
  }
  // Other atomic stores have a simple pattern.
  return Op;
}

static SDValue LowerADDC_ADDE_SUBC_SUBE(SDValue Op, SelectionDAG &DAG) {
  EVT VT = Op.getNode()->getSimpleValueType(0);

  // Let legalize expand this if it isn't a legal type yet.
  if (!DAG.getTargetLoweringInfo().isTypeLegal(VT))
    return SDValue();

  SDVTList VTs = DAG.getVTList(VT, MVT::i32);

  unsigned Opc;
  bool ExtraOp = false;
  switch (Op.getOpcode()) {
  default: llvm_unreachable("Invalid code");
  case ISD::ADDC: Opc = X86ISD::ADD; break;
  case ISD::ADDE: Opc = X86ISD::ADC; ExtraOp = true; break;
  case ISD::SUBC: Opc = X86ISD::SUB; break;
  case ISD::SUBE: Opc = X86ISD::SBB; ExtraOp = true; break;
  }

  if (!ExtraOp)
    return DAG.getNode(Opc, SDLoc(Op), VTs, Op.getOperand(0),
                       Op.getOperand(1));
  return DAG.getNode(Opc, SDLoc(Op), VTs, Op.getOperand(0),
                     Op.getOperand(1), Op.getOperand(2));
}

static SDValue LowerFSINCOS(SDValue Op, const X86Subtarget *Subtarget,
                            SelectionDAG &DAG) {
  assert(Subtarget->isTargetDarwin() && Subtarget->is64Bit());

  // For MacOSX, we want to call an alternative entry point: __sincos_stret,
  // which returns the values as { float, float } (in XMM0) or
  // { double, double } (which is returned in XMM0, XMM1).
  SDLoc dl(Op);
  SDValue Arg = Op.getOperand(0);
  EVT ArgVT = Arg.getValueType();
  Type *ArgTy = ArgVT.getTypeForEVT(*DAG.getContext());

  TargetLowering::ArgListTy Args;
  TargetLowering::ArgListEntry Entry;

  Entry.Node = Arg;
  Entry.Ty = ArgTy;
  Entry.isSExt = false;
  Entry.isZExt = false;
  Args.push_back(Entry);

  bool isF64 = ArgVT == MVT::f64;
  // Only optimize x86_64 for now. i386 is a bit messy. For f32,
  // the small struct {f32, f32} is returned in (eax, edx). For f64,
  // the results are returned via SRet in memory.
  const char *LibcallName =  isF64 ? "__sincos_stret" : "__sincosf_stret";
  const TargetLowering &TLI = DAG.getTargetLoweringInfo();
  SDValue Callee = DAG.getExternalSymbol(LibcallName, TLI.getPointerTy());

  Type *RetTy = isF64
    ? (Type*)StructType::get(ArgTy, ArgTy, nullptr)
    : (Type*)VectorType::get(ArgTy, 4);

  TargetLowering::CallLoweringInfo CLI(DAG);
  CLI.setDebugLoc(dl).setChain(DAG.getEntryNode())
    .setCallee(CallingConv::C, RetTy, Callee, std::move(Args), 0);

  std::pair<SDValue, SDValue> CallResult = TLI.LowerCallTo(CLI);

  if (isF64)
    // Returned in xmm0 and xmm1.
    return CallResult.first;

  // Returned in bits 0:31 and 32:64 xmm0.
  SDValue SinVal = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, ArgVT,
                               CallResult.first, DAG.getIntPtrConstant(0));
  SDValue CosVal = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, ArgVT,
                               CallResult.first, DAG.getIntPtrConstant(1));
  SDVTList Tys = DAG.getVTList(ArgVT, ArgVT);
  return DAG.getNode(ISD::MERGE_VALUES, dl, Tys, SinVal, CosVal);
}

/// LowerOperation - Provide custom lowering hooks for some operations.
///
SDValue X86TargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG) const {
  switch (Op.getOpcode()) {
  default: llvm_unreachable("Should not custom lower this!");
  case ISD::SIGN_EXTEND_INREG:  return LowerSIGN_EXTEND_INREG(Op,DAG);
  case ISD::ATOMIC_FENCE:       return LowerATOMIC_FENCE(Op, Subtarget, DAG);
  case ISD::ATOMIC_CMP_SWAP_WITH_SUCCESS:
    return LowerCMP_SWAP(Op, Subtarget, DAG);
  case ISD::CTPOP:              return LowerCTPOP(Op, Subtarget, DAG);
  case ISD::ATOMIC_LOAD_SUB:    return LowerLOAD_SUB(Op,DAG);
  case ISD::ATOMIC_STORE:       return LowerATOMIC_STORE(Op,DAG);
  case ISD::BUILD_VECTOR:       return LowerBUILD_VECTOR(Op, DAG);
  case ISD::CONCAT_VECTORS:     return LowerCONCAT_VECTORS(Op, DAG);
  case ISD::VECTOR_SHUFFLE:     return LowerVECTOR_SHUFFLE(Op, DAG);
  case ISD::VSELECT:            return LowerVSELECT(Op, DAG);
  case ISD::EXTRACT_VECTOR_ELT: return LowerEXTRACT_VECTOR_ELT(Op, DAG);
  case ISD::INSERT_VECTOR_ELT:  return LowerINSERT_VECTOR_ELT(Op, DAG);
  case ISD::EXTRACT_SUBVECTOR:  return LowerEXTRACT_SUBVECTOR(Op,Subtarget,DAG);
  case ISD::INSERT_SUBVECTOR:   return LowerINSERT_SUBVECTOR(Op, Subtarget,DAG);
  case ISD::SCALAR_TO_VECTOR:   return LowerSCALAR_TO_VECTOR(Op, DAG);
  case ISD::ConstantPool:       return LowerConstantPool(Op, DAG);
  case ISD::GlobalAddress:      return LowerGlobalAddress(Op, DAG);
  case ISD::GlobalTLSAddress:   return LowerGlobalTLSAddress(Op, DAG);
  case ISD::ExternalSymbol:     return LowerExternalSymbol(Op, DAG);
  case ISD::BlockAddress:       return LowerBlockAddress(Op, DAG);
  case ISD::SHL_PARTS:
  case ISD::SRA_PARTS:
  case ISD::SRL_PARTS:          return LowerShiftParts(Op, DAG);
  case ISD::SINT_TO_FP:         return LowerSINT_TO_FP(Op, DAG);
  case ISD::UINT_TO_FP:         return LowerUINT_TO_FP(Op, DAG);
  case ISD::TRUNCATE:           return LowerTRUNCATE(Op, DAG);
  case ISD::ZERO_EXTEND:        return LowerZERO_EXTEND(Op, Subtarget, DAG);
  case ISD::SIGN_EXTEND:        return LowerSIGN_EXTEND(Op, Subtarget, DAG);
  case ISD::ANY_EXTEND:         return LowerANY_EXTEND(Op, Subtarget, DAG);
  case ISD::FP_TO_SINT:         return LowerFP_TO_SINT(Op, DAG);
  case ISD::FP_TO_UINT:         return LowerFP_TO_UINT(Op, DAG);
  case ISD::FP_EXTEND:          return LowerFP_EXTEND(Op, DAG);
  case ISD::LOAD:               return LowerExtendedLoad(Op, Subtarget, DAG);
  case ISD::FABS:
  case ISD::FNEG:               return LowerFABSorFNEG(Op, DAG);
  case ISD::FCOPYSIGN:          return LowerFCOPYSIGN(Op, DAG);
  case ISD::FGETSIGN:           return LowerFGETSIGN(Op, DAG);
  case ISD::SETCC:              return LowerSETCC(Op, DAG);
  case ISD::SELECT:             return LowerSELECT(Op, DAG);
  case ISD::BRCOND:             return LowerBRCOND(Op, DAG);
  case ISD::JumpTable:          return LowerJumpTable(Op, DAG);
  case ISD::VASTART:            return LowerVASTART(Op, DAG);
  case ISD::VAARG:              return LowerVAARG(Op, DAG);
  case ISD::VACOPY:             return LowerVACOPY(Op, Subtarget, DAG);
  case ISD::INTRINSIC_WO_CHAIN: return LowerINTRINSIC_WO_CHAIN(Op, Subtarget, DAG);
  case ISD::INTRINSIC_VOID:
  case ISD::INTRINSIC_W_CHAIN:  return LowerINTRINSIC_W_CHAIN(Op, Subtarget, DAG);
  case ISD::RETURNADDR:         return LowerRETURNADDR(Op, DAG);
  case ISD::FRAMEADDR:          return LowerFRAMEADDR(Op, DAG);
  case ISD::FRAME_TO_ARGS_OFFSET:
                                return LowerFRAME_TO_ARGS_OFFSET(Op, DAG);
  case ISD::DYNAMIC_STACKALLOC: return LowerDYNAMIC_STACKALLOC(Op, DAG);
  case ISD::EH_RETURN:          return LowerEH_RETURN(Op, DAG);
  case ISD::EH_SJLJ_SETJMP:     return lowerEH_SJLJ_SETJMP(Op, DAG);
  case ISD::EH_SJLJ_LONGJMP:    return lowerEH_SJLJ_LONGJMP(Op, DAG);
  case ISD::INIT_TRAMPOLINE:    return LowerINIT_TRAMPOLINE(Op, DAG);
  case ISD::ADJUST_TRAMPOLINE:  return LowerADJUST_TRAMPOLINE(Op, DAG);
  case ISD::FLT_ROUNDS_:        return LowerFLT_ROUNDS_(Op, DAG);
  case ISD::CTLZ:               return LowerCTLZ(Op, DAG);
  case ISD::CTLZ_ZERO_UNDEF:    return LowerCTLZ_ZERO_UNDEF(Op, DAG);
  case ISD::CTTZ:               return LowerCTTZ(Op, DAG);
  case ISD::MUL:                return LowerMUL(Op, Subtarget, DAG);
  case ISD::UMUL_LOHI:
  case ISD::SMUL_LOHI:          return LowerMUL_LOHI(Op, Subtarget, DAG);
  case ISD::SRA:
  case ISD::SRL:
  case ISD::SHL:                return LowerShift(Op, Subtarget, DAG);
  case ISD::SADDO:
  case ISD::UADDO:
  case ISD::SSUBO:
  case ISD::USUBO:
  case ISD::SMULO:
  case ISD::UMULO:              return LowerXALUO(Op, DAG);
  case ISD::READCYCLECOUNTER:   return LowerREADCYCLECOUNTER(Op, Subtarget,DAG);
  case ISD::BITCAST:            return LowerBITCAST(Op, Subtarget, DAG);
  case ISD::ADDC:
  case ISD::ADDE:
  case ISD::SUBC:
  case ISD::SUBE:               return LowerADDC_ADDE_SUBC_SUBE(Op, DAG);
  case ISD::ADD:                return LowerADD(Op, DAG);
  case ISD::SUB:                return LowerSUB(Op, DAG);
  case ISD::FSINCOS:            return LowerFSINCOS(Op, Subtarget, DAG);
  }
}

/// ReplaceNodeResults - Replace a node with an illegal result type
/// with a new node built out of custom code.
void X86TargetLowering::ReplaceNodeResults(SDNode *N,
                                           SmallVectorImpl<SDValue>&Results,
                                           SelectionDAG &DAG) const {
  SDLoc dl(N);
  const TargetLowering &TLI = DAG.getTargetLoweringInfo();
  switch (N->getOpcode()) {
  default:
    llvm_unreachable("Do not know how to custom type legalize this operation!");
  // We might have generated v2f32 FMIN/FMAX operations. Widen them to v4f32.
  case X86ISD::FMINC:
  case X86ISD::FMIN:
  case X86ISD::FMAXC:
  case X86ISD::FMAX: {
    EVT VT = N->getValueType(0);
    if (VT != MVT::v2f32)
      llvm_unreachable("Unexpected type (!= v2f32) on FMIN/FMAX.");
    SDValue UNDEF = DAG.getUNDEF(VT);
    SDValue LHS = DAG.getNode(ISD::CONCAT_VECTORS, dl, MVT::v4f32,
                              N->getOperand(0), UNDEF);
    SDValue RHS = DAG.getNode(ISD::CONCAT_VECTORS, dl, MVT::v4f32,
                              N->getOperand(1), UNDEF);
    Results.push_back(DAG.getNode(N->getOpcode(), dl, MVT::v4f32, LHS, RHS));
    return;
  }
  case ISD::SIGN_EXTEND_INREG:
  case ISD::ADDC:
  case ISD::ADDE:
  case ISD::SUBC:
  case ISD::SUBE:
    // We don't want to expand or promote these.
    return;
  case ISD::SDIV:
  case ISD::UDIV:
  case ISD::SREM:
  case ISD::UREM:
  case ISD::SDIVREM:
  case ISD::UDIVREM: {
    SDValue V = LowerWin64_i128OP(SDValue(N,0), DAG);
    Results.push_back(V);
    return;
  }
  case ISD::FP_TO_SINT:
  case ISD::FP_TO_UINT: {
    bool IsSigned = N->getOpcode() == ISD::FP_TO_SINT;

    if (!IsSigned && !isIntegerTypeFTOL(SDValue(N, 0).getValueType()))
      return;

    std::pair<SDValue,SDValue> Vals =
        FP_TO_INTHelper(SDValue(N, 0), DAG, IsSigned, /*IsReplace=*/ true);
    SDValue FIST = Vals.first, StackSlot = Vals.second;
    if (FIST.getNode()) {
      EVT VT = N->getValueType(0);
      // Return a load from the stack slot.
      if (StackSlot.getNode())
        Results.push_back(DAG.getLoad(VT, dl, FIST, StackSlot,
                                      MachinePointerInfo(),
                                      false, false, false, 0));
      else
        Results.push_back(FIST);
    }
    return;
  }
  case ISD::UINT_TO_FP: {
    assert(Subtarget->hasSSE2() && "Requires at least SSE2!");
    if (N->getOperand(0).getValueType() != MVT::v2i32 ||
        N->getValueType(0) != MVT::v2f32)
      return;
    SDValue ZExtIn = DAG.getNode(ISD::ZERO_EXTEND, dl, MVT::v2i64,
                                 N->getOperand(0));
    SDValue Bias = DAG.getConstantFP(BitsToDouble(0x4330000000000000ULL),
                                     MVT::f64);
    SDValue VBias = DAG.getNode(ISD::BUILD_VECTOR, dl, MVT::v2f64, Bias, Bias);
    SDValue Or = DAG.getNode(ISD::OR, dl, MVT::v2i64, ZExtIn,
                             DAG.getNode(ISD::BITCAST, dl, MVT::v2i64, VBias));
    Or = DAG.getNode(ISD::BITCAST, dl, MVT::v2f64, Or);
    SDValue Sub = DAG.getNode(ISD::FSUB, dl, MVT::v2f64, Or, VBias);
    Results.push_back(DAG.getNode(X86ISD::VFPROUND, dl, MVT::v4f32, Sub));
    return;
  }
  case ISD::FP_ROUND: {
    if (!TLI.isTypeLegal(N->getOperand(0).getValueType()))
        return;
    SDValue V = DAG.getNode(X86ISD::VFPROUND, dl, MVT::v4f32, N->getOperand(0));
    Results.push_back(V);
    return;
  }
  case ISD::INTRINSIC_W_CHAIN: {
    unsigned IntNo = cast<ConstantSDNode>(N->getOperand(1))->getZExtValue();
    switch (IntNo) {
    default : llvm_unreachable("Do not know how to custom type "
                               "legalize this intrinsic operation!");
    case Intrinsic::x86_rdtsc:
      return getReadTimeStampCounter(N, dl, X86ISD::RDTSC_DAG, DAG, Subtarget,
                                     Results);
    case Intrinsic::x86_rdtscp:
      return getReadTimeStampCounter(N, dl, X86ISD::RDTSCP_DAG, DAG, Subtarget,
                                     Results);
    case Intrinsic::x86_rdpmc:
      return getReadPerformanceCounter(N, dl, DAG, Subtarget, Results);
    }
  }
  case ISD::READCYCLECOUNTER: {
    return getReadTimeStampCounter(N, dl, X86ISD::RDTSC_DAG, DAG, Subtarget,
                                   Results);
  }
  case ISD::ATOMIC_CMP_SWAP_WITH_SUCCESS: {
    EVT T = N->getValueType(0);
    assert((T == MVT::i64 || T == MVT::i128) && "can only expand cmpxchg pair");
    bool Regs64bit = T == MVT::i128;
    EVT HalfT = Regs64bit ? MVT::i64 : MVT::i32;
    SDValue cpInL, cpInH;
    cpInL = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, HalfT, N->getOperand(2),
                        DAG.getConstant(0, HalfT));
    cpInH = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, HalfT, N->getOperand(2),
                        DAG.getConstant(1, HalfT));
    cpInL = DAG.getCopyToReg(N->getOperand(0), dl,
                             Regs64bit ? X86::RAX : X86::EAX,
                             cpInL, SDValue());
    cpInH = DAG.getCopyToReg(cpInL.getValue(0), dl,
                             Regs64bit ? X86::RDX : X86::EDX,
                             cpInH, cpInL.getValue(1));
    SDValue swapInL, swapInH;
    swapInL = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, HalfT, N->getOperand(3),
                          DAG.getConstant(0, HalfT));
    swapInH = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, HalfT, N->getOperand(3),
                          DAG.getConstant(1, HalfT));
    swapInL = DAG.getCopyToReg(cpInH.getValue(0), dl,
                               Regs64bit ? X86::RBX : X86::EBX,
                               swapInL, cpInH.getValue(1));
    swapInH = DAG.getCopyToReg(swapInL.getValue(0), dl,
                               Regs64bit ? X86::RCX : X86::ECX,
                               swapInH, swapInL.getValue(1));
    SDValue Ops[] = { swapInH.getValue(0),
                      N->getOperand(1),
                      swapInH.getValue(1) };
    SDVTList Tys = DAG.getVTList(MVT::Other, MVT::Glue);
    MachineMemOperand *MMO = cast<AtomicSDNode>(N)->getMemOperand();
    unsigned Opcode = Regs64bit ? X86ISD::LCMPXCHG16_DAG :
                                  X86ISD::LCMPXCHG8_DAG;
    SDValue Result = DAG.getMemIntrinsicNode(Opcode, dl, Tys, Ops, T, MMO);
    SDValue cpOutL = DAG.getCopyFromReg(Result.getValue(0), dl,
                                        Regs64bit ? X86::RAX : X86::EAX,
                                        HalfT, Result.getValue(1));
    SDValue cpOutH = DAG.getCopyFromReg(cpOutL.getValue(1), dl,
                                        Regs64bit ? X86::RDX : X86::EDX,
                                        HalfT, cpOutL.getValue(2));
    SDValue OpsF[] = { cpOutL.getValue(0), cpOutH.getValue(0)};

    SDValue EFLAGS = DAG.getCopyFromReg(cpOutH.getValue(1), dl, X86::EFLAGS,
                                        MVT::i32, cpOutH.getValue(2));
    SDValue Success =
        DAG.getNode(X86ISD::SETCC, dl, MVT::i8,
                    DAG.getConstant(X86::COND_E, MVT::i8), EFLAGS);
    Success = DAG.getZExtOrTrunc(Success, dl, N->getValueType(1));

    Results.push_back(DAG.getNode(ISD::BUILD_PAIR, dl, T, OpsF));
    Results.push_back(Success);
    Results.push_back(EFLAGS.getValue(1));
    return;
  }
  case ISD::ATOMIC_SWAP:
  case ISD::ATOMIC_LOAD_ADD:
  case ISD::ATOMIC_LOAD_SUB:
  case ISD::ATOMIC_LOAD_AND:
  case ISD::ATOMIC_LOAD_OR:
  case ISD::ATOMIC_LOAD_XOR:
  case ISD::ATOMIC_LOAD_NAND:
  case ISD::ATOMIC_LOAD_MIN:
  case ISD::ATOMIC_LOAD_MAX:
  case ISD::ATOMIC_LOAD_UMIN:
  case ISD::ATOMIC_LOAD_UMAX:
  case ISD::ATOMIC_LOAD: {
    // Delegate to generic TypeLegalization. Situations we can really handle
    // should have already been dealt with by AtomicExpandPass.cpp.
    break;
  }
  case ISD::BITCAST: {
    assert(Subtarget->hasSSE2() && "Requires at least SSE2!");
    EVT DstVT = N->getValueType(0);
    EVT SrcVT = N->getOperand(0)->getValueType(0);

    if (SrcVT != MVT::f64 ||
        (DstVT != MVT::v2i32 && DstVT != MVT::v4i16 && DstVT != MVT::v8i8))
      return;

    unsigned NumElts = DstVT.getVectorNumElements();
    EVT SVT = DstVT.getVectorElementType();
    EVT WiderVT = EVT::getVectorVT(*DAG.getContext(), SVT, NumElts * 2);
    SDValue Expanded = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl,
                                   MVT::v2f64, N->getOperand(0));
    SDValue ToVecInt = DAG.getNode(ISD::BITCAST, dl, WiderVT, Expanded);

    if (ExperimentalVectorWideningLegalization) {
      // If we are legalizing vectors by widening, we already have the desired
      // legal vector type, just return it.
      Results.push_back(ToVecInt);
      return;
    }

    SmallVector<SDValue, 8> Elts;
    for (unsigned i = 0, e = NumElts; i != e; ++i)
      Elts.push_back(DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, SVT,
                                   ToVecInt, DAG.getIntPtrConstant(i)));

    Results.push_back(DAG.getNode(ISD::BUILD_VECTOR, dl, DstVT, Elts));
  }
  }
}

const char *X86TargetLowering::getTargetNodeName(unsigned Opcode) const {
  switch (Opcode) {
  default: return nullptr;
  case X86ISD::BSF:                return "X86ISD::BSF";
  case X86ISD::BSR:                return "X86ISD::BSR";
  case X86ISD::SHLD:               return "X86ISD::SHLD";
  case X86ISD::SHRD:               return "X86ISD::SHRD";
  case X86ISD::FAND:               return "X86ISD::FAND";
  case X86ISD::FANDN:              return "X86ISD::FANDN";
  case X86ISD::FOR:                return "X86ISD::FOR";
  case X86ISD::FXOR:               return "X86ISD::FXOR";
  case X86ISD::FSRL:               return "X86ISD::FSRL";
  case X86ISD::FILD:               return "X86ISD::FILD";
  case X86ISD::FILD_FLAG:          return "X86ISD::FILD_FLAG";
  case X86ISD::FP_TO_INT16_IN_MEM: return "X86ISD::FP_TO_INT16_IN_MEM";
  case X86ISD::FP_TO_INT32_IN_MEM: return "X86ISD::FP_TO_INT32_IN_MEM";
  case X86ISD::FP_TO_INT64_IN_MEM: return "X86ISD::FP_TO_INT64_IN_MEM";
  case X86ISD::FLD:                return "X86ISD::FLD";
  case X86ISD::FST:                return "X86ISD::FST";
  case X86ISD::CALL:               return "X86ISD::CALL";
  case X86ISD::RDTSC_DAG:          return "X86ISD::RDTSC_DAG";
  case X86ISD::RDTSCP_DAG:         return "X86ISD::RDTSCP_DAG";
  case X86ISD::RDPMC_DAG:          return "X86ISD::RDPMC_DAG";
  case X86ISD::BT:                 return "X86ISD::BT";
  case X86ISD::CMP:                return "X86ISD::CMP";
  case X86ISD::COMI:               return "X86ISD::COMI";
  case X86ISD::UCOMI:              return "X86ISD::UCOMI";
  case X86ISD::CMPM:               return "X86ISD::CMPM";
  case X86ISD::CMPMU:              return "X86ISD::CMPMU";
  case X86ISD::SETCC:              return "X86ISD::SETCC";
  case X86ISD::SETCC_CARRY:        return "X86ISD::SETCC_CARRY";
  case X86ISD::FSETCC:             return "X86ISD::FSETCC";
  case X86ISD::CMOV:               return "X86ISD::CMOV";
  case X86ISD::BRCOND:             return "X86ISD::BRCOND";
  case X86ISD::RET_FLAG:           return "X86ISD::RET_FLAG";
  case X86ISD::REP_STOS:           return "X86ISD::REP_STOS";
  case X86ISD::REP_MOVS:           return "X86ISD::REP_MOVS";
  case X86ISD::GlobalBaseReg:      return "X86ISD::GlobalBaseReg";
  case X86ISD::Wrapper:            return "X86ISD::Wrapper";
  case X86ISD::WrapperRIP:         return "X86ISD::WrapperRIP";
  case X86ISD::PEXTRB:             return "X86ISD::PEXTRB";
  case X86ISD::PEXTRW:             return "X86ISD::PEXTRW";
  case X86ISD::INSERTPS:           return "X86ISD::INSERTPS";
  case X86ISD::PINSRB:             return "X86ISD::PINSRB";
  case X86ISD::PINSRW:             return "X86ISD::PINSRW";
  case X86ISD::PSHUFB:             return "X86ISD::PSHUFB";
  case X86ISD::ANDNP:              return "X86ISD::ANDNP";
  case X86ISD::PSIGN:              return "X86ISD::PSIGN";
  case X86ISD::BLENDI:             return "X86ISD::BLENDI";
  case X86ISD::SHRUNKBLEND:        return "X86ISD::SHRUNKBLEND";
  case X86ISD::SUBUS:              return "X86ISD::SUBUS";
  case X86ISD::HADD:               return "X86ISD::HADD";
  case X86ISD::HSUB:               return "X86ISD::HSUB";
  case X86ISD::FHADD:              return "X86ISD::FHADD";
  case X86ISD::FHSUB:              return "X86ISD::FHSUB";
  case X86ISD::UMAX:               return "X86ISD::UMAX";
  case X86ISD::UMIN:               return "X86ISD::UMIN";
  case X86ISD::SMAX:               return "X86ISD::SMAX";
  case X86ISD::SMIN:               return "X86ISD::SMIN";
  case X86ISD::FMAX:               return "X86ISD::FMAX";
  case X86ISD::FMIN:               return "X86ISD::FMIN";
  case X86ISD::FMAXC:              return "X86ISD::FMAXC";
  case X86ISD::FMINC:              return "X86ISD::FMINC";
  case X86ISD::FRSQRT:             return "X86ISD::FRSQRT";
  case X86ISD::FRCP:               return "X86ISD::FRCP";
  case X86ISD::TLSADDR:            return "X86ISD::TLSADDR";
  case X86ISD::TLSBASEADDR:        return "X86ISD::TLSBASEADDR";
  case X86ISD::TLSCALL:            return "X86ISD::TLSCALL";
  case X86ISD::EH_SJLJ_SETJMP:     return "X86ISD::EH_SJLJ_SETJMP";
  case X86ISD::EH_SJLJ_LONGJMP:    return "X86ISD::EH_SJLJ_LONGJMP";
  case X86ISD::EH_RETURN:          return "X86ISD::EH_RETURN";
  case X86ISD::TC_RETURN:          return "X86ISD::TC_RETURN";
  case X86ISD::FNSTCW16m:          return "X86ISD::FNSTCW16m";
  case X86ISD::FNSTSW16r:          return "X86ISD::FNSTSW16r";
  case X86ISD::LCMPXCHG_DAG:       return "X86ISD::LCMPXCHG_DAG";
  case X86ISD::LCMPXCHG8_DAG:      return "X86ISD::LCMPXCHG8_DAG";
  case X86ISD::LCMPXCHG16_DAG:     return "X86ISD::LCMPXCHG16_DAG";
  case X86ISD::VZEXT_MOVL:         return "X86ISD::VZEXT_MOVL";
  case X86ISD::VZEXT_LOAD:         return "X86ISD::VZEXT_LOAD";
  case X86ISD::VZEXT:              return "X86ISD::VZEXT";
  case X86ISD::VSEXT:              return "X86ISD::VSEXT";
  case X86ISD::VTRUNC:             return "X86ISD::VTRUNC";
  case X86ISD::VTRUNCM:            return "X86ISD::VTRUNCM";
  case X86ISD::VINSERT:            return "X86ISD::VINSERT";
  case X86ISD::VFPEXT:             return "X86ISD::VFPEXT";
  case X86ISD::VFPROUND:           return "X86ISD::VFPROUND";
  case X86ISD::VSHLDQ:             return "X86ISD::VSHLDQ";
  case X86ISD::VSRLDQ:             return "X86ISD::VSRLDQ";
  case X86ISD::VSHL:               return "X86ISD::VSHL";
  case X86ISD::VSRL:               return "X86ISD::VSRL";
  case X86ISD::VSRA:               return "X86ISD::VSRA";
  case X86ISD::VSHLI:              return "X86ISD::VSHLI";
  case X86ISD::VSRLI:              return "X86ISD::VSRLI";
  case X86ISD::VSRAI:              return "X86ISD::VSRAI";
  case X86ISD::CMPP:               return "X86ISD::CMPP";
  case X86ISD::PCMPEQ:             return "X86ISD::PCMPEQ";
  case X86ISD::PCMPGT:             return "X86ISD::PCMPGT";
  case X86ISD::PCMPEQM:            return "X86ISD::PCMPEQM";
  case X86ISD::PCMPGTM:            return "X86ISD::PCMPGTM";
  case X86ISD::ADD:                return "X86ISD::ADD";
  case X86ISD::SUB:                return "X86ISD::SUB";
  case X86ISD::ADC:                return "X86ISD::ADC";
  case X86ISD::SBB:                return "X86ISD::SBB";
  case X86ISD::SMUL:               return "X86ISD::SMUL";
  case X86ISD::UMUL:               return "X86ISD::UMUL";
  case X86ISD::SMUL8:              return "X86ISD::SMUL8";
  case X86ISD::UMUL8:              return "X86ISD::UMUL8";
  case X86ISD::SDIVREM8_SEXT_HREG: return "X86ISD::SDIVREM8_SEXT_HREG";
  case X86ISD::UDIVREM8_ZEXT_HREG: return "X86ISD::UDIVREM8_ZEXT_HREG";
  case X86ISD::INC:                return "X86ISD::INC";
  case X86ISD::DEC:                return "X86ISD::DEC";
  case X86ISD::OR:                 return "X86ISD::OR";
  case X86ISD::XOR:                return "X86ISD::XOR";
  case X86ISD::AND:                return "X86ISD::AND";
  case X86ISD::BEXTR:              return "X86ISD::BEXTR";
  case X86ISD::MUL_IMM:            return "X86ISD::MUL_IMM";
  case X86ISD::PTEST:              return "X86ISD::PTEST";
  case X86ISD::TESTP:              return "X86ISD::TESTP";
  case X86ISD::TESTM:              return "X86ISD::TESTM";
  case X86ISD::TESTNM:             return "X86ISD::TESTNM";
  case X86ISD::KORTEST:            return "X86ISD::KORTEST";
  case X86ISD::PACKSS:             return "X86ISD::PACKSS";
  case X86ISD::PACKUS:             return "X86ISD::PACKUS";
  case X86ISD::PALIGNR:            return "X86ISD::PALIGNR";
  case X86ISD::VALIGN:             return "X86ISD::VALIGN";
  case X86ISD::PSHUFD:             return "X86ISD::PSHUFD";
  case X86ISD::PSHUFHW:            return "X86ISD::PSHUFHW";
  case X86ISD::PSHUFLW:            return "X86ISD::PSHUFLW";
  case X86ISD::SHUFP:              return "X86ISD::SHUFP";
  case X86ISD::MOVLHPS:            return "X86ISD::MOVLHPS";
  case X86ISD::MOVLHPD:            return "X86ISD::MOVLHPD";
  case X86ISD::MOVHLPS:            return "X86ISD::MOVHLPS";
  case X86ISD::MOVLPS:             return "X86ISD::MOVLPS";
  case X86ISD::MOVLPD:             return "X86ISD::MOVLPD";
  case X86ISD::MOVDDUP:            return "X86ISD::MOVDDUP";
  case X86ISD::MOVSHDUP:           return "X86ISD::MOVSHDUP";
  case X86ISD::MOVSLDUP:           return "X86ISD::MOVSLDUP";
  case X86ISD::MOVSD:              return "X86ISD::MOVSD";
  case X86ISD::MOVSS:              return "X86ISD::MOVSS";
  case X86ISD::UNPCKL:             return "X86ISD::UNPCKL";
  case X86ISD::UNPCKH:             return "X86ISD::UNPCKH";
  case X86ISD::VBROADCAST:         return "X86ISD::VBROADCAST";
  case X86ISD::VBROADCASTM:        return "X86ISD::VBROADCASTM";
  case X86ISD::VEXTRACT:           return "X86ISD::VEXTRACT";
  case X86ISD::VPERMILPI:          return "X86ISD::VPERMILPI";
  case X86ISD::VPERM2X128:         return "X86ISD::VPERM2X128";
  case X86ISD::VPERMV:             return "X86ISD::VPERMV";
  case X86ISD::VPERMV3:            return "X86ISD::VPERMV3";
  case X86ISD::VPERMIV3:           return "X86ISD::VPERMIV3";
  case X86ISD::VPERMI:             return "X86ISD::VPERMI";
  case X86ISD::PMULUDQ:            return "X86ISD::PMULUDQ";
  case X86ISD::PMULDQ:             return "X86ISD::PMULDQ";
  case X86ISD::VASTART_SAVE_XMM_REGS: return "X86ISD::VASTART_SAVE_XMM_REGS";
  case X86ISD::VAARG_64:           return "X86ISD::VAARG_64";
  case X86ISD::WIN_ALLOCA:         return "X86ISD::WIN_ALLOCA";
  case X86ISD::MEMBARRIER:         return "X86ISD::MEMBARRIER";
  case X86ISD::SEG_ALLOCA:         return "X86ISD::SEG_ALLOCA";
  case X86ISD::WIN_FTOL:           return "X86ISD::WIN_FTOL";
  case X86ISD::SAHF:               return "X86ISD::SAHF";
  case X86ISD::RDRAND:             return "X86ISD::RDRAND";
  case X86ISD::RDSEED:             return "X86ISD::RDSEED";
  case X86ISD::FMADD:              return "X86ISD::FMADD";
  case X86ISD::FMSUB:              return "X86ISD::FMSUB";
  case X86ISD::FNMADD:             return "X86ISD::FNMADD";
  case X86ISD::FNMSUB:             return "X86ISD::FNMSUB";
  case X86ISD::FMADDSUB:           return "X86ISD::FMADDSUB";
  case X86ISD::FMSUBADD:           return "X86ISD::FMSUBADD";
  case X86ISD::PCMPESTRI:          return "X86ISD::PCMPESTRI";
  case X86ISD::PCMPISTRI:          return "X86ISD::PCMPISTRI";
  case X86ISD::XTEST:              return "X86ISD::XTEST";
  case X86ISD::COMPRESS:           return "X86ISD::COMPRESS";
  case X86ISD::EXPAND:             return "X86ISD::EXPAND";
  case X86ISD::SELECT:             return "X86ISD::SELECT";
  case X86ISD::ADDSUB:             return "X86ISD::ADDSUB";
  case X86ISD::RCP28:              return "X86ISD::RCP28";
  case X86ISD::RSQRT28:            return "X86ISD::RSQRT28";
  case X86ISD::FADD_RND:           return "X86ISD::FADD_RND";
  case X86ISD::FSUB_RND:           return "X86ISD::FSUB_RND";
  case X86ISD::FMUL_RND:           return "X86ISD::FMUL_RND";
  case X86ISD::FDIV_RND:           return "X86ISD::FDIV_RND";
  }
}

// isLegalAddressingMode - Return true if the addressing mode represented
// by AM is legal for this target, for a load/store of the specified type.
bool X86TargetLowering::isLegalAddressingMode(const AddrMode &AM,
                                              Type *Ty) const {
  // X86 supports extremely general addressing modes.
  CodeModel::Model M = getTargetMachine().getCodeModel();
  Reloc::Model R = getTargetMachine().getRelocationModel();

  // X86 allows a sign-extended 32-bit immediate field as a displacement.
  if (!X86::isOffsetSuitableForCodeModel(AM.BaseOffs, M, AM.BaseGV != nullptr))
    return false;

  if (AM.BaseGV) {
    unsigned GVFlags =
      Subtarget->ClassifyGlobalReference(AM.BaseGV, getTargetMachine());

    // If a reference to this global requires an extra load, we can't fold it.
    if (isGlobalStubReference(GVFlags))
      return false;

    // If BaseGV requires a register for the PIC base, we cannot also have a
    // BaseReg specified.
    if (AM.HasBaseReg && isGlobalRelativeToPICBase(GVFlags))
      return false;

    // If lower 4G is not available, then we must use rip-relative addressing.
    if ((M != CodeModel::Small || R != Reloc::Static) &&
        Subtarget->is64Bit() && (AM.BaseOffs || AM.Scale > 1))
      return false;
  }

  switch (AM.Scale) {
  case 0:
  case 1:
  case 2:
  case 4:
  case 8:
    // These scales always work.
    break;
  case 3:
  case 5:
  case 9:
    // These scales are formed with basereg+scalereg.  Only accept if there is
    // no basereg yet.
    if (AM.HasBaseReg)
      return false;
    break;
  default:  // Other stuff never works.
    return false;
  }

  return true;
}

bool X86TargetLowering::isVectorShiftByScalarCheap(Type *Ty) const {
  unsigned Bits = Ty->getScalarSizeInBits();

  // 8-bit shifts are always expensive, but versions with a scalar amount aren't
  // particularly cheaper than those without.
  if (Bits == 8)
    return false;

  // On AVX2 there are new vpsllv[dq] instructions (and other shifts), that make
  // variable shifts just as cheap as scalar ones.
  if (Subtarget->hasInt256() && (Bits == 32 || Bits == 64))
    return false;

  // Otherwise, it's significantly cheaper to shift by a scalar amount than by a
  // fully general vector.
  return true;
}

bool X86TargetLowering::isTruncateFree(Type *Ty1, Type *Ty2) const {
  if (!Ty1->isIntegerTy() || !Ty2->isIntegerTy())
    return false;
  unsigned NumBits1 = Ty1->getPrimitiveSizeInBits();
  unsigned NumBits2 = Ty2->getPrimitiveSizeInBits();
  return NumBits1 > NumBits2;
}

bool X86TargetLowering::allowTruncateForTailCall(Type *Ty1, Type *Ty2) const {
  if (!Ty1->isIntegerTy() || !Ty2->isIntegerTy())
    return false;

  if (!isTypeLegal(EVT::getEVT(Ty1)))
    return false;

  assert(Ty1->getPrimitiveSizeInBits() <= 64 && "i128 is probably not a noop");

  // Assuming the caller doesn't have a zeroext or signext return parameter,
  // truncation all the way down to i1 is valid.
  return true;
}

bool X86TargetLowering::isLegalICmpImmediate(int64_t Imm) const {
  return isInt<32>(Imm);
}

bool X86TargetLowering::isLegalAddImmediate(int64_t Imm) const {
  // Can also use sub to handle negated immediates.
  return isInt<32>(Imm);
}

bool X86TargetLowering::isTruncateFree(EVT VT1, EVT VT2) const {
  if (!VT1.isInteger() || !VT2.isInteger())
    return false;
  unsigned NumBits1 = VT1.getSizeInBits();
  unsigned NumBits2 = VT2.getSizeInBits();
  return NumBits1 > NumBits2;
}

bool X86TargetLowering::isZExtFree(Type *Ty1, Type *Ty2) const {
  // x86-64 implicitly zero-extends 32-bit results in 64-bit registers.
  return Ty1->isIntegerTy(32) && Ty2->isIntegerTy(64) && Subtarget->is64Bit();
}

bool X86TargetLowering::isZExtFree(EVT VT1, EVT VT2) const {
  // x86-64 implicitly zero-extends 32-bit results in 64-bit registers.
  return VT1 == MVT::i32 && VT2 == MVT::i64 && Subtarget->is64Bit();
}

bool X86TargetLowering::isZExtFree(SDValue Val, EVT VT2) const {
  EVT VT1 = Val.getValueType();
  if (isZExtFree(VT1, VT2))
    return true;

  if (Val.getOpcode() != ISD::LOAD)
    return false;

  if (!VT1.isSimple() || !VT1.isInteger() ||
      !VT2.isSimple() || !VT2.isInteger())
    return false;

  switch (VT1.getSimpleVT().SimpleTy) {
  default: break;
  case MVT::i8:
  case MVT::i16:
  case MVT::i32:
    // X86 has 8, 16, and 32-bit zero-extending loads.
    return true;
  }

  return false;
}

bool X86TargetLowering::isVectorLoadExtDesirable(SDValue) const { return true; }

bool
X86TargetLowering::isFMAFasterThanFMulAndFAdd(EVT VT) const {
  if (!(Subtarget->hasFMA() || Subtarget->hasFMA4()))
    return false;

  VT = VT.getScalarType();

  if (!VT.isSimple())
    return false;

  switch (VT.getSimpleVT().SimpleTy) {
  case MVT::f32:
  case MVT::f64:
    return true;
  default:
    break;
  }

  return false;
}

bool X86TargetLowering::isNarrowingProfitable(EVT VT1, EVT VT2) const {
  // i16 instructions are longer (0x66 prefix) and potentially slower.
  return !(VT1 == MVT::i32 && VT2 == MVT::i16);
}

/// isShuffleMaskLegal - Targets can use this to indicate that they only
/// support *some* VECTOR_SHUFFLE operations, those with specific masks.
/// By default, if a target supports the VECTOR_SHUFFLE node, all mask values
/// are assumed to be legal.
bool
X86TargetLowering::isShuffleMaskLegal(const SmallVectorImpl<int> &M,
                                      EVT VT) const {
  if (!VT.isSimple())
    return false;

  MVT SVT = VT.getSimpleVT();

  // Very little shuffling can be done for 64-bit vectors right now.
  if (VT.getSizeInBits() == 64)
    return false;

  // This is an experimental legality test that is tailored to match the
  // legality test of the experimental lowering more closely. They are gated
  // separately to ease testing of performance differences.
  if (ExperimentalVectorShuffleLegality)
    // We only care that the types being shuffled are legal. The lowering can
    // handle any possible shuffle mask that results.
    return isTypeLegal(SVT);

  // If this is a single-input shuffle with no 128 bit lane crossings we can
  // lower it into pshufb.
  if ((SVT.is128BitVector() && Subtarget->hasSSSE3()) ||
      (SVT.is256BitVector() && Subtarget->hasInt256())) {
    bool isLegal = true;
    for (unsigned I = 0, E = M.size(); I != E; ++I) {
      if (M[I] >= (int)SVT.getVectorNumElements() ||
          ShuffleCrosses128bitLane(SVT, I, M[I])) {
        isLegal = false;
        break;
      }
    }
    if (isLegal)
      return true;
  }

  // FIXME: blends, shifts.
  return (SVT.getVectorNumElements() == 2 ||
          ShuffleVectorSDNode::isSplatMask(&M[0], VT) ||
          isMOVLMask(M, SVT) ||
          isCommutedMOVLMask(M, SVT) ||
          isMOVHLPSMask(M, SVT) ||
          isSHUFPMask(M, SVT) ||
          isSHUFPMask(M, SVT, /* Commuted */ true) ||
          isPSHUFDMask(M, SVT) ||
          isPSHUFDMask(M, SVT, /* SecondOperand */ true) ||
          isPSHUFHWMask(M, SVT, Subtarget->hasInt256()) ||
          isPSHUFLWMask(M, SVT, Subtarget->hasInt256()) ||
          isPALIGNRMask(M, SVT, Subtarget) ||
          isUNPCKLMask(M, SVT, Subtarget->hasInt256()) ||
          isUNPCKHMask(M, SVT, Subtarget->hasInt256()) ||
          isUNPCKL_v_undef_Mask(M, SVT, Subtarget->hasInt256()) ||
          isUNPCKH_v_undef_Mask(M, SVT, Subtarget->hasInt256()) ||
          isBlendMask(M, SVT, Subtarget->hasSSE41(), Subtarget->hasInt256()) ||
          (Subtarget->hasSSE41() && isINSERTPSMask(M, SVT)));
}

bool
X86TargetLowering::isVectorClearMaskLegal(const SmallVectorImpl<int> &Mask,
                                          EVT VT) const {
  if (!VT.isSimple())
    return false;

  MVT SVT = VT.getSimpleVT();

  // This is an experimental legality test that is tailored to match the
  // legality test of the experimental lowering more closely. They are gated
  // separately to ease testing of performance differences.
  if (ExperimentalVectorShuffleLegality)
    // The new vector shuffle lowering is very good at managing zero-inputs.
    return isShuffleMaskLegal(Mask, VT);

  unsigned NumElts = SVT.getVectorNumElements();
  // FIXME: This collection of masks seems suspect.
  if (NumElts == 2)
    return true;
  if (NumElts == 4 && SVT.is128BitVector()) {
    return (isMOVLMask(Mask, SVT)  ||
            isCommutedMOVLMask(Mask, SVT, true) ||
            isSHUFPMask(Mask, SVT) ||
            isSHUFPMask(Mask, SVT, /* Commuted */ true) ||
            isBlendMask(Mask, SVT, Subtarget->hasSSE41(),
                        Subtarget->hasInt256()));
  }
  return false;
}

//===----------------------------------------------------------------------===//
//                           X86 Scheduler Hooks
//===----------------------------------------------------------------------===//

/// Utility function to emit xbegin specifying the start of an RTM region.
static MachineBasicBlock *EmitXBegin(MachineInstr *MI, MachineBasicBlock *MBB,
                                     const TargetInstrInfo *TII) {
  DebugLoc DL = MI->getDebugLoc();

  const BasicBlock *BB = MBB->getBasicBlock();
  MachineFunction::iterator I = MBB;
  ++I;

  // For the v = xbegin(), we generate
  //
  // thisMBB:
  //  xbegin sinkMBB
  //
  // mainMBB:
  //  eax = -1
  //
  // sinkMBB:
  //  v = eax

  MachineBasicBlock *thisMBB = MBB;
  MachineFunction *MF = MBB->getParent();
  MachineBasicBlock *mainMBB = MF->CreateMachineBasicBlock(BB);
  MachineBasicBlock *sinkMBB = MF->CreateMachineBasicBlock(BB);
  MF->insert(I, mainMBB);
  MF->insert(I, sinkMBB);

  // Transfer the remainder of BB and its successor edges to sinkMBB.
  sinkMBB->splice(sinkMBB->begin(), MBB,
                  std::next(MachineBasicBlock::iterator(MI)), MBB->end());
  sinkMBB->transferSuccessorsAndUpdatePHIs(MBB);

  // thisMBB:
  //  xbegin sinkMBB
  //  # fallthrough to mainMBB
  //  # abortion to sinkMBB
  BuildMI(thisMBB, DL, TII->get(X86::XBEGIN_4)).addMBB(sinkMBB);
  thisMBB->addSuccessor(mainMBB);
  thisMBB->addSuccessor(sinkMBB);

  // mainMBB:
  //  EAX = -1
  BuildMI(mainMBB, DL, TII->get(X86::MOV32ri), X86::EAX).addImm(-1);
  mainMBB->addSuccessor(sinkMBB);

  // sinkMBB:
  // EAX is live into the sinkMBB
  sinkMBB->addLiveIn(X86::EAX);
  BuildMI(*sinkMBB, sinkMBB->begin(), DL,
          TII->get(TargetOpcode::COPY), MI->getOperand(0).getReg())
    .addReg(X86::EAX);

  MI->eraseFromParent();
  return sinkMBB;
}

// FIXME: When we get size specific XMM0 registers, i.e. XMM0_V16I8
// or XMM0_V32I8 in AVX all of this code can be replaced with that
// in the .td file.
static MachineBasicBlock *EmitPCMPSTRM(MachineInstr *MI, MachineBasicBlock *BB,
                                       const TargetInstrInfo *TII) {
  unsigned Opc;
  switch (MI->getOpcode()) {
  default: llvm_unreachable("illegal opcode!");
  case X86::PCMPISTRM128REG:  Opc = X86::PCMPISTRM128rr;  break;
  case X86::VPCMPISTRM128REG: Opc = X86::VPCMPISTRM128rr; break;
  case X86::PCMPISTRM128MEM:  Opc = X86::PCMPISTRM128rm;  break;
  case X86::VPCMPISTRM128MEM: Opc = X86::VPCMPISTRM128rm; break;
  case X86::PCMPESTRM128REG:  Opc = X86::PCMPESTRM128rr;  break;
  case X86::VPCMPESTRM128REG: Opc = X86::VPCMPESTRM128rr; break;
  case X86::PCMPESTRM128MEM:  Opc = X86::PCMPESTRM128rm;  break;
  case X86::VPCMPESTRM128MEM: Opc = X86::VPCMPESTRM128rm; break;
  }

  DebugLoc dl = MI->getDebugLoc();
  MachineInstrBuilder MIB = BuildMI(*BB, MI, dl, TII->get(Opc));

  unsigned NumArgs = MI->getNumOperands();
  for (unsigned i = 1; i < NumArgs; ++i) {
    MachineOperand &Op = MI->getOperand(i);
    if (!(Op.isReg() && Op.isImplicit()))
      MIB.addOperand(Op);
  }
  if (MI->hasOneMemOperand())
    MIB->setMemRefs(MI->memoperands_begin(), MI->memoperands_end());

  BuildMI(*BB, MI, dl,
    TII->get(TargetOpcode::COPY), MI->getOperand(0).getReg())
    .addReg(X86::XMM0);

  MI->eraseFromParent();
  return BB;
}

// FIXME: Custom handling because TableGen doesn't support multiple implicit
// defs in an instruction pattern
static MachineBasicBlock *EmitPCMPSTRI(MachineInstr *MI, MachineBasicBlock *BB,
                                       const TargetInstrInfo *TII) {
  unsigned Opc;
  switch (MI->getOpcode()) {
  default: llvm_unreachable("illegal opcode!");
  case X86::PCMPISTRIREG:  Opc = X86::PCMPISTRIrr;  break;
  case X86::VPCMPISTRIREG: Opc = X86::VPCMPISTRIrr; break;
  case X86::PCMPISTRIMEM:  Opc = X86::PCMPISTRIrm;  break;
  case X86::VPCMPISTRIMEM: Opc = X86::VPCMPISTRIrm; break;
  case X86::PCMPESTRIREG:  Opc = X86::PCMPESTRIrr;  break;
  case X86::VPCMPESTRIREG: Opc = X86::VPCMPESTRIrr; break;
  case X86::PCMPESTRIMEM:  Opc = X86::PCMPESTRIrm;  break;
  case X86::VPCMPESTRIMEM: Opc = X86::VPCMPESTRIrm; break;
  }

  DebugLoc dl = MI->getDebugLoc();
  MachineInstrBuilder MIB = BuildMI(*BB, MI, dl, TII->get(Opc));

  unsigned NumArgs = MI->getNumOperands(); // remove the results
  for (unsigned i = 1; i < NumArgs; ++i) {
    MachineOperand &Op = MI->getOperand(i);
    if (!(Op.isReg() && Op.isImplicit()))
      MIB.addOperand(Op);
  }
  if (MI->hasOneMemOperand())
    MIB->setMemRefs(MI->memoperands_begin(), MI->memoperands_end());

  BuildMI(*BB, MI, dl,
    TII->get(TargetOpcode::COPY), MI->getOperand(0).getReg())
    .addReg(X86::ECX);

  MI->eraseFromParent();
  return BB;
}

static MachineBasicBlock *EmitMonitor(MachineInstr *MI, MachineBasicBlock *BB,
                                      const X86Subtarget *Subtarget) {
  DebugLoc dl = MI->getDebugLoc();
  const TargetInstrInfo *TII = Subtarget->getInstrInfo();
  // Address into RAX/EAX, other two args into ECX, EDX.
  unsigned MemOpc = Subtarget->is64Bit() ? X86::LEA64r : X86::LEA32r;
  unsigned MemReg = Subtarget->is64Bit() ? X86::RAX : X86::EAX;
  MachineInstrBuilder MIB = BuildMI(*BB, MI, dl, TII->get(MemOpc), MemReg);
  for (int i = 0; i < X86::AddrNumOperands; ++i)
    MIB.addOperand(MI->getOperand(i));

  unsigned ValOps = X86::AddrNumOperands;
  BuildMI(*BB, MI, dl, TII->get(TargetOpcode::COPY), X86::ECX)
    .addReg(MI->getOperand(ValOps).getReg());
  BuildMI(*BB, MI, dl, TII->get(TargetOpcode::COPY), X86::EDX)
    .addReg(MI->getOperand(ValOps+1).getReg());

  // The instruction doesn't actually take any operands though.
  BuildMI(*BB, MI, dl, TII->get(X86::MONITORrrr));

  MI->eraseFromParent(); // The pseudo is gone now.
  return BB;
}

MachineBasicBlock *
X86TargetLowering::EmitVAARG64WithCustomInserter(MachineInstr *MI,
                                                 MachineBasicBlock *MBB) const {
  // Emit va_arg instruction on X86-64.

  // Operands to this pseudo-instruction:
  // 0  ) Output        : destination address (reg)
  // 1-5) Input         : va_list address (addr, i64mem)
  // 6  ) ArgSize       : Size (in bytes) of vararg type
  // 7  ) ArgMode       : 0=overflow only, 1=use gp_offset, 2=use fp_offset
  // 8  ) Align         : Alignment of type
  // 9  ) EFLAGS (implicit-def)

  assert(MI->getNumOperands() == 10 && "VAARG_64 should have 10 operands!");
  assert(X86::AddrNumOperands == 5 && "VAARG_64 assumes 5 address operands");

  unsigned DestReg = MI->getOperand(0).getReg();
  MachineOperand &Base = MI->getOperand(1);
  MachineOperand &Scale = MI->getOperand(2);
  MachineOperand &Index = MI->getOperand(3);
  MachineOperand &Disp = MI->getOperand(4);
  MachineOperand &Segment = MI->getOperand(5);
  unsigned ArgSize = MI->getOperand(6).getImm();
  unsigned ArgMode = MI->getOperand(7).getImm();
  unsigned Align = MI->getOperand(8).getImm();

  // Memory Reference
  assert(MI->hasOneMemOperand() && "Expected VAARG_64 to have one memoperand");
  MachineInstr::mmo_iterator MMOBegin = MI->memoperands_begin();
  MachineInstr::mmo_iterator MMOEnd = MI->memoperands_end();

  // Machine Information
  const TargetInstrInfo *TII = Subtarget->getInstrInfo();
  MachineRegisterInfo &MRI = MBB->getParent()->getRegInfo();
  const TargetRegisterClass *AddrRegClass = getRegClassFor(MVT::i64);
  const TargetRegisterClass *OffsetRegClass = getRegClassFor(MVT::i32);
  DebugLoc DL = MI->getDebugLoc();

  // struct va_list {
  //   i32   gp_offset
  //   i32   fp_offset
  //   i64   overflow_area (address)
  //   i64   reg_save_area (address)
  // }
  // sizeof(va_list) = 24
  // alignment(va_list) = 8

  unsigned TotalNumIntRegs = 6;
  unsigned TotalNumXMMRegs = 8;
  bool UseGPOffset = (ArgMode == 1);
  bool UseFPOffset = (ArgMode == 2);
  unsigned MaxOffset = TotalNumIntRegs * 8 +
                       (UseFPOffset ? TotalNumXMMRegs * 16 : 0);

  /* Align ArgSize to a multiple of 8 */
  unsigned ArgSizeA8 = (ArgSize + 7) & ~7;
  bool NeedsAlign = (Align > 8);

  MachineBasicBlock *thisMBB = MBB;
  MachineBasicBlock *overflowMBB;
  MachineBasicBlock *offsetMBB;
  MachineBasicBlock *endMBB;

  unsigned OffsetDestReg = 0;    // Argument address computed by offsetMBB
  unsigned OverflowDestReg = 0;  // Argument address computed by overflowMBB
  unsigned OffsetReg = 0;

  if (!UseGPOffset && !UseFPOffset) {
    // If we only pull from the overflow region, we don't create a branch.
    // We don't need to alter control flow.
    OffsetDestReg = 0; // unused
    OverflowDestReg = DestReg;

    offsetMBB = nullptr;
    overflowMBB = thisMBB;
    endMBB = thisMBB;
  } else {
    // First emit code to check if gp_offset (or fp_offset) is below the bound.
    // If so, pull the argument from reg_save_area. (branch to offsetMBB)
    // If not, pull from overflow_area. (branch to overflowMBB)
    //
    //       thisMBB
    //         |     .
    //         |        .
    //     offsetMBB   overflowMBB
    //         |        .
    //         |     .
    //        endMBB

    // Registers for the PHI in endMBB
    OffsetDestReg = MRI.createVirtualRegister(AddrRegClass);
    OverflowDestReg = MRI.createVirtualRegister(AddrRegClass);

    const BasicBlock *LLVM_BB = MBB->getBasicBlock();
    MachineFunction *MF = MBB->getParent();
    overflowMBB = MF->CreateMachineBasicBlock(LLVM_BB);
    offsetMBB = MF->CreateMachineBasicBlock(LLVM_BB);
    endMBB = MF->CreateMachineBasicBlock(LLVM_BB);

    MachineFunction::iterator MBBIter = MBB;
    ++MBBIter;

    // Insert the new basic blocks
    MF->insert(MBBIter, offsetMBB);
    MF->insert(MBBIter, overflowMBB);
    MF->insert(MBBIter, endMBB);

    // Transfer the remainder of MBB and its successor edges to endMBB.
    endMBB->splice(endMBB->begin(), thisMBB,
                   std::next(MachineBasicBlock::iterator(MI)), thisMBB->end());
    endMBB->transferSuccessorsAndUpdatePHIs(thisMBB);

    // Make offsetMBB and overflowMBB successors of thisMBB
    thisMBB->addSuccessor(offsetMBB);
    thisMBB->addSuccessor(overflowMBB);

    // endMBB is a successor of both offsetMBB and overflowMBB
    offsetMBB->addSuccessor(endMBB);
    overflowMBB->addSuccessor(endMBB);

    // Load the offset value into a register
    OffsetReg = MRI.createVirtualRegister(OffsetRegClass);
    BuildMI(thisMBB, DL, TII->get(X86::MOV32rm), OffsetReg)
      .addOperand(Base)
      .addOperand(Scale)
      .addOperand(Index)
      .addDisp(Disp, UseFPOffset ? 4 : 0)
      .addOperand(Segment)
      .setMemRefs(MMOBegin, MMOEnd);

    // Check if there is enough room left to pull this argument.
    BuildMI(thisMBB, DL, TII->get(X86::CMP32ri))
      .addReg(OffsetReg)
      .addImm(MaxOffset + 8 - ArgSizeA8);

    // Branch to "overflowMBB" if offset >= max
    // Fall through to "offsetMBB" otherwise
    BuildMI(thisMBB, DL, TII->get(X86::GetCondBranchFromCond(X86::COND_AE)))
      .addMBB(overflowMBB);
  }

  // In offsetMBB, emit code to use the reg_save_area.
  if (offsetMBB) {
    assert(OffsetReg != 0);

    // Read the reg_save_area address.
    unsigned RegSaveReg = MRI.createVirtualRegister(AddrRegClass);
    BuildMI(offsetMBB, DL, TII->get(X86::MOV64rm), RegSaveReg)
      .addOperand(Base)
      .addOperand(Scale)
      .addOperand(Index)
      .addDisp(Disp, 16)
      .addOperand(Segment)
      .setMemRefs(MMOBegin, MMOEnd);

    // Zero-extend the offset
    unsigned OffsetReg64 = MRI.createVirtualRegister(AddrRegClass);
      BuildMI(offsetMBB, DL, TII->get(X86::SUBREG_TO_REG), OffsetReg64)
        .addImm(0)
        .addReg(OffsetReg)
        .addImm(X86::sub_32bit);

    // Add the offset to the reg_save_area to get the final address.
    BuildMI(offsetMBB, DL, TII->get(X86::ADD64rr), OffsetDestReg)
      .addReg(OffsetReg64)
      .addReg(RegSaveReg);

    // Compute the offset for the next argument
    unsigned NextOffsetReg = MRI.createVirtualRegister(OffsetRegClass);
    BuildMI(offsetMBB, DL, TII->get(X86::ADD32ri), NextOffsetReg)
      .addReg(OffsetReg)
      .addImm(UseFPOffset ? 16 : 8);

    // Store it back into the va_list.
    BuildMI(offsetMBB, DL, TII->get(X86::MOV32mr))
      .addOperand(Base)
      .addOperand(Scale)
      .addOperand(Index)
      .addDisp(Disp, UseFPOffset ? 4 : 0)
      .addOperand(Segment)
      .addReg(NextOffsetReg)
      .setMemRefs(MMOBegin, MMOEnd);

    // Jump to endMBB
    BuildMI(offsetMBB, DL, TII->get(X86::JMP_1))
      .addMBB(endMBB);
  }

  //
  // Emit code to use overflow area
  //

  // Load the overflow_area address into a register.
  unsigned OverflowAddrReg = MRI.createVirtualRegister(AddrRegClass);
  BuildMI(overflowMBB, DL, TII->get(X86::MOV64rm), OverflowAddrReg)
    .addOperand(Base)
    .addOperand(Scale)
    .addOperand(Index)
    .addDisp(Disp, 8)
    .addOperand(Segment)
    .setMemRefs(MMOBegin, MMOEnd);

  // If we need to align it, do so. Otherwise, just copy the address
  // to OverflowDestReg.
  if (NeedsAlign) {
    // Align the overflow address
    assert((Align & (Align-1)) == 0 && "Alignment must be a power of 2");
    unsigned TmpReg = MRI.createVirtualRegister(AddrRegClass);

    // aligned_addr = (addr + (align-1)) & ~(align-1)
    BuildMI(overflowMBB, DL, TII->get(X86::ADD64ri32), TmpReg)
      .addReg(OverflowAddrReg)
      .addImm(Align-1);

    BuildMI(overflowMBB, DL, TII->get(X86::AND64ri32), OverflowDestReg)
      .addReg(TmpReg)
      .addImm(~(uint64_t)(Align-1));
  } else {
    BuildMI(overflowMBB, DL, TII->get(TargetOpcode::COPY), OverflowDestReg)
      .addReg(OverflowAddrReg);
  }

  // Compute the next overflow address after this argument.
  // (the overflow address should be kept 8-byte aligned)
  unsigned NextAddrReg = MRI.createVirtualRegister(AddrRegClass);
  BuildMI(overflowMBB, DL, TII->get(X86::ADD64ri32), NextAddrReg)
    .addReg(OverflowDestReg)
    .addImm(ArgSizeA8);

  // Store the new overflow address.
  BuildMI(overflowMBB, DL, TII->get(X86::MOV64mr))
    .addOperand(Base)
    .addOperand(Scale)
    .addOperand(Index)
    .addDisp(Disp, 8)
    .addOperand(Segment)
    .addReg(NextAddrReg)
    .setMemRefs(MMOBegin, MMOEnd);

  // If we branched, emit the PHI to the front of endMBB.
  if (offsetMBB) {
    BuildMI(*endMBB, endMBB->begin(), DL,
            TII->get(X86::PHI), DestReg)
      .addReg(OffsetDestReg).addMBB(offsetMBB)
      .addReg(OverflowDestReg).addMBB(overflowMBB);
  }

  // Erase the pseudo instruction
  MI->eraseFromParent();

  return endMBB;
}

MachineBasicBlock *
X86TargetLowering::EmitVAStartSaveXMMRegsWithCustomInserter(
                                                 MachineInstr *MI,
                                                 MachineBasicBlock *MBB) const {
  // Emit code to save XMM registers to the stack. The ABI says that the
  // number of registers to save is given in %al, so it's theoretically
  // possible to do an indirect jump trick to avoid saving all of them,
  // however this code takes a simpler approach and just executes all
  // of the stores if %al is non-zero. It's less code, and it's probably
  // easier on the hardware branch predictor, and stores aren't all that
  // expensive anyway.

  // Create the new basic blocks. One block contains all the XMM stores,
  // and one block is the final destination regardless of whether any
  // stores were performed.
  const BasicBlock *LLVM_BB = MBB->getBasicBlock();
  MachineFunction *F = MBB->getParent();
  MachineFunction::iterator MBBIter = MBB;
  ++MBBIter;
  MachineBasicBlock *XMMSaveMBB = F->CreateMachineBasicBlock(LLVM_BB);
  MachineBasicBlock *EndMBB = F->CreateMachineBasicBlock(LLVM_BB);
  F->insert(MBBIter, XMMSaveMBB);
  F->insert(MBBIter, EndMBB);

  // Transfer the remainder of MBB and its successor edges to EndMBB.
  EndMBB->splice(EndMBB->begin(), MBB,
                 std::next(MachineBasicBlock::iterator(MI)), MBB->end());
  EndMBB->transferSuccessorsAndUpdatePHIs(MBB);

  // The original block will now fall through to the XMM save block.
  MBB->addSuccessor(XMMSaveMBB);
  // The XMMSaveMBB will fall through to the end block.
  XMMSaveMBB->addSuccessor(EndMBB);

  // Now add the instructions.
  const TargetInstrInfo *TII = Subtarget->getInstrInfo();
  DebugLoc DL = MI->getDebugLoc();

  unsigned CountReg = MI->getOperand(0).getReg();
  int64_t RegSaveFrameIndex = MI->getOperand(1).getImm();
  int64_t VarArgsFPOffset = MI->getOperand(2).getImm();

  if (!Subtarget->isTargetWin64()) {
    // If %al is 0, branch around the XMM save block.
    BuildMI(MBB, DL, TII->get(X86::TEST8rr)).addReg(CountReg).addReg(CountReg);
    BuildMI(MBB, DL, TII->get(X86::JE_1)).addMBB(EndMBB);
    MBB->addSuccessor(EndMBB);
  }

  // Make sure the last operand is EFLAGS, which gets clobbered by the branch
  // that was just emitted, but clearly shouldn't be "saved".
  assert((MI->getNumOperands() <= 3 ||
          !MI->getOperand(MI->getNumOperands() - 1).isReg() ||
          MI->getOperand(MI->getNumOperands() - 1).getReg() == X86::EFLAGS)
         && "Expected last argument to be EFLAGS");
  unsigned MOVOpc = Subtarget->hasFp256() ? X86::VMOVAPSmr : X86::MOVAPSmr;
  // In the XMM save block, save all the XMM argument registers.
  for (int i = 3, e = MI->getNumOperands() - 1; i != e; ++i) {
    int64_t Offset = (i - 3) * 16 + VarArgsFPOffset;
    MachineMemOperand *MMO =
      F->getMachineMemOperand(
          MachinePointerInfo::getFixedStack(RegSaveFrameIndex, Offset),
        MachineMemOperand::MOStore,
        /*Size=*/16, /*Align=*/16);
    BuildMI(XMMSaveMBB, DL, TII->get(MOVOpc))
      .addFrameIndex(RegSaveFrameIndex)
      .addImm(/*Scale=*/1)
      .addReg(/*IndexReg=*/0)
      .addImm(/*Disp=*/Offset)
      .addReg(/*Segment=*/0)
      .addReg(MI->getOperand(i).getReg())
      .addMemOperand(MMO);
  }

  MI->eraseFromParent();   // The pseudo instruction is gone now.

  return EndMBB;
}

// The EFLAGS operand of SelectItr might be missing a kill marker
// because there were multiple uses of EFLAGS, and ISel didn't know
// which to mark. Figure out whether SelectItr should have had a
// kill marker, and set it if it should. Returns the correct kill
// marker value.
static bool checkAndUpdateEFLAGSKill(MachineBasicBlock::iterator SelectItr,
                                     MachineBasicBlock* BB,
                                     const TargetRegisterInfo* TRI) {
  // Scan forward through BB for a use/def of EFLAGS.
  MachineBasicBlock::iterator miI(std::next(SelectItr));
  for (MachineBasicBlock::iterator miE = BB->end(); miI != miE; ++miI) {
    const MachineInstr& mi = *miI;
    if (mi.readsRegister(X86::EFLAGS))
      return false;
    if (mi.definesRegister(X86::EFLAGS))
      break; // Should have kill-flag - update below.
  }

  // If we hit the end of the block, check whether EFLAGS is live into a
  // successor.
  if (miI == BB->end()) {
    for (MachineBasicBlock::succ_iterator sItr = BB->succ_begin(),
                                          sEnd = BB->succ_end();
         sItr != sEnd; ++sItr) {
      MachineBasicBlock* succ = *sItr;
      if (succ->isLiveIn(X86::EFLAGS))
        return false;
    }
  }

  // We found a def, or hit the end of the basic block and EFLAGS wasn't live
  // out. SelectMI should have a kill flag on EFLAGS.
  SelectItr->addRegisterKilled(X86::EFLAGS, TRI);
  return true;
}

MachineBasicBlock *
X86TargetLowering::EmitLoweredSelect(MachineInstr *MI,
                                     MachineBasicBlock *BB) const {
  const TargetInstrInfo *TII = Subtarget->getInstrInfo();
  DebugLoc DL = MI->getDebugLoc();

  // To "insert" a SELECT_CC instruction, we actually have to insert the
  // diamond control-flow pattern.  The incoming instruction knows the
  // destination vreg to set, the condition code register to branch on, the
  // true/false values to select between, and a branch opcode to use.
  const BasicBlock *LLVM_BB = BB->getBasicBlock();
  MachineFunction::iterator It = BB;
  ++It;

  //  thisMBB:
  //  ...
  //   TrueVal = ...
  //   cmpTY ccX, r1, r2
  //   bCC copy1MBB
  //   fallthrough --> copy0MBB
  MachineBasicBlock *thisMBB = BB;
  MachineFunction *F = BB->getParent();
  MachineBasicBlock *copy0MBB = F->CreateMachineBasicBlock(LLVM_BB);
  MachineBasicBlock *sinkMBB = F->CreateMachineBasicBlock(LLVM_BB);
  F->insert(It, copy0MBB);
  F->insert(It, sinkMBB);

  // If the EFLAGS register isn't dead in the terminator, then claim that it's
  // live into the sink and copy blocks.
  const TargetRegisterInfo *TRI = Subtarget->getRegisterInfo();
  if (!MI->killsRegister(X86::EFLAGS) &&
      !checkAndUpdateEFLAGSKill(MI, BB, TRI)) {
    copy0MBB->addLiveIn(X86::EFLAGS);
    sinkMBB->addLiveIn(X86::EFLAGS);
  }

  // Transfer the remainder of BB and its successor edges to sinkMBB.
  sinkMBB->splice(sinkMBB->begin(), BB,
                  std::next(MachineBasicBlock::iterator(MI)), BB->end());
  sinkMBB->transferSuccessorsAndUpdatePHIs(BB);

  // Add the true and fallthrough blocks as its successors.
  BB->addSuccessor(copy0MBB);
  BB->addSuccessor(sinkMBB);

  // Create the conditional branch instruction.
  unsigned Opc =
    X86::GetCondBranchFromCond((X86::CondCode)MI->getOperand(3).getImm());
  BuildMI(BB, DL, TII->get(Opc)).addMBB(sinkMBB);

  //  copy0MBB:
  //   %FalseValue = ...
  //   # fallthrough to sinkMBB
  copy0MBB->addSuccessor(sinkMBB);

  //  sinkMBB:
  //   %Result = phi [ %FalseValue, copy0MBB ], [ %TrueValue, thisMBB ]
  //  ...
  BuildMI(*sinkMBB, sinkMBB->begin(), DL,
          TII->get(X86::PHI), MI->getOperand(0).getReg())
    .addReg(MI->getOperand(1).getReg()).addMBB(copy0MBB)
    .addReg(MI->getOperand(2).getReg()).addMBB(thisMBB);

  MI->eraseFromParent();   // The pseudo instruction is gone now.
  return sinkMBB;
}

MachineBasicBlock *
X86TargetLowering::EmitLoweredSegAlloca(MachineInstr *MI,
                                        MachineBasicBlock *BB) const {
  MachineFunction *MF = BB->getParent();
  const TargetInstrInfo *TII = Subtarget->getInstrInfo();
  DebugLoc DL = MI->getDebugLoc();
  const BasicBlock *LLVM_BB = BB->getBasicBlock();

  assert(MF->shouldSplitStack());

  const bool Is64Bit = Subtarget->is64Bit();
  const bool IsLP64 = Subtarget->isTarget64BitLP64();

  const unsigned TlsReg = Is64Bit ? X86::FS : X86::GS;
  const unsigned TlsOffset = IsLP64 ? 0x70 : Is64Bit ? 0x40 : 0x30;

  // BB:
  //  ... [Till the alloca]
  // If stacklet is not large enough, jump to mallocMBB
  //
  // bumpMBB:
  //  Allocate by subtracting from RSP
  //  Jump to continueMBB
  //
  // mallocMBB:
  //  Allocate by call to runtime
  //
  // continueMBB:
  //  ...
  //  [rest of original BB]
  //

  MachineBasicBlock *mallocMBB = MF->CreateMachineBasicBlock(LLVM_BB);
  MachineBasicBlock *bumpMBB = MF->CreateMachineBasicBlock(LLVM_BB);
  MachineBasicBlock *continueMBB = MF->CreateMachineBasicBlock(LLVM_BB);

  MachineRegisterInfo &MRI = MF->getRegInfo();
  const TargetRegisterClass *AddrRegClass =
    getRegClassFor(getPointerTy());

  unsigned mallocPtrVReg = MRI.createVirtualRegister(AddrRegClass),
    bumpSPPtrVReg = MRI.createVirtualRegister(AddrRegClass),
    tmpSPVReg = MRI.createVirtualRegister(AddrRegClass),
    SPLimitVReg = MRI.createVirtualRegister(AddrRegClass),
    sizeVReg = MI->getOperand(1).getReg(),
    physSPReg = IsLP64 || Subtarget->isTargetNaCl64() ? X86::RSP : X86::ESP;

  MachineFunction::iterator MBBIter = BB;
  ++MBBIter;

  MF->insert(MBBIter, bumpMBB);
  MF->insert(MBBIter, mallocMBB);
  MF->insert(MBBIter, continueMBB);

  continueMBB->splice(continueMBB->begin(), BB,
                      std::next(MachineBasicBlock::iterator(MI)), BB->end());
  continueMBB->transferSuccessorsAndUpdatePHIs(BB);

  // Add code to the main basic block to check if the stack limit has been hit,
  // and if so, jump to mallocMBB otherwise to bumpMBB.
  BuildMI(BB, DL, TII->get(TargetOpcode::COPY), tmpSPVReg).addReg(physSPReg);
  BuildMI(BB, DL, TII->get(IsLP64 ? X86::SUB64rr:X86::SUB32rr), SPLimitVReg)
    .addReg(tmpSPVReg).addReg(sizeVReg);
  BuildMI(BB, DL, TII->get(IsLP64 ? X86::CMP64mr:X86::CMP32mr))
    .addReg(0).addImm(1).addReg(0).addImm(TlsOffset).addReg(TlsReg)
    .addReg(SPLimitVReg);
  BuildMI(BB, DL, TII->get(X86::JG_1)).addMBB(mallocMBB);

  // bumpMBB simply decreases the stack pointer, since we know the current
  // stacklet has enough space.
  BuildMI(bumpMBB, DL, TII->get(TargetOpcode::COPY), physSPReg)
    .addReg(SPLimitVReg);
  BuildMI(bumpMBB, DL, TII->get(TargetOpcode::COPY), bumpSPPtrVReg)
    .addReg(SPLimitVReg);
  BuildMI(bumpMBB, DL, TII->get(X86::JMP_1)).addMBB(continueMBB);

  // Calls into a routine in libgcc to allocate more space from the heap.
  const uint32_t *RegMask =
      Subtarget->getRegisterInfo()->getCallPreservedMask(CallingConv::C);
  if (IsLP64) {
    BuildMI(mallocMBB, DL, TII->get(X86::MOV64rr), X86::RDI)
      .addReg(sizeVReg);
    BuildMI(mallocMBB, DL, TII->get(X86::CALL64pcrel32))
      .addExternalSymbol("__morestack_allocate_stack_space")
      .addRegMask(RegMask)
      .addReg(X86::RDI, RegState::Implicit)
      .addReg(X86::RAX, RegState::ImplicitDefine);
  } else if (Is64Bit) {
    BuildMI(mallocMBB, DL, TII->get(X86::MOV32rr), X86::EDI)
      .addReg(sizeVReg);
    BuildMI(mallocMBB, DL, TII->get(X86::CALL64pcrel32))
      .addExternalSymbol("__morestack_allocate_stack_space")
      .addRegMask(RegMask)
      .addReg(X86::EDI, RegState::Implicit)
      .addReg(X86::EAX, RegState::ImplicitDefine);
  } else {
    BuildMI(mallocMBB, DL, TII->get(X86::SUB32ri), physSPReg).addReg(physSPReg)
      .addImm(12);
    BuildMI(mallocMBB, DL, TII->get(X86::PUSH32r)).addReg(sizeVReg);
    BuildMI(mallocMBB, DL, TII->get(X86::CALLpcrel32))
      .addExternalSymbol("__morestack_allocate_stack_space")
      .addRegMask(RegMask)
      .addReg(X86::EAX, RegState::ImplicitDefine);
  }

  if (!Is64Bit)
    BuildMI(mallocMBB, DL, TII->get(X86::ADD32ri), physSPReg).addReg(physSPReg)
      .addImm(16);

  BuildMI(mallocMBB, DL, TII->get(TargetOpcode::COPY), mallocPtrVReg)
    .addReg(IsLP64 ? X86::RAX : X86::EAX);
  BuildMI(mallocMBB, DL, TII->get(X86::JMP_1)).addMBB(continueMBB);

  // Set up the CFG correctly.
  BB->addSuccessor(bumpMBB);
  BB->addSuccessor(mallocMBB);
  mallocMBB->addSuccessor(continueMBB);
  bumpMBB->addSuccessor(continueMBB);

  // Take care of the PHI nodes.
  BuildMI(*continueMBB, continueMBB->begin(), DL, TII->get(X86::PHI),
          MI->getOperand(0).getReg())
    .addReg(mallocPtrVReg).addMBB(mallocMBB)
    .addReg(bumpSPPtrVReg).addMBB(bumpMBB);

  // Delete the original pseudo instruction.
  MI->eraseFromParent();

  // And we're done.
  return continueMBB;
}

MachineBasicBlock *
X86TargetLowering::EmitLoweredWinAlloca(MachineInstr *MI,
                                        MachineBasicBlock *BB) const {
  DebugLoc DL = MI->getDebugLoc();

  assert(!Subtarget->isTargetMachO());

  X86FrameLowering::emitStackProbeCall(*BB->getParent(), *BB, MI, DL);

  MI->eraseFromParent();   // The pseudo instruction is gone now.
  return BB;
}

MachineBasicBlock *
X86TargetLowering::EmitLoweredTLSCall(MachineInstr *MI,
                                      MachineBasicBlock *BB) const {
  // This is pretty easy.  We're taking the value that we received from
  // our load from the relocation, sticking it in either RDI (x86-64)
  // or EAX and doing an indirect call.  The return value will then
  // be in the normal return register.
  MachineFunction *F = BB->getParent();
  const X86InstrInfo *TII = Subtarget->getInstrInfo();
  DebugLoc DL = MI->getDebugLoc();

  assert(Subtarget->isTargetDarwin() && "Darwin only instr emitted?");
  assert(MI->getOperand(3).isGlobal() && "This should be a global");

  // Get a register mask for the lowered call.
  // FIXME: The 32-bit calls have non-standard calling conventions. Use a
  // proper register mask.
  const uint32_t *RegMask =
      Subtarget->getRegisterInfo()->getCallPreservedMask(CallingConv::C);
  if (Subtarget->is64Bit()) {
    MachineInstrBuilder MIB = BuildMI(*BB, MI, DL,
                                      TII->get(X86::MOV64rm), X86::RDI)
    .addReg(X86::RIP)
    .addImm(0).addReg(0)
    .addGlobalAddress(MI->getOperand(3).getGlobal(), 0,
                      MI->getOperand(3).getTargetFlags())
    .addReg(0);
    MIB = BuildMI(*BB, MI, DL, TII->get(X86::CALL64m));
    addDirectMem(MIB, X86::RDI);
    MIB.addReg(X86::RAX, RegState::ImplicitDefine).addRegMask(RegMask);
  } else if (F->getTarget().getRelocationModel() != Reloc::PIC_) {
    MachineInstrBuilder MIB = BuildMI(*BB, MI, DL,
                                      TII->get(X86::MOV32rm), X86::EAX)
    .addReg(0)
    .addImm(0).addReg(0)
    .addGlobalAddress(MI->getOperand(3).getGlobal(), 0,
                      MI->getOperand(3).getTargetFlags())
    .addReg(0);
    MIB = BuildMI(*BB, MI, DL, TII->get(X86::CALL32m));
    addDirectMem(MIB, X86::EAX);
    MIB.addReg(X86::EAX, RegState::ImplicitDefine).addRegMask(RegMask);
  } else {
    MachineInstrBuilder MIB = BuildMI(*BB, MI, DL,
                                      TII->get(X86::MOV32rm), X86::EAX)
    .addReg(TII->getGlobalBaseReg(F))
    .addImm(0).addReg(0)
    .addGlobalAddress(MI->getOperand(3).getGlobal(), 0,
                      MI->getOperand(3).getTargetFlags())
    .addReg(0);
    MIB = BuildMI(*BB, MI, DL, TII->get(X86::CALL32m));
    addDirectMem(MIB, X86::EAX);
    MIB.addReg(X86::EAX, RegState::ImplicitDefine).addRegMask(RegMask);
  }

  MI->eraseFromParent(); // The pseudo instruction is gone now.
  return BB;
}

MachineBasicBlock *
X86TargetLowering::emitEHSjLjSetJmp(MachineInstr *MI,
                                    MachineBasicBlock *MBB) const {
  DebugLoc DL = MI->getDebugLoc();
  MachineFunction *MF = MBB->getParent();
  const TargetInstrInfo *TII = Subtarget->getInstrInfo();
  MachineRegisterInfo &MRI = MF->getRegInfo();

  const BasicBlock *BB = MBB->getBasicBlock();
  MachineFunction::iterator I = MBB;
  ++I;

  // Memory Reference
  MachineInstr::mmo_iterator MMOBegin = MI->memoperands_begin();
  MachineInstr::mmo_iterator MMOEnd = MI->memoperands_end();

  unsigned DstReg;
  unsigned MemOpndSlot = 0;

  unsigned CurOp = 0;

  DstReg = MI->getOperand(CurOp++).getReg();
  const TargetRegisterClass *RC = MRI.getRegClass(DstReg);
  assert(RC->hasType(MVT::i32) && "Invalid destination!");
  unsigned mainDstReg = MRI.createVirtualRegister(RC);
  unsigned restoreDstReg = MRI.createVirtualRegister(RC);

  MemOpndSlot = CurOp;

  MVT PVT = getPointerTy();
  assert((PVT == MVT::i64 || PVT == MVT::i32) &&
         "Invalid Pointer Size!");

  // For v = setjmp(buf), we generate
  //
  // thisMBB:
  //  buf[LabelOffset] = restoreMBB
  //  SjLjSetup restoreMBB
  //
  // mainMBB:
  //  v_main = 0
  //
  // sinkMBB:
  //  v = phi(main, restore)
  //
  // restoreMBB:
  //  if base pointer being used, load it from frame
  //  v_restore = 1

  MachineBasicBlock *thisMBB = MBB;
  MachineBasicBlock *mainMBB = MF->CreateMachineBasicBlock(BB);
  MachineBasicBlock *sinkMBB = MF->CreateMachineBasicBlock(BB);
  MachineBasicBlock *restoreMBB = MF->CreateMachineBasicBlock(BB);
  MF->insert(I, mainMBB);
  MF->insert(I, sinkMBB);
  MF->push_back(restoreMBB);

  MachineInstrBuilder MIB;

  // Transfer the remainder of BB and its successor edges to sinkMBB.
  sinkMBB->splice(sinkMBB->begin(), MBB,
                  std::next(MachineBasicBlock::iterator(MI)), MBB->end());
  sinkMBB->transferSuccessorsAndUpdatePHIs(MBB);

  // thisMBB:
  unsigned PtrStoreOpc = 0;
  unsigned LabelReg = 0;
  const int64_t LabelOffset = 1 * PVT.getStoreSize();
  Reloc::Model RM = MF->getTarget().getRelocationModel();
  bool UseImmLabel = (MF->getTarget().getCodeModel() == CodeModel::Small) &&
                     (RM == Reloc::Static || RM == Reloc::DynamicNoPIC);

  // Prepare IP either in reg or imm.
  if (!UseImmLabel) {
    PtrStoreOpc = (PVT == MVT::i64) ? X86::MOV64mr : X86::MOV32mr;
    const TargetRegisterClass *PtrRC = getRegClassFor(PVT);
    LabelReg = MRI.createVirtualRegister(PtrRC);
    if (Subtarget->is64Bit()) {
      MIB = BuildMI(*thisMBB, MI, DL, TII->get(X86::LEA64r), LabelReg)
              .addReg(X86::RIP)
              .addImm(0)
              .addReg(0)
              .addMBB(restoreMBB)
              .addReg(0);
    } else {
      const X86InstrInfo *XII = static_cast<const X86InstrInfo*>(TII);
      MIB = BuildMI(*thisMBB, MI, DL, TII->get(X86::LEA32r), LabelReg)
              .addReg(XII->getGlobalBaseReg(MF))
              .addImm(0)
              .addReg(0)
              .addMBB(restoreMBB, Subtarget->ClassifyBlockAddressReference())
              .addReg(0);
    }
  } else
    PtrStoreOpc = (PVT == MVT::i64) ? X86::MOV64mi32 : X86::MOV32mi;
  // Store IP
  MIB = BuildMI(*thisMBB, MI, DL, TII->get(PtrStoreOpc));
  for (unsigned i = 0; i < X86::AddrNumOperands; ++i) {
    if (i == X86::AddrDisp)
      MIB.addDisp(MI->getOperand(MemOpndSlot + i), LabelOffset);
    else
      MIB.addOperand(MI->getOperand(MemOpndSlot + i));
  }
  if (!UseImmLabel)
    MIB.addReg(LabelReg);
  else
    MIB.addMBB(restoreMBB);
  MIB.setMemRefs(MMOBegin, MMOEnd);
  // Setup
  MIB = BuildMI(*thisMBB, MI, DL, TII->get(X86::EH_SjLj_Setup))
          .addMBB(restoreMBB);

  const X86RegisterInfo *RegInfo = Subtarget->getRegisterInfo();
  MIB.addRegMask(RegInfo->getNoPreservedMask());
  thisMBB->addSuccessor(mainMBB);
  thisMBB->addSuccessor(restoreMBB);

  // mainMBB:
  //  EAX = 0
  BuildMI(mainMBB, DL, TII->get(X86::MOV32r0), mainDstReg);
  mainMBB->addSuccessor(sinkMBB);

  // sinkMBB:
  BuildMI(*sinkMBB, sinkMBB->begin(), DL,
          TII->get(X86::PHI), DstReg)
    .addReg(mainDstReg).addMBB(mainMBB)
    .addReg(restoreDstReg).addMBB(restoreMBB);

  // restoreMBB:
  if (RegInfo->hasBasePointer(*MF)) {
    const bool Uses64BitFramePtr =
        Subtarget->isTarget64BitLP64() || Subtarget->isTargetNaCl64();
    X86MachineFunctionInfo *X86FI = MF->getInfo<X86MachineFunctionInfo>();
    X86FI->setRestoreBasePointer(MF);
    unsigned FramePtr = RegInfo->getFrameRegister(*MF);
    unsigned BasePtr = RegInfo->getBaseRegister();
    unsigned Opm = Uses64BitFramePtr ? X86::MOV64rm : X86::MOV32rm;
    addRegOffset(BuildMI(restoreMBB, DL, TII->get(Opm), BasePtr),
                 FramePtr, true, X86FI->getRestoreBasePointerOffset())
      .setMIFlag(MachineInstr::FrameSetup);
  }
  BuildMI(restoreMBB, DL, TII->get(X86::MOV32ri), restoreDstReg).addImm(1);
  BuildMI(restoreMBB, DL, TII->get(X86::JMP_1)).addMBB(sinkMBB);
  restoreMBB->addSuccessor(sinkMBB);

  MI->eraseFromParent();
  return sinkMBB;
}

MachineBasicBlock *
X86TargetLowering::emitEHSjLjLongJmp(MachineInstr *MI,
                                     MachineBasicBlock *MBB) const {
  DebugLoc DL = MI->getDebugLoc();
  MachineFunction *MF = MBB->getParent();
  const TargetInstrInfo *TII = Subtarget->getInstrInfo();
  MachineRegisterInfo &MRI = MF->getRegInfo();

  // Memory Reference
  MachineInstr::mmo_iterator MMOBegin = MI->memoperands_begin();
  MachineInstr::mmo_iterator MMOEnd = MI->memoperands_end();

  MVT PVT = getPointerTy();
  assert((PVT == MVT::i64 || PVT == MVT::i32) &&
         "Invalid Pointer Size!");

  const TargetRegisterClass *RC =
    (PVT == MVT::i64) ? &X86::GR64RegClass : &X86::GR32RegClass;
  unsigned Tmp = MRI.createVirtualRegister(RC);
  // Since FP is only updated here but NOT referenced, it's treated as GPR.
  const X86RegisterInfo *RegInfo = Subtarget->getRegisterInfo();
  unsigned FP = (PVT == MVT::i64) ? X86::RBP : X86::EBP;
  unsigned SP = RegInfo->getStackRegister();

  MachineInstrBuilder MIB;

  const int64_t LabelOffset = 1 * PVT.getStoreSize();
  const int64_t SPOffset = 2 * PVT.getStoreSize();

  unsigned PtrLoadOpc = (PVT == MVT::i64) ? X86::MOV64rm : X86::MOV32rm;
  unsigned IJmpOpc = (PVT == MVT::i64) ? X86::JMP64r : X86::JMP32r;

  // Reload FP
  MIB = BuildMI(*MBB, MI, DL, TII->get(PtrLoadOpc), FP);
  for (unsigned i = 0; i < X86::AddrNumOperands; ++i)
    MIB.addOperand(MI->getOperand(i));
  MIB.setMemRefs(MMOBegin, MMOEnd);
  // Reload IP
  MIB = BuildMI(*MBB, MI, DL, TII->get(PtrLoadOpc), Tmp);
  for (unsigned i = 0; i < X86::AddrNumOperands; ++i) {
    if (i == X86::AddrDisp)
      MIB.addDisp(MI->getOperand(i), LabelOffset);
    else
      MIB.addOperand(MI->getOperand(i));
  }
  MIB.setMemRefs(MMOBegin, MMOEnd);
  // Reload SP
  MIB = BuildMI(*MBB, MI, DL, TII->get(PtrLoadOpc), SP);
  for (unsigned i = 0; i < X86::AddrNumOperands; ++i) {
    if (i == X86::AddrDisp)
      MIB.addDisp(MI->getOperand(i), SPOffset);
    else
      MIB.addOperand(MI->getOperand(i));
  }
  MIB.setMemRefs(MMOBegin, MMOEnd);
  // Jump
  BuildMI(*MBB, MI, DL, TII->get(IJmpOpc)).addReg(Tmp);

  MI->eraseFromParent();
  return MBB;
}

// Replace 213-type (isel default) FMA3 instructions with 231-type for
// accumulator loops. Writing back to the accumulator allows the coalescer
// to remove extra copies in the loop.
MachineBasicBlock *
X86TargetLowering::emitFMA3Instr(MachineInstr *MI,
                                 MachineBasicBlock *MBB) const {
  MachineOperand &AddendOp = MI->getOperand(3);

  // Bail out early if the addend isn't a register - we can't switch these.
  if (!AddendOp.isReg())
    return MBB;

  MachineFunction &MF = *MBB->getParent();
  MachineRegisterInfo &MRI = MF.getRegInfo();

  // Check whether the addend is defined by a PHI:
  assert(MRI.hasOneDef(AddendOp.getReg()) && "Multiple defs in SSA?");
  MachineInstr &AddendDef = *MRI.def_instr_begin(AddendOp.getReg());
  if (!AddendDef.isPHI())
    return MBB;

  // Look for the following pattern:
  // loop:
  //   %addend = phi [%entry, 0], [%loop, %result]
  //   ...
  //   %result<tied1> = FMA213 %m2<tied0>, %m1, %addend

  // Replace with:
  //   loop:
  //   %addend = phi [%entry, 0], [%loop, %result]
  //   ...
  //   %result<tied1> = FMA231 %addend<tied0>, %m1, %m2

  for (unsigned i = 1, e = AddendDef.getNumOperands(); i < e; i += 2) {
    assert(AddendDef.getOperand(i).isReg());
    MachineOperand PHISrcOp = AddendDef.getOperand(i);
    MachineInstr &PHISrcInst = *MRI.def_instr_begin(PHISrcOp.getReg());
    if (&PHISrcInst == MI) {
      // Found a matching instruction.
      unsigned NewFMAOpc = 0;
      switch (MI->getOpcode()) {
        case X86::VFMADDPDr213r: NewFMAOpc = X86::VFMADDPDr231r; break;
        case X86::VFMADDPSr213r: NewFMAOpc = X86::VFMADDPSr231r; break;
        case X86::VFMADDSDr213r: NewFMAOpc = X86::VFMADDSDr231r; break;
        case X86::VFMADDSSr213r: NewFMAOpc = X86::VFMADDSSr231r; break;
        case X86::VFMSUBPDr213r: NewFMAOpc = X86::VFMSUBPDr231r; break;
        case X86::VFMSUBPSr213r: NewFMAOpc = X86::VFMSUBPSr231r; break;
        case X86::VFMSUBSDr213r: NewFMAOpc = X86::VFMSUBSDr231r; break;
        case X86::VFMSUBSSr213r: NewFMAOpc = X86::VFMSUBSSr231r; break;
        case X86::VFNMADDPDr213r: NewFMAOpc = X86::VFNMADDPDr231r; break;
        case X86::VFNMADDPSr213r: NewFMAOpc = X86::VFNMADDPSr231r; break;
        case X86::VFNMADDSDr213r: NewFMAOpc = X86::VFNMADDSDr231r; break;
        case X86::VFNMADDSSr213r: NewFMAOpc = X86::VFNMADDSSr231r; break;
        case X86::VFNMSUBPDr213r: NewFMAOpc = X86::VFNMSUBPDr231r; break;
        case X86::VFNMSUBPSr213r: NewFMAOpc = X86::VFNMSUBPSr231r; break;
        case X86::VFNMSUBSDr213r: NewFMAOpc = X86::VFNMSUBSDr231r; break;
        case X86::VFNMSUBSSr213r: NewFMAOpc = X86::VFNMSUBSSr231r; break;
        case X86::VFMADDSUBPDr213r: NewFMAOpc = X86::VFMADDSUBPDr231r; break;
        case X86::VFMADDSUBPSr213r: NewFMAOpc = X86::VFMADDSUBPSr231r; break;
        case X86::VFMSUBADDPDr213r: NewFMAOpc = X86::VFMSUBADDPDr231r; break;
        case X86::VFMSUBADDPSr213r: NewFMAOpc = X86::VFMSUBADDPSr231r; break;

        case X86::VFMADDPDr213rY: NewFMAOpc = X86::VFMADDPDr231rY; break;
        case X86::VFMADDPSr213rY: NewFMAOpc = X86::VFMADDPSr231rY; break;
        case X86::VFMSUBPDr213rY: NewFMAOpc = X86::VFMSUBPDr231rY; break;
        case X86::VFMSUBPSr213rY: NewFMAOpc = X86::VFMSUBPSr231rY; break;
        case X86::VFNMADDPDr213rY: NewFMAOpc = X86::VFNMADDPDr231rY; break;
        case X86::VFNMADDPSr213rY: NewFMAOpc = X86::VFNMADDPSr231rY; break;
        case X86::VFNMSUBPDr213rY: NewFMAOpc = X86::VFNMSUBPDr231rY; break;
        case X86::VFNMSUBPSr213rY: NewFMAOpc = X86::VFNMSUBPSr231rY; break;
        case X86::VFMADDSUBPDr213rY: NewFMAOpc = X86::VFMADDSUBPDr231rY; break;
        case X86::VFMADDSUBPSr213rY: NewFMAOpc = X86::VFMADDSUBPSr231rY; break;
        case X86::VFMSUBADDPDr213rY: NewFMAOpc = X86::VFMSUBADDPDr231rY; break;
        case X86::VFMSUBADDPSr213rY: NewFMAOpc = X86::VFMSUBADDPSr231rY; break;
        default: llvm_unreachable("Unrecognized FMA variant.");
      }

      const TargetInstrInfo &TII = *Subtarget->getInstrInfo();
      MachineInstrBuilder MIB =
        BuildMI(MF, MI->getDebugLoc(), TII.get(NewFMAOpc))
        .addOperand(MI->getOperand(0))
        .addOperand(MI->getOperand(3))
        .addOperand(MI->getOperand(2))
        .addOperand(MI->getOperand(1));
      MBB->insert(MachineBasicBlock::iterator(MI), MIB);
      MI->eraseFromParent();
    }
  }

  return MBB;
}

MachineBasicBlock *
X86TargetLowering::EmitInstrWithCustomInserter(MachineInstr *MI,
                                               MachineBasicBlock *BB) const {
  switch (MI->getOpcode()) {
  default: llvm_unreachable("Unexpected instr type to insert");
  case X86::TAILJMPd64:
  case X86::TAILJMPr64:
  case X86::TAILJMPm64:
  case X86::TAILJMPd64_REX:
  case X86::TAILJMPr64_REX:
  case X86::TAILJMPm64_REX:
    llvm_unreachable("TAILJMP64 would not be touched here.");
  case X86::TCRETURNdi64:
  case X86::TCRETURNri64:
  case X86::TCRETURNmi64:
    return BB;
  case X86::WIN_ALLOCA:
    return EmitLoweredWinAlloca(MI, BB);
  case X86::SEG_ALLOCA_32:
  case X86::SEG_ALLOCA_64:
    return EmitLoweredSegAlloca(MI, BB);
  case X86::TLSCall_32:
  case X86::TLSCall_64:
    return EmitLoweredTLSCall(MI, BB);
  case X86::CMOV_GR8:
  case X86::CMOV_FR32:
  case X86::CMOV_FR64:
  case X86::CMOV_V4F32:
  case X86::CMOV_V2F64:
  case X86::CMOV_V2I64:
  case X86::CMOV_V8F32:
  case X86::CMOV_V4F64:
  case X86::CMOV_V4I64:
  case X86::CMOV_V16F32:
  case X86::CMOV_V8F64:
  case X86::CMOV_V8I64:
  case X86::CMOV_GR16:
  case X86::CMOV_GR32:
  case X86::CMOV_RFP32:
  case X86::CMOV_RFP64:
  case X86::CMOV_RFP80:
    return EmitLoweredSelect(MI, BB);

  case X86::FP32_TO_INT16_IN_MEM:
  case X86::FP32_TO_INT32_IN_MEM:
  case X86::FP32_TO_INT64_IN_MEM:
  case X86::FP64_TO_INT16_IN_MEM:
  case X86::FP64_TO_INT32_IN_MEM:
  case X86::FP64_TO_INT64_IN_MEM:
  case X86::FP80_TO_INT16_IN_MEM:
  case X86::FP80_TO_INT32_IN_MEM:
  case X86::FP80_TO_INT64_IN_MEM: {
    MachineFunction *F = BB->getParent();
    const TargetInstrInfo *TII = Subtarget->getInstrInfo();
    DebugLoc DL = MI->getDebugLoc();

    // Change the floating point control register to use "round towards zero"
    // mode when truncating to an integer value.
    int CWFrameIdx = F->getFrameInfo()->CreateStackObject(2, 2, false);
    addFrameReference(BuildMI(*BB, MI, DL,
                              TII->get(X86::FNSTCW16m)), CWFrameIdx);

    // Load the old value of the high byte of the control word...
    unsigned OldCW =
      F->getRegInfo().createVirtualRegister(&X86::GR16RegClass);
    addFrameReference(BuildMI(*BB, MI, DL, TII->get(X86::MOV16rm), OldCW),
                      CWFrameIdx);

    // Set the high part to be round to zero...
    addFrameReference(BuildMI(*BB, MI, DL, TII->get(X86::MOV16mi)), CWFrameIdx)
      .addImm(0xC7F);

    // Reload the modified control word now...
    addFrameReference(BuildMI(*BB, MI, DL,
                              TII->get(X86::FLDCW16m)), CWFrameIdx);

    // Restore the memory image of control word to original value
    addFrameReference(BuildMI(*BB, MI, DL, TII->get(X86::MOV16mr)), CWFrameIdx)
      .addReg(OldCW);

    // Get the X86 opcode to use.
    unsigned Opc;
    switch (MI->getOpcode()) {
    default: llvm_unreachable("illegal opcode!");
    case X86::FP32_TO_INT16_IN_MEM: Opc = X86::IST_Fp16m32; break;
    case X86::FP32_TO_INT32_IN_MEM: Opc = X86::IST_Fp32m32; break;
    case X86::FP32_TO_INT64_IN_MEM: Opc = X86::IST_Fp64m32; break;
    case X86::FP64_TO_INT16_IN_MEM: Opc = X86::IST_Fp16m64; break;
    case X86::FP64_TO_INT32_IN_MEM: Opc = X86::IST_Fp32m64; break;
    case X86::FP64_TO_INT64_IN_MEM: Opc = X86::IST_Fp64m64; break;
    case X86::FP80_TO_INT16_IN_MEM: Opc = X86::IST_Fp16m80; break;
    case X86::FP80_TO_INT32_IN_MEM: Opc = X86::IST_Fp32m80; break;
    case X86::FP80_TO_INT64_IN_MEM: Opc = X86::IST_Fp64m80; break;
    }

    X86AddressMode AM;
    MachineOperand &Op = MI->getOperand(0);
    if (Op.isReg()) {
      AM.BaseType = X86AddressMode::RegBase;
      AM.Base.Reg = Op.getReg();
    } else {
      AM.BaseType = X86AddressMode::FrameIndexBase;
      AM.Base.FrameIndex = Op.getIndex();
    }
    Op = MI->getOperand(1);
    if (Op.isImm())
      AM.Scale = Op.getImm();
    Op = MI->getOperand(2);
    if (Op.isImm())
      AM.IndexReg = Op.getImm();
    Op = MI->getOperand(3);
    if (Op.isGlobal()) {
      AM.GV = Op.getGlobal();
    } else {
      AM.Disp = Op.getImm();
    }
    addFullAddress(BuildMI(*BB, MI, DL, TII->get(Opc)), AM)
                      .addReg(MI->getOperand(X86::AddrNumOperands).getReg());

    // Reload the original control word now.
    addFrameReference(BuildMI(*BB, MI, DL,
                              TII->get(X86::FLDCW16m)), CWFrameIdx);

    MI->eraseFromParent();   // The pseudo instruction is gone now.
    return BB;
  }
    // String/text processing lowering.
  case X86::PCMPISTRM128REG:
  case X86::VPCMPISTRM128REG:
  case X86::PCMPISTRM128MEM:
  case X86::VPCMPISTRM128MEM:
  case X86::PCMPESTRM128REG:
  case X86::VPCMPESTRM128REG:
  case X86::PCMPESTRM128MEM:
  case X86::VPCMPESTRM128MEM:
    assert(Subtarget->hasSSE42() &&
           "Target must have SSE4.2 or AVX features enabled");
    return EmitPCMPSTRM(MI, BB, Subtarget->getInstrInfo());

  // String/text processing lowering.
  case X86::PCMPISTRIREG:
  case X86::VPCMPISTRIREG:
  case X86::PCMPISTRIMEM:
  case X86::VPCMPISTRIMEM:
  case X86::PCMPESTRIREG:
  case X86::VPCMPESTRIREG:
  case X86::PCMPESTRIMEM:
  case X86::VPCMPESTRIMEM:
    assert(Subtarget->hasSSE42() &&
           "Target must have SSE4.2 or AVX features enabled");
    return EmitPCMPSTRI(MI, BB, Subtarget->getInstrInfo());

  // Thread synchronization.
  case X86::MONITOR:
    return EmitMonitor(MI, BB, Subtarget);

  // xbegin
  case X86::XBEGIN:
    return EmitXBegin(MI, BB, Subtarget->getInstrInfo());

  case X86::VASTART_SAVE_XMM_REGS:
    return EmitVAStartSaveXMMRegsWithCustomInserter(MI, BB);

  case X86::VAARG_64:
    return EmitVAARG64WithCustomInserter(MI, BB);

  case X86::EH_SjLj_SetJmp32:
  case X86::EH_SjLj_SetJmp64:
    return emitEHSjLjSetJmp(MI, BB);

  case X86::EH_SjLj_LongJmp32:
  case X86::EH_SjLj_LongJmp64:
    return emitEHSjLjLongJmp(MI, BB);

  case TargetOpcode::STATEPOINT:
    // As an implementation detail, STATEPOINT shares the STACKMAP format at
    // this point in the process.  We diverge later.
    return emitPatchPoint(MI, BB);

  case TargetOpcode::STACKMAP:
  case TargetOpcode::PATCHPOINT:
    return emitPatchPoint(MI, BB);

  case X86::VFMADDPDr213r:
  case X86::VFMADDPSr213r:
  case X86::VFMADDSDr213r:
  case X86::VFMADDSSr213r:
  case X86::VFMSUBPDr213r:
  case X86::VFMSUBPSr213r:
  case X86::VFMSUBSDr213r:
  case X86::VFMSUBSSr213r:
  case X86::VFNMADDPDr213r:
  case X86::VFNMADDPSr213r:
  case X86::VFNMADDSDr213r:
  case X86::VFNMADDSSr213r:
  case X86::VFNMSUBPDr213r:
  case X86::VFNMSUBPSr213r:
  case X86::VFNMSUBSDr213r:
  case X86::VFNMSUBSSr213r:
  case X86::VFMADDSUBPDr213r:
  case X86::VFMADDSUBPSr213r:
  case X86::VFMSUBADDPDr213r:
  case X86::VFMSUBADDPSr213r:
  case X86::VFMADDPDr213rY:
  case X86::VFMADDPSr213rY:
  case X86::VFMSUBPDr213rY:
  case X86::VFMSUBPSr213rY:
  case X86::VFNMADDPDr213rY:
  case X86::VFNMADDPSr213rY:
  case X86::VFNMSUBPDr213rY:
  case X86::VFNMSUBPSr213rY:
  case X86::VFMADDSUBPDr213rY:
  case X86::VFMADDSUBPSr213rY:
  case X86::VFMSUBADDPDr213rY:
  case X86::VFMSUBADDPSr213rY:
    return emitFMA3Instr(MI, BB);
  }
}

//===----------------------------------------------------------------------===//
//                           X86 Optimization Hooks
//===----------------------------------------------------------------------===//

void X86TargetLowering::computeKnownBitsForTargetNode(const SDValue Op,
                                                      APInt &KnownZero,
                                                      APInt &KnownOne,
                                                      const SelectionDAG &DAG,
                                                      unsigned Depth) const {
  unsigned BitWidth = KnownZero.getBitWidth();
  unsigned Opc = Op.getOpcode();
  assert((Opc >= ISD::BUILTIN_OP_END ||
          Opc == ISD::INTRINSIC_WO_CHAIN ||
          Opc == ISD::INTRINSIC_W_CHAIN ||
          Opc == ISD::INTRINSIC_VOID) &&
         "Should use MaskedValueIsZero if you don't know whether Op"
         " is a target node!");

  KnownZero = KnownOne = APInt(BitWidth, 0);   // Don't know anything.
  switch (Opc) {
  default: break;
  case X86ISD::ADD:
  case X86ISD::SUB:
  case X86ISD::ADC:
  case X86ISD::SBB:
  case X86ISD::SMUL:
  case X86ISD::UMUL:
  case X86ISD::INC:
  case X86ISD::DEC:
  case X86ISD::OR:
  case X86ISD::XOR:
  case X86ISD::AND:
    // These nodes' second result is a boolean.
    if (Op.getResNo() == 0)
      break;
    // Fallthrough
  case X86ISD::SETCC:
    KnownZero |= APInt::getHighBitsSet(BitWidth, BitWidth - 1);
    break;
  case ISD::INTRINSIC_WO_CHAIN: {
    unsigned IntId = cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue();
    unsigned NumLoBits = 0;
    switch (IntId) {
    default: break;
    case Intrinsic::x86_sse_movmsk_ps:
    case Intrinsic::x86_avx_movmsk_ps_256:
    case Intrinsic::x86_sse2_movmsk_pd:
    case Intrinsic::x86_avx_movmsk_pd_256:
    case Intrinsic::x86_mmx_pmovmskb:
    case Intrinsic::x86_sse2_pmovmskb_128:
    case Intrinsic::x86_avx2_pmovmskb: {
      // High bits of movmskp{s|d}, pmovmskb are known zero.
      switch (IntId) {
        default: llvm_unreachable("Impossible intrinsic");  // Can't reach here.
        case Intrinsic::x86_sse_movmsk_ps:      NumLoBits = 4; break;
        case Intrinsic::x86_avx_movmsk_ps_256:  NumLoBits = 8; break;
        case Intrinsic::x86_sse2_movmsk_pd:     NumLoBits = 2; break;
        case Intrinsic::x86_avx_movmsk_pd_256:  NumLoBits = 4; break;
        case Intrinsic::x86_mmx_pmovmskb:       NumLoBits = 8; break;
        case Intrinsic::x86_sse2_pmovmskb_128:  NumLoBits = 16; break;
        case Intrinsic::x86_avx2_pmovmskb:      NumLoBits = 32; break;
      }
      KnownZero = APInt::getHighBitsSet(BitWidth, BitWidth - NumLoBits);
      break;
    }
    }
    break;
  }
  }
}

unsigned X86TargetLowering::ComputeNumSignBitsForTargetNode(
  SDValue Op,
  const SelectionDAG &,
  unsigned Depth) const {
  // SETCC_CARRY sets the dest to ~0 for true or 0 for false.
  if (Op.getOpcode() == X86ISD::SETCC_CARRY)
    return Op.getValueType().getScalarType().getSizeInBits();

  // Fallback case.
  return 1;
}

/// isGAPlusOffset - Returns true (and the GlobalValue and the offset) if the
/// node is a GlobalAddress + offset.
bool X86TargetLowering::isGAPlusOffset(SDNode *N,
                                       const GlobalValue* &GA,
                                       int64_t &Offset) const {
  if (N->getOpcode() == X86ISD::Wrapper) {
    if (isa<GlobalAddressSDNode>(N->getOperand(0))) {
      GA = cast<GlobalAddressSDNode>(N->getOperand(0))->getGlobal();
      Offset = cast<GlobalAddressSDNode>(N->getOperand(0))->getOffset();
      return true;
    }
  }
  return TargetLowering::isGAPlusOffset(N, GA, Offset);
}

/// isShuffleHigh128VectorInsertLow - Checks whether the shuffle node is the
/// same as extracting the high 128-bit part of 256-bit vector and then
/// inserting the result into the low part of a new 256-bit vector
static bool isShuffleHigh128VectorInsertLow(ShuffleVectorSDNode *SVOp) {
  EVT VT = SVOp->getValueType(0);
  unsigned NumElems = VT.getVectorNumElements();

  // vector_shuffle <4, 5, 6, 7, u, u, u, u> or <2, 3, u, u>
  for (unsigned i = 0, j = NumElems/2; i != NumElems/2; ++i, ++j)
    if (!isUndefOrEqual(SVOp->getMaskElt(i), j) ||
        SVOp->getMaskElt(j) >= 0)
      return false;

  return true;
}

/// isShuffleLow128VectorInsertHigh - Checks whether the shuffle node is the
/// same as extracting the low 128-bit part of 256-bit vector and then
/// inserting the result into the high part of a new 256-bit vector
static bool isShuffleLow128VectorInsertHigh(ShuffleVectorSDNode *SVOp) {
  EVT VT = SVOp->getValueType(0);
  unsigned NumElems = VT.getVectorNumElements();

  // vector_shuffle <u, u, u, u, 0, 1, 2, 3> or <u, u, 0, 1>
  for (unsigned i = NumElems/2, j = 0; i != NumElems; ++i, ++j)
    if (!isUndefOrEqual(SVOp->getMaskElt(i), j) ||
        SVOp->getMaskElt(j) >= 0)
      return false;

  return true;
}

/// PerformShuffleCombine256 - Performs shuffle combines for 256-bit vectors.
static SDValue PerformShuffleCombine256(SDNode *N, SelectionDAG &DAG,
                                        TargetLowering::DAGCombinerInfo &DCI,
                                        const X86Subtarget* Subtarget) {
  SDLoc dl(N);
  ShuffleVectorSDNode *SVOp = cast<ShuffleVectorSDNode>(N);
  SDValue V1 = SVOp->getOperand(0);
  SDValue V2 = SVOp->getOperand(1);
  EVT VT = SVOp->getValueType(0);
  unsigned NumElems = VT.getVectorNumElements();

  if (V1.getOpcode() == ISD::CONCAT_VECTORS &&
      V2.getOpcode() == ISD::CONCAT_VECTORS) {
    //
    //                   0,0,0,...
    //                      |
    //    V      UNDEF    BUILD_VECTOR    UNDEF
    //     \      /           \           /
    //  CONCAT_VECTOR         CONCAT_VECTOR
    //         \                  /
    //          \                /
    //          RESULT: V + zero extended
    //
    if (V2.getOperand(0).getOpcode() != ISD::BUILD_VECTOR ||
        V2.getOperand(1).getOpcode() != ISD::UNDEF ||
        V1.getOperand(1).getOpcode() != ISD::UNDEF)
      return SDValue();

    if (!ISD::isBuildVectorAllZeros(V2.getOperand(0).getNode()))
      return SDValue();

    // To match the shuffle mask, the first half of the mask should
    // be exactly the first vector, and all the rest a splat with the
    // first element of the second one.
    for (unsigned i = 0; i != NumElems/2; ++i)
      if (!isUndefOrEqual(SVOp->getMaskElt(i), i) ||
          !isUndefOrEqual(SVOp->getMaskElt(i+NumElems/2), NumElems))
        return SDValue();

    // If V1 is coming from a vector load then just fold to a VZEXT_LOAD.
    if (LoadSDNode *Ld = dyn_cast<LoadSDNode>(V1.getOperand(0))) {
      if (Ld->hasNUsesOfValue(1, 0)) {
        SDVTList Tys = DAG.getVTList(MVT::v4i64, MVT::Other);
        SDValue Ops[] = { Ld->getChain(), Ld->getBasePtr() };
        SDValue ResNode =
          DAG.getMemIntrinsicNode(X86ISD::VZEXT_LOAD, dl, Tys, Ops,
                                  Ld->getMemoryVT(),
                                  Ld->getPointerInfo(),
                                  Ld->getAlignment(),
                                  false/*isVolatile*/, true/*ReadMem*/,
                                  false/*WriteMem*/);

        // Make sure the newly-created LOAD is in the same position as Ld in
        // terms of dependency. We create a TokenFactor for Ld and ResNode,
        // and update uses of Ld's output chain to use the TokenFactor.
        if (Ld->hasAnyUseOfValue(1)) {
          SDValue NewChain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
                             SDValue(Ld, 1), SDValue(ResNode.getNode(), 1));
          DAG.ReplaceAllUsesOfValueWith(SDValue(Ld, 1), NewChain);
          DAG.UpdateNodeOperands(NewChain.getNode(), SDValue(Ld, 1),
                                 SDValue(ResNode.getNode(), 1));
        }

        return DAG.getNode(ISD::BITCAST, dl, VT, ResNode);
      }
    }

    // Emit a zeroed vector and insert the desired subvector on its
    // first half.
    SDValue Zeros = getZeroVector(VT, Subtarget, DAG, dl);
    SDValue InsV = Insert128BitVector(Zeros, V1.getOperand(0), 0, DAG, dl);
    return DCI.CombineTo(N, InsV);
  }

  //===--------------------------------------------------------------------===//
  // Combine some shuffles into subvector extracts and inserts:
  //

  // vector_shuffle <4, 5, 6, 7, u, u, u, u> or <2, 3, u, u>
  if (isShuffleHigh128VectorInsertLow(SVOp)) {
    SDValue V = Extract128BitVector(V1, NumElems/2, DAG, dl);
    SDValue InsV = Insert128BitVector(DAG.getUNDEF(VT), V, 0, DAG, dl);
    return DCI.CombineTo(N, InsV);
  }

  // vector_shuffle <u, u, u, u, 0, 1, 2, 3> or <u, u, 0, 1>
  if (isShuffleLow128VectorInsertHigh(SVOp)) {
    SDValue V = Extract128BitVector(V1, 0, DAG, dl);
    SDValue InsV = Insert128BitVector(DAG.getUNDEF(VT), V, NumElems/2, DAG, dl);
    return DCI.CombineTo(N, InsV);
  }

  return SDValue();
}

/// \brief Combine an arbitrary chain of shuffles into a single instruction if
/// possible.
///
/// This is the leaf of the recursive combinine below. When we have found some
/// chain of single-use x86 shuffle instructions and accumulated the combined
/// shuffle mask represented by them, this will try to pattern match that mask
/// into either a single instruction if there is a special purpose instruction
/// for this operation, or into a PSHUFB instruction which is a fully general
/// instruction but should only be used to replace chains over a certain depth.
static bool combineX86ShuffleChain(SDValue Op, SDValue Root, ArrayRef<int> Mask,
                                   int Depth, bool HasPSHUFB, SelectionDAG &DAG,
                                   TargetLowering::DAGCombinerInfo &DCI,
                                   const X86Subtarget *Subtarget) {
  assert(!Mask.empty() && "Cannot combine an empty shuffle mask!");

  // Find the operand that enters the chain. Note that multiple uses are OK
  // here, we're not going to remove the operand we find.
  SDValue Input = Op.getOperand(0);
  while (Input.getOpcode() == ISD::BITCAST)
    Input = Input.getOperand(0);

  MVT VT = Input.getSimpleValueType();
  MVT RootVT = Root.getSimpleValueType();
  SDLoc DL(Root);

  // Just remove no-op shuffle masks.
  if (Mask.size() == 1) {
    DCI.CombineTo(Root.getNode(), DAG.getNode(ISD::BITCAST, DL, RootVT, Input),
                  /*AddTo*/ true);
    return true;
  }

  // Use the float domain if the operand type is a floating point type.
  bool FloatDomain = VT.isFloatingPoint();

  // For floating point shuffles, we don't have free copies in the shuffle
  // instructions or the ability to load as part of the instruction, so
  // canonicalize their shuffles to UNPCK or MOV variants.
  //
  // Note that even with AVX we prefer the PSHUFD form of shuffle for integer
  // vectors because it can have a load folded into it that UNPCK cannot. This
  // doesn't preclude something switching to the shorter encoding post-RA.
  if (FloatDomain) {
    if (Mask.equals(0, 0) || Mask.equals(1, 1)) {
      bool Lo = Mask.equals(0, 0);
      unsigned Shuffle;
      MVT ShuffleVT;
      // Check if we have SSE3 which will let us use MOVDDUP. That instruction
      // is no slower than UNPCKLPD but has the option to fold the input operand
      // into even an unaligned memory load.
      if (Lo && Subtarget->hasSSE3()) {
        Shuffle = X86ISD::MOVDDUP;
        ShuffleVT = MVT::v2f64;
      } else {
        // We have MOVLHPS and MOVHLPS throughout SSE and they encode smaller
        // than the UNPCK variants.
        Shuffle = Lo ? X86ISD::MOVLHPS : X86ISD::MOVHLPS;
        ShuffleVT = MVT::v4f32;
      }
      if (Depth == 1 && Root->getOpcode() == Shuffle)
        return false; // Nothing to do!
      Op = DAG.getNode(ISD::BITCAST, DL, ShuffleVT, Input);
      DCI.AddToWorklist(Op.getNode());
      if (Shuffle == X86ISD::MOVDDUP)
        Op = DAG.getNode(Shuffle, DL, ShuffleVT, Op);
      else
        Op = DAG.getNode(Shuffle, DL, ShuffleVT, Op, Op);
      DCI.AddToWorklist(Op.getNode());
      DCI.CombineTo(Root.getNode(), DAG.getNode(ISD::BITCAST, DL, RootVT, Op),
                    /*AddTo*/ true);
      return true;
    }
    if (Subtarget->hasSSE3() &&
        (Mask.equals(0, 0, 2, 2) || Mask.equals(1, 1, 3, 3))) {
      bool Lo = Mask.equals(0, 0, 2, 2);
      unsigned Shuffle = Lo ? X86ISD::MOVSLDUP : X86ISD::MOVSHDUP;
      MVT ShuffleVT = MVT::v4f32;
      if (Depth == 1 && Root->getOpcode() == Shuffle)
        return false; // Nothing to do!
      Op = DAG.getNode(ISD::BITCAST, DL, ShuffleVT, Input);
      DCI.AddToWorklist(Op.getNode());
      Op = DAG.getNode(Shuffle, DL, ShuffleVT, Op);
      DCI.AddToWorklist(Op.getNode());
      DCI.CombineTo(Root.getNode(), DAG.getNode(ISD::BITCAST, DL, RootVT, Op),
                    /*AddTo*/ true);
      return true;
    }
    if (Mask.equals(0, 0, 1, 1) || Mask.equals(2, 2, 3, 3)) {
      bool Lo = Mask.equals(0, 0, 1, 1);
      unsigned Shuffle = Lo ? X86ISD::UNPCKL : X86ISD::UNPCKH;
      MVT ShuffleVT = MVT::v4f32;
      if (Depth == 1 && Root->getOpcode() == Shuffle)
        return false; // Nothing to do!
      Op = DAG.getNode(ISD::BITCAST, DL, ShuffleVT, Input);
      DCI.AddToWorklist(Op.getNode());
      Op = DAG.getNode(Shuffle, DL, ShuffleVT, Op, Op);
      DCI.AddToWorklist(Op.getNode());
      DCI.CombineTo(Root.getNode(), DAG.getNode(ISD::BITCAST, DL, RootVT, Op),
                    /*AddTo*/ true);
      return true;
    }
  }

  // We always canonicalize the 8 x i16 and 16 x i8 shuffles into their UNPCK
  // variants as none of these have single-instruction variants that are
  // superior to the UNPCK formulation.
  if (!FloatDomain &&
      (Mask.equals(0, 0, 1, 1, 2, 2, 3, 3) ||
       Mask.equals(4, 4, 5, 5, 6, 6, 7, 7) ||
       Mask.equals(0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7) ||
       Mask.equals(8, 8, 9, 9, 10, 10, 11, 11, 12, 12, 13, 13, 14, 14, 15,
                   15))) {
    bool Lo = Mask[0] == 0;
    unsigned Shuffle = Lo ? X86ISD::UNPCKL : X86ISD::UNPCKH;
    if (Depth == 1 && Root->getOpcode() == Shuffle)
      return false; // Nothing to do!
    MVT ShuffleVT;
    switch (Mask.size()) {
    case 8:
      ShuffleVT = MVT::v8i16;
      break;
    case 16:
      ShuffleVT = MVT::v16i8;
      break;
    default:
      llvm_unreachable("Impossible mask size!");
    };
    Op = DAG.getNode(ISD::BITCAST, DL, ShuffleVT, Input);
    DCI.AddToWorklist(Op.getNode());
    Op = DAG.getNode(Shuffle, DL, ShuffleVT, Op, Op);
    DCI.AddToWorklist(Op.getNode());
    DCI.CombineTo(Root.getNode(), DAG.getNode(ISD::BITCAST, DL, RootVT, Op),
                  /*AddTo*/ true);
    return true;
  }

  // Don't try to re-form single instruction chains under any circumstances now
  // that we've done encoding canonicalization for them.
  if (Depth < 2)
    return false;

  // If we have 3 or more shuffle instructions or a chain involving PSHUFB, we
  // can replace them with a single PSHUFB instruction profitably. Intel's
  // manuals suggest only using PSHUFB if doing so replacing 5 instructions, but
  // in practice PSHUFB tends to be *very* fast so we're more aggressive.
  if ((Depth >= 3 || HasPSHUFB) && Subtarget->hasSSSE3()) {
    SmallVector<SDValue, 16> PSHUFBMask;
    assert(Mask.size() <= 16 && "Can't shuffle elements smaller than bytes!");
    int Ratio = 16 / Mask.size();
    for (unsigned i = 0; i < 16; ++i) {
      if (Mask[i / Ratio] == SM_SentinelUndef) {
        PSHUFBMask.push_back(DAG.getUNDEF(MVT::i8));
        continue;
      }
      int M = Mask[i / Ratio] != SM_SentinelZero
                  ? Ratio * Mask[i / Ratio] + i % Ratio
                  : 255;
      PSHUFBMask.push_back(DAG.getConstant(M, MVT::i8));
    }
    Op = DAG.getNode(ISD::BITCAST, DL, MVT::v16i8, Input);
    DCI.AddToWorklist(Op.getNode());
    SDValue PSHUFBMaskOp =
        DAG.getNode(ISD::BUILD_VECTOR, DL, MVT::v16i8, PSHUFBMask);
    DCI.AddToWorklist(PSHUFBMaskOp.getNode());
    Op = DAG.getNode(X86ISD::PSHUFB, DL, MVT::v16i8, Op, PSHUFBMaskOp);
    DCI.AddToWorklist(Op.getNode());
    DCI.CombineTo(Root.getNode(), DAG.getNode(ISD::BITCAST, DL, RootVT, Op),
                  /*AddTo*/ true);
    return true;
  }

  // Failed to find any combines.
  return false;
}

/// \brief Fully generic combining of x86 shuffle instructions.
///
/// This should be the last combine run over the x86 shuffle instructions. Once
/// they have been fully optimized, this will recursively consider all chains
/// of single-use shuffle instructions, build a generic model of the cumulative
/// shuffle operation, and check for simpler instructions which implement this
/// operation. We use this primarily for two purposes:
///
/// 1) Collapse generic shuffles to specialized single instructions when
///    equivalent. In most cases, this is just an encoding size win, but
///    sometimes we will collapse multiple generic shuffles into a single
///    special-purpose shuffle.
/// 2) Look for sequences of shuffle instructions with 3 or more total
///    instructions, and replace them with the slightly more expensive SSSE3
///    PSHUFB instruction if available. We do this as the last combining step
///    to ensure we avoid using PSHUFB if we can implement the shuffle with
///    a suitable short sequence of other instructions. The PHUFB will either
///    use a register or have to read from memory and so is slightly (but only
///    slightly) more expensive than the other shuffle instructions.
///
/// Because this is inherently a quadratic operation (for each shuffle in
/// a chain, we recurse up the chain), the depth is limited to 8 instructions.
/// This should never be an issue in practice as the shuffle lowering doesn't
/// produce sequences of more than 8 instructions.
///
/// FIXME: We will currently miss some cases where the redundant shuffling
/// would simplify under the threshold for PSHUFB formation because of
/// combine-ordering. To fix this, we should do the redundant instruction
/// combining in this recursive walk.
static bool combineX86ShufflesRecursively(SDValue Op, SDValue Root,
                                          ArrayRef<int> RootMask,
                                          int Depth, bool HasPSHUFB,
                                          SelectionDAG &DAG,
                                          TargetLowering::DAGCombinerInfo &DCI,
                                          const X86Subtarget *Subtarget) {
  // Bound the depth of our recursive combine because this is ultimately
  // quadratic in nature.
  if (Depth > 8)
    return false;

  // Directly rip through bitcasts to find the underlying operand.
  while (Op.getOpcode() == ISD::BITCAST && Op.getOperand(0).hasOneUse())
    Op = Op.getOperand(0);

  MVT VT = Op.getSimpleValueType();
  if (!VT.isVector())
    return false; // Bail if we hit a non-vector.
  // FIXME: This routine should be taught about 256-bit shuffles, or a 256-bit
  // version should be added.
  if (VT.getSizeInBits() != 128)
    return false;

  assert(Root.getSimpleValueType().isVector() &&
         "Shuffles operate on vector types!");
  assert(VT.getSizeInBits() == Root.getSimpleValueType().getSizeInBits() &&
         "Can only combine shuffles of the same vector register size.");

  if (!isTargetShuffle(Op.getOpcode()))
    return false;
  SmallVector<int, 16> OpMask;
  bool IsUnary;
  bool HaveMask = getTargetShuffleMask(Op.getNode(), VT, OpMask, IsUnary);
  // We only can combine unary shuffles which we can decode the mask for.
  if (!HaveMask || !IsUnary)
    return false;

  assert(VT.getVectorNumElements() == OpMask.size() &&
         "Different mask size from vector size!");
  assert(((RootMask.size() > OpMask.size() &&
           RootMask.size() % OpMask.size() == 0) ||
          (OpMask.size() > RootMask.size() &&
           OpMask.size() % RootMask.size() == 0) ||
          OpMask.size() == RootMask.size()) &&
         "The smaller number of elements must divide the larger.");
  int RootRatio = std::max<int>(1, OpMask.size() / RootMask.size());
  int OpRatio = std::max<int>(1, RootMask.size() / OpMask.size());
  assert(((RootRatio == 1 && OpRatio == 1) ||
          (RootRatio == 1) != (OpRatio == 1)) &&
         "Must not have a ratio for both incoming and op masks!");

  SmallVector<int, 16> Mask;
  Mask.reserve(std::max(OpMask.size(), RootMask.size()));

  // Merge this shuffle operation's mask into our accumulated mask. Note that
  // this shuffle's mask will be the first applied to the input, followed by the
  // root mask to get us all the way to the root value arrangement. The reason
  // for this order is that we are recursing up the operation chain.
  for (int i = 0, e = std::max(OpMask.size(), RootMask.size()); i < e; ++i) {
    int RootIdx = i / RootRatio;
    if (RootMask[RootIdx] < 0) {
      // This is a zero or undef lane, we're done.
      Mask.push_back(RootMask[RootIdx]);
      continue;
    }

    int RootMaskedIdx = RootMask[RootIdx] * RootRatio + i % RootRatio;
    int OpIdx = RootMaskedIdx / OpRatio;
    if (OpMask[OpIdx] < 0) {
      // The incoming lanes are zero or undef, it doesn't matter which ones we
      // are using.
      Mask.push_back(OpMask[OpIdx]);
      continue;
    }

    // Ok, we have non-zero lanes, map them through.
    Mask.push_back(OpMask[OpIdx] * OpRatio +
                   RootMaskedIdx % OpRatio);
  }

  // See if we can recurse into the operand to combine more things.
  switch (Op.getOpcode()) {
    case X86ISD::PSHUFB:
      HasPSHUFB = true;
    case X86ISD::PSHUFD:
    case X86ISD::PSHUFHW:
    case X86ISD::PSHUFLW:
      if (Op.getOperand(0).hasOneUse() &&
          combineX86ShufflesRecursively(Op.getOperand(0), Root, Mask, Depth + 1,
                                        HasPSHUFB, DAG, DCI, Subtarget))
        return true;
      break;

    case X86ISD::UNPCKL:
    case X86ISD::UNPCKH:
      assert(Op.getOperand(0) == Op.getOperand(1) && "We only combine unary shuffles!");
      // We can't check for single use, we have to check that this shuffle is the only user.
      if (Op->isOnlyUserOf(Op.getOperand(0).getNode()) &&
          combineX86ShufflesRecursively(Op.getOperand(0), Root, Mask, Depth + 1,
                                        HasPSHUFB, DAG, DCI, Subtarget))
          return true;
      break;
  }

  // Minor canonicalization of the accumulated shuffle mask to make it easier
  // to match below. All this does is detect masks with squential pairs of
  // elements, and shrink them to the half-width mask. It does this in a loop
  // so it will reduce the size of the mask to the minimal width mask which
  // performs an equivalent shuffle.
  SmallVector<int, 16> WidenedMask;
  while (Mask.size() > 1 && canWidenShuffleElements(Mask, WidenedMask)) {
    Mask = std::move(WidenedMask);
    WidenedMask.clear();
  }

  return combineX86ShuffleChain(Op, Root, Mask, Depth, HasPSHUFB, DAG, DCI,
                                Subtarget);
}

/// \brief Get the PSHUF-style mask from PSHUF node.
///
/// This is a very minor wrapper around getTargetShuffleMask to easy forming v4
/// PSHUF-style masks that can be reused with such instructions.
static SmallVector<int, 4> getPSHUFShuffleMask(SDValue N) {
  SmallVector<int, 4> Mask;
  bool IsUnary;
  bool HaveMask = getTargetShuffleMask(N.getNode(), N.getSimpleValueType(), Mask, IsUnary);
  (void)HaveMask;
  assert(HaveMask);

  switch (N.getOpcode()) {
  case X86ISD::PSHUFD:
    return Mask;
  case X86ISD::PSHUFLW:
    Mask.resize(4);
    return Mask;
  case X86ISD::PSHUFHW:
    Mask.erase(Mask.begin(), Mask.begin() + 4);
    for (int &M : Mask)
      M -= 4;
    return Mask;
  default:
    llvm_unreachable("No valid shuffle instruction found!");
  }
}

/// \brief Search for a combinable shuffle across a chain ending in pshufd.
///
/// We walk up the chain and look for a combinable shuffle, skipping over
/// shuffles that we could hoist this shuffle's transformation past without
/// altering anything.
static SDValue
combineRedundantDWordShuffle(SDValue N, MutableArrayRef<int> Mask,
                             SelectionDAG &DAG,
                             TargetLowering::DAGCombinerInfo &DCI) {
  assert(N.getOpcode() == X86ISD::PSHUFD &&
         "Called with something other than an x86 128-bit half shuffle!");
  SDLoc DL(N);

  // Walk up a single-use chain looking for a combinable shuffle. Keep a stack
  // of the shuffles in the chain so that we can form a fresh chain to replace
  // this one.
  SmallVector<SDValue, 8> Chain;
  SDValue V = N.getOperand(0);
  for (; V.hasOneUse(); V = V.getOperand(0)) {
    switch (V.getOpcode()) {
    default:
      return SDValue(); // Nothing combined!

    case ISD::BITCAST:
      // Skip bitcasts as we always know the type for the target specific
      // instructions.
      continue;

    case X86ISD::PSHUFD:
      // Found another dword shuffle.
      break;

    case X86ISD::PSHUFLW:
      // Check that the low words (being shuffled) are the identity in the
      // dword shuffle, and the high words are self-contained.
      if (Mask[0] != 0 || Mask[1] != 1 ||
          !(Mask[2] >= 2 && Mask[2] < 4 && Mask[3] >= 2 && Mask[3] < 4))
        return SDValue();

      Chain.push_back(V);
      continue;

    case X86ISD::PSHUFHW:
      // Check that the high words (being shuffled) are the identity in the
      // dword shuffle, and the low words are self-contained.
      if (Mask[2] != 2 || Mask[3] != 3 ||
          !(Mask[0] >= 0 && Mask[0] < 2 && Mask[1] >= 0 && Mask[1] < 2))
        return SDValue();

      Chain.push_back(V);
      continue;

    case X86ISD::UNPCKL:
    case X86ISD::UNPCKH:
      // For either i8 -> i16 or i16 -> i32 unpacks, we can combine a dword
      // shuffle into a preceding word shuffle.
      if (V.getValueType() != MVT::v16i8 && V.getValueType() != MVT::v8i16)
        return SDValue();

      // Search for a half-shuffle which we can combine with.
      unsigned CombineOp =
          V.getOpcode() == X86ISD::UNPCKL ? X86ISD::PSHUFLW : X86ISD::PSHUFHW;
      if (V.getOperand(0) != V.getOperand(1) ||
          !V->isOnlyUserOf(V.getOperand(0).getNode()))
        return SDValue();
      Chain.push_back(V);
      V = V.getOperand(0);
      do {
        switch (V.getOpcode()) {
        default:
          return SDValue(); // Nothing to combine.

        case X86ISD::PSHUFLW:
        case X86ISD::PSHUFHW:
          if (V.getOpcode() == CombineOp)
            break;

          Chain.push_back(V);

          // Fallthrough!
        case ISD::BITCAST:
          V = V.getOperand(0);
          continue;
        }
        break;
      } while (V.hasOneUse());
      break;
    }
    // Break out of the loop if we break out of the switch.
    break;
  }

  if (!V.hasOneUse())
    // We fell out of the loop without finding a viable combining instruction.
    return SDValue();

  // Merge this node's mask and our incoming mask.
  SmallVector<int, 4> VMask = getPSHUFShuffleMask(V);
  for (int &M : Mask)
    M = VMask[M];
  V = DAG.getNode(V.getOpcode(), DL, V.getValueType(), V.getOperand(0),
                  getV4X86ShuffleImm8ForMask(Mask, DAG));

  // Rebuild the chain around this new shuffle.
  while (!Chain.empty()) {
    SDValue W = Chain.pop_back_val();

    if (V.getValueType() != W.getOperand(0).getValueType())
      V = DAG.getNode(ISD::BITCAST, DL, W.getOperand(0).getValueType(), V);

    switch (W.getOpcode()) {
    default:
      llvm_unreachable("Only PSHUF and UNPCK instructions get here!");

    case X86ISD::UNPCKL:
    case X86ISD::UNPCKH:
      V = DAG.getNode(W.getOpcode(), DL, W.getValueType(), V, V);
      break;

    case X86ISD::PSHUFD:
    case X86ISD::PSHUFLW:
    case X86ISD::PSHUFHW:
      V = DAG.getNode(W.getOpcode(), DL, W.getValueType(), V, W.getOperand(1));
      break;
    }
  }
  if (V.getValueType() != N.getValueType())
    V = DAG.getNode(ISD::BITCAST, DL, N.getValueType(), V);

  // Return the new chain to replace N.
  return V;
}

/// \brief Search for a combinable shuffle across a chain ending in pshuflw or pshufhw.
///
/// We walk up the chain, skipping shuffles of the other half and looking
/// through shuffles which switch halves trying to find a shuffle of the same
/// pair of dwords.
static bool combineRedundantHalfShuffle(SDValue N, MutableArrayRef<int> Mask,
                                        SelectionDAG &DAG,
                                        TargetLowering::DAGCombinerInfo &DCI) {
  assert(
      (N.getOpcode() == X86ISD::PSHUFLW || N.getOpcode() == X86ISD::PSHUFHW) &&
      "Called with something other than an x86 128-bit half shuffle!");
  SDLoc DL(N);
  unsigned CombineOpcode = N.getOpcode();

  // Walk up a single-use chain looking for a combinable shuffle.
  SDValue V = N.getOperand(0);
  for (; V.hasOneUse(); V = V.getOperand(0)) {
    switch (V.getOpcode()) {
    default:
      return false; // Nothing combined!

    case ISD::BITCAST:
      // Skip bitcasts as we always know the type for the target specific
      // instructions.
      continue;

    case X86ISD::PSHUFLW:
    case X86ISD::PSHUFHW:
      if (V.getOpcode() == CombineOpcode)
        break;

      // Other-half shuffles are no-ops.
      continue;
    }
    // Break out of the loop if we break out of the switch.
    break;
  }

  if (!V.hasOneUse())
    // We fell out of the loop without finding a viable combining instruction.
    return false;

  // Combine away the bottom node as its shuffle will be accumulated into
  // a preceding shuffle.
  DCI.CombineTo(N.getNode(), N.getOperand(0), /*AddTo*/ true);

  // Record the old value.
  SDValue Old = V;

  // Merge this node's mask and our incoming mask (adjusted to account for all
  // the pshufd instructions encountered).
  SmallVector<int, 4> VMask = getPSHUFShuffleMask(V);
  for (int &M : Mask)
    M = VMask[M];
  V = DAG.getNode(V.getOpcode(), DL, MVT::v8i16, V.getOperand(0),
                  getV4X86ShuffleImm8ForMask(Mask, DAG));

  // Check that the shuffles didn't cancel each other out. If not, we need to
  // combine to the new one.
  if (Old != V)
    // Replace the combinable shuffle with the combined one, updating all users
    // so that we re-evaluate the chain here.
    DCI.CombineTo(Old.getNode(), V, /*AddTo*/ true);

  return true;
}

/// \brief Try to combine x86 target specific shuffles.
static SDValue PerformTargetShuffleCombine(SDValue N, SelectionDAG &DAG,
                                           TargetLowering::DAGCombinerInfo &DCI,
                                           const X86Subtarget *Subtarget) {
  SDLoc DL(N);
  MVT VT = N.getSimpleValueType();
  SmallVector<int, 4> Mask;

  switch (N.getOpcode()) {
  case X86ISD::PSHUFD:
  case X86ISD::PSHUFLW:
  case X86ISD::PSHUFHW:
    Mask = getPSHUFShuffleMask(N);
    assert(Mask.size() == 4);
    break;
  default:
    return SDValue();
  }

  // Nuke no-op shuffles that show up after combining.
  if (isNoopShuffleMask(Mask))
    return DCI.CombineTo(N.getNode(), N.getOperand(0), /*AddTo*/ true);

  // Look for simplifications involving one or two shuffle instructions.
  SDValue V = N.getOperand(0);
  switch (N.getOpcode()) {
  default:
    break;
  case X86ISD::PSHUFLW:
  case X86ISD::PSHUFHW:
    assert(VT == MVT::v8i16);
    (void)VT;

    if (combineRedundantHalfShuffle(N, Mask, DAG, DCI))
      return SDValue(); // We combined away this shuffle, so we're done.

    // See if this reduces to a PSHUFD which is no more expensive and can
    // combine with more operations. Note that it has to at least flip the
    // dwords as otherwise it would have been removed as a no-op.
    if (Mask[0] == 2 && Mask[1] == 3 && Mask[2] == 0 && Mask[3] == 1) {
      int DMask[] = {0, 1, 2, 3};
      int DOffset = N.getOpcode() == X86ISD::PSHUFLW ? 0 : 2;
      DMask[DOffset + 0] = DOffset + 1;
      DMask[DOffset + 1] = DOffset + 0;
      V = DAG.getNode(ISD::BITCAST, DL, MVT::v4i32, V);
      DCI.AddToWorklist(V.getNode());
      V = DAG.getNode(X86ISD::PSHUFD, DL, MVT::v4i32, V,
                      getV4X86ShuffleImm8ForMask(DMask, DAG));
      DCI.AddToWorklist(V.getNode());
      return DAG.getNode(ISD::BITCAST, DL, MVT::v8i16, V);
    }

    // Look for shuffle patterns which can be implemented as a single unpack.
    // FIXME: This doesn't handle the location of the PSHUFD generically, and
    // only works when we have a PSHUFD followed by two half-shuffles.
    if (Mask[0] == Mask[1] && Mask[2] == Mask[3] &&
        (V.getOpcode() == X86ISD::PSHUFLW ||
         V.getOpcode() == X86ISD::PSHUFHW) &&
        V.getOpcode() != N.getOpcode() &&
        V.hasOneUse()) {
      SDValue D = V.getOperand(0);
      while (D.getOpcode() == ISD::BITCAST && D.hasOneUse())
        D = D.getOperand(0);
      if (D.getOpcode() == X86ISD::PSHUFD && D.hasOneUse()) {
        SmallVector<int, 4> VMask = getPSHUFShuffleMask(V);
        SmallVector<int, 4> DMask = getPSHUFShuffleMask(D);
        int NOffset = N.getOpcode() == X86ISD::PSHUFLW ? 0 : 4;
        int VOffset = V.getOpcode() == X86ISD::PSHUFLW ? 0 : 4;
        int WordMask[8];
        for (int i = 0; i < 4; ++i) {
          WordMask[i + NOffset] = Mask[i] + NOffset;
          WordMask[i + VOffset] = VMask[i] + VOffset;
        }
        // Map the word mask through the DWord mask.
        int MappedMask[8];
        for (int i = 0; i < 8; ++i)
          MappedMask[i] = 2 * DMask[WordMask[i] / 2] + WordMask[i] % 2;
        const int UnpackLoMask[] = {0, 0, 1, 1, 2, 2, 3, 3};
        const int UnpackHiMask[] = {4, 4, 5, 5, 6, 6, 7, 7};
        if (std::equal(std::begin(MappedMask), std::end(MappedMask),
                       std::begin(UnpackLoMask)) ||
            std::equal(std::begin(MappedMask), std::end(MappedMask),
                       std::begin(UnpackHiMask))) {
          // We can replace all three shuffles with an unpack.
          V = DAG.getNode(ISD::BITCAST, DL, MVT::v8i16, D.getOperand(0));
          DCI.AddToWorklist(V.getNode());
          return DAG.getNode(MappedMask[0] == 0 ? X86ISD::UNPCKL
                                                : X86ISD::UNPCKH,
                             DL, MVT::v8i16, V, V);
        }
      }
    }

    break;

  case X86ISD::PSHUFD:
    if (SDValue NewN = combineRedundantDWordShuffle(N, Mask, DAG, DCI))
      return NewN;

    break;
  }

  return SDValue();
}

/// \brief Try to combine a shuffle into a target-specific add-sub node.
///
/// We combine this directly on the abstract vector shuffle nodes so it is
/// easier to generically match. We also insert dummy vector shuffle nodes for
/// the operands which explicitly discard the lanes which are unused by this
/// operation to try to flow through the rest of the combiner the fact that
/// they're unused.
static SDValue combineShuffleToAddSub(SDNode *N, SelectionDAG &DAG) {
  SDLoc DL(N);
  EVT VT = N->getValueType(0);

  // We only handle target-independent shuffles.
  // FIXME: It would be easy and harmless to use the target shuffle mask
  // extraction tool to support more.
  if (N->getOpcode() != ISD::VECTOR_SHUFFLE)
    return SDValue();

  auto *SVN = cast<ShuffleVectorSDNode>(N);
  ArrayRef<int> Mask = SVN->getMask();
  SDValue V1 = N->getOperand(0);
  SDValue V2 = N->getOperand(1);

  // We require the first shuffle operand to be the SUB node, and the second to
  // be the ADD node.
  // FIXME: We should support the commuted patterns.
  if (V1->getOpcode() != ISD::FSUB || V2->getOpcode() != ISD::FADD)
    return SDValue();

  // If there are other uses of these operations we can't fold them.
  if (!V1->hasOneUse() || !V2->hasOneUse())
    return SDValue();

  // Ensure that both operations have the same operands. Note that we can
  // commute the FADD operands.
  SDValue LHS = V1->getOperand(0), RHS = V1->getOperand(1);
  if ((V2->getOperand(0) != LHS || V2->getOperand(1) != RHS) &&
      (V2->getOperand(0) != RHS || V2->getOperand(1) != LHS))
    return SDValue();

  // We're looking for blends between FADD and FSUB nodes. We insist on these
  // nodes being lined up in a specific expected pattern.
  if (!(isShuffleEquivalent(V1, V2, Mask, 0, 3) ||
        isShuffleEquivalent(V1, V2, Mask, 0, 5, 2, 7) ||
        isShuffleEquivalent(V1, V2, Mask, 0, 9, 2, 11, 4, 13, 6, 15)))
    return SDValue();

  // Only specific types are legal at this point, assert so we notice if and
  // when these change.
  assert((VT == MVT::v4f32 || VT == MVT::v2f64 || VT == MVT::v8f32 ||
          VT == MVT::v4f64) &&
         "Unknown vector type encountered!");

  return DAG.getNode(X86ISD::ADDSUB, DL, VT, LHS, RHS);
}

/// PerformShuffleCombine - Performs several different shuffle combines.
static SDValue PerformShuffleCombine(SDNode *N, SelectionDAG &DAG,
                                     TargetLowering::DAGCombinerInfo &DCI,
                                     const X86Subtarget *Subtarget) {
  SDLoc dl(N);
  SDValue N0 = N->getOperand(0);
  SDValue N1 = N->getOperand(1);
  EVT VT = N->getValueType(0);

  // Don't create instructions with illegal types after legalize types has run.
  const TargetLowering &TLI = DAG.getTargetLoweringInfo();
  if (!DCI.isBeforeLegalize() && !TLI.isTypeLegal(VT.getVectorElementType()))
    return SDValue();

  // If we have legalized the vector types, look for blends of FADD and FSUB
  // nodes that we can fuse into an ADDSUB node.
  if (TLI.isTypeLegal(VT) && Subtarget->hasSSE3())
    if (SDValue AddSub = combineShuffleToAddSub(N, DAG))
      return AddSub;

  // Combine 256-bit vector shuffles. This is only profitable when in AVX mode
  if (Subtarget->hasFp256() && VT.is256BitVector() &&
      N->getOpcode() == ISD::VECTOR_SHUFFLE)
    return PerformShuffleCombine256(N, DAG, DCI, Subtarget);

  // During Type Legalization, when promoting illegal vector types,
  // the backend might introduce new shuffle dag nodes and bitcasts.
  //
  // This code performs the following transformation:
  // fold: (shuffle (bitcast (BINOP A, B)), Undef, <Mask>) ->
  //       (shuffle (BINOP (bitcast A), (bitcast B)), Undef, <Mask>)
  //
  // We do this only if both the bitcast and the BINOP dag nodes have
  // one use. Also, perform this transformation only if the new binary
  // operation is legal. This is to avoid introducing dag nodes that
  // potentially need to be further expanded (or custom lowered) into a
  // less optimal sequence of dag nodes.
  if (!DCI.isBeforeLegalize() && DCI.isBeforeLegalizeOps() &&
      N1.getOpcode() == ISD::UNDEF && N0.hasOneUse() &&
      N0.getOpcode() == ISD::BITCAST) {
    SDValue BC0 = N0.getOperand(0);
    EVT SVT = BC0.getValueType();
    unsigned Opcode = BC0.getOpcode();
    unsigned NumElts = VT.getVectorNumElements();

    if (BC0.hasOneUse() && SVT.isVector() &&
        SVT.getVectorNumElements() * 2 == NumElts &&
        TLI.isOperationLegal(Opcode, VT)) {
      bool CanFold = false;
      switch (Opcode) {
      default : break;
      case ISD::ADD :
      case ISD::FADD :
      case ISD::SUB :
      case ISD::FSUB :
      case ISD::MUL :
      case ISD::FMUL :
        CanFold = true;
      }

      unsigned SVTNumElts = SVT.getVectorNumElements();
      ShuffleVectorSDNode *SVOp = cast<ShuffleVectorSDNode>(N);
      for (unsigned i = 0, e = SVTNumElts; i != e && CanFold; ++i)
        CanFold = SVOp->getMaskElt(i) == (int)(i * 2);
      for (unsigned i = SVTNumElts, e = NumElts; i != e && CanFold; ++i)
        CanFold = SVOp->getMaskElt(i) < 0;

      if (CanFold) {
        SDValue BC00 = DAG.getNode(ISD::BITCAST, dl, VT, BC0.getOperand(0));
        SDValue BC01 = DAG.getNode(ISD::BITCAST, dl, VT, BC0.getOperand(1));
        SDValue NewBinOp = DAG.getNode(BC0.getOpcode(), dl, VT, BC00, BC01);
        return DAG.getVectorShuffle(VT, dl, NewBinOp, N1, &SVOp->getMask()[0]);
      }
    }
  }

  // Only handle 128 wide vector from here on.
  if (!VT.is128BitVector())
    return SDValue();

  // Combine a vector_shuffle that is equal to build_vector load1, load2, load3,
  // load4, <0, 1, 2, 3> into a 128-bit load if the load addresses are
  // consecutive, non-overlapping, and in the right order.
  SmallVector<SDValue, 16> Elts;
  for (unsigned i = 0, e = VT.getVectorNumElements(); i != e; ++i)
    Elts.push_back(getShuffleScalarElt(N, i, DAG, 0));

  SDValue LD = EltsFromConsecutiveLoads(VT, Elts, dl, DAG, true);
  if (LD.getNode())
    return LD;

  if (isTargetShuffle(N->getOpcode())) {
    SDValue Shuffle =
        PerformTargetShuffleCombine(SDValue(N, 0), DAG, DCI, Subtarget);
    if (Shuffle.getNode())
      return Shuffle;

    // Try recursively combining arbitrary sequences of x86 shuffle
    // instructions into higher-order shuffles. We do this after combining
    // specific PSHUF instruction sequences into their minimal form so that we
    // can evaluate how many specialized shuffle instructions are involved in
    // a particular chain.
    SmallVector<int, 1> NonceMask; // Just a placeholder.
    NonceMask.push_back(0);
    if (combineX86ShufflesRecursively(SDValue(N, 0), SDValue(N, 0), NonceMask,
                                      /*Depth*/ 1, /*HasPSHUFB*/ false, DAG,
                                      DCI, Subtarget))
      return SDValue(); // This routine will use CombineTo to replace N.
  }

  return SDValue();
}

/// PerformTruncateCombine - Converts truncate operation to
/// a sequence of vector shuffle operations.
/// It is possible when we truncate 256-bit vector to 128-bit vector
static SDValue PerformTruncateCombine(SDNode *N, SelectionDAG &DAG,
                                      TargetLowering::DAGCombinerInfo &DCI,
                                      const X86Subtarget *Subtarget)  {
  return SDValue();
}

/// XFormVExtractWithShuffleIntoLoad - Check if a vector extract from a target
/// specific shuffle of a load can be folded into a single element load.
/// Similar handling for VECTOR_SHUFFLE is performed by DAGCombiner, but
/// shuffles have been custom lowered so we need to handle those here.
static SDValue XFormVExtractWithShuffleIntoLoad(SDNode *N, SelectionDAG &DAG,
                                         TargetLowering::DAGCombinerInfo &DCI) {
  if (DCI.isBeforeLegalizeOps())
    return SDValue();

  SDValue InVec = N->getOperand(0);
  SDValue EltNo = N->getOperand(1);

  if (!isa<ConstantSDNode>(EltNo))
    return SDValue();

  EVT OriginalVT = InVec.getValueType();

  if (InVec.getOpcode() == ISD::BITCAST) {
    // Don't duplicate a load with other uses.
    if (!InVec.hasOneUse())
      return SDValue();
    EVT BCVT = InVec.getOperand(0).getValueType();
    if (BCVT.getVectorNumElements() != OriginalVT.getVectorNumElements())
      return SDValue();
    InVec = InVec.getOperand(0);
  }

  EVT CurrentVT = InVec.getValueType();

  if (!isTargetShuffle(InVec.getOpcode()))
    return SDValue();

  // Don't duplicate a load with other uses.
  if (!InVec.hasOneUse())
    return SDValue();

  SmallVector<int, 16> ShuffleMask;
  bool UnaryShuffle;
  if (!getTargetShuffleMask(InVec.getNode(), CurrentVT.getSimpleVT(),
                            ShuffleMask, UnaryShuffle))
    return SDValue();

  // Select the input vector, guarding against out of range extract vector.
  unsigned NumElems = CurrentVT.getVectorNumElements();
  int Elt = cast<ConstantSDNode>(EltNo)->getZExtValue();
  int Idx = (Elt > (int)NumElems) ? -1 : ShuffleMask[Elt];
  SDValue LdNode = (Idx < (int)NumElems) ? InVec.getOperand(0)
                                         : InVec.getOperand(1);

  // If inputs to shuffle are the same for both ops, then allow 2 uses
  unsigned AllowedUses = InVec.getNumOperands() > 1 &&
                         InVec.getOperand(0) == InVec.getOperand(1) ? 2 : 1;

  if (LdNode.getOpcode() == ISD::BITCAST) {
    // Don't duplicate a load with other uses.
    if (!LdNode.getNode()->hasNUsesOfValue(AllowedUses, 0))
      return SDValue();

    AllowedUses = 1; // only allow 1 load use if we have a bitcast
    LdNode = LdNode.getOperand(0);
  }

  if (!ISD::isNormalLoad(LdNode.getNode()))
    return SDValue();

  LoadSDNode *LN0 = cast<LoadSDNode>(LdNode);

  if (!LN0 ||!LN0->hasNUsesOfValue(AllowedUses, 0) || LN0->isVolatile())
    return SDValue();

  EVT EltVT = N->getValueType(0);
  // If there's a bitcast before the shuffle, check if the load type and
  // alignment is valid.
  unsigned Align = LN0->getAlignment();
  const TargetLowering &TLI = DAG.getTargetLoweringInfo();
  unsigned NewAlign = TLI.getDataLayout()->getABITypeAlignment(
      EltVT.getTypeForEVT(*DAG.getContext()));

  if (NewAlign > Align || !TLI.isOperationLegalOrCustom(ISD::LOAD, EltVT))
    return SDValue();

  // All checks match so transform back to vector_shuffle so that DAG combiner
  // can finish the job
  SDLoc dl(N);

  // Create shuffle node taking into account the case that its a unary shuffle
  SDValue Shuffle = (UnaryShuffle) ? DAG.getUNDEF(CurrentVT)
                                   : InVec.getOperand(1);
  Shuffle = DAG.getVectorShuffle(CurrentVT, dl,
                                 InVec.getOperand(0), Shuffle,
                                 &ShuffleMask[0]);
  Shuffle = DAG.getNode(ISD::BITCAST, dl, OriginalVT, Shuffle);
  return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, N->getValueType(0), Shuffle,
                     EltNo);
}

/// \brief Detect bitcasts between i32 to x86mmx low word. Since MMX types are
/// special and don't usually play with other vector types, it's better to
/// handle them early to be sure we emit efficient code by avoiding
/// store-load conversions.
static SDValue PerformBITCASTCombine(SDNode *N, SelectionDAG &DAG) {
  if (N->getValueType(0) != MVT::x86mmx ||
      N->getOperand(0)->getOpcode() != ISD::BUILD_VECTOR ||
      N->getOperand(0)->getValueType(0) != MVT::v2i32)
    return SDValue();

  SDValue V = N->getOperand(0);
  ConstantSDNode *C = dyn_cast<ConstantSDNode>(V.getOperand(1));
  if (C && C->getZExtValue() == 0 && V.getOperand(0).getValueType() == MVT::i32)
    return DAG.getNode(X86ISD::MMX_MOVW2D, SDLoc(V.getOperand(0)),
                       N->getValueType(0), V.getOperand(0));

  return SDValue();
}

/// PerformEXTRACT_VECTOR_ELTCombine - Detect vector gather/scatter index
/// generation and convert it from being a bunch of shuffles and extracts
/// into a somewhat faster sequence. For i686, the best sequence is apparently
/// storing the value and loading scalars back, while for x64 we should
/// use 64-bit extracts and shifts.
static SDValue PerformEXTRACT_VECTOR_ELTCombine(SDNode *N, SelectionDAG &DAG,
                                         TargetLowering::DAGCombinerInfo &DCI) {
  SDValue NewOp = XFormVExtractWithShuffleIntoLoad(N, DAG, DCI);
  if (NewOp.getNode())
    return NewOp;

  SDValue InputVector = N->getOperand(0);

  // Detect mmx to i32 conversion through a v2i32 elt extract.
  if (InputVector.getOpcode() == ISD::BITCAST && InputVector.hasOneUse() &&
      N->getValueType(0) == MVT::i32 &&
      InputVector.getValueType() == MVT::v2i32) {

    // The bitcast source is a direct mmx result.
    SDValue MMXSrc = InputVector.getNode()->getOperand(0);
    if (MMXSrc.getValueType() == MVT::x86mmx)
      return DAG.getNode(X86ISD::MMX_MOVD2W, SDLoc(InputVector),
                         N->getValueType(0),
                         InputVector.getNode()->getOperand(0));

    // The mmx is indirect: (i64 extract_elt (v1i64 bitcast (x86mmx ...))).
    SDValue MMXSrcOp = MMXSrc.getOperand(0);
    if (MMXSrc.getOpcode() == ISD::EXTRACT_VECTOR_ELT && MMXSrc.hasOneUse() &&
        MMXSrc.getValueType() == MVT::i64 && MMXSrcOp.hasOneUse() &&
        MMXSrcOp.getOpcode() == ISD::BITCAST &&
        MMXSrcOp.getValueType() == MVT::v1i64 &&
        MMXSrcOp.getOperand(0).getValueType() == MVT::x86mmx)
      return DAG.getNode(X86ISD::MMX_MOVD2W, SDLoc(InputVector),
                         N->getValueType(0),
                         MMXSrcOp.getOperand(0));
  }

  // Only operate on vectors of 4 elements, where the alternative shuffling
  // gets to be more expensive.
  if (InputVector.getValueType() != MVT::v4i32)
    return SDValue();

  // Check whether every use of InputVector is an EXTRACT_VECTOR_ELT with a
  // single use which is a sign-extend or zero-extend, and all elements are
  // used.
  SmallVector<SDNode *, 4> Uses;
  unsigned ExtractedElements = 0;
  for (SDNode::use_iterator UI = InputVector.getNode()->use_begin(),
       UE = InputVector.getNode()->use_end(); UI != UE; ++UI) {
    if (UI.getUse().getResNo() != InputVector.getResNo())
      return SDValue();

    SDNode *Extract = *UI;
    if (Extract->getOpcode() != ISD::EXTRACT_VECTOR_ELT)
      return SDValue();

    if (Extract->getValueType(0) != MVT::i32)
      return SDValue();
    if (!Extract->hasOneUse())
      return SDValue();
    if (Extract->use_begin()->getOpcode() != ISD::SIGN_EXTEND &&
        Extract->use_begin()->getOpcode() != ISD::ZERO_EXTEND)
      return SDValue();
    if (!isa<ConstantSDNode>(Extract->getOperand(1)))
      return SDValue();

    // Record which element was extracted.
    ExtractedElements |=
      1 << cast<ConstantSDNode>(Extract->getOperand(1))->getZExtValue();

    Uses.push_back(Extract);
  }

  // If not all the elements were used, this may not be worthwhile.
  if (ExtractedElements != 15)
    return SDValue();

  // Ok, we've now decided to do the transformation.
  // If 64-bit shifts are legal, use the extract-shift sequence,
  // otherwise bounce the vector off the cache.
  const TargetLowering &TLI = DAG.getTargetLoweringInfo();
  SDValue Vals[4];
  SDLoc dl(InputVector);

  if (TLI.isOperationLegal(ISD::SRA, MVT::i64)) {
    SDValue Cst = DAG.getNode(ISD::BITCAST, dl, MVT::v2i64, InputVector);
    EVT VecIdxTy = DAG.getTargetLoweringInfo().getVectorIdxTy();
    SDValue BottomHalf = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, MVT::i64, Cst,
      DAG.getConstant(0, VecIdxTy));
    SDValue TopHalf = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, MVT::i64, Cst,
      DAG.getConstant(1, VecIdxTy));

    SDValue ShAmt = DAG.getConstant(32,
      DAG.getTargetLoweringInfo().getShiftAmountTy(MVT::i64));
    Vals[0] = DAG.getNode(ISD::TRUNCATE, dl, MVT::i32, BottomHalf);
    Vals[1] = DAG.getNode(ISD::TRUNCATE, dl, MVT::i32,
      DAG.getNode(ISD::SRA, dl, MVT::i64, BottomHalf, ShAmt));
    Vals[2] = DAG.getNode(ISD::TRUNCATE, dl, MVT::i32, TopHalf);
    Vals[3] = DAG.getNode(ISD::TRUNCATE, dl, MVT::i32,
      DAG.getNode(ISD::SRA, dl, MVT::i64, TopHalf, ShAmt));
  } else {
    // Store the value to a temporary stack slot.
    SDValue StackPtr = DAG.CreateStackTemporary(InputVector.getValueType());
    SDValue Ch = DAG.getStore(DAG.getEntryNode(), dl, InputVector, StackPtr,
      MachinePointerInfo(), false, false, 0);

    EVT ElementType = InputVector.getValueType().getVectorElementType();
    unsigned EltSize = ElementType.getSizeInBits() / 8;

    // Replace each use (extract) with a load of the appropriate element.
    for (unsigned i = 0; i < 4; ++i) {
      uint64_t Offset = EltSize * i;
      SDValue OffsetVal = DAG.getConstant(Offset, TLI.getPointerTy());

      SDValue ScalarAddr = DAG.getNode(ISD::ADD, dl, TLI.getPointerTy(),
                                       StackPtr, OffsetVal);

      // Load the scalar.
      Vals[i] = DAG.getLoad(ElementType, dl, Ch,
                            ScalarAddr, MachinePointerInfo(),
                            false, false, false, 0);

    }
  }

  // Replace the extracts
  for (SmallVectorImpl<SDNode *>::iterator UI = Uses.begin(),
    UE = Uses.end(); UI != UE; ++UI) {
    SDNode *Extract = *UI;

    SDValue Idx = Extract->getOperand(1);
    uint64_t IdxVal = cast<ConstantSDNode>(Idx)->getZExtValue();
    DAG.ReplaceAllUsesOfValueWith(SDValue(Extract, 0), Vals[IdxVal]);
  }

  // The replacement was made in place; don't return anything.
  return SDValue();
}

/// \brief Matches a VSELECT onto min/max or return 0 if the node doesn't match.
static std::pair<unsigned, bool>
matchIntegerMINMAX(SDValue Cond, EVT VT, SDValue LHS, SDValue RHS,
                   SelectionDAG &DAG, const X86Subtarget *Subtarget) {
  if (!VT.isVector())
    return std::make_pair(0, false);

  bool NeedSplit = false;
  switch (VT.getSimpleVT().SimpleTy) {
  default: return std::make_pair(0, false);
  case MVT::v4i64:
  case MVT::v2i64:
    if (!Subtarget->hasVLX())
      return std::make_pair(0, false);
    break;
  case MVT::v64i8:
  case MVT::v32i16:
    if (!Subtarget->hasBWI())
      return std::make_pair(0, false);
    break;
  case MVT::v16i32:
  case MVT::v8i64:
    if (!Subtarget->hasAVX512())
      return std::make_pair(0, false);
    break;
  case MVT::v32i8:
  case MVT::v16i16:
  case MVT::v8i32:
    if (!Subtarget->hasAVX2())
      NeedSplit = true;
    if (!Subtarget->hasAVX())
      return std::make_pair(0, false);
    break;
  case MVT::v16i8:
  case MVT::v8i16:
  case MVT::v4i32:
    if (!Subtarget->hasSSE2())
      return std::make_pair(0, false);
  }

  // SSE2 has only a small subset of the operations.
  bool hasUnsigned = Subtarget->hasSSE41() ||
                     (Subtarget->hasSSE2() && VT == MVT::v16i8);
  bool hasSigned = Subtarget->hasSSE41() ||
                   (Subtarget->hasSSE2() && VT == MVT::v8i16);

  ISD::CondCode CC = cast<CondCodeSDNode>(Cond.getOperand(2))->get();

  unsigned Opc = 0;
  // Check for x CC y ? x : y.
  if (DAG.isEqualTo(LHS, Cond.getOperand(0)) &&
      DAG.isEqualTo(RHS, Cond.getOperand(1))) {
    switch (CC) {
    default: break;
    case ISD::SETULT:
    case ISD::SETULE:
      Opc = hasUnsigned ? X86ISD::UMIN : 0; break;
    case ISD::SETUGT:
    case ISD::SETUGE:
      Opc = hasUnsigned ? X86ISD::UMAX : 0; break;
    case ISD::SETLT:
    case ISD::SETLE:
      Opc = hasSigned ? X86ISD::SMIN : 0; break;
    case ISD::SETGT:
    case ISD::SETGE:
      Opc = hasSigned ? X86ISD::SMAX : 0; break;
    }
  // Check for x CC y ? y : x -- a min/max with reversed arms.
  } else if (DAG.isEqualTo(LHS, Cond.getOperand(1)) &&
             DAG.isEqualTo(RHS, Cond.getOperand(0))) {
    switch (CC) {
    default: break;
    case ISD::SETULT:
    case ISD::SETULE:
      Opc = hasUnsigned ? X86ISD::UMAX : 0; break;
    case ISD::SETUGT:
    case ISD::SETUGE:
      Opc = hasUnsigned ? X86ISD::UMIN : 0; break;
    case ISD::SETLT:
    case ISD::SETLE:
      Opc = hasSigned ? X86ISD::SMAX : 0; break;
    case ISD::SETGT:
    case ISD::SETGE:
      Opc = hasSigned ? X86ISD::SMIN : 0; break;
    }
  }

  return std::make_pair(Opc, NeedSplit);
}

static SDValue
transformVSELECTtoBlendVECTOR_SHUFFLE(SDNode *N, SelectionDAG &DAG,
                                      const X86Subtarget *Subtarget) {
  SDLoc dl(N);
  SDValue Cond = N->getOperand(0);
  SDValue LHS = N->getOperand(1);
  SDValue RHS = N->getOperand(2);

  if (Cond.getOpcode() == ISD::SIGN_EXTEND) {
    SDValue CondSrc = Cond->getOperand(0);
    if (CondSrc->getOpcode() == ISD::SIGN_EXTEND_INREG)
      Cond = CondSrc->getOperand(0);
  }

  if (!ISD::isBuildVectorOfConstantSDNodes(Cond.getNode()))
    return SDValue();

  // A vselect where all conditions and data are constants can be optimized into
  // a single vector load by SelectionDAGLegalize::ExpandBUILD_VECTOR().
  if (ISD::isBuildVectorOfConstantSDNodes(LHS.getNode()) &&
      ISD::isBuildVectorOfConstantSDNodes(RHS.getNode()))
    return SDValue();

  unsigned MaskValue = 0;
  if (!BUILD_VECTORtoBlendMask(cast<BuildVectorSDNode>(Cond), MaskValue))
    return SDValue();

  MVT VT = N->getSimpleValueType(0);
  unsigned NumElems = VT.getVectorNumElements();
  SmallVector<int, 8> ShuffleMask(NumElems, -1);
  for (unsigned i = 0; i < NumElems; ++i) {
    // Be sure we emit undef where we can.
    if (Cond.getOperand(i)->getOpcode() == ISD::UNDEF)
      ShuffleMask[i] = -1;
    else
      ShuffleMask[i] = i + NumElems * ((MaskValue >> i) & 1);
  }

  const TargetLowering &TLI = DAG.getTargetLoweringInfo();
  if (!TLI.isShuffleMaskLegal(ShuffleMask, VT))
    return SDValue();
  return DAG.getVectorShuffle(VT, dl, LHS, RHS, &ShuffleMask[0]);
}

/// PerformSELECTCombine - Do target-specific dag combines on SELECT and VSELECT
/// nodes.
static SDValue PerformSELECTCombine(SDNode *N, SelectionDAG &DAG,
                                    TargetLowering::DAGCombinerInfo &DCI,
                                    const X86Subtarget *Subtarget) {
  SDLoc DL(N);
  SDValue Cond = N->getOperand(0);
  // Get the LHS/RHS of the select.
  SDValue LHS = N->getOperand(1);
  SDValue RHS = N->getOperand(2);
  EVT VT = LHS.getValueType();
  const TargetLowering &TLI = DAG.getTargetLoweringInfo();

  // If we have SSE[12] support, try to form min/max nodes. SSE min/max
  // instructions match the semantics of the common C idiom x<y?x:y but not
  // x<=y?x:y, because of how they handle negative zero (which can be
  // ignored in unsafe-math mode).
  // We also try to create v2f32 min/max nodes, which we later widen to v4f32.
  if (Cond.getOpcode() == ISD::SETCC && VT.isFloatingPoint() &&
      VT != MVT::f80 && (TLI.isTypeLegal(VT) || VT == MVT::v2f32) &&
      (Subtarget->hasSSE2() ||
       (Subtarget->hasSSE1() && VT.getScalarType() == MVT::f32))) {
    ISD::CondCode CC = cast<CondCodeSDNode>(Cond.getOperand(2))->get();

    unsigned Opcode = 0;
    // Check for x CC y ? x : y.
    if (DAG.isEqualTo(LHS, Cond.getOperand(0)) &&
        DAG.isEqualTo(RHS, Cond.getOperand(1))) {
      switch (CC) {
      default: break;
      case ISD::SETULT:
        // Converting this to a min would handle NaNs incorrectly, and swapping
        // the operands would cause it to handle comparisons between positive
        // and negative zero incorrectly.
        if (!DAG.isKnownNeverNaN(LHS) || !DAG.isKnownNeverNaN(RHS)) {
          if (!DAG.getTarget().Options.UnsafeFPMath &&
              !(DAG.isKnownNeverZero(LHS) || DAG.isKnownNeverZero(RHS)))
            break;
          std::swap(LHS, RHS);
        }
        Opcode = X86ISD::FMIN;
        break;
      case ISD::SETOLE:
        // Converting this to a min would handle comparisons between positive
        // and negative zero incorrectly.
        if (!DAG.getTarget().Options.UnsafeFPMath &&
            !DAG.isKnownNeverZero(LHS) && !DAG.isKnownNeverZero(RHS))
          break;
        Opcode = X86ISD::FMIN;
        break;
      case ISD::SETULE:
        // Converting this to a min would handle both negative zeros and NaNs
        // incorrectly, but we can swap the operands to fix both.
        std::swap(LHS, RHS);
      case ISD::SETOLT:
      case ISD::SETLT:
      case ISD::SETLE:
        Opcode = X86ISD::FMIN;
        break;

      case ISD::SETOGE:
        // Converting this to a max would handle comparisons between positive
        // and negative zero incorrectly.
        if (!DAG.getTarget().Options.UnsafeFPMath &&
            !DAG.isKnownNeverZero(LHS) && !DAG.isKnownNeverZero(RHS))
          break;
        Opcode = X86ISD::FMAX;
        break;
      case ISD::SETUGT:
        // Converting this to a max would handle NaNs incorrectly, and swapping
        // the operands would cause it to handle comparisons between positive
        // and negative zero incorrectly.
        if (!DAG.isKnownNeverNaN(LHS) || !DAG.isKnownNeverNaN(RHS)) {
          if (!DAG.getTarget().Options.UnsafeFPMath &&
              !(DAG.isKnownNeverZero(LHS) || DAG.isKnownNeverZero(RHS)))
            break;
          std::swap(LHS, RHS);
        }
        Opcode = X86ISD::FMAX;
        break;
      case ISD::SETUGE:
        // Converting this to a max would handle both negative zeros and NaNs
        // incorrectly, but we can swap the operands to fix both.
        std::swap(LHS, RHS);
      case ISD::SETOGT:
      case ISD::SETGT:
      case ISD::SETGE:
        Opcode = X86ISD::FMAX;
        break;
      }
    // Check for x CC y ? y : x -- a min/max with reversed arms.
    } else if (DAG.isEqualTo(LHS, Cond.getOperand(1)) &&
               DAG.isEqualTo(RHS, Cond.getOperand(0))) {
      switch (CC) {
      default: break;
      case ISD::SETOGE:
        // Converting this to a min would handle comparisons between positive
        // and negative zero incorrectly, and swapping the operands would
        // cause it to handle NaNs incorrectly.
        if (!DAG.getTarget().Options.UnsafeFPMath &&
            !(DAG.isKnownNeverZero(LHS) || DAG.isKnownNeverZero(RHS))) {
          if (!DAG.isKnownNeverNaN(LHS) || !DAG.isKnownNeverNaN(RHS))
            break;
          std::swap(LHS, RHS);
        }
        Opcode = X86ISD::FMIN;
        break;
      case ISD::SETUGT:
        // Converting this to a min would handle NaNs incorrectly.
        if (!DAG.getTarget().Options.UnsafeFPMath &&
            (!DAG.isKnownNeverNaN(LHS) || !DAG.isKnownNeverNaN(RHS)))
          break;
        Opcode = X86ISD::FMIN;
        break;
      case ISD::SETUGE:
        // Converting this to a min would handle both negative zeros and NaNs
        // incorrectly, but we can swap the operands to fix both.
        std::swap(LHS, RHS);
      case ISD::SETOGT:
      case ISD::SETGT:
      case ISD::SETGE:
        Opcode = X86ISD::FMIN;
        break;

      case ISD::SETULT:
        // Converting this to a max would handle NaNs incorrectly.
        if (!DAG.isKnownNeverNaN(LHS) || !DAG.isKnownNeverNaN(RHS))
          break;
        Opcode = X86ISD::FMAX;
        break;
      case ISD::SETOLE:
        // Converting this to a max would handle comparisons between positive
        // and negative zero incorrectly, and swapping the operands would
        // cause it to handle NaNs incorrectly.
        if (!DAG.getTarget().Options.UnsafeFPMath &&
            !DAG.isKnownNeverZero(LHS) && !DAG.isKnownNeverZero(RHS)) {
          if (!DAG.isKnownNeverNaN(LHS) || !DAG.isKnownNeverNaN(RHS))
            break;
          std::swap(LHS, RHS);
        }
        Opcode = X86ISD::FMAX;
        break;
      case ISD::SETULE:
        // Converting this to a max would handle both negative zeros and NaNs
        // incorrectly, but we can swap the operands to fix both.
        std::swap(LHS, RHS);
      case ISD::SETOLT:
      case ISD::SETLT:
      case ISD::SETLE:
        Opcode = X86ISD::FMAX;
        break;
      }
    }

    if (Opcode)
      return DAG.getNode(Opcode, DL, N->getValueType(0), LHS, RHS);
  }

  EVT CondVT = Cond.getValueType();
  if (Subtarget->hasAVX512() && VT.isVector() && CondVT.isVector() &&
      CondVT.getVectorElementType() == MVT::i1) {
    // v16i8 (select v16i1, v16i8, v16i8) does not have a proper
    // lowering on KNL. In this case we convert it to
    // v16i8 (select v16i8, v16i8, v16i8) and use AVX instruction.
    // The same situation for all 128 and 256-bit vectors of i8 and i16.
    // Since SKX these selects have a proper lowering.
    EVT OpVT = LHS.getValueType();
    if ((OpVT.is128BitVector() || OpVT.is256BitVector()) &&
        (OpVT.getVectorElementType() == MVT::i8 ||
         OpVT.getVectorElementType() == MVT::i16) &&
        !(Subtarget->hasBWI() && Subtarget->hasVLX())) {
      Cond = DAG.getNode(ISD::SIGN_EXTEND, DL, OpVT, Cond);
      DCI.AddToWorklist(Cond.getNode());
      return DAG.getNode(N->getOpcode(), DL, OpVT, Cond, LHS, RHS);
    }
  }
  // If this is a select between two integer constants, try to do some
  // optimizations.
  if (ConstantSDNode *TrueC = dyn_cast<ConstantSDNode>(LHS)) {
    if (ConstantSDNode *FalseC = dyn_cast<ConstantSDNode>(RHS))
      // Don't do this for crazy integer types.
      if (DAG.getTargetLoweringInfo().isTypeLegal(LHS.getValueType())) {
        // If this is efficiently invertible, canonicalize the LHSC/RHSC values
        // so that TrueC (the true value) is larger than FalseC.
        bool NeedsCondInvert = false;

        if (TrueC->getAPIntValue().ult(FalseC->getAPIntValue()) &&
            // Efficiently invertible.
            (Cond.getOpcode() == ISD::SETCC ||  // setcc -> invertible.
             (Cond.getOpcode() == ISD::XOR &&   // xor(X, C) -> invertible.
              isa<ConstantSDNode>(Cond.getOperand(1))))) {
          NeedsCondInvert = true;
          std::swap(TrueC, FalseC);
        }

        // Optimize C ? 8 : 0 -> zext(C) << 3.  Likewise for any pow2/0.
        if (FalseC->getAPIntValue() == 0 &&
            TrueC->getAPIntValue().isPowerOf2()) {
          if (NeedsCondInvert) // Invert the condition if needed.
            Cond = DAG.getNode(ISD::XOR, DL, Cond.getValueType(), Cond,
                               DAG.getConstant(1, Cond.getValueType()));

          // Zero extend the condition if needed.
          Cond = DAG.getNode(ISD::ZERO_EXTEND, DL, LHS.getValueType(), Cond);

          unsigned ShAmt = TrueC->getAPIntValue().logBase2();
          return DAG.getNode(ISD::SHL, DL, LHS.getValueType(), Cond,
                             DAG.getConstant(ShAmt, MVT::i8));
        }

        // Optimize Cond ? cst+1 : cst -> zext(setcc(C)+cst.
        if (FalseC->getAPIntValue()+1 == TrueC->getAPIntValue()) {
          if (NeedsCondInvert) // Invert the condition if needed.
            Cond = DAG.getNode(ISD::XOR, DL, Cond.getValueType(), Cond,
                               DAG.getConstant(1, Cond.getValueType()));

          // Zero extend the condition if needed.
          Cond = DAG.getNode(ISD::ZERO_EXTEND, DL,
                             FalseC->getValueType(0), Cond);
          return DAG.getNode(ISD::ADD, DL, Cond.getValueType(), Cond,
                             SDValue(FalseC, 0));
        }

        // Optimize cases that will turn into an LEA instruction.  This requires
        // an i32 or i64 and an efficient multiplier (1, 2, 3, 4, 5, 8, 9).
        if (N->getValueType(0) == MVT::i32 || N->getValueType(0) == MVT::i64) {
          uint64_t Diff = TrueC->getZExtValue()-FalseC->getZExtValue();
          if (N->getValueType(0) == MVT::i32) Diff = (unsigned)Diff;

          bool isFastMultiplier = false;
          if (Diff < 10) {
            switch ((unsigned char)Diff) {
              default: break;
              case 1:  // result = add base, cond
              case 2:  // result = lea base(    , cond*2)
              case 3:  // result = lea base(cond, cond*2)
              case 4:  // result = lea base(    , cond*4)
              case 5:  // result = lea base(cond, cond*4)
              case 8:  // result = lea base(    , cond*8)
              case 9:  // result = lea base(cond, cond*8)
                isFastMultiplier = true;
                break;
            }
          }

          if (isFastMultiplier) {
            APInt Diff = TrueC->getAPIntValue()-FalseC->getAPIntValue();
            if (NeedsCondInvert) // Invert the condition if needed.
              Cond = DAG.getNode(ISD::XOR, DL, Cond.getValueType(), Cond,
                                 DAG.getConstant(1, Cond.getValueType()));

            // Zero extend the condition if needed.
            Cond = DAG.getNode(ISD::ZERO_EXTEND, DL, FalseC->getValueType(0),
                               Cond);
            // Scale the condition by the difference.
            if (Diff != 1)
              Cond = DAG.getNode(ISD::MUL, DL, Cond.getValueType(), Cond,
                                 DAG.getConstant(Diff, Cond.getValueType()));

            // Add the base if non-zero.
            if (FalseC->getAPIntValue() != 0)
              Cond = DAG.getNode(ISD::ADD, DL, Cond.getValueType(), Cond,
                                 SDValue(FalseC, 0));
            return Cond;
          }
        }
      }
  }

  // Canonicalize max and min:
  // (x > y) ? x : y -> (x >= y) ? x : y
  // (x < y) ? x : y -> (x <= y) ? x : y
  // This allows use of COND_S / COND_NS (see TranslateX86CC) which eliminates
  // the need for an extra compare
  // against zero. e.g.
  // (x - y) > 0 : (x - y) ? 0 -> (x - y) >= 0 : (x - y) ? 0
  // subl   %esi, %edi
  // testl  %edi, %edi
  // movl   $0, %eax
  // cmovgl %edi, %eax
  // =>
  // xorl   %eax, %eax
  // subl   %esi, $edi
  // cmovsl %eax, %edi
  if (N->getOpcode() == ISD::SELECT && Cond.getOpcode() == ISD::SETCC &&
      DAG.isEqualTo(LHS, Cond.getOperand(0)) &&
      DAG.isEqualTo(RHS, Cond.getOperand(1))) {
    ISD::CondCode CC = cast<CondCodeSDNode>(Cond.getOperand(2))->get();
    switch (CC) {
    default: break;
    case ISD::SETLT:
    case ISD::SETGT: {
      ISD::CondCode NewCC = (CC == ISD::SETLT) ? ISD::SETLE : ISD::SETGE;
      Cond = DAG.getSetCC(SDLoc(Cond), Cond.getValueType(),
                          Cond.getOperand(0), Cond.getOperand(1), NewCC);
      return DAG.getNode(ISD::SELECT, DL, VT, Cond, LHS, RHS);
    }
    }
  }

  // Early exit check
  if (!TLI.isTypeLegal(VT))
    return SDValue();

  // Match VSELECTs into subs with unsigned saturation.
  if (N->getOpcode() == ISD::VSELECT && Cond.getOpcode() == ISD::SETCC &&
      // psubus is available in SSE2 and AVX2 for i8 and i16 vectors.
      ((Subtarget->hasSSE2() && (VT == MVT::v16i8 || VT == MVT::v8i16)) ||
       (Subtarget->hasAVX2() && (VT == MVT::v32i8 || VT == MVT::v16i16)))) {
    ISD::CondCode CC = cast<CondCodeSDNode>(Cond.getOperand(2))->get();

    // Check if one of the arms of the VSELECT is a zero vector. If it's on the
    // left side invert the predicate to simplify logic below.
    SDValue Other;
    if (ISD::isBuildVectorAllZeros(LHS.getNode())) {
      Other = RHS;
      CC = ISD::getSetCCInverse(CC, true);
    } else if (ISD::isBuildVectorAllZeros(RHS.getNode())) {
      Other = LHS;
    }

    if (Other.getNode() && Other->getNumOperands() == 2 &&
        DAG.isEqualTo(Other->getOperand(0), Cond.getOperand(0))) {
      SDValue OpLHS = Other->getOperand(0), OpRHS = Other->getOperand(1);
      SDValue CondRHS = Cond->getOperand(1);

      // Look for a general sub with unsigned saturation first.
      // x >= y ? x-y : 0 --> subus x, y
      // x >  y ? x-y : 0 --> subus x, y
      if ((CC == ISD::SETUGE || CC == ISD::SETUGT) &&
          Other->getOpcode() == ISD::SUB && DAG.isEqualTo(OpRHS, CondRHS))
        return DAG.getNode(X86ISD::SUBUS, DL, VT, OpLHS, OpRHS);

      if (auto *OpRHSBV = dyn_cast<BuildVectorSDNode>(OpRHS))
        if (auto *OpRHSConst = OpRHSBV->getConstantSplatNode()) {
          if (auto *CondRHSBV = dyn_cast<BuildVectorSDNode>(CondRHS))
            if (auto *CondRHSConst = CondRHSBV->getConstantSplatNode())
              // If the RHS is a constant we have to reverse the const
              // canonicalization.
              // x > C-1 ? x+-C : 0 --> subus x, C
              if (CC == ISD::SETUGT && Other->getOpcode() == ISD::ADD &&
                  CondRHSConst->getAPIntValue() ==
                      (-OpRHSConst->getAPIntValue() - 1))
                return DAG.getNode(
                    X86ISD::SUBUS, DL, VT, OpLHS,
                    DAG.getConstant(-OpRHSConst->getAPIntValue(), VT));

          // Another special case: If C was a sign bit, the sub has been
          // canonicalized into a xor.
          // FIXME: Would it be better to use computeKnownBits to determine
          //        whether it's safe to decanonicalize the xor?
          // x s< 0 ? x^C : 0 --> subus x, C
          if (CC == ISD::SETLT && Other->getOpcode() == ISD::XOR &&
              ISD::isBuildVectorAllZeros(CondRHS.getNode()) &&
              OpRHSConst->getAPIntValue().isSignBit())
            // Note that we have to rebuild the RHS constant here to ensure we
            // don't rely on particular values of undef lanes.
            return DAG.getNode(
                X86ISD::SUBUS, DL, VT, OpLHS,
                DAG.getConstant(OpRHSConst->getAPIntValue(), VT));
        }
    }
  }

  // Try to match a min/max vector operation.
  if (N->getOpcode() == ISD::VSELECT && Cond.getOpcode() == ISD::SETCC) {
    std::pair<unsigned, bool> ret = matchIntegerMINMAX(Cond, VT, LHS, RHS, DAG, Subtarget);
    unsigned Opc = ret.first;
    bool NeedSplit = ret.second;

    if (Opc && NeedSplit) {
      unsigned NumElems = VT.getVectorNumElements();
      // Extract the LHS vectors
      SDValue LHS1 = Extract128BitVector(LHS, 0, DAG, DL);
      SDValue LHS2 = Extract128BitVector(LHS, NumElems/2, DAG, DL);

      // Extract the RHS vectors
      SDValue RHS1 = Extract128BitVector(RHS, 0, DAG, DL);
      SDValue RHS2 = Extract128BitVector(RHS, NumElems/2, DAG, DL);

      // Create min/max for each subvector
      LHS = DAG.getNode(Opc, DL, LHS1.getValueType(), LHS1, RHS1);
      RHS = DAG.getNode(Opc, DL, LHS2.getValueType(), LHS2, RHS2);

      // Merge the result
      return DAG.getNode(ISD::CONCAT_VECTORS, DL, VT, LHS, RHS);
    } else if (Opc)
      return DAG.getNode(Opc, DL, VT, LHS, RHS);
  }

  // Simplify vector selection if condition value type matches vselect
  // operand type
  if (N->getOpcode() == ISD::VSELECT && CondVT == VT) {
    assert(Cond.getValueType().isVector() &&
           "vector select expects a vector selector!");

    bool TValIsAllOnes = ISD::isBuildVectorAllOnes(LHS.getNode());
    bool FValIsAllZeros = ISD::isBuildVectorAllZeros(RHS.getNode());

    // Try invert the condition if true value is not all 1s and false value
    // is not all 0s.
    if (!TValIsAllOnes && !FValIsAllZeros &&
        // Check if the selector will be produced by CMPP*/PCMP*
        Cond.getOpcode() == ISD::SETCC &&
        // Check if SETCC has already been promoted
        TLI.getSetCCResultType(*DAG.getContext(), VT) == CondVT) {
      bool TValIsAllZeros = ISD::isBuildVectorAllZeros(LHS.getNode());
      bool FValIsAllOnes = ISD::isBuildVectorAllOnes(RHS.getNode());

      if (TValIsAllZeros || FValIsAllOnes) {
        SDValue CC = Cond.getOperand(2);
        ISD::CondCode NewCC =
          ISD::getSetCCInverse(cast<CondCodeSDNode>(CC)->get(),
                               Cond.getOperand(0).getValueType().isInteger());
        Cond = DAG.getSetCC(DL, CondVT, Cond.getOperand(0), Cond.getOperand(1), NewCC);
        std::swap(LHS, RHS);
        TValIsAllOnes = FValIsAllOnes;
        FValIsAllZeros = TValIsAllZeros;
      }
    }

    if (TValIsAllOnes || FValIsAllZeros) {
      SDValue Ret;

      if (TValIsAllOnes && FValIsAllZeros)
        Ret = Cond;
      else if (TValIsAllOnes)
        Ret = DAG.getNode(ISD::OR, DL, CondVT, Cond,
                          DAG.getNode(ISD::BITCAST, DL, CondVT, RHS));
      else if (FValIsAllZeros)
        Ret = DAG.getNode(ISD::AND, DL, CondVT, Cond,
                          DAG.getNode(ISD::BITCAST, DL, CondVT, LHS));

      return DAG.getNode(ISD::BITCAST, DL, VT, Ret);
    }
  }

  // If we know that this node is legal then we know that it is going to be
  // matched by one of the SSE/AVX BLEND instructions. These instructions only
  // depend on the highest bit in each word. Try to use SimplifyDemandedBits
  // to simplify previous instructions.
  if (N->getOpcode() == ISD::VSELECT && DCI.isBeforeLegalizeOps() &&
      !DCI.isBeforeLegalize() &&
      // We explicitly check against v8i16 and v16i16 because, although
      // they're marked as Custom, they might only be legal when Cond is a
      // build_vector of constants. This will be taken care in a later
      // condition.
      (TLI.isOperationLegalOrCustom(ISD::VSELECT, VT) && VT != MVT::v16i16 &&
       VT != MVT::v8i16) &&
      // Don't optimize vector of constants. Those are handled by
      // the generic code and all the bits must be properly set for
      // the generic optimizer.
      !ISD::isBuildVectorOfConstantSDNodes(Cond.getNode())) {
    unsigned BitWidth = Cond.getValueType().getScalarType().getSizeInBits();

    // Don't optimize vector selects that map to mask-registers.
    if (BitWidth == 1)
      return SDValue();

    assert(BitWidth >= 8 && BitWidth <= 64 && "Invalid mask size");
    APInt DemandedMask = APInt::getHighBitsSet(BitWidth, 1);

    APInt KnownZero, KnownOne;
    TargetLowering::TargetLoweringOpt TLO(DAG, DCI.isBeforeLegalize(),
                                          DCI.isBeforeLegalizeOps());
    if (TLO.ShrinkDemandedConstant(Cond, DemandedMask) ||
        TLI.SimplifyDemandedBits(Cond, DemandedMask, KnownZero, KnownOne,
                                 TLO)) {
      // If we changed the computation somewhere in the DAG, this change
      // will affect all users of Cond.
      // Make sure it is fine and update all the nodes so that we do not
      // use the generic VSELECT anymore. Otherwise, we may perform
      // wrong optimizations as we messed up with the actual expectation
      // for the vector boolean values.
      if (Cond != TLO.Old) {
        // Check all uses of that condition operand to check whether it will be
        // consumed by non-BLEND instructions, which may depend on all bits are
        // set properly.
        for (SDNode::use_iterator I = Cond->use_begin(), E = Cond->use_end();
             I != E; ++I)
          if (I->getOpcode() != ISD::VSELECT)
            // TODO: Add other opcodes eventually lowered into BLEND.
            return SDValue();

        // Update all the users of the condition, before committing the change,
        // so that the VSELECT optimizations that expect the correct vector
        // boolean value will not be triggered.
        for (SDNode::use_iterator I = Cond->use_begin(), E = Cond->use_end();
             I != E; ++I)
          DAG.ReplaceAllUsesOfValueWith(
              SDValue(*I, 0),
              DAG.getNode(X86ISD::SHRUNKBLEND, SDLoc(*I), I->getValueType(0),
                          Cond, I->getOperand(1), I->getOperand(2)));
        DCI.CommitTargetLoweringOpt(TLO);
        return SDValue();
      }
      // At this point, only Cond is changed. Change the condition
      // just for N to keep the opportunity to optimize all other
      // users their own way.
      DAG.ReplaceAllUsesOfValueWith(
          SDValue(N, 0),
          DAG.getNode(X86ISD::SHRUNKBLEND, SDLoc(N), N->getValueType(0),
                      TLO.New, N->getOperand(1), N->getOperand(2)));
      return SDValue();
    }
  }

  // We should generate an X86ISD::BLENDI from a vselect if its argument
  // is a sign_extend_inreg of an any_extend of a BUILD_VECTOR of
  // constants. This specific pattern gets generated when we split a
  // selector for a 512 bit vector in a machine without AVX512 (but with
  // 256-bit vectors), during legalization:
  //
  // (vselect (sign_extend (any_extend (BUILD_VECTOR)) i1) LHS RHS)
  //
  // Iff we find this pattern and the build_vectors are built from
  // constants, we translate the vselect into a shuffle_vector that we
  // know will be matched by LowerVECTOR_SHUFFLEtoBlend.
  if ((N->getOpcode() == ISD::VSELECT ||
       N->getOpcode() == X86ISD::SHRUNKBLEND) &&
      !DCI.isBeforeLegalize()) {
    SDValue Shuffle = transformVSELECTtoBlendVECTOR_SHUFFLE(N, DAG, Subtarget);
    if (Shuffle.getNode())
      return Shuffle;
  }

  return SDValue();
}

// Check whether a boolean test is testing a boolean value generated by
// X86ISD::SETCC. If so, return the operand of that SETCC and proper condition
// code.
//
// Simplify the following patterns:
// (Op (CMP (SETCC Cond EFLAGS) 1) EQ) or
// (Op (CMP (SETCC Cond EFLAGS) 0) NEQ)
// to (Op EFLAGS Cond)
//
// (Op (CMP (SETCC Cond EFLAGS) 0) EQ) or
// (Op (CMP (SETCC Cond EFLAGS) 1) NEQ)
// to (Op EFLAGS !Cond)
//
// where Op could be BRCOND or CMOV.
//
static SDValue checkBoolTestSetCCCombine(SDValue Cmp, X86::CondCode &CC) {
  // Quit if not CMP and SUB with its value result used.
  if (Cmp.getOpcode() != X86ISD::CMP &&
      (Cmp.getOpcode() != X86ISD::SUB || Cmp.getNode()->hasAnyUseOfValue(0)))
      return SDValue();

  // Quit if not used as a boolean value.
  if (CC != X86::COND_E && CC != X86::COND_NE)
    return SDValue();

  // Check CMP operands. One of them should be 0 or 1 and the other should be
  // an SetCC or extended from it.
  SDValue Op1 = Cmp.getOperand(0);
  SDValue Op2 = Cmp.getOperand(1);

  SDValue SetCC;
  const ConstantSDNode* C = nullptr;
  bool needOppositeCond = (CC == X86::COND_E);
  bool checkAgainstTrue = false; // Is it a comparison against 1?

  if ((C = dyn_cast<ConstantSDNode>(Op1)))
    SetCC = Op2;
  else if ((C = dyn_cast<ConstantSDNode>(Op2)))
    SetCC = Op1;
  else // Quit if all operands are not constants.
    return SDValue();

  if (C->getZExtValue() == 1) {
    needOppositeCond = !needOppositeCond;
    checkAgainstTrue = true;
  } else if (C->getZExtValue() != 0)
    // Quit if the constant is neither 0 or 1.
    return SDValue();

  bool truncatedToBoolWithAnd = false;
  // Skip (zext $x), (trunc $x), or (and $x, 1) node.
  while (SetCC.getOpcode() == ISD::ZERO_EXTEND ||
         SetCC.getOpcode() == ISD::TRUNCATE ||
         SetCC.getOpcode() == ISD::AND) {
    if (SetCC.getOpcode() == ISD::AND) {
      int OpIdx = -1;
      ConstantSDNode *CS;
      if ((CS = dyn_cast<ConstantSDNode>(SetCC.getOperand(0))) &&
          CS->getZExtValue() == 1)
        OpIdx = 1;
      if ((CS = dyn_cast<ConstantSDNode>(SetCC.getOperand(1))) &&
          CS->getZExtValue() == 1)
        OpIdx = 0;
      if (OpIdx == -1)
        break;
      SetCC = SetCC.getOperand(OpIdx);
      truncatedToBoolWithAnd = true;
    } else
      SetCC = SetCC.getOperand(0);
  }

  switch (SetCC.getOpcode()) {
  case X86ISD::SETCC_CARRY:
    // Since SETCC_CARRY gives output based on R = CF ? ~0 : 0, it's unsafe to
    // simplify it if the result of SETCC_CARRY is not canonicalized to 0 or 1,
    // i.e. it's a comparison against true but the result of SETCC_CARRY is not
    // truncated to i1 using 'and'.
    if (checkAgainstTrue && !truncatedToBoolWithAnd)
      break;
    assert(X86::CondCode(SetCC.getConstantOperandVal(0)) == X86::COND_B &&
           "Invalid use of SETCC_CARRY!");
    // FALL THROUGH
  case X86ISD::SETCC:
    // Set the condition code or opposite one if necessary.
    CC = X86::CondCode(SetCC.getConstantOperandVal(0));
    if (needOppositeCond)
      CC = X86::GetOppositeBranchCondition(CC);
    return SetCC.getOperand(1);
  case X86ISD::CMOV: {
    // Check whether false/true value has canonical one, i.e. 0 or 1.
    ConstantSDNode *FVal = dyn_cast<ConstantSDNode>(SetCC.getOperand(0));
    ConstantSDNode *TVal = dyn_cast<ConstantSDNode>(SetCC.getOperand(1));
    // Quit if true value is not a constant.
    if (!TVal)
      return SDValue();
    // Quit if false value is not a constant.
    if (!FVal) {
      SDValue Op = SetCC.getOperand(0);
      // Skip 'zext' or 'trunc' node.
      if (Op.getOpcode() == ISD::ZERO_EXTEND ||
          Op.getOpcode() == ISD::TRUNCATE)
        Op = Op.getOperand(0);
      // A special case for rdrand/rdseed, where 0 is set if false cond is
      // found.
      if ((Op.getOpcode() != X86ISD::RDRAND &&
           Op.getOpcode() != X86ISD::RDSEED) || Op.getResNo() != 0)
        return SDValue();
    }
    // Quit if false value is not the constant 0 or 1.
    bool FValIsFalse = true;
    if (FVal && FVal->getZExtValue() != 0) {
      if (FVal->getZExtValue() != 1)
        return SDValue();
      // If FVal is 1, opposite cond is needed.
      needOppositeCond = !needOppositeCond;
      FValIsFalse = false;
    }
    // Quit if TVal is not the constant opposite of FVal.
    if (FValIsFalse && TVal->getZExtValue() != 1)
      return SDValue();
    if (!FValIsFalse && TVal->getZExtValue() != 0)
      return SDValue();
    CC = X86::CondCode(SetCC.getConstantOperandVal(2));
    if (needOppositeCond)
      CC = X86::GetOppositeBranchCondition(CC);
    return SetCC.getOperand(3);
  }
  }

  return SDValue();
}

/// Optimize X86ISD::CMOV [LHS, RHS, CONDCODE (e.g. X86::COND_NE), CONDVAL]
static SDValue PerformCMOVCombine(SDNode *N, SelectionDAG &DAG,
                                  TargetLowering::DAGCombinerInfo &DCI,
                                  const X86Subtarget *Subtarget) {
  SDLoc DL(N);

  // If the flag operand isn't dead, don't touch this CMOV.
  if (N->getNumValues() == 2 && !SDValue(N, 1).use_empty())
    return SDValue();

  SDValue FalseOp = N->getOperand(0);
  SDValue TrueOp = N->getOperand(1);
  X86::CondCode CC = (X86::CondCode)N->getConstantOperandVal(2);
  SDValue Cond = N->getOperand(3);

  if (CC == X86::COND_E || CC == X86::COND_NE) {
    switch (Cond.getOpcode()) {
    default: break;
    case X86ISD::BSR:
    case X86ISD::BSF:
      // If operand of BSR / BSF are proven never zero, then ZF cannot be set.
      if (DAG.isKnownNeverZero(Cond.getOperand(0)))
        return (CC == X86::COND_E) ? FalseOp : TrueOp;
    }
  }

  SDValue Flags;

  Flags = checkBoolTestSetCCCombine(Cond, CC);
  if (Flags.getNode() &&
      // Extra check as FCMOV only supports a subset of X86 cond.
      (FalseOp.getValueType() != MVT::f80 || hasFPCMov(CC))) {
    SDValue Ops[] = { FalseOp, TrueOp,
                      DAG.getConstant(CC, MVT::i8), Flags };
    return DAG.getNode(X86ISD::CMOV, DL, N->getVTList(), Ops);
  }

  // If this is a select between two integer constants, try to do some
  // optimizations.  Note that the operands are ordered the opposite of SELECT
  // operands.
  if (ConstantSDNode *TrueC = dyn_cast<ConstantSDNode>(TrueOp)) {
    if (ConstantSDNode *FalseC = dyn_cast<ConstantSDNode>(FalseOp)) {
      // Canonicalize the TrueC/FalseC values so that TrueC (the true value) is
      // larger than FalseC (the false value).
      if (TrueC->getAPIntValue().ult(FalseC->getAPIntValue())) {
        CC = X86::GetOppositeBranchCondition(CC);
        std::swap(TrueC, FalseC);
        std::swap(TrueOp, FalseOp);
      }

      // Optimize C ? 8 : 0 -> zext(setcc(C)) << 3.  Likewise for any pow2/0.
      // This is efficient for any integer data type (including i8/i16) and
      // shift amount.
      if (FalseC->getAPIntValue() == 0 && TrueC->getAPIntValue().isPowerOf2()) {
        Cond = DAG.getNode(X86ISD::SETCC, DL, MVT::i8,
                           DAG.getConstant(CC, MVT::i8), Cond);

        // Zero extend the condition if needed.
        Cond = DAG.getNode(ISD::ZERO_EXTEND, DL, TrueC->getValueType(0), Cond);

        unsigned ShAmt = TrueC->getAPIntValue().logBase2();
        Cond = DAG.getNode(ISD::SHL, DL, Cond.getValueType(), Cond,
                           DAG.getConstant(ShAmt, MVT::i8));
        if (N->getNumValues() == 2)  // Dead flag value?
          return DCI.CombineTo(N, Cond, SDValue());
        return Cond;
      }

      // Optimize Cond ? cst+1 : cst -> zext(setcc(C)+cst.  This is efficient
      // for any integer data type, including i8/i16.
      if (FalseC->getAPIntValue()+1 == TrueC->getAPIntValue()) {
        Cond = DAG.getNode(X86ISD::SETCC, DL, MVT::i8,
                           DAG.getConstant(CC, MVT::i8), Cond);

        // Zero extend the condition if needed.
        Cond = DAG.getNode(ISD::ZERO_EXTEND, DL,
                           FalseC->getValueType(0), Cond);
        Cond = DAG.getNode(ISD::ADD, DL, Cond.getValueType(), Cond,
                           SDValue(FalseC, 0));

        if (N->getNumValues() == 2)  // Dead flag value?
          return DCI.CombineTo(N, Cond, SDValue());
        return Cond;
      }

      // Optimize cases that will turn into an LEA instruction.  This requires
      // an i32 or i64 and an efficient multiplier (1, 2, 3, 4, 5, 8, 9).
      if (N->getValueType(0) == MVT::i32 || N->getValueType(0) == MVT::i64) {
        uint64_t Diff = TrueC->getZExtValue()-FalseC->getZExtValue();
        if (N->getValueType(0) == MVT::i32) Diff = (unsigned)Diff;

        bool isFastMultiplier = false;
        if (Diff < 10) {
          switch ((unsigned char)Diff) {
          default: break;
          case 1:  // result = add base, cond
          case 2:  // result = lea base(    , cond*2)
          case 3:  // result = lea base(cond, cond*2)
          case 4:  // result = lea base(    , cond*4)
          case 5:  // result = lea base(cond, cond*4)
          case 8:  // result = lea base(    , cond*8)
          case 9:  // result = lea base(cond, cond*8)
            isFastMultiplier = true;
            break;
          }
        }

        if (isFastMultiplier) {
          APInt Diff = TrueC->getAPIntValue()-FalseC->getAPIntValue();
          Cond = DAG.getNode(X86ISD::SETCC, DL, MVT::i8,
                             DAG.getConstant(CC, MVT::i8), Cond);
          // Zero extend the condition if needed.
          Cond = DAG.getNode(ISD::ZERO_EXTEND, DL, FalseC->getValueType(0),
                             Cond);
          // Scale the condition by the difference.
          if (Diff != 1)
            Cond = DAG.getNode(ISD::MUL, DL, Cond.getValueType(), Cond,
                               DAG.getConstant(Diff, Cond.getValueType()));

          // Add the base if non-zero.
          if (FalseC->getAPIntValue() != 0)
            Cond = DAG.getNode(ISD::ADD, DL, Cond.getValueType(), Cond,
                               SDValue(FalseC, 0));
          if (N->getNumValues() == 2)  // Dead flag value?
            return DCI.CombineTo(N, Cond, SDValue());
          return Cond;
        }
      }
    }
  }

  // Handle these cases:
  //   (select (x != c), e, c) -> select (x != c), e, x),
  //   (select (x == c), c, e) -> select (x == c), x, e)
  // where the c is an integer constant, and the "select" is the combination
  // of CMOV and CMP.
  //
  // The rationale for this change is that the conditional-move from a constant
  // needs two instructions, however, conditional-move from a register needs
  // only one instruction.
  //
  // CAVEAT: By replacing a constant with a symbolic value, it may obscure
  //  some instruction-combining opportunities. This opt needs to be
  //  postponed as late as possible.
  //
  if (!DCI.isBeforeLegalize() && !DCI.isBeforeLegalizeOps()) {
    // the DCI.xxxx conditions are provided to postpone the optimization as
    // late as possible.

    ConstantSDNode *CmpAgainst = nullptr;
    if ((Cond.getOpcode() == X86ISD::CMP || Cond.getOpcode() == X86ISD::SUB) &&
        (CmpAgainst = dyn_cast<ConstantSDNode>(Cond.getOperand(1))) &&
        !isa<ConstantSDNode>(Cond.getOperand(0))) {

      if (CC == X86::COND_NE &&
          CmpAgainst == dyn_cast<ConstantSDNode>(FalseOp)) {
        CC = X86::GetOppositeBranchCondition(CC);
        std::swap(TrueOp, FalseOp);
      }

      if (CC == X86::COND_E &&
          CmpAgainst == dyn_cast<ConstantSDNode>(TrueOp)) {
        SDValue Ops[] = { FalseOp, Cond.getOperand(0),
                          DAG.getConstant(CC, MVT::i8), Cond };
        return DAG.getNode(X86ISD::CMOV, DL, N->getVTList (), Ops);
      }
    }
  }

  return SDValue();
}

static SDValue PerformINTRINSIC_WO_CHAINCombine(SDNode *N, SelectionDAG &DAG,
                                                const X86Subtarget *Subtarget) {
  unsigned IntNo = cast<ConstantSDNode>(N->getOperand(0))->getZExtValue();
  switch (IntNo) {
  default: return SDValue();
  // SSE/AVX/AVX2 blend intrinsics.
  case Intrinsic::x86_avx2_pblendvb:
  case Intrinsic::x86_avx2_pblendw:
  case Intrinsic::x86_avx2_pblendd_128:
  case Intrinsic::x86_avx2_pblendd_256:
    // Don't try to simplify this intrinsic if we don't have AVX2.
    if (!Subtarget->hasAVX2())
      return SDValue();
    // FALL-THROUGH
  case Intrinsic::x86_avx_blend_pd_256:
  case Intrinsic::x86_avx_blend_ps_256:
  case Intrinsic::x86_avx_blendv_pd_256:
  case Intrinsic::x86_avx_blendv_ps_256:
    // Don't try to simplify this intrinsic if we don't have AVX.
    if (!Subtarget->hasAVX())
      return SDValue();
    // FALL-THROUGH
  case Intrinsic::x86_sse41_pblendw:
  case Intrinsic::x86_sse41_blendpd:
  case Intrinsic::x86_sse41_blendps:
  case Intrinsic::x86_sse41_blendvps:
  case Intrinsic::x86_sse41_blendvpd:
  case Intrinsic::x86_sse41_pblendvb: {
    SDValue Op0 = N->getOperand(1);
    SDValue Op1 = N->getOperand(2);
    SDValue Mask = N->getOperand(3);

    // Don't try to simplify this intrinsic if we don't have SSE4.1.
    if (!Subtarget->hasSSE41())
      return SDValue();

    // fold (blend A, A, Mask) -> A
    if (Op0 == Op1)
      return Op0;
    // fold (blend A, B, allZeros) -> A
    if (ISD::isBuildVectorAllZeros(Mask.getNode()))
      return Op0;
    // fold (blend A, B, allOnes) -> B
    if (ISD::isBuildVectorAllOnes(Mask.getNode()))
      return Op1;

    // Simplify the case where the mask is a constant i32 value.
    if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Mask)) {
      if (C->isNullValue())
        return Op0;
      if (C->isAllOnesValue())
        return Op1;
    }

    return SDValue();
  }

  // Packed SSE2/AVX2 arithmetic shift immediate intrinsics.
  case Intrinsic::x86_sse2_psrai_w:
  case Intrinsic::x86_sse2_psrai_d:
  case Intrinsic::x86_avx2_psrai_w:
  case Intrinsic::x86_avx2_psrai_d:
  case Intrinsic::x86_sse2_psra_w:
  case Intrinsic::x86_sse2_psra_d:
  case Intrinsic::x86_avx2_psra_w:
  case Intrinsic::x86_avx2_psra_d: {
    SDValue Op0 = N->getOperand(1);
    SDValue Op1 = N->getOperand(2);
    EVT VT = Op0.getValueType();
    assert(VT.isVector() && "Expected a vector type!");

    if (isa<BuildVectorSDNode>(Op1))
      Op1 = Op1.getOperand(0);

    if (!isa<ConstantSDNode>(Op1))
      return SDValue();

    EVT SVT = VT.getVectorElementType();
    unsigned SVTBits = SVT.getSizeInBits();

    ConstantSDNode *CND = cast<ConstantSDNode>(Op1);
    const APInt &C = APInt(SVTBits, CND->getAPIntValue().getZExtValue());
    uint64_t ShAmt = C.getZExtValue();

    // Don't try to convert this shift into a ISD::SRA if the shift
    // count is bigger than or equal to the element size.
    if (ShAmt >= SVTBits)
      return SDValue();

    // Trivial case: if the shift count is zero, then fold this
    // into the first operand.
    if (ShAmt == 0)
      return Op0;

    // Replace this packed shift intrinsic with a target independent
    // shift dag node.
    SDValue Splat = DAG.getConstant(C, VT);
    return DAG.getNode(ISD::SRA, SDLoc(N), VT, Op0, Splat);
  }
  }
}

/// PerformMulCombine - Optimize a single multiply with constant into two
/// in order to implement it with two cheaper instructions, e.g.
/// LEA + SHL, LEA + LEA.
static SDValue PerformMulCombine(SDNode *N, SelectionDAG &DAG,
                                 TargetLowering::DAGCombinerInfo &DCI) {
  if (DCI.isBeforeLegalize() || DCI.isCalledByLegalizer())
    return SDValue();

  EVT VT = N->getValueType(0);
  if (VT != MVT::i64 && VT != MVT::i32)
    return SDValue();

  ConstantSDNode *C = dyn_cast<ConstantSDNode>(N->getOperand(1));
  if (!C)
    return SDValue();
  uint64_t MulAmt = C->getZExtValue();
  if (isPowerOf2_64(MulAmt) || MulAmt == 3 || MulAmt == 5 || MulAmt == 9)
    return SDValue();

  uint64_t MulAmt1 = 0;
  uint64_t MulAmt2 = 0;
  if ((MulAmt % 9) == 0) {
    MulAmt1 = 9;
    MulAmt2 = MulAmt / 9;
  } else if ((MulAmt % 5) == 0) {
    MulAmt1 = 5;
    MulAmt2 = MulAmt / 5;
  } else if ((MulAmt % 3) == 0) {
    MulAmt1 = 3;
    MulAmt2 = MulAmt / 3;
  }
  if (MulAmt2 &&
      (isPowerOf2_64(MulAmt2) || MulAmt2 == 3 || MulAmt2 == 5 || MulAmt2 == 9)){
    SDLoc DL(N);

    if (isPowerOf2_64(MulAmt2) &&
        !(N->hasOneUse() && N->use_begin()->getOpcode() == ISD::ADD))
      // If second multiplifer is pow2, issue it first. We want the multiply by
      // 3, 5, or 9 to be folded into the addressing mode unless the lone use
      // is an add.
      std::swap(MulAmt1, MulAmt2);

    SDValue NewMul;
    if (isPowerOf2_64(MulAmt1))
      NewMul = DAG.getNode(ISD::SHL, DL, VT, N->getOperand(0),
                           DAG.getConstant(Log2_64(MulAmt1), MVT::i8));
    else
      NewMul = DAG.getNode(X86ISD::MUL_IMM, DL, VT, N->getOperand(0),
                           DAG.getConstant(MulAmt1, VT));

    if (isPowerOf2_64(MulAmt2))
      NewMul = DAG.getNode(ISD::SHL, DL, VT, NewMul,
                           DAG.getConstant(Log2_64(MulAmt2), MVT::i8));
    else
      NewMul = DAG.getNode(X86ISD::MUL_IMM, DL, VT, NewMul,
                           DAG.getConstant(MulAmt2, VT));

    // Do not add new nodes to DAG combiner worklist.
    DCI.CombineTo(N, NewMul, false);
  }
  return SDValue();
}

static SDValue PerformSHLCombine(SDNode *N, SelectionDAG &DAG) {
  SDValue N0 = N->getOperand(0);
  SDValue N1 = N->getOperand(1);
  ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
  EVT VT = N0.getValueType();

  // fold (shl (and (setcc_c), c1), c2) -> (and setcc_c, (c1 << c2))
  // since the result of setcc_c is all zero's or all ones.
  if (VT.isInteger() && !VT.isVector() &&
      N1C && N0.getOpcode() == ISD::AND &&
      N0.getOperand(1).getOpcode() == ISD::Constant) {
    SDValue N00 = N0.getOperand(0);
    if (N00.getOpcode() == X86ISD::SETCC_CARRY ||
        ((N00.getOpcode() == ISD::ANY_EXTEND ||
          N00.getOpcode() == ISD::ZERO_EXTEND) &&
         N00.getOperand(0).getOpcode() == X86ISD::SETCC_CARRY)) {
      APInt Mask = cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
      APInt ShAmt = N1C->getAPIntValue();
      Mask = Mask.shl(ShAmt);
      if (Mask != 0)
        return DAG.getNode(ISD::AND, SDLoc(N), VT,
                           N00, DAG.getConstant(Mask, VT));
    }
  }

  // Hardware support for vector shifts is sparse which makes us scalarize the
  // vector operations in many cases. Also, on sandybridge ADD is faster than
  // shl.
  // (shl V, 1) -> add V,V
  if (auto *N1BV = dyn_cast<BuildVectorSDNode>(N1))
    if (auto *N1SplatC = N1BV->getConstantSplatNode()) {
      assert(N0.getValueType().isVector() && "Invalid vector shift type");
      // We shift all of the values by one. In many cases we do not have
      // hardware support for this operation. This is better expressed as an ADD
      // of two values.
      if (N1SplatC->getZExtValue() == 1)
        return DAG.getNode(ISD::ADD, SDLoc(N), VT, N0, N0);
    }

  return SDValue();
}

/// \brief Returns a vector of 0s if the node in input is a vector logical
/// shift by a constant amount which is known to be bigger than or equal
/// to the vector element size in bits.
static SDValue performShiftToAllZeros(SDNode *N, SelectionDAG &DAG,
                                      const X86Subtarget *Subtarget) {
  EVT VT = N->getValueType(0);

  if (VT != MVT::v2i64 && VT != MVT::v4i32 && VT != MVT::v8i16 &&
      (!Subtarget->hasInt256() ||
       (VT != MVT::v4i64 && VT != MVT::v8i32 && VT != MVT::v16i16)))
    return SDValue();

  SDValue Amt = N->getOperand(1);
  SDLoc DL(N);
  if (auto *AmtBV = dyn_cast<BuildVectorSDNode>(Amt))
    if (auto *AmtSplat = AmtBV->getConstantSplatNode()) {
      APInt ShiftAmt = AmtSplat->getAPIntValue();
      unsigned MaxAmount = VT.getVectorElementType().getSizeInBits();

      // SSE2/AVX2 logical shifts always return a vector of 0s
      // if the shift amount is bigger than or equal to
      // the element size. The constant shift amount will be
      // encoded as a 8-bit immediate.
      if (ShiftAmt.trunc(8).uge(MaxAmount))
        return getZeroVector(VT, Subtarget, DAG, DL);
    }

  return SDValue();
}

/// PerformShiftCombine - Combine shifts.
static SDValue PerformShiftCombine(SDNode* N, SelectionDAG &DAG,
                                   TargetLowering::DAGCombinerInfo &DCI,
                                   const X86Subtarget *Subtarget) {
  if (N->getOpcode() == ISD::SHL) {
    SDValue V = PerformSHLCombine(N, DAG);
    if (V.getNode()) return V;
  }

  if (N->getOpcode() != ISD::SRA) {
    // Try to fold this logical shift into a zero vector.
    SDValue V = performShiftToAllZeros(N, DAG, Subtarget);
    if (V.getNode()) return V;
  }

  return SDValue();
}

// CMPEQCombine - Recognize the distinctive  (AND (setcc ...) (setcc ..))
// where both setccs reference the same FP CMP, and rewrite for CMPEQSS
// and friends.  Likewise for OR -> CMPNEQSS.
static SDValue CMPEQCombine(SDNode *N, SelectionDAG &DAG,
                            TargetLowering::DAGCombinerInfo &DCI,
                            const X86Subtarget *Subtarget) {
  unsigned opcode;

  // SSE1 supports CMP{eq|ne}SS, and SSE2 added CMP{eq|ne}SD, but
  // we're requiring SSE2 for both.
  if (Subtarget->hasSSE2() && isAndOrOfSetCCs(SDValue(N, 0U), opcode)) {
    SDValue N0 = N->getOperand(0);
    SDValue N1 = N->getOperand(1);
    SDValue CMP0 = N0->getOperand(1);
    SDValue CMP1 = N1->getOperand(1);
    SDLoc DL(N);

    // The SETCCs should both refer to the same CMP.
    if (CMP0.getOpcode() != X86ISD::CMP || CMP0 != CMP1)
      return SDValue();

    SDValue CMP00 = CMP0->getOperand(0);
    SDValue CMP01 = CMP0->getOperand(1);
    EVT     VT    = CMP00.getValueType();

    if (VT == MVT::f32 || VT == MVT::f64) {
      bool ExpectingFlags = false;
      // Check for any users that want flags:
      for (SDNode::use_iterator UI = N->use_begin(), UE = N->use_end();
           !ExpectingFlags && UI != UE; ++UI)
        switch (UI->getOpcode()) {
        default:
        case ISD::BR_CC:
        case ISD::BRCOND:
        case ISD::SELECT:
          ExpectingFlags = true;
          break;
        case ISD::CopyToReg:
        case ISD::SIGN_EXTEND:
        case ISD::ZERO_EXTEND:
        case ISD::ANY_EXTEND:
          break;
        }

      if (!ExpectingFlags) {
        enum X86::CondCode cc0 = (enum X86::CondCode)N0.getConstantOperandVal(0);
        enum X86::CondCode cc1 = (enum X86::CondCode)N1.getConstantOperandVal(0);

        if (cc1 == X86::COND_E || cc1 == X86::COND_NE) {
          X86::CondCode tmp = cc0;
          cc0 = cc1;
          cc1 = tmp;
        }

        if ((cc0 == X86::COND_E  && cc1 == X86::COND_NP) ||
            (cc0 == X86::COND_NE && cc1 == X86::COND_P)) {
          // FIXME: need symbolic constants for these magic numbers.
          // See X86ATTInstPrinter.cpp:printSSECC().
          unsigned x86cc = (cc0 == X86::COND_E) ? 0 : 4;
          if (Subtarget->hasAVX512()) {
            SDValue FSetCC = DAG.getNode(X86ISD::FSETCC, DL, MVT::i1, CMP00,
                                         CMP01, DAG.getConstant(x86cc, MVT::i8));
            if (N->getValueType(0) != MVT::i1)
              return DAG.getNode(ISD::ZERO_EXTEND, DL, N->getValueType(0),
                                 FSetCC);
            return FSetCC;
          }
          SDValue OnesOrZeroesF = DAG.getNode(X86ISD::FSETCC, DL,
                                              CMP00.getValueType(), CMP00, CMP01,
                                              DAG.getConstant(x86cc, MVT::i8));

          bool is64BitFP = (CMP00.getValueType() == MVT::f64);
          MVT IntVT = is64BitFP ? MVT::i64 : MVT::i32;

          if (is64BitFP && !Subtarget->is64Bit()) {
            // On a 32-bit target, we cannot bitcast the 64-bit float to a
            // 64-bit integer, since that's not a legal type. Since
            // OnesOrZeroesF is all ones of all zeroes, we don't need all the
            // bits, but can do this little dance to extract the lowest 32 bits
            // and work with those going forward.
            SDValue Vector64 = DAG.getNode(ISD::SCALAR_TO_VECTOR, DL, MVT::v2f64,
                                           OnesOrZeroesF);
            SDValue Vector32 = DAG.getNode(ISD::BITCAST, DL, MVT::v4f32,
                                           Vector64);
            OnesOrZeroesF = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, DL, MVT::f32,
                                        Vector32, DAG.getIntPtrConstant(0));
            IntVT = MVT::i32;
          }

          SDValue OnesOrZeroesI = DAG.getNode(ISD::BITCAST, DL, IntVT, OnesOrZeroesF);
          SDValue ANDed = DAG.getNode(ISD::AND, DL, IntVT, OnesOrZeroesI,
                                      DAG.getConstant(1, IntVT));
          SDValue OneBitOfTruth = DAG.getNode(ISD::TRUNCATE, DL, MVT::i8, ANDed);
          return OneBitOfTruth;
        }
      }
    }
  }
  return SDValue();
}

/// CanFoldXORWithAllOnes - Test whether the XOR operand is a AllOnes vector
/// so it can be folded inside ANDNP.
static bool CanFoldXORWithAllOnes(const SDNode *N) {
  EVT VT = N->getValueType(0);

  // Match direct AllOnes for 128 and 256-bit vectors
  if (ISD::isBuildVectorAllOnes(N))
    return true;

  // Look through a bit convert.
  if (N->getOpcode() == ISD::BITCAST)
    N = N->getOperand(0).getNode();

  // Sometimes the operand may come from a insert_subvector building a 256-bit
  // allones vector
  if (VT.is256BitVector() &&
      N->getOpcode() == ISD::INSERT_SUBVECTOR) {
    SDValue V1 = N->getOperand(0);
    SDValue V2 = N->getOperand(1);

    if (V1.getOpcode() == ISD::INSERT_SUBVECTOR &&
        V1.getOperand(0).getOpcode() == ISD::UNDEF &&
        ISD::isBuildVectorAllOnes(V1.getOperand(1).getNode()) &&
        ISD::isBuildVectorAllOnes(V2.getNode()))
      return true;
  }

  return false;
}

// On AVX/AVX2 the type v8i1 is legalized to v8i16, which is an XMM sized
// register. In most cases we actually compare or select YMM-sized registers
// and mixing the two types creates horrible code. This method optimizes
// some of the transition sequences.
static SDValue WidenMaskArithmetic(SDNode *N, SelectionDAG &DAG,
                                 TargetLowering::DAGCombinerInfo &DCI,
                                 const X86Subtarget *Subtarget) {
  EVT VT = N->getValueType(0);
  if (!VT.is256BitVector())
    return SDValue();

  assert((N->getOpcode() == ISD::ANY_EXTEND ||
          N->getOpcode() == ISD::ZERO_EXTEND ||
          N->getOpcode() == ISD::SIGN_EXTEND) && "Invalid Node");

  SDValue Narrow = N->getOperand(0);
  EVT NarrowVT = Narrow->getValueType(0);
  if (!NarrowVT.is128BitVector())
    return SDValue();

  if (Narrow->getOpcode() != ISD::XOR &&
      Narrow->getOpcode() != ISD::AND &&
      Narrow->getOpcode() != ISD::OR)
    return SDValue();

  SDValue N0  = Narrow->getOperand(0);
  SDValue N1  = Narrow->getOperand(1);
  SDLoc DL(Narrow);

  // The Left side has to be a trunc.
  if (N0.getOpcode() != ISD::TRUNCATE)
    return SDValue();

  // The type of the truncated inputs.
  EVT WideVT = N0->getOperand(0)->getValueType(0);
  if (WideVT != VT)
    return SDValue();

  // The right side has to be a 'trunc' or a constant vector.
  bool RHSTrunc = N1.getOpcode() == ISD::TRUNCATE;
  ConstantSDNode *RHSConstSplat = nullptr;
  if (auto *RHSBV = dyn_cast<BuildVectorSDNode>(N1))
    RHSConstSplat = RHSBV->getConstantSplatNode();
  if (!RHSTrunc && !RHSConstSplat)
    return SDValue();

  const TargetLowering &TLI = DAG.getTargetLoweringInfo();

  if (!TLI.isOperationLegalOrPromote(Narrow->getOpcode(), WideVT))
    return SDValue();

  // Set N0 and N1 to hold the inputs to the new wide operation.
  N0 = N0->getOperand(0);
  if (RHSConstSplat) {
    N1 = DAG.getNode(ISD::ZERO_EXTEND, DL, WideVT.getScalarType(),
                     SDValue(RHSConstSplat, 0));
    SmallVector<SDValue, 8> C(WideVT.getVectorNumElements(), N1);
    N1 = DAG.getNode(ISD::BUILD_VECTOR, DL, WideVT, C);
  } else if (RHSTrunc) {
    N1 = N1->getOperand(0);
  }

  // Generate the wide operation.
  SDValue Op = DAG.getNode(Narrow->getOpcode(), DL, WideVT, N0, N1);
  unsigned Opcode = N->getOpcode();
  switch (Opcode) {
  case ISD::ANY_EXTEND:
    return Op;
  case ISD::ZERO_EXTEND: {
    unsigned InBits = NarrowVT.getScalarType().getSizeInBits();
    APInt Mask = APInt::getAllOnesValue(InBits);
    Mask = Mask.zext(VT.getScalarType().getSizeInBits());
    return DAG.getNode(ISD::AND, DL, VT,
                       Op, DAG.getConstant(Mask, VT));
  }
  case ISD::SIGN_EXTEND:
    return DAG.getNode(ISD::SIGN_EXTEND_INREG, DL, VT,
                       Op, DAG.getValueType(NarrowVT));
  default:
    llvm_unreachable("Unexpected opcode");
  }
}

static SDValue VectorZextCombine(SDNode *N, SelectionDAG &DAG,
                                 TargetLowering::DAGCombinerInfo &DCI,
                                 const X86Subtarget *Subtarget) {
  SDValue N0 = N->getOperand(0);
  SDValue N1 = N->getOperand(1);
  SDLoc DL(N);

  // A vector zext_in_reg may be represented as a shuffle,
  // feeding into a bitcast (this represents anyext) feeding into
  // an and with a mask.
  // We'd like to try to combine that into a shuffle with zero
  // plus a bitcast, removing the and.
  if (N0.getOpcode() != ISD::BITCAST || 
      N0.getOperand(0).getOpcode() != ISD::VECTOR_SHUFFLE)
    return SDValue();

  // The other side of the AND should be a splat of 2^C, where C
  // is the number of bits in the source type.
  if (N1.getOpcode() == ISD::BITCAST)
    N1 = N1.getOperand(0);
  if (N1.getOpcode() != ISD::BUILD_VECTOR)
    return SDValue();
  BuildVectorSDNode *Vector = cast<BuildVectorSDNode>(N1);

  ShuffleVectorSDNode *Shuffle = cast<ShuffleVectorSDNode>(N0.getOperand(0));
  EVT SrcType = Shuffle->getValueType(0);

  // We expect a single-source shuffle
  if (Shuffle->getOperand(1)->getOpcode() != ISD::UNDEF)
    return SDValue();

  unsigned SrcSize = SrcType.getScalarSizeInBits();

  APInt SplatValue, SplatUndef;
  unsigned SplatBitSize;
  bool HasAnyUndefs;
  if (!Vector->isConstantSplat(SplatValue, SplatUndef,
                                SplatBitSize, HasAnyUndefs))
    return SDValue();

  unsigned ResSize = N1.getValueType().getScalarSizeInBits();
  // Make sure the splat matches the mask we expect
  if (SplatBitSize > ResSize || 
      (SplatValue + 1).exactLogBase2() != (int)SrcSize)
    return SDValue();

  // Make sure the input and output size make sense
  if (SrcSize >= ResSize || ResSize % SrcSize)
    return SDValue();

  // We expect a shuffle of the form <0, u, u, u, 1, u, u, u...>
  // The number of u's between each two values depends on the ratio between
  // the source and dest type.
  unsigned ZextRatio = ResSize / SrcSize;
  bool IsZext = true;
  for (unsigned i = 0; i < SrcType.getVectorNumElements(); ++i) {
    if (i % ZextRatio) {
      if (Shuffle->getMaskElt(i) > 0) {
        // Expected undef
        IsZext = false;
        break;
      }
    } else {
      if (Shuffle->getMaskElt(i) != (int)(i / ZextRatio)) {
        // Expected element number
        IsZext = false;
        break;
      }
    }
  }

  if (!IsZext)
    return SDValue();

  // Ok, perform the transformation - replace the shuffle with
  // a shuffle of the form <0, k, k, k, 1, k, k, k> with zero
  // (instead of undef) where the k elements come from the zero vector.
  SmallVector<int, 8> Mask;
  unsigned NumElems = SrcType.getVectorNumElements();
  for (unsigned i = 0; i < NumElems; ++i)
    if (i % ZextRatio)
      Mask.push_back(NumElems);
    else
      Mask.push_back(i / ZextRatio);

  SDValue NewShuffle = DAG.getVectorShuffle(Shuffle->getValueType(0), DL,
    Shuffle->getOperand(0), DAG.getConstant(0, SrcType), Mask);
  return DAG.getNode(ISD::BITCAST, DL,  N0.getValueType(), NewShuffle);
}

static SDValue PerformAndCombine(SDNode *N, SelectionDAG &DAG,
                                 TargetLowering::DAGCombinerInfo &DCI,
                                 const X86Subtarget *Subtarget) {
  if (DCI.isBeforeLegalizeOps())
    return SDValue();

  SDValue Zext = VectorZextCombine(N, DAG, DCI, Subtarget);
  if (Zext.getNode())
    return Zext;

  SDValue R = CMPEQCombine(N, DAG, DCI, Subtarget);
  if (R.getNode())
    return R;

  EVT VT = N->getValueType(0);
  SDValue N0 = N->getOperand(0);
  SDValue N1 = N->getOperand(1);
  SDLoc DL(N);

  // Create BEXTR instructions
  // BEXTR is ((X >> imm) & (2**size-1))
  if (VT == MVT::i32 || VT == MVT::i64) {
    // Check for BEXTR.
    if ((Subtarget->hasBMI() || Subtarget->hasTBM()) &&
        (N0.getOpcode() == ISD::SRA || N0.getOpcode() == ISD::SRL)) {
      ConstantSDNode *MaskNode = dyn_cast<ConstantSDNode>(N1);
      ConstantSDNode *ShiftNode = dyn_cast<ConstantSDNode>(N0.getOperand(1));
      if (MaskNode && ShiftNode) {
        uint64_t Mask = MaskNode->getZExtValue();
        uint64_t Shift = ShiftNode->getZExtValue();
        if (isMask_64(Mask)) {
          uint64_t MaskSize = countPopulation(Mask);
          if (Shift + MaskSize <= VT.getSizeInBits())
            return DAG.getNode(X86ISD::BEXTR, DL, VT, N0.getOperand(0),
                               DAG.getConstant(Shift | (MaskSize << 8), VT));
        }
      }
    } // BEXTR

    return SDValue();
  }

  // Want to form ANDNP nodes:
  // 1) In the hopes of then easily combining them with OR and AND nodes
  //    to form PBLEND/PSIGN.
  // 2) To match ANDN packed intrinsics
  if (VT != MVT::v2i64 && VT != MVT::v4i64)
    return SDValue();

  // Check LHS for vnot
  if (N0.getOpcode() == ISD::XOR &&
      //ISD::isBuildVectorAllOnes(N0.getOperand(1).getNode()))
      CanFoldXORWithAllOnes(N0.getOperand(1).getNode()))
    return DAG.getNode(X86ISD::ANDNP, DL, VT, N0.getOperand(0), N1);

  // Check RHS for vnot
  if (N1.getOpcode() == ISD::XOR &&
      //ISD::isBuildVectorAllOnes(N1.getOperand(1).getNode()))
      CanFoldXORWithAllOnes(N1.getOperand(1).getNode()))
    return DAG.getNode(X86ISD::ANDNP, DL, VT, N1.getOperand(0), N0);

  return SDValue();
}

static SDValue PerformOrCombine(SDNode *N, SelectionDAG &DAG,
                                TargetLowering::DAGCombinerInfo &DCI,
                                const X86Subtarget *Subtarget) {
  if (DCI.isBeforeLegalizeOps())
    return SDValue();

  SDValue R = CMPEQCombine(N, DAG, DCI, Subtarget);
  if (R.getNode())
    return R;

  SDValue N0 = N->getOperand(0);
  SDValue N1 = N->getOperand(1);
  EVT VT = N->getValueType(0);

  // look for psign/blend
  if (VT == MVT::v2i64 || VT == MVT::v4i64) {
    if (!Subtarget->hasSSSE3() ||
        (VT == MVT::v4i64 && !Subtarget->hasInt256()))
      return SDValue();

    // Canonicalize pandn to RHS
    if (N0.getOpcode() == X86ISD::ANDNP)
      std::swap(N0, N1);
    // or (and (m, y), (pandn m, x))
    if (N0.getOpcode() == ISD::AND && N1.getOpcode() == X86ISD::ANDNP) {
      SDValue Mask = N1.getOperand(0);
      SDValue X    = N1.getOperand(1);
      SDValue Y;
      if (N0.getOperand(0) == Mask)
        Y = N0.getOperand(1);
      if (N0.getOperand(1) == Mask)
        Y = N0.getOperand(0);

      // Check to see if the mask appeared in both the AND and ANDNP and
      if (!Y.getNode())
        return SDValue();

      // Validate that X, Y, and Mask are BIT_CONVERTS, and see through them.
      // Look through mask bitcast.
      if (Mask.getOpcode() == ISD::BITCAST)
        Mask = Mask.getOperand(0);
      if (X.getOpcode() == ISD::BITCAST)
        X = X.getOperand(0);
      if (Y.getOpcode() == ISD::BITCAST)
        Y = Y.getOperand(0);

      EVT MaskVT = Mask.getValueType();

      // Validate that the Mask operand is a vector sra node.
      // FIXME: what to do for bytes, since there is a psignb/pblendvb, but
      // there is no psrai.b
      unsigned EltBits = MaskVT.getVectorElementType().getSizeInBits();
      unsigned SraAmt = ~0;
      if (Mask.getOpcode() == ISD::SRA) {
        if (auto *AmtBV = dyn_cast<BuildVectorSDNode>(Mask.getOperand(1)))
          if (auto *AmtConst = AmtBV->getConstantSplatNode())
            SraAmt = AmtConst->getZExtValue();
      } else if (Mask.getOpcode() == X86ISD::VSRAI) {
        SDValue SraC = Mask.getOperand(1);
        SraAmt  = cast<ConstantSDNode>(SraC)->getZExtValue();
      }
      if ((SraAmt + 1) != EltBits)
        return SDValue();

      SDLoc DL(N);

      // Now we know we at least have a plendvb with the mask val.  See if
      // we can form a psignb/w/d.
      // psign = x.type == y.type == mask.type && y = sub(0, x);
      if (Y.getOpcode() == ISD::SUB && Y.getOperand(1) == X &&
          ISD::isBuildVectorAllZeros(Y.getOperand(0).getNode()) &&
          X.getValueType() == MaskVT && Y.getValueType() == MaskVT) {
        assert((EltBits == 8 || EltBits == 16 || EltBits == 32) &&
               "Unsupported VT for PSIGN");
        Mask = DAG.getNode(X86ISD::PSIGN, DL, MaskVT, X, Mask.getOperand(0));
        return DAG.getNode(ISD::BITCAST, DL, VT, Mask);
      }
      // PBLENDVB only available on SSE 4.1
      if (!Subtarget->hasSSE41())
        return SDValue();

      EVT BlendVT = (VT == MVT::v4i64) ? MVT::v32i8 : MVT::v16i8;

      X = DAG.getNode(ISD::BITCAST, DL, BlendVT, X);
      Y = DAG.getNode(ISD::BITCAST, DL, BlendVT, Y);
      Mask = DAG.getNode(ISD::BITCAST, DL, BlendVT, Mask);
      Mask = DAG.getNode(ISD::VSELECT, DL, BlendVT, Mask, Y, X);
      return DAG.getNode(ISD::BITCAST, DL, VT, Mask);
    }
  }

  if (VT != MVT::i16 && VT != MVT::i32 && VT != MVT::i64)
    return SDValue();

  // fold (or (x << c) | (y >> (64 - c))) ==> (shld64 x, y, c)
  MachineFunction &MF = DAG.getMachineFunction();
  bool OptForSize =
      MF.getFunction()->hasFnAttribute(Attribute::OptimizeForSize);

  // SHLD/SHRD instructions have lower register pressure, but on some
  // platforms they have higher latency than the equivalent
  // series of shifts/or that would otherwise be generated.
  // Don't fold (or (x << c) | (y >> (64 - c))) if SHLD/SHRD instructions
  // have higher latencies and we are not optimizing for size.
  if (!OptForSize && Subtarget->isSHLDSlow())
    return SDValue();

  if (N0.getOpcode() == ISD::SRL && N1.getOpcode() == ISD::SHL)
    std::swap(N0, N1);
  if (N0.getOpcode() != ISD::SHL || N1.getOpcode() != ISD::SRL)
    return SDValue();
  if (!N0.hasOneUse() || !N1.hasOneUse())
    return SDValue();

  SDValue ShAmt0 = N0.getOperand(1);
  if (ShAmt0.getValueType() != MVT::i8)
    return SDValue();
  SDValue ShAmt1 = N1.getOperand(1);
  if (ShAmt1.getValueType() != MVT::i8)
    return SDValue();
  if (ShAmt0.getOpcode() == ISD::TRUNCATE)
    ShAmt0 = ShAmt0.getOperand(0);
  if (ShAmt1.getOpcode() == ISD::TRUNCATE)
    ShAmt1 = ShAmt1.getOperand(0);

  SDLoc DL(N);
  unsigned Opc = X86ISD::SHLD;
  SDValue Op0 = N0.getOperand(0);
  SDValue Op1 = N1.getOperand(0);
  if (ShAmt0.getOpcode() == ISD::SUB) {
    Opc = X86ISD::SHRD;
    std::swap(Op0, Op1);
    std::swap(ShAmt0, ShAmt1);
  }

  unsigned Bits = VT.getSizeInBits();
  if (ShAmt1.getOpcode() == ISD::SUB) {
    SDValue Sum = ShAmt1.getOperand(0);
    if (ConstantSDNode *SumC = dyn_cast<ConstantSDNode>(Sum)) {
      SDValue ShAmt1Op1 = ShAmt1.getOperand(1);
      if (ShAmt1Op1.getNode()->getOpcode() == ISD::TRUNCATE)
        ShAmt1Op1 = ShAmt1Op1.getOperand(0);
      if (SumC->getSExtValue() == Bits && ShAmt1Op1 == ShAmt0)
        return DAG.getNode(Opc, DL, VT,
                           Op0, Op1,
                           DAG.getNode(ISD::TRUNCATE, DL,
                                       MVT::i8, ShAmt0));
    }
  } else if (ConstantSDNode *ShAmt1C = dyn_cast<ConstantSDNode>(ShAmt1)) {
    ConstantSDNode *ShAmt0C = dyn_cast<ConstantSDNode>(ShAmt0);
    if (ShAmt0C &&
        ShAmt0C->getSExtValue() + ShAmt1C->getSExtValue() == Bits)
      return DAG.getNode(Opc, DL, VT,
                         N0.getOperand(0), N1.getOperand(0),
                         DAG.getNode(ISD::TRUNCATE, DL,
                                       MVT::i8, ShAmt0));
  }

  return SDValue();
}

// Generate NEG and CMOV for integer abs.
static SDValue performIntegerAbsCombine(SDNode *N, SelectionDAG &DAG) {
  EVT VT = N->getValueType(0);

  // Since X86 does not have CMOV for 8-bit integer, we don't convert
  // 8-bit integer abs to NEG and CMOV.
  if (VT.isInteger() && VT.getSizeInBits() == 8)
    return SDValue();

  SDValue N0 = N->getOperand(0);
  SDValue N1 = N->getOperand(1);
  SDLoc DL(N);

  // Check pattern of XOR(ADD(X,Y), Y) where Y is SRA(X, size(X)-1)
  // and change it to SUB and CMOV.
  if (VT.isInteger() && N->getOpcode() == ISD::XOR &&
      N0.getOpcode() == ISD::ADD &&
      N0.getOperand(1) == N1 &&
      N1.getOpcode() == ISD::SRA &&
      N1.getOperand(0) == N0.getOperand(0))
    if (ConstantSDNode *Y1C = dyn_cast<ConstantSDNode>(N1.getOperand(1)))
      if (Y1C->getAPIntValue() == VT.getSizeInBits()-1) {
        // Generate SUB & CMOV.
        SDValue Neg = DAG.getNode(X86ISD::SUB, DL, DAG.getVTList(VT, MVT::i32),
                                  DAG.getConstant(0, VT), N0.getOperand(0));

        SDValue Ops[] = { N0.getOperand(0), Neg,
                          DAG.getConstant(X86::COND_GE, MVT::i8),
                          SDValue(Neg.getNode(), 1) };
        return DAG.getNode(X86ISD::CMOV, DL, DAG.getVTList(VT, MVT::Glue), Ops);
      }
  return SDValue();
}

// PerformXorCombine - Attempts to turn XOR nodes into BLSMSK nodes
static SDValue PerformXorCombine(SDNode *N, SelectionDAG &DAG,
                                 TargetLowering::DAGCombinerInfo &DCI,
                                 const X86Subtarget *Subtarget) {
  if (DCI.isBeforeLegalizeOps())
    return SDValue();

  if (Subtarget->hasCMov()) {
    SDValue RV = performIntegerAbsCombine(N, DAG);
    if (RV.getNode())
      return RV;
  }

  return SDValue();
}

/// PerformLOADCombine - Do target-specific dag combines on LOAD nodes.
static SDValue PerformLOADCombine(SDNode *N, SelectionDAG &DAG,
                                  TargetLowering::DAGCombinerInfo &DCI,
                                  const X86Subtarget *Subtarget) {
  LoadSDNode *Ld = cast<LoadSDNode>(N);
  EVT RegVT = Ld->getValueType(0);
  EVT MemVT = Ld->getMemoryVT();
  SDLoc dl(Ld);
  const TargetLowering &TLI = DAG.getTargetLoweringInfo();

  // For chips with slow 32-byte unaligned loads, break the 32-byte operation
  // into two 16-byte operations.
  ISD::LoadExtType Ext = Ld->getExtensionType();
  unsigned Alignment = Ld->getAlignment();
  bool IsAligned = Alignment == 0 || Alignment >= MemVT.getSizeInBits()/8;
  if (RegVT.is256BitVector() && Subtarget->isUnalignedMem32Slow() &&
      !DCI.isBeforeLegalizeOps() && !IsAligned && Ext == ISD::NON_EXTLOAD) {
    unsigned NumElems = RegVT.getVectorNumElements();
    if (NumElems < 2)
      return SDValue();

    SDValue Ptr = Ld->getBasePtr();
    SDValue Increment = DAG.getConstant(16, TLI.getPointerTy());

    EVT HalfVT = EVT::getVectorVT(*DAG.getContext(), MemVT.getScalarType(),
                                  NumElems/2);
    SDValue Load1 = DAG.getLoad(HalfVT, dl, Ld->getChain(), Ptr,
                                Ld->getPointerInfo(), Ld->isVolatile(),
                                Ld->isNonTemporal(), Ld->isInvariant(),
                                Alignment);
    Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr, Increment);
    SDValue Load2 = DAG.getLoad(HalfVT, dl, Ld->getChain(), Ptr,
                                Ld->getPointerInfo(), Ld->isVolatile(),
                                Ld->isNonTemporal(), Ld->isInvariant(),
                                std::min(16U, Alignment));
    SDValue TF = DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
                             Load1.getValue(1),
                             Load2.getValue(1));

    SDValue NewVec = DAG.getUNDEF(RegVT);
    NewVec = Insert128BitVector(NewVec, Load1, 0, DAG, dl);
    NewVec = Insert128BitVector(NewVec, Load2, NumElems/2, DAG, dl);
    return DCI.CombineTo(N, NewVec, TF, true);
  }

  return SDValue();
}

/// PerformMLOADCombine - Resolve extending loads
static SDValue PerformMLOADCombine(SDNode *N, SelectionDAG &DAG,
                                   TargetLowering::DAGCombinerInfo &DCI,
                                   const X86Subtarget *Subtarget) {
  MaskedLoadSDNode *Mld = cast<MaskedLoadSDNode>(N);
  if (Mld->getExtensionType() != ISD::SEXTLOAD)
    return SDValue();

  EVT VT = Mld->getValueType(0);
  unsigned NumElems = VT.getVectorNumElements();
  EVT LdVT = Mld->getMemoryVT();
  SDLoc dl(Mld);

  assert(LdVT != VT && "Cannot extend to the same type");
  unsigned ToSz = VT.getVectorElementType().getSizeInBits();
  unsigned FromSz = LdVT.getVectorElementType().getSizeInBits();
  // From, To sizes and ElemCount must be pow of two
  assert (isPowerOf2_32(NumElems * FromSz * ToSz) &&
    "Unexpected size for extending masked load");

  unsigned SizeRatio  = ToSz / FromSz;
  assert(SizeRatio * NumElems * FromSz == VT.getSizeInBits());

  // Create a type on which we perform the shuffle
  EVT WideVecVT = EVT::getVectorVT(*DAG.getContext(),
          LdVT.getScalarType(), NumElems*SizeRatio);
  assert(WideVecVT.getSizeInBits() == VT.getSizeInBits());

  // Convert Src0 value
  SDValue WideSrc0 = DAG.getNode(ISD::BITCAST, dl, WideVecVT, Mld->getSrc0());
  if (Mld->getSrc0().getOpcode() != ISD::UNDEF) {
    SmallVector<int, 16> ShuffleVec(NumElems * SizeRatio, -1);
    for (unsigned i = 0; i != NumElems; ++i)
      ShuffleVec[i] = i * SizeRatio;

    // Can't shuffle using an illegal type.
    assert (DAG.getTargetLoweringInfo().isTypeLegal(WideVecVT)
            && "WideVecVT should be legal");
    WideSrc0 = DAG.getVectorShuffle(WideVecVT, dl, WideSrc0,
                                    DAG.getUNDEF(WideVecVT), &ShuffleVec[0]);
  }
  // Prepare the new mask
  SDValue NewMask;
  SDValue Mask = Mld->getMask();
  if (Mask.getValueType() == VT) {
    // Mask and original value have the same type
    NewMask = DAG.getNode(ISD::BITCAST, dl, WideVecVT, Mask);
    SmallVector<int, 16> ShuffleVec(NumElems * SizeRatio, -1);
    for (unsigned i = 0; i != NumElems; ++i)
      ShuffleVec[i] = i * SizeRatio;
    for (unsigned i = NumElems; i != NumElems*SizeRatio; ++i)
      ShuffleVec[i] = NumElems*SizeRatio;
    NewMask = DAG.getVectorShuffle(WideVecVT, dl, NewMask,
                                   DAG.getConstant(0, WideVecVT),
                                   &ShuffleVec[0]);
  }
  else {
    assert(Mask.getValueType().getVectorElementType() == MVT::i1);
    unsigned WidenNumElts = NumElems*SizeRatio;
    unsigned MaskNumElts = VT.getVectorNumElements();
    EVT NewMaskVT = EVT::getVectorVT(*DAG.getContext(),  MVT::i1,
                                     WidenNumElts);

    unsigned NumConcat = WidenNumElts / MaskNumElts;
    SmallVector<SDValue, 16> Ops(NumConcat);
    SDValue ZeroVal = DAG.getConstant(0, Mask.getValueType());
    Ops[0] = Mask;
    for (unsigned i = 1; i != NumConcat; ++i)
      Ops[i] = ZeroVal;

    NewMask = DAG.getNode(ISD::CONCAT_VECTORS, dl, NewMaskVT, Ops);
  }

  SDValue WideLd = DAG.getMaskedLoad(WideVecVT, dl, Mld->getChain(),
                                     Mld->getBasePtr(), NewMask, WideSrc0,
                                     Mld->getMemoryVT(), Mld->getMemOperand(),
                                     ISD::NON_EXTLOAD);
  SDValue NewVec = DAG.getNode(X86ISD::VSEXT, dl, VT, WideLd);
  return DCI.CombineTo(N, NewVec, WideLd.getValue(1), true);

}
/// PerformMSTORECombine - Resolve truncating stores
static SDValue PerformMSTORECombine(SDNode *N, SelectionDAG &DAG,
                                    const X86Subtarget *Subtarget) {
  MaskedStoreSDNode *Mst = cast<MaskedStoreSDNode>(N);
  if (!Mst->isTruncatingStore())
    return SDValue();

  EVT VT = Mst->getValue().getValueType();
  unsigned NumElems = VT.getVectorNumElements();
  EVT StVT = Mst->getMemoryVT();
  SDLoc dl(Mst);

  assert(StVT != VT && "Cannot truncate to the same type");
  unsigned FromSz = VT.getVectorElementType().getSizeInBits();
  unsigned ToSz = StVT.getVectorElementType().getSizeInBits();

  // From, To sizes and ElemCount must be pow of two
  assert (isPowerOf2_32(NumElems * FromSz * ToSz) &&
    "Unexpected size for truncating masked store");
  // We are going to use the original vector elt for storing.
  // Accumulated smaller vector elements must be a multiple of the store size.
  assert (((NumElems * FromSz) % ToSz) == 0 &&
          "Unexpected ratio for truncating masked store");

  unsigned SizeRatio  = FromSz / ToSz;
  assert(SizeRatio * NumElems * ToSz == VT.getSizeInBits());

  // Create a type on which we perform the shuffle
  EVT WideVecVT = EVT::getVectorVT(*DAG.getContext(),
          StVT.getScalarType(), NumElems*SizeRatio);

  assert(WideVecVT.getSizeInBits() == VT.getSizeInBits());

  SDValue WideVec = DAG.getNode(ISD::BITCAST, dl, WideVecVT, Mst->getValue());
  SmallVector<int, 16> ShuffleVec(NumElems * SizeRatio, -1);
  for (unsigned i = 0; i != NumElems; ++i)
    ShuffleVec[i] = i * SizeRatio;

  // Can't shuffle using an illegal type.
  assert (DAG.getTargetLoweringInfo().isTypeLegal(WideVecVT)
          && "WideVecVT should be legal");

  SDValue TruncatedVal = DAG.getVectorShuffle(WideVecVT, dl, WideVec,
                                        DAG.getUNDEF(WideVecVT),
                                        &ShuffleVec[0]);

  SDValue NewMask;
  SDValue Mask = Mst->getMask();
  if (Mask.getValueType() == VT) {
    // Mask and original value have the same type
    NewMask = DAG.getNode(ISD::BITCAST, dl, WideVecVT, Mask);
    for (unsigned i = 0; i != NumElems; ++i)
      ShuffleVec[i] = i * SizeRatio;
    for (unsigned i = NumElems; i != NumElems*SizeRatio; ++i)
      ShuffleVec[i] = NumElems*SizeRatio;
    NewMask = DAG.getVectorShuffle(WideVecVT, dl, NewMask,
                                   DAG.getConstant(0, WideVecVT),
                                   &ShuffleVec[0]);
  }
  else {
    assert(Mask.getValueType().getVectorElementType() == MVT::i1);
    unsigned WidenNumElts = NumElems*SizeRatio;
    unsigned MaskNumElts = VT.getVectorNumElements();
    EVT NewMaskVT = EVT::getVectorVT(*DAG.getContext(),  MVT::i1,
                                     WidenNumElts);

    unsigned NumConcat = WidenNumElts / MaskNumElts;
    SmallVector<SDValue, 16> Ops(NumConcat);
    SDValue ZeroVal = DAG.getConstant(0, Mask.getValueType());
    Ops[0] = Mask;
    for (unsigned i = 1; i != NumConcat; ++i)
      Ops[i] = ZeroVal;

    NewMask = DAG.getNode(ISD::CONCAT_VECTORS, dl, NewMaskVT, Ops);
  }

  return DAG.getMaskedStore(Mst->getChain(), dl, TruncatedVal, Mst->getBasePtr(),
                            NewMask, StVT, Mst->getMemOperand(), false);
}
/// PerformSTORECombine - Do target-specific dag combines on STORE nodes.
static SDValue PerformSTORECombine(SDNode *N, SelectionDAG &DAG,
                                   const X86Subtarget *Subtarget) {
  StoreSDNode *St = cast<StoreSDNode>(N);
  EVT VT = St->getValue().getValueType();
  EVT StVT = St->getMemoryVT();
  SDLoc dl(St);
  SDValue StoredVal = St->getOperand(1);
  const TargetLowering &TLI = DAG.getTargetLoweringInfo();

  // If we are saving a concatenation of two XMM registers and 32-byte stores
  // are slow, such as on Sandy Bridge, perform two 16-byte stores.
  unsigned Alignment = St->getAlignment();
  bool IsAligned = Alignment == 0 || Alignment >= VT.getSizeInBits()/8;
  if (VT.is256BitVector() && Subtarget->isUnalignedMem32Slow() &&
      StVT == VT && !IsAligned) {
    unsigned NumElems = VT.getVectorNumElements();
    if (NumElems < 2)
      return SDValue();

    SDValue Value0 = Extract128BitVector(StoredVal, 0, DAG, dl);
    SDValue Value1 = Extract128BitVector(StoredVal, NumElems/2, DAG, dl);

    SDValue Stride = DAG.getConstant(16, TLI.getPointerTy());
    SDValue Ptr0 = St->getBasePtr();
    SDValue Ptr1 = DAG.getNode(ISD::ADD, dl, Ptr0.getValueType(), Ptr0, Stride);

    SDValue Ch0 = DAG.getStore(St->getChain(), dl, Value0, Ptr0,
                                St->getPointerInfo(), St->isVolatile(),
                                St->isNonTemporal(), Alignment);
    SDValue Ch1 = DAG.getStore(St->getChain(), dl, Value1, Ptr1,
                                St->getPointerInfo(), St->isVolatile(),
                                St->isNonTemporal(),
                                std::min(16U, Alignment));
    return DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Ch0, Ch1);
  }

  // Optimize trunc store (of multiple scalars) to shuffle and store.
  // First, pack all of the elements in one place. Next, store to memory
  // in fewer chunks.
  if (St->isTruncatingStore() && VT.isVector()) {
    const TargetLowering &TLI = DAG.getTargetLoweringInfo();
    unsigned NumElems = VT.getVectorNumElements();
    assert(StVT != VT && "Cannot truncate to the same type");
    unsigned FromSz = VT.getVectorElementType().getSizeInBits();
    unsigned ToSz = StVT.getVectorElementType().getSizeInBits();

    // From, To sizes and ElemCount must be pow of two
    if (!isPowerOf2_32(NumElems * FromSz * ToSz)) return SDValue();
    // We are going to use the original vector elt for storing.
    // Accumulated smaller vector elements must be a multiple of the store size.
    if (0 != (NumElems * FromSz) % ToSz) return SDValue();

    unsigned SizeRatio  = FromSz / ToSz;

    assert(SizeRatio * NumElems * ToSz == VT.getSizeInBits());

    // Create a type on which we perform the shuffle
    EVT WideVecVT = EVT::getVectorVT(*DAG.getContext(),
            StVT.getScalarType(), NumElems*SizeRatio);

    assert(WideVecVT.getSizeInBits() == VT.getSizeInBits());

    SDValue WideVec = DAG.getNode(ISD::BITCAST, dl, WideVecVT, St->getValue());
    SmallVector<int, 8> ShuffleVec(NumElems * SizeRatio, -1);
    for (unsigned i = 0; i != NumElems; ++i)
      ShuffleVec[i] = i * SizeRatio;

    // Can't shuffle using an illegal type.
    if (!TLI.isTypeLegal(WideVecVT))
      return SDValue();

    SDValue Shuff = DAG.getVectorShuffle(WideVecVT, dl, WideVec,
                                         DAG.getUNDEF(WideVecVT),
                                         &ShuffleVec[0]);
    // At this point all of the data is stored at the bottom of the
    // register. We now need to save it to mem.

    // Find the largest store unit
    MVT StoreType = MVT::i8;
    for (MVT Tp : MVT::integer_valuetypes()) {
      if (TLI.isTypeLegal(Tp) && Tp.getSizeInBits() <= NumElems * ToSz)
        StoreType = Tp;
    }

    // On 32bit systems, we can't save 64bit integers. Try bitcasting to F64.
    if (TLI.isTypeLegal(MVT::f64) && StoreType.getSizeInBits() < 64 &&
        (64 <= NumElems * ToSz))
      StoreType = MVT::f64;

    // Bitcast the original vector into a vector of store-size units
    EVT StoreVecVT = EVT::getVectorVT(*DAG.getContext(),
            StoreType, VT.getSizeInBits()/StoreType.getSizeInBits());
    assert(StoreVecVT.getSizeInBits() == VT.getSizeInBits());
    SDValue ShuffWide = DAG.getNode(ISD::BITCAST, dl, StoreVecVT, Shuff);
    SmallVector<SDValue, 8> Chains;
    SDValue Increment = DAG.getConstant(StoreType.getSizeInBits()/8,
                                        TLI.getPointerTy());
    SDValue Ptr = St->getBasePtr();

    // Perform one or more big stores into memory.
    for (unsigned i=0, e=(ToSz*NumElems)/StoreType.getSizeInBits(); i!=e; ++i) {
      SDValue SubVec = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl,
                                   StoreType, ShuffWide,
                                   DAG.getIntPtrConstant(i));
      SDValue Ch = DAG.getStore(St->getChain(), dl, SubVec, Ptr,
                                St->getPointerInfo(), St->isVolatile(),
                                St->isNonTemporal(), St->getAlignment());
      Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr, Increment);
      Chains.push_back(Ch);
    }

    return DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Chains);
  }

  // Turn load->store of MMX types into GPR load/stores.  This avoids clobbering
  // the FP state in cases where an emms may be missing.
  // A preferable solution to the general problem is to figure out the right
  // places to insert EMMS.  This qualifies as a quick hack.

  // Similarly, turn load->store of i64 into double load/stores in 32-bit mode.
  if (VT.getSizeInBits() != 64)
    return SDValue();

  const Function *F = DAG.getMachineFunction().getFunction();
  bool NoImplicitFloatOps = F->hasFnAttribute(Attribute::NoImplicitFloat);
  bool F64IsLegal = !DAG.getTarget().Options.UseSoftFloat && !NoImplicitFloatOps
                     && Subtarget->hasSSE2();
  if ((VT.isVector() ||
       (VT == MVT::i64 && F64IsLegal && !Subtarget->is64Bit())) &&
      isa<LoadSDNode>(St->getValue()) &&
      !cast<LoadSDNode>(St->getValue())->isVolatile() &&
      St->getChain().hasOneUse() && !St->isVolatile()) {
    SDNode* LdVal = St->getValue().getNode();
    LoadSDNode *Ld = nullptr;
    int TokenFactorIndex = -1;
    SmallVector<SDValue, 8> Ops;
    SDNode* ChainVal = St->getChain().getNode();
    // Must be a store of a load.  We currently handle two cases:  the load
    // is a direct child, and it's under an intervening TokenFactor.  It is
    // possible to dig deeper under nested TokenFactors.
    if (ChainVal == LdVal)
      Ld = cast<LoadSDNode>(St->getChain());
    else if (St->getValue().hasOneUse() &&
             ChainVal->getOpcode() == ISD::TokenFactor) {
      for (unsigned i = 0, e = ChainVal->getNumOperands(); i != e; ++i) {
        if (ChainVal->getOperand(i).getNode() == LdVal) {
          TokenFactorIndex = i;
          Ld = cast<LoadSDNode>(St->getValue());
        } else
          Ops.push_back(ChainVal->getOperand(i));
      }
    }

    if (!Ld || !ISD::isNormalLoad(Ld))
      return SDValue();

    // If this is not the MMX case, i.e. we are just turning i64 load/store
    // into f64 load/store, avoid the transformation if there are multiple
    // uses of the loaded value.
    if (!VT.isVector() && !Ld->hasNUsesOfValue(1, 0))
      return SDValue();

    SDLoc LdDL(Ld);
    SDLoc StDL(N);
    // If we are a 64-bit capable x86, lower to a single movq load/store pair.
    // Otherwise, if it's legal to use f64 SSE instructions, use f64 load/store
    // pair instead.
    if (Subtarget->is64Bit() || F64IsLegal) {
      EVT LdVT = Subtarget->is64Bit() ? MVT::i64 : MVT::f64;
      SDValue NewLd = DAG.getLoad(LdVT, LdDL, Ld->getChain(), Ld->getBasePtr(),
                                  Ld->getPointerInfo(), Ld->isVolatile(),
                                  Ld->isNonTemporal(), Ld->isInvariant(),
                                  Ld->getAlignment());
      SDValue NewChain = NewLd.getValue(1);
      if (TokenFactorIndex != -1) {
        Ops.push_back(NewChain);
        NewChain = DAG.getNode(ISD::TokenFactor, LdDL, MVT::Other, Ops);
      }
      return DAG.getStore(NewChain, StDL, NewLd, St->getBasePtr(),
                          St->getPointerInfo(),
                          St->isVolatile(), St->isNonTemporal(),
                          St->getAlignment());
    }

    // Otherwise, lower to two pairs of 32-bit loads / stores.
    SDValue LoAddr = Ld->getBasePtr();
    SDValue HiAddr = DAG.getNode(ISD::ADD, LdDL, MVT::i32, LoAddr,
                                 DAG.getConstant(4, MVT::i32));

    SDValue LoLd = DAG.getLoad(MVT::i32, LdDL, Ld->getChain(), LoAddr,
                               Ld->getPointerInfo(),
                               Ld->isVolatile(), Ld->isNonTemporal(),
                               Ld->isInvariant(), Ld->getAlignment());
    SDValue HiLd = DAG.getLoad(MVT::i32, LdDL, Ld->getChain(), HiAddr,
                               Ld->getPointerInfo().getWithOffset(4),
                               Ld->isVolatile(), Ld->isNonTemporal(),
                               Ld->isInvariant(),
                               MinAlign(Ld->getAlignment(), 4));

    SDValue NewChain = LoLd.getValue(1);
    if (TokenFactorIndex != -1) {
      Ops.push_back(LoLd);
      Ops.push_back(HiLd);
      NewChain = DAG.getNode(ISD::TokenFactor, LdDL, MVT::Other, Ops);
    }

    LoAddr = St->getBasePtr();
    HiAddr = DAG.getNode(ISD::ADD, StDL, MVT::i32, LoAddr,
                         DAG.getConstant(4, MVT::i32));

    SDValue LoSt = DAG.getStore(NewChain, StDL, LoLd, LoAddr,
                                St->getPointerInfo(),
                                St->isVolatile(), St->isNonTemporal(),
                                St->getAlignment());
    SDValue HiSt = DAG.getStore(NewChain, StDL, HiLd, HiAddr,
                                St->getPointerInfo().getWithOffset(4),
                                St->isVolatile(),
                                St->isNonTemporal(),
                                MinAlign(St->getAlignment(), 4));
    return DAG.getNode(ISD::TokenFactor, StDL, MVT::Other, LoSt, HiSt);
  }
  return SDValue();
}

/// Return 'true' if this vector operation is "horizontal"
/// and return the operands for the horizontal operation in LHS and RHS.  A
/// horizontal operation performs the binary operation on successive elements
/// of its first operand, then on successive elements of its second operand,
/// returning the resulting values in a vector.  For example, if
///   A = < float a0, float a1, float a2, float a3 >
/// and
///   B = < float b0, float b1, float b2, float b3 >
/// then the result of doing a horizontal operation on A and B is
///   A horizontal-op B = < a0 op a1, a2 op a3, b0 op b1, b2 op b3 >.
/// In short, LHS and RHS are inspected to see if LHS op RHS is of the form
/// A horizontal-op B, for some already available A and B, and if so then LHS is
/// set to A, RHS to B, and the routine returns 'true'.
/// Note that the binary operation should have the property that if one of the
/// operands is UNDEF then the result is UNDEF.
static bool isHorizontalBinOp(SDValue &LHS, SDValue &RHS, bool IsCommutative) {
  // Look for the following pattern: if
  //   A = < float a0, float a1, float a2, float a3 >
  //   B = < float b0, float b1, float b2, float b3 >
  // and
  //   LHS = VECTOR_SHUFFLE A, B, <0, 2, 4, 6>
  //   RHS = VECTOR_SHUFFLE A, B, <1, 3, 5, 7>
  // then LHS op RHS = < a0 op a1, a2 op a3, b0 op b1, b2 op b3 >
  // which is A horizontal-op B.

  // At least one of the operands should be a vector shuffle.
  if (LHS.getOpcode() != ISD::VECTOR_SHUFFLE &&
      RHS.getOpcode() != ISD::VECTOR_SHUFFLE)
    return false;

  MVT VT = LHS.getSimpleValueType();

  assert((VT.is128BitVector() || VT.is256BitVector()) &&
         "Unsupported vector type for horizontal add/sub");

  // Handle 128 and 256-bit vector lengths. AVX defines horizontal add/sub to
  // operate independently on 128-bit lanes.
  unsigned NumElts = VT.getVectorNumElements();
  unsigned NumLanes = VT.getSizeInBits()/128;
  unsigned NumLaneElts = NumElts / NumLanes;
  assert((NumLaneElts % 2 == 0) &&
         "Vector type should have an even number of elements in each lane");
  unsigned HalfLaneElts = NumLaneElts/2;

  // View LHS in the form
  //   LHS = VECTOR_SHUFFLE A, B, LMask
  // If LHS is not a shuffle then pretend it is the shuffle
  //   LHS = VECTOR_SHUFFLE LHS, undef, <0, 1, ..., N-1>
  // NOTE: in what follows a default initialized SDValue represents an UNDEF of
  // type VT.
  SDValue A, B;
  SmallVector<int, 16> LMask(NumElts);
  if (LHS.getOpcode() == ISD::VECTOR_SHUFFLE) {
    if (LHS.getOperand(0).getOpcode() != ISD::UNDEF)
      A = LHS.getOperand(0);
    if (LHS.getOperand(1).getOpcode() != ISD::UNDEF)
      B = LHS.getOperand(1);
    ArrayRef<int> Mask = cast<ShuffleVectorSDNode>(LHS.getNode())->getMask();
    std::copy(Mask.begin(), Mask.end(), LMask.begin());
  } else {
    if (LHS.getOpcode() != ISD::UNDEF)
      A = LHS;
    for (unsigned i = 0; i != NumElts; ++i)
      LMask[i] = i;
  }

  // Likewise, view RHS in the form
  //   RHS = VECTOR_SHUFFLE C, D, RMask
  SDValue C, D;
  SmallVector<int, 16> RMask(NumElts);
  if (RHS.getOpcode() == ISD::VECTOR_SHUFFLE) {
    if (RHS.getOperand(0).getOpcode() != ISD::UNDEF)
      C = RHS.getOperand(0);
    if (RHS.getOperand(1).getOpcode() != ISD::UNDEF)
      D = RHS.getOperand(1);
    ArrayRef<int> Mask = cast<ShuffleVectorSDNode>(RHS.getNode())->getMask();
    std::copy(Mask.begin(), Mask.end(), RMask.begin());
  } else {
    if (RHS.getOpcode() != ISD::UNDEF)
      C = RHS;
    for (unsigned i = 0; i != NumElts; ++i)
      RMask[i] = i;
  }

  // Check that the shuffles are both shuffling the same vectors.
  if (!(A == C && B == D) && !(A == D && B == C))
    return false;

  // If everything is UNDEF then bail out: it would be better to fold to UNDEF.
  if (!A.getNode() && !B.getNode())
    return false;

  // If A and B occur in reverse order in RHS, then "swap" them (which means
  // rewriting the mask).
  if (A != C)
    CommuteVectorShuffleMask(RMask, NumElts);

  // At this point LHS and RHS are equivalent to
  //   LHS = VECTOR_SHUFFLE A, B, LMask
  //   RHS = VECTOR_SHUFFLE A, B, RMask
  // Check that the masks correspond to performing a horizontal operation.
  for (unsigned l = 0; l != NumElts; l += NumLaneElts) {
    for (unsigned i = 0; i != NumLaneElts; ++i) {
      int LIdx = LMask[i+l], RIdx = RMask[i+l];

      // Ignore any UNDEF components.
      if (LIdx < 0 || RIdx < 0 ||
          (!A.getNode() && (LIdx < (int)NumElts || RIdx < (int)NumElts)) ||
          (!B.getNode() && (LIdx >= (int)NumElts || RIdx >= (int)NumElts)))
        continue;

      // Check that successive elements are being operated on.  If not, this is
      // not a horizontal operation.
      unsigned Src = (i/HalfLaneElts); // each lane is split between srcs
      int Index = 2*(i%HalfLaneElts) + NumElts*Src + l;
      if (!(LIdx == Index && RIdx == Index + 1) &&
          !(IsCommutative && LIdx == Index + 1 && RIdx == Index))
        return false;
    }
  }

  LHS = A.getNode() ? A : B; // If A is 'UNDEF', use B for it.
  RHS = B.getNode() ? B : A; // If B is 'UNDEF', use A for it.
  return true;
}

/// Do target-specific dag combines on floating point adds.
static SDValue PerformFADDCombine(SDNode *N, SelectionDAG &DAG,
                                  const X86Subtarget *Subtarget) {
  EVT VT = N->getValueType(0);
  SDValue LHS = N->getOperand(0);
  SDValue RHS = N->getOperand(1);

  // Try to synthesize horizontal adds from adds of shuffles.
  if (((Subtarget->hasSSE3() && (VT == MVT::v4f32 || VT == MVT::v2f64)) ||
       (Subtarget->hasFp256() && (VT == MVT::v8f32 || VT == MVT::v4f64))) &&
      isHorizontalBinOp(LHS, RHS, true))
    return DAG.getNode(X86ISD::FHADD, SDLoc(N), VT, LHS, RHS);
  return SDValue();
}

/// Do target-specific dag combines on floating point subs.
static SDValue PerformFSUBCombine(SDNode *N, SelectionDAG &DAG,
                                  const X86Subtarget *Subtarget) {
  EVT VT = N->getValueType(0);
  SDValue LHS = N->getOperand(0);
  SDValue RHS = N->getOperand(1);

  // Try to synthesize horizontal subs from subs of shuffles.
  if (((Subtarget->hasSSE3() && (VT == MVT::v4f32 || VT == MVT::v2f64)) ||
       (Subtarget->hasFp256() && (VT == MVT::v8f32 || VT == MVT::v4f64))) &&
      isHorizontalBinOp(LHS, RHS, false))
    return DAG.getNode(X86ISD::FHSUB, SDLoc(N), VT, LHS, RHS);
  return SDValue();
}

/// Do target-specific dag combines on X86ISD::FOR and X86ISD::FXOR nodes.
static SDValue PerformFORCombine(SDNode *N, SelectionDAG &DAG) {
  assert(N->getOpcode() == X86ISD::FOR || N->getOpcode() == X86ISD::FXOR);

  // F[X]OR(0.0, x) -> x
  if (ConstantFPSDNode *C = dyn_cast<ConstantFPSDNode>(N->getOperand(0)))
    if (C->getValueAPF().isPosZero())
      return N->getOperand(1);

  // F[X]OR(x, 0.0) -> x
  if (ConstantFPSDNode *C = dyn_cast<ConstantFPSDNode>(N->getOperand(1)))
    if (C->getValueAPF().isPosZero())
      return N->getOperand(0);
  return SDValue();
}

/// Do target-specific dag combines on X86ISD::FMIN and X86ISD::FMAX nodes.
static SDValue PerformFMinFMaxCombine(SDNode *N, SelectionDAG &DAG) {
  assert(N->getOpcode() == X86ISD::FMIN || N->getOpcode() == X86ISD::FMAX);

  // Only perform optimizations if UnsafeMath is used.
  if (!DAG.getTarget().Options.UnsafeFPMath)
    return SDValue();

  // If we run in unsafe-math mode, then convert the FMAX and FMIN nodes
  // into FMINC and FMAXC, which are Commutative operations.
  unsigned NewOp = 0;
  switch (N->getOpcode()) {
    default: llvm_unreachable("unknown opcode");
    case X86ISD::FMIN:  NewOp = X86ISD::FMINC; break;
    case X86ISD::FMAX:  NewOp = X86ISD::FMAXC; break;
  }

  return DAG.getNode(NewOp, SDLoc(N), N->getValueType(0),
                     N->getOperand(0), N->getOperand(1));
}

/// Do target-specific dag combines on X86ISD::FAND nodes.
static SDValue PerformFANDCombine(SDNode *N, SelectionDAG &DAG) {
  // FAND(0.0, x) -> 0.0
  if (ConstantFPSDNode *C = dyn_cast<ConstantFPSDNode>(N->getOperand(0)))
    if (C->getValueAPF().isPosZero())
      return N->getOperand(0);

  // FAND(x, 0.0) -> 0.0
  if (ConstantFPSDNode *C = dyn_cast<ConstantFPSDNode>(N->getOperand(1)))
    if (C->getValueAPF().isPosZero())
      return N->getOperand(1);
  
  return SDValue();
}

/// Do target-specific dag combines on X86ISD::FANDN nodes
static SDValue PerformFANDNCombine(SDNode *N, SelectionDAG &DAG) {
  // FANDN(0.0, x) -> x
  if (ConstantFPSDNode *C = dyn_cast<ConstantFPSDNode>(N->getOperand(0)))
    if (C->getValueAPF().isPosZero())
      return N->getOperand(1);

  // FANDN(x, 0.0) -> 0.0
  if (ConstantFPSDNode *C = dyn_cast<ConstantFPSDNode>(N->getOperand(1)))
    if (C->getValueAPF().isPosZero())
      return N->getOperand(1);

  return SDValue();
}

static SDValue PerformBTCombine(SDNode *N,
                                SelectionDAG &DAG,
                                TargetLowering::DAGCombinerInfo &DCI) {
  // BT ignores high bits in the bit index operand.
  SDValue Op1 = N->getOperand(1);
  if (Op1.hasOneUse()) {
    unsigned BitWidth = Op1.getValueSizeInBits();
    APInt DemandedMask = APInt::getLowBitsSet(BitWidth, Log2_32(BitWidth));
    APInt KnownZero, KnownOne;
    TargetLowering::TargetLoweringOpt TLO(DAG, !DCI.isBeforeLegalize(),
                                          !DCI.isBeforeLegalizeOps());
    const TargetLowering &TLI = DAG.getTargetLoweringInfo();
    if (TLO.ShrinkDemandedConstant(Op1, DemandedMask) ||
        TLI.SimplifyDemandedBits(Op1, DemandedMask, KnownZero, KnownOne, TLO))
      DCI.CommitTargetLoweringOpt(TLO);
  }
  return SDValue();
}

static SDValue PerformVZEXT_MOVLCombine(SDNode *N, SelectionDAG &DAG) {
  SDValue Op = N->getOperand(0);
  if (Op.getOpcode() == ISD::BITCAST)
    Op = Op.getOperand(0);
  EVT VT = N->getValueType(0), OpVT = Op.getValueType();
  if (Op.getOpcode() == X86ISD::VZEXT_LOAD &&
      VT.getVectorElementType().getSizeInBits() ==
      OpVT.getVectorElementType().getSizeInBits()) {
    return DAG.getNode(ISD::BITCAST, SDLoc(N), VT, Op);
  }
  return SDValue();
}

static SDValue PerformSIGN_EXTEND_INREGCombine(SDNode *N, SelectionDAG &DAG,
                                               const X86Subtarget *Subtarget) {
  EVT VT = N->getValueType(0);
  if (!VT.isVector())
    return SDValue();

  SDValue N0 = N->getOperand(0);
  SDValue N1 = N->getOperand(1);
  EVT ExtraVT = cast<VTSDNode>(N1)->getVT();
  SDLoc dl(N);

  // The SIGN_EXTEND_INREG to v4i64 is expensive operation on the
  // both SSE and AVX2 since there is no sign-extended shift right
  // operation on a vector with 64-bit elements.
  //(sext_in_reg (v4i64 anyext (v4i32 x )), ExtraVT) ->
  // (v4i64 sext (v4i32 sext_in_reg (v4i32 x , ExtraVT)))
  if (VT == MVT::v4i64 && (N0.getOpcode() == ISD::ANY_EXTEND ||
      N0.getOpcode() == ISD::SIGN_EXTEND)) {
    SDValue N00 = N0.getOperand(0);

    // EXTLOAD has a better solution on AVX2,
    // it may be replaced with X86ISD::VSEXT node.
    if (N00.getOpcode() == ISD::LOAD && Subtarget->hasInt256())
      if (!ISD::isNormalLoad(N00.getNode()))
        return SDValue();

    if (N00.getValueType() == MVT::v4i32 && ExtraVT.getSizeInBits() < 128) {
        SDValue Tmp = DAG.getNode(ISD::SIGN_EXTEND_INREG, dl, MVT::v4i32,
                                  N00, N1);
      return DAG.getNode(ISD::SIGN_EXTEND, dl, MVT::v4i64, Tmp);
    }
  }
  return SDValue();
}

static SDValue PerformSExtCombine(SDNode *N, SelectionDAG &DAG,
                                  TargetLowering::DAGCombinerInfo &DCI,
                                  const X86Subtarget *Subtarget) {
  SDValue N0 = N->getOperand(0);
  EVT VT = N->getValueType(0);

  // (i8,i32 sext (sdivrem (i8 x, i8 y)) ->
  // (i8,i32 (sdivrem_sext_hreg (i8 x, i8 y)
  // This exposes the sext to the sdivrem lowering, so that it directly extends
  // from AH (which we otherwise need to do contortions to access).
  if (N0.getOpcode() == ISD::SDIVREM && N0.getResNo() == 1 &&
      N0.getValueType() == MVT::i8 && VT == MVT::i32) {
    SDLoc dl(N);
    SDVTList NodeTys = DAG.getVTList(MVT::i8, VT);
    SDValue R = DAG.getNode(X86ISD::SDIVREM8_SEXT_HREG, dl, NodeTys,
                            N0.getOperand(0), N0.getOperand(1));
    DAG.ReplaceAllUsesOfValueWith(N0.getValue(0), R.getValue(0));
    return R.getValue(1);
  }

  if (!DCI.isBeforeLegalizeOps())
    return SDValue();

  if (!Subtarget->hasFp256())
    return SDValue();

  if (VT.isVector() && VT.getSizeInBits() == 256) {
    SDValue R = WidenMaskArithmetic(N, DAG, DCI, Subtarget);
    if (R.getNode())
      return R;
  }

  return SDValue();
}

static SDValue PerformFMACombine(SDNode *N, SelectionDAG &DAG,
                                 const X86Subtarget* Subtarget) {
  SDLoc dl(N);
  EVT VT = N->getValueType(0);

  // Let legalize expand this if it isn't a legal type yet.
  if (!DAG.getTargetLoweringInfo().isTypeLegal(VT))
    return SDValue();

  EVT ScalarVT = VT.getScalarType();
  if ((ScalarVT != MVT::f32 && ScalarVT != MVT::f64) ||
      (!Subtarget->hasFMA() && !Subtarget->hasFMA4()))
    return SDValue();

  SDValue A = N->getOperand(0);
  SDValue B = N->getOperand(1);
  SDValue C = N->getOperand(2);

  bool NegA = (A.getOpcode() == ISD::FNEG);
  bool NegB = (B.getOpcode() == ISD::FNEG);
  bool NegC = (C.getOpcode() == ISD::FNEG);

  // Negative multiplication when NegA xor NegB
  bool NegMul = (NegA != NegB);
  if (NegA)
    A = A.getOperand(0);
  if (NegB)
    B = B.getOperand(0);
  if (NegC)
    C = C.getOperand(0);

  unsigned Opcode;
  if (!NegMul)
    Opcode = (!NegC) ? X86ISD::FMADD : X86ISD::FMSUB;
  else
    Opcode = (!NegC) ? X86ISD::FNMADD : X86ISD::FNMSUB;

  return DAG.getNode(Opcode, dl, VT, A, B, C);
}

static SDValue PerformZExtCombine(SDNode *N, SelectionDAG &DAG,
                                  TargetLowering::DAGCombinerInfo &DCI,
                                  const X86Subtarget *Subtarget) {
  // (i32 zext (and (i8  x86isd::setcc_carry), 1)) ->
  //           (and (i32 x86isd::setcc_carry), 1)
  // This eliminates the zext. This transformation is necessary because
  // ISD::SETCC is always legalized to i8.
  SDLoc dl(N);
  SDValue N0 = N->getOperand(0);
  EVT VT = N->getValueType(0);

  if (N0.getOpcode() == ISD::AND &&
      N0.hasOneUse() &&
      N0.getOperand(0).hasOneUse()) {
    SDValue N00 = N0.getOperand(0);
    if (N00.getOpcode() == X86ISD::SETCC_CARRY) {
      ConstantSDNode *C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
      if (!C || C->getZExtValue() != 1)
        return SDValue();
      return DAG.getNode(ISD::AND, dl, VT,
                         DAG.getNode(X86ISD::SETCC_CARRY, dl, VT,
                                     N00.getOperand(0), N00.getOperand(1)),
                         DAG.getConstant(1, VT));
    }
  }

  if (N0.getOpcode() == ISD::TRUNCATE &&
      N0.hasOneUse() &&
      N0.getOperand(0).hasOneUse()) {
    SDValue N00 = N0.getOperand(0);
    if (N00.getOpcode() == X86ISD::SETCC_CARRY) {
      return DAG.getNode(ISD::AND, dl, VT,
                         DAG.getNode(X86ISD::SETCC_CARRY, dl, VT,
                                     N00.getOperand(0), N00.getOperand(1)),
                         DAG.getConstant(1, VT));
    }
  }
  if (VT.is256BitVector()) {
    SDValue R = WidenMaskArithmetic(N, DAG, DCI, Subtarget);
    if (R.getNode())
      return R;
  }

  // (i8,i32 zext (udivrem (i8 x, i8 y)) ->
  // (i8,i32 (udivrem_zext_hreg (i8 x, i8 y)
  // This exposes the zext to the udivrem lowering, so that it directly extends
  // from AH (which we otherwise need to do contortions to access).
  if (N0.getOpcode() == ISD::UDIVREM &&
      N0.getResNo() == 1 && N0.getValueType() == MVT::i8 &&
      (VT == MVT::i32 || VT == MVT::i64)) {
    SDVTList NodeTys = DAG.getVTList(MVT::i8, VT);
    SDValue R = DAG.getNode(X86ISD::UDIVREM8_ZEXT_HREG, dl, NodeTys,
                            N0.getOperand(0), N0.getOperand(1));
    DAG.ReplaceAllUsesOfValueWith(N0.getValue(0), R.getValue(0));
    return R.getValue(1);
  }

  return SDValue();
}

// Optimize x == -y --> x+y == 0
//          x != -y --> x+y != 0
static SDValue PerformISDSETCCCombine(SDNode *N, SelectionDAG &DAG,
                                      const X86Subtarget* Subtarget) {
  ISD::CondCode CC = cast<CondCodeSDNode>(N->getOperand(2))->get();
  SDValue LHS = N->getOperand(0);
  SDValue RHS = N->getOperand(1);
  EVT VT = N->getValueType(0);
  SDLoc DL(N);

  if ((CC == ISD::SETNE || CC == ISD::SETEQ) && LHS.getOpcode() == ISD::SUB)
    if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(LHS.getOperand(0)))
      if (C->getAPIntValue() == 0 && LHS.hasOneUse()) {
        SDValue addV = DAG.getNode(ISD::ADD, SDLoc(N),
                                   LHS.getValueType(), RHS, LHS.getOperand(1));
        return DAG.getSetCC(SDLoc(N), N->getValueType(0),
                            addV, DAG.getConstant(0, addV.getValueType()), CC);
      }
  if ((CC == ISD::SETNE || CC == ISD::SETEQ) && RHS.getOpcode() == ISD::SUB)
    if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(RHS.getOperand(0)))
      if (C->getAPIntValue() == 0 && RHS.hasOneUse()) {
        SDValue addV = DAG.getNode(ISD::ADD, SDLoc(N),
                                   RHS.getValueType(), LHS, RHS.getOperand(1));
        return DAG.getSetCC(SDLoc(N), N->getValueType(0),
                            addV, DAG.getConstant(0, addV.getValueType()), CC);
      }

  if (VT.getScalarType() == MVT::i1) {
    bool IsSEXT0 = (LHS.getOpcode() == ISD::SIGN_EXTEND) &&
      (LHS.getOperand(0).getValueType().getScalarType() ==  MVT::i1);
    bool IsVZero0 = ISD::isBuildVectorAllZeros(LHS.getNode());
    if (!IsSEXT0 && !IsVZero0)
      return SDValue();
    bool IsSEXT1 = (RHS.getOpcode() == ISD::SIGN_EXTEND) &&
      (RHS.getOperand(0).getValueType().getScalarType() ==  MVT::i1);
    bool IsVZero1 = ISD::isBuildVectorAllZeros(RHS.getNode());

    if (!IsSEXT1 && !IsVZero1)
      return SDValue();

    if (IsSEXT0 && IsVZero1) {
      assert(VT == LHS.getOperand(0).getValueType() && "Uexpected operand type");
      if (CC == ISD::SETEQ)
        return DAG.getNOT(DL, LHS.getOperand(0), VT);
      return LHS.getOperand(0);
    }
    if (IsSEXT1 && IsVZero0) {
      assert(VT == RHS.getOperand(0).getValueType() && "Uexpected operand type");
      if (CC == ISD::SETEQ)
        return DAG.getNOT(DL, RHS.getOperand(0), VT);
      return RHS.getOperand(0);
    }
  }

  return SDValue();
}

static SDValue PerformINSERTPSCombine(SDNode *N, SelectionDAG &DAG,
                                      const X86Subtarget *Subtarget) {
  SDLoc dl(N);
  MVT VT = N->getOperand(1)->getSimpleValueType(0);
  assert((VT == MVT::v4f32 || VT == MVT::v4i32) &&
         "X86insertps is only defined for v4x32");

  SDValue Ld = N->getOperand(1);
  if (MayFoldLoad(Ld)) {
    // Extract the countS bits from the immediate so we can get the proper
    // address when narrowing the vector load to a specific element.
    // When the second source op is a memory address, interps doesn't use
    // countS and just gets an f32 from that address.
    unsigned DestIndex =
        cast<ConstantSDNode>(N->getOperand(2))->getZExtValue() >> 6;
    Ld = NarrowVectorLoadToElement(cast<LoadSDNode>(Ld), DestIndex, DAG);
  } else
    return SDValue();

  // Create this as a scalar to vector to match the instruction pattern.
  SDValue LoadScalarToVector = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, Ld);
  // countS bits are ignored when loading from memory on insertps, which
  // means we don't need to explicitly set them to 0.
  return DAG.getNode(X86ISD::INSERTPS, dl, VT, N->getOperand(0),
                     LoadScalarToVector, N->getOperand(2));
}

// Helper function of PerformSETCCCombine. It is to materialize "setb reg"
// as "sbb reg,reg", since it can be extended without zext and produces
// an all-ones bit which is more useful than 0/1 in some cases.
static SDValue MaterializeSETB(SDLoc DL, SDValue EFLAGS, SelectionDAG &DAG,
                               MVT VT) {
  if (VT == MVT::i8)
    return DAG.getNode(ISD::AND, DL, VT,
                       DAG.getNode(X86ISD::SETCC_CARRY, DL, MVT::i8,
                                   DAG.getConstant(X86::COND_B, MVT::i8), EFLAGS),
                       DAG.getConstant(1, VT));
  assert (VT == MVT::i1 && "Unexpected type for SECCC node");
  return DAG.getNode(ISD::TRUNCATE, DL, MVT::i1,
                     DAG.getNode(X86ISD::SETCC_CARRY, DL, MVT::i8,
                                 DAG.getConstant(X86::COND_B, MVT::i8), EFLAGS));
}

// Optimize  RES = X86ISD::SETCC CONDCODE, EFLAG_INPUT
static SDValue PerformSETCCCombine(SDNode *N, SelectionDAG &DAG,
                                   TargetLowering::DAGCombinerInfo &DCI,
                                   const X86Subtarget *Subtarget) {
  SDLoc DL(N);
  X86::CondCode CC = X86::CondCode(N->getConstantOperandVal(0));
  SDValue EFLAGS = N->getOperand(1);

  if (CC == X86::COND_A) {
    // Try to convert COND_A into COND_B in an attempt to facilitate
    // materializing "setb reg".
    //
    // Do not flip "e > c", where "c" is a constant, because Cmp instruction
    // cannot take an immediate as its first operand.
    //
    if (EFLAGS.getOpcode() == X86ISD::SUB && EFLAGS.hasOneUse() &&
        EFLAGS.getValueType().isInteger() &&
        !isa<ConstantSDNode>(EFLAGS.getOperand(1))) {
      SDValue NewSub = DAG.getNode(X86ISD::SUB, SDLoc(EFLAGS),
                                   EFLAGS.getNode()->getVTList(),
                                   EFLAGS.getOperand(1), EFLAGS.getOperand(0));
      SDValue NewEFLAGS = SDValue(NewSub.getNode(), EFLAGS.getResNo());
      return MaterializeSETB(DL, NewEFLAGS, DAG, N->getSimpleValueType(0));
    }
  }

  // Materialize "setb reg" as "sbb reg,reg", since it can be extended without
  // a zext and produces an all-ones bit which is more useful than 0/1 in some
  // cases.
  if (CC == X86::COND_B)
    return MaterializeSETB(DL, EFLAGS, DAG, N->getSimpleValueType(0));

  SDValue Flags;

  Flags = checkBoolTestSetCCCombine(EFLAGS, CC);
  if (Flags.getNode()) {
    SDValue Cond = DAG.getConstant(CC, MVT::i8);
    return DAG.getNode(X86ISD::SETCC, DL, N->getVTList(), Cond, Flags);
  }

  return SDValue();
}

// Optimize branch condition evaluation.
//
static SDValue PerformBrCondCombine(SDNode *N, SelectionDAG &DAG,
                                    TargetLowering::DAGCombinerInfo &DCI,
                                    const X86Subtarget *Subtarget) {
  SDLoc DL(N);
  SDValue Chain = N->getOperand(0);
  SDValue Dest = N->getOperand(1);
  SDValue EFLAGS = N->getOperand(3);
  X86::CondCode CC = X86::CondCode(N->getConstantOperandVal(2));

  SDValue Flags;

  Flags = checkBoolTestSetCCCombine(EFLAGS, CC);
  if (Flags.getNode()) {
    SDValue Cond = DAG.getConstant(CC, MVT::i8);
    return DAG.getNode(X86ISD::BRCOND, DL, N->getVTList(), Chain, Dest, Cond,
                       Flags);
  }

  return SDValue();
}

static SDValue performVectorCompareAndMaskUnaryOpCombine(SDNode *N,
                                                         SelectionDAG &DAG) {
  // Take advantage of vector comparisons producing 0 or -1 in each lane to
  // optimize away operation when it's from a constant.
  //
  // The general transformation is:
  //    UNARYOP(AND(VECTOR_CMP(x,y), constant)) -->
  //       AND(VECTOR_CMP(x,y), constant2)
  //    constant2 = UNARYOP(constant)

  // Early exit if this isn't a vector operation, the operand of the
  // unary operation isn't a bitwise AND, or if the sizes of the operations
  // aren't the same.
  EVT VT = N->getValueType(0);
  if (!VT.isVector() || N->getOperand(0)->getOpcode() != ISD::AND ||
      N->getOperand(0)->getOperand(0)->getOpcode() != ISD::SETCC ||
      VT.getSizeInBits() != N->getOperand(0)->getValueType(0).getSizeInBits())
    return SDValue();

  // Now check that the other operand of the AND is a constant. We could
  // make the transformation for non-constant splats as well, but it's unclear
  // that would be a benefit as it would not eliminate any operations, just
  // perform one more step in scalar code before moving to the vector unit.
  if (BuildVectorSDNode *BV =
          dyn_cast<BuildVectorSDNode>(N->getOperand(0)->getOperand(1))) {
    // Bail out if the vector isn't a constant.
    if (!BV->isConstant())
      return SDValue();

    // Everything checks out. Build up the new and improved node.
    SDLoc DL(N);
    EVT IntVT = BV->getValueType(0);
    // Create a new constant of the appropriate type for the transformed
    // DAG.
    SDValue SourceConst = DAG.getNode(N->getOpcode(), DL, VT, SDValue(BV, 0));
    // The AND node needs bitcasts to/from an integer vector type around it.
    SDValue MaskConst = DAG.getNode(ISD::BITCAST, DL, IntVT, SourceConst);
    SDValue NewAnd = DAG.getNode(ISD::AND, DL, IntVT,
                                 N->getOperand(0)->getOperand(0), MaskConst);
    SDValue Res = DAG.getNode(ISD::BITCAST, DL, VT, NewAnd);
    return Res;
  }

  return SDValue();
}

static SDValue PerformSINT_TO_FPCombine(SDNode *N, SelectionDAG &DAG,
                                        const X86Subtarget *Subtarget) {
  // First try to optimize away the conversion entirely when it's
  // conditionally from a constant. Vectors only.
  SDValue Res = performVectorCompareAndMaskUnaryOpCombine(N, DAG);
  if (Res != SDValue())
    return Res;

  // Now move on to more general possibilities.
  SDValue Op0 = N->getOperand(0);
  EVT InVT = Op0->getValueType(0);

  // SINT_TO_FP(v4i8) -> SINT_TO_FP(SEXT(v4i8 to v4i32))
  if (InVT == MVT::v8i8 || InVT == MVT::v4i8) {
    SDLoc dl(N);
    MVT DstVT = InVT == MVT::v4i8 ? MVT::v4i32 : MVT::v8i32;
    SDValue P = DAG.getNode(ISD::SIGN_EXTEND, dl, DstVT, Op0);
    return DAG.getNode(ISD::SINT_TO_FP, dl, N->getValueType(0), P);
  }

  // Transform (SINT_TO_FP (i64 ...)) into an x87 operation if we have
  // a 32-bit target where SSE doesn't support i64->FP operations.
  if (Op0.getOpcode() == ISD::LOAD) {
    LoadSDNode *Ld = cast<LoadSDNode>(Op0.getNode());
    EVT VT = Ld->getValueType(0);
    if (!Ld->isVolatile() && !N->getValueType(0).isVector() &&
        ISD::isNON_EXTLoad(Op0.getNode()) && Op0.hasOneUse() &&
        !Subtarget->is64Bit() && VT == MVT::i64) {
      SDValue FILDChain = Subtarget->getTargetLowering()->BuildFILD(
          SDValue(N, 0), Ld->getValueType(0), Ld->getChain(), Op0, DAG);
      DAG.ReplaceAllUsesOfValueWith(Op0.getValue(1), FILDChain.getValue(1));
      return FILDChain;
    }
  }
  return SDValue();
}

// Optimize RES, EFLAGS = X86ISD::ADC LHS, RHS, EFLAGS
static SDValue PerformADCCombine(SDNode *N, SelectionDAG &DAG,
                                 X86TargetLowering::DAGCombinerInfo &DCI) {
  // If the LHS and RHS of the ADC node are zero, then it can't overflow and
  // the result is either zero or one (depending on the input carry bit).
  // Strength reduce this down to a "set on carry" aka SETCC_CARRY&1.
  if (X86::isZeroNode(N->getOperand(0)) &&
      X86::isZeroNode(N->getOperand(1)) &&
      // We don't have a good way to replace an EFLAGS use, so only do this when
      // dead right now.
      SDValue(N, 1).use_empty()) {
    SDLoc DL(N);
    EVT VT = N->getValueType(0);
    SDValue CarryOut = DAG.getConstant(0, N->getValueType(1));
    SDValue Res1 = DAG.getNode(ISD::AND, DL, VT,
                               DAG.getNode(X86ISD::SETCC_CARRY, DL, VT,
                                           DAG.getConstant(X86::COND_B,MVT::i8),
                                           N->getOperand(2)),
                               DAG.getConstant(1, VT));
    return DCI.CombineTo(N, Res1, CarryOut);
  }

  return SDValue();
}

// fold (add Y, (sete  X, 0)) -> adc  0, Y
//      (add Y, (setne X, 0)) -> sbb -1, Y
//      (sub (sete  X, 0), Y) -> sbb  0, Y
//      (sub (setne X, 0), Y) -> adc -1, Y
static SDValue OptimizeConditionalInDecrement(SDNode *N, SelectionDAG &DAG) {
  SDLoc DL(N);

  // Look through ZExts.
  SDValue Ext = N->getOperand(N->getOpcode() == ISD::SUB ? 1 : 0);
  if (Ext.getOpcode() != ISD::ZERO_EXTEND || !Ext.hasOneUse())
    return SDValue();

  SDValue SetCC = Ext.getOperand(0);
  if (SetCC.getOpcode() != X86ISD::SETCC || !SetCC.hasOneUse())
    return SDValue();

  X86::CondCode CC = (X86::CondCode)SetCC.getConstantOperandVal(0);
  if (CC != X86::COND_E && CC != X86::COND_NE)
    return SDValue();

  SDValue Cmp = SetCC.getOperand(1);
  if (Cmp.getOpcode() != X86ISD::CMP || !Cmp.hasOneUse() ||
      !X86::isZeroNode(Cmp.getOperand(1)) ||
      !Cmp.getOperand(0).getValueType().isInteger())
    return SDValue();

  SDValue CmpOp0 = Cmp.getOperand(0);
  SDValue NewCmp = DAG.getNode(X86ISD::CMP, DL, MVT::i32, CmpOp0,
                               DAG.getConstant(1, CmpOp0.getValueType()));

  SDValue OtherVal = N->getOperand(N->getOpcode() == ISD::SUB ? 0 : 1);
  if (CC == X86::COND_NE)
    return DAG.getNode(N->getOpcode() == ISD::SUB ? X86ISD::ADC : X86ISD::SBB,
                       DL, OtherVal.getValueType(), OtherVal,
                       DAG.getConstant(-1ULL, OtherVal.getValueType()), NewCmp);
  return DAG.getNode(N->getOpcode() == ISD::SUB ? X86ISD::SBB : X86ISD::ADC,
                     DL, OtherVal.getValueType(), OtherVal,
                     DAG.getConstant(0, OtherVal.getValueType()), NewCmp);
}

/// PerformADDCombine - Do target-specific dag combines on integer adds.
static SDValue PerformAddCombine(SDNode *N, SelectionDAG &DAG,
                                 const X86Subtarget *Subtarget) {
  EVT VT = N->getValueType(0);
  SDValue Op0 = N->getOperand(0);
  SDValue Op1 = N->getOperand(1);

  // Try to synthesize horizontal adds from adds of shuffles.
  if (((Subtarget->hasSSSE3() && (VT == MVT::v8i16 || VT == MVT::v4i32)) ||
       (Subtarget->hasInt256() && (VT == MVT::v16i16 || VT == MVT::v8i32))) &&
      isHorizontalBinOp(Op0, Op1, true))
    return DAG.getNode(X86ISD::HADD, SDLoc(N), VT, Op0, Op1);

  return OptimizeConditionalInDecrement(N, DAG);
}

static SDValue PerformSubCombine(SDNode *N, SelectionDAG &DAG,
                                 const X86Subtarget *Subtarget) {
  SDValue Op0 = N->getOperand(0);
  SDValue Op1 = N->getOperand(1);

  // X86 can't encode an immediate LHS of a sub. See if we can push the
  // negation into a preceding instruction.
  if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op0)) {
    // If the RHS of the sub is a XOR with one use and a constant, invert the
    // immediate. Then add one to the LHS of the sub so we can turn
    // X-Y -> X+~Y+1, saving one register.
    if (Op1->hasOneUse() && Op1.getOpcode() == ISD::XOR &&
        isa<ConstantSDNode>(Op1.getOperand(1))) {
      APInt XorC = cast<ConstantSDNode>(Op1.getOperand(1))->getAPIntValue();
      EVT VT = Op0.getValueType();
      SDValue NewXor = DAG.getNode(ISD::XOR, SDLoc(Op1), VT,
                                   Op1.getOperand(0),
                                   DAG.getConstant(~XorC, VT));
      return DAG.getNode(ISD::ADD, SDLoc(N), VT, NewXor,
                         DAG.getConstant(C->getAPIntValue()+1, VT));
    }
  }

  // Try to synthesize horizontal adds from adds of shuffles.
  EVT VT = N->getValueType(0);
  if (((Subtarget->hasSSSE3() && (VT == MVT::v8i16 || VT == MVT::v4i32)) ||
       (Subtarget->hasInt256() && (VT == MVT::v16i16 || VT == MVT::v8i32))) &&
      isHorizontalBinOp(Op0, Op1, true))
    return DAG.getNode(X86ISD::HSUB, SDLoc(N), VT, Op0, Op1);

  return OptimizeConditionalInDecrement(N, DAG);
}

/// performVZEXTCombine - Performs build vector combines
static SDValue performVZEXTCombine(SDNode *N, SelectionDAG &DAG,
                                   TargetLowering::DAGCombinerInfo &DCI,
                                   const X86Subtarget *Subtarget) {
  SDLoc DL(N);
  MVT VT = N->getSimpleValueType(0);
  SDValue Op = N->getOperand(0);
  MVT OpVT = Op.getSimpleValueType();
  MVT OpEltVT = OpVT.getVectorElementType();
  unsigned InputBits = OpEltVT.getSizeInBits() * VT.getVectorNumElements();

  // (vzext (bitcast (vzext (x)) -> (vzext x)
  SDValue V = Op;
  while (V.getOpcode() == ISD::BITCAST)
    V = V.getOperand(0);

  if (V != Op && V.getOpcode() == X86ISD::VZEXT) {
    MVT InnerVT = V.getSimpleValueType();
    MVT InnerEltVT = InnerVT.getVectorElementType();

    // If the element sizes match exactly, we can just do one larger vzext. This
    // is always an exact type match as vzext operates on integer types.
    if (OpEltVT == InnerEltVT) {
      assert(OpVT == InnerVT && "Types must match for vzext!");
      return DAG.getNode(X86ISD::VZEXT, DL, VT, V.getOperand(0));
    }

    // The only other way we can combine them is if only a single element of the
    // inner vzext is used in the input to the outer vzext.
    if (InnerEltVT.getSizeInBits() < InputBits)
      return SDValue();

    // In this case, the inner vzext is completely dead because we're going to
    // only look at bits inside of the low element. Just do the outer vzext on
    // a bitcast of the input to the inner.
    return DAG.getNode(X86ISD::VZEXT, DL, VT,
                       DAG.getNode(ISD::BITCAST, DL, OpVT, V));
  }

  // Check if we can bypass extracting and re-inserting an element of an input
  // vector. Essentialy:
  // (bitcast (sclr2vec (ext_vec_elt x))) -> (bitcast x)
  if (V.getOpcode() == ISD::SCALAR_TO_VECTOR &&
      V.getOperand(0).getOpcode() == ISD::EXTRACT_VECTOR_ELT &&
      V.getOperand(0).getSimpleValueType().getSizeInBits() == InputBits) {
    SDValue ExtractedV = V.getOperand(0);
    SDValue OrigV = ExtractedV.getOperand(0);
    if (auto *ExtractIdx = dyn_cast<ConstantSDNode>(ExtractedV.getOperand(1)))
      if (ExtractIdx->getZExtValue() == 0) {
        MVT OrigVT = OrigV.getSimpleValueType();
        // Extract a subvector if necessary...
        if (OrigVT.getSizeInBits() > OpVT.getSizeInBits()) {
          int Ratio = OrigVT.getSizeInBits() / OpVT.getSizeInBits();
          OrigVT = MVT::getVectorVT(OrigVT.getVectorElementType(),
                                    OrigVT.getVectorNumElements() / Ratio);
          OrigV = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, OrigVT, OrigV,
                              DAG.getIntPtrConstant(0));
        }
        Op = DAG.getNode(ISD::BITCAST, DL, OpVT, OrigV);
        return DAG.getNode(X86ISD::VZEXT, DL, VT, Op);
      }
  }

  return SDValue();
}

SDValue X86TargetLowering::PerformDAGCombine(SDNode *N,
                                             DAGCombinerInfo &DCI) const {
  SelectionDAG &DAG = DCI.DAG;
  switch (N->getOpcode()) {
  default: break;
  case ISD::EXTRACT_VECTOR_ELT:
    return PerformEXTRACT_VECTOR_ELTCombine(N, DAG, DCI);
  case ISD::VSELECT:
  case ISD::SELECT:
  case X86ISD::SHRUNKBLEND:
    return PerformSELECTCombine(N, DAG, DCI, Subtarget);
  case ISD::BITCAST:        return PerformBITCASTCombine(N, DAG);
  case X86ISD::CMOV:        return PerformCMOVCombine(N, DAG, DCI, Subtarget);
  case ISD::ADD:            return PerformAddCombine(N, DAG, Subtarget);
  case ISD::SUB:            return PerformSubCombine(N, DAG, Subtarget);
  case X86ISD::ADC:         return PerformADCCombine(N, DAG, DCI);
  case ISD::MUL:            return PerformMulCombine(N, DAG, DCI);
  case ISD::SHL:
  case ISD::SRA:
  case ISD::SRL:            return PerformShiftCombine(N, DAG, DCI, Subtarget);
  case ISD::AND:            return PerformAndCombine(N, DAG, DCI, Subtarget);
  case ISD::OR:             return PerformOrCombine(N, DAG, DCI, Subtarget);
  case ISD::XOR:            return PerformXorCombine(N, DAG, DCI, Subtarget);
  case ISD::LOAD:           return PerformLOADCombine(N, DAG, DCI, Subtarget);
  case ISD::MLOAD:          return PerformMLOADCombine(N, DAG, DCI, Subtarget);
  case ISD::STORE:          return PerformSTORECombine(N, DAG, Subtarget);
  case ISD::MSTORE:         return PerformMSTORECombine(N, DAG, Subtarget);
  case ISD::SINT_TO_FP:     return PerformSINT_TO_FPCombine(N, DAG, Subtarget);
  case ISD::FADD:           return PerformFADDCombine(N, DAG, Subtarget);
  case ISD::FSUB:           return PerformFSUBCombine(N, DAG, Subtarget);
  case X86ISD::FXOR:
  case X86ISD::FOR:         return PerformFORCombine(N, DAG);
  case X86ISD::FMIN:
  case X86ISD::FMAX:        return PerformFMinFMaxCombine(N, DAG);
  case X86ISD::FAND:        return PerformFANDCombine(N, DAG);
  case X86ISD::FANDN:       return PerformFANDNCombine(N, DAG);
  case X86ISD::BT:          return PerformBTCombine(N, DAG, DCI);
  case X86ISD::VZEXT_MOVL:  return PerformVZEXT_MOVLCombine(N, DAG);
  case ISD::ANY_EXTEND:
  case ISD::ZERO_EXTEND:    return PerformZExtCombine(N, DAG, DCI, Subtarget);
  case ISD::SIGN_EXTEND:    return PerformSExtCombine(N, DAG, DCI, Subtarget);
  case ISD::SIGN_EXTEND_INREG:
    return PerformSIGN_EXTEND_INREGCombine(N, DAG, Subtarget);
  case ISD::TRUNCATE:       return PerformTruncateCombine(N, DAG,DCI,Subtarget);
  case ISD::SETCC:          return PerformISDSETCCCombine(N, DAG, Subtarget);
  case X86ISD::SETCC:       return PerformSETCCCombine(N, DAG, DCI, Subtarget);
  case X86ISD::BRCOND:      return PerformBrCondCombine(N, DAG, DCI, Subtarget);
  case X86ISD::VZEXT:       return performVZEXTCombine(N, DAG, DCI, Subtarget);
  case X86ISD::SHUFP:       // Handle all target specific shuffles
  case X86ISD::PALIGNR:
  case X86ISD::UNPCKH:
  case X86ISD::UNPCKL:
  case X86ISD::MOVHLPS:
  case X86ISD::MOVLHPS:
  case X86ISD::PSHUFB:
  case X86ISD::PSHUFD:
  case X86ISD::PSHUFHW:
  case X86ISD::PSHUFLW:
  case X86ISD::MOVSS:
  case X86ISD::MOVSD:
  case X86ISD::VPERMILPI:
  case X86ISD::VPERM2X128:
  case ISD::VECTOR_SHUFFLE: return PerformShuffleCombine(N, DAG, DCI,Subtarget);
  case ISD::FMA:            return PerformFMACombine(N, DAG, Subtarget);
  case ISD::INTRINSIC_WO_CHAIN:
    return PerformINTRINSIC_WO_CHAINCombine(N, DAG, Subtarget);
  case X86ISD::INSERTPS: {
    if (getTargetMachine().getOptLevel() > CodeGenOpt::None)
      return PerformINSERTPSCombine(N, DAG, Subtarget);
    break;
  }
  case ISD::BUILD_VECTOR: return PerformBUILD_VECTORCombine(N, DAG, Subtarget);
  }

  return SDValue();
}

/// isTypeDesirableForOp - Return true if the target has native support for
/// the specified value type and it is 'desirable' to use the type for the
/// given node type. e.g. On x86 i16 is legal, but undesirable since i16
/// instruction encodings are longer and some i16 instructions are slow.
bool X86TargetLowering::isTypeDesirableForOp(unsigned Opc, EVT VT) const {
  if (!isTypeLegal(VT))
    return false;
  if (VT != MVT::i16)
    return true;

  switch (Opc) {
  default:
    return true;
  case ISD::LOAD:
  case ISD::SIGN_EXTEND:
  case ISD::ZERO_EXTEND:
  case ISD::ANY_EXTEND:
  case ISD::SHL:
  case ISD::SRL:
  case ISD::SUB:
  case ISD::ADD:
  case ISD::MUL:
  case ISD::AND:
  case ISD::OR:
  case ISD::XOR:
    return false;
  }
}

/// IsDesirableToPromoteOp - This method query the target whether it is
/// beneficial for dag combiner to promote the specified node. If true, it
/// should return the desired promotion type by reference.
bool X86TargetLowering::IsDesirableToPromoteOp(SDValue Op, EVT &PVT) const {
  EVT VT = Op.getValueType();
  if (VT != MVT::i16)
    return false;

  bool Promote = false;
  bool Commute = false;
  switch (Op.getOpcode()) {
  default: break;
  case ISD::LOAD: {
    LoadSDNode *LD = cast<LoadSDNode>(Op);
    // If the non-extending load has a single use and it's not live out, then it
    // might be folded.
    if (LD->getExtensionType() == ISD::NON_EXTLOAD /*&&
                                                     Op.hasOneUse()*/) {
      for (SDNode::use_iterator UI = Op.getNode()->use_begin(),
             UE = Op.getNode()->use_end(); UI != UE; ++UI) {
        // The only case where we'd want to promote LOAD (rather then it being
        // promoted as an operand is when it's only use is liveout.
        if (UI->getOpcode() != ISD::CopyToReg)
          return false;
      }
    }
    Promote = true;
    break;
  }
  case ISD::SIGN_EXTEND:
  case ISD::ZERO_EXTEND:
  case ISD::ANY_EXTEND:
    Promote = true;
    break;
  case ISD::SHL:
  case ISD::SRL: {
    SDValue N0 = Op.getOperand(0);
    // Look out for (store (shl (load), x)).
    if (MayFoldLoad(N0) && MayFoldIntoStore(Op))
      return false;
    Promote = true;
    break;
  }
  case ISD::ADD:
  case ISD::MUL:
  case ISD::AND:
  case ISD::OR:
  case ISD::XOR:
    Commute = true;
    // fallthrough
  case ISD::SUB: {
    SDValue N0 = Op.getOperand(0);
    SDValue N1 = Op.getOperand(1);
    if (!Commute && MayFoldLoad(N1))
      return false;
    // Avoid disabling potential load folding opportunities.
    if (MayFoldLoad(N0) && (!isa<ConstantSDNode>(N1) || MayFoldIntoStore(Op)))
      return false;
    if (MayFoldLoad(N1) && (!isa<ConstantSDNode>(N0) || MayFoldIntoStore(Op)))
      return false;
    Promote = true;
  }
  }

  PVT = MVT::i32;
  return Promote;
}

//===----------------------------------------------------------------------===//
//                           X86 Inline Assembly Support
//===----------------------------------------------------------------------===//

namespace {
  // Helper to match a string separated by whitespace.
  bool matchAsmImpl(StringRef s, ArrayRef<const StringRef *> args) {
    s = s.substr(s.find_first_not_of(" \t")); // Skip leading whitespace.

    for (unsigned i = 0, e = args.size(); i != e; ++i) {
      StringRef piece(*args[i]);
      if (!s.startswith(piece)) // Check if the piece matches.
        return false;

      s = s.substr(piece.size());
      StringRef::size_type pos = s.find_first_not_of(" \t");
      if (pos == 0) // We matched a prefix.
        return false;

      s = s.substr(pos);
    }

    return s.empty();
  }
  const VariadicFunction1<bool, StringRef, StringRef, matchAsmImpl> matchAsm={};
}

static bool clobbersFlagRegisters(const SmallVector<StringRef, 4> &AsmPieces) {

  if (AsmPieces.size() == 3 || AsmPieces.size() == 4) {
    if (std::count(AsmPieces.begin(), AsmPieces.end(), "~{cc}") &&
        std::count(AsmPieces.begin(), AsmPieces.end(), "~{flags}") &&
        std::count(AsmPieces.begin(), AsmPieces.end(), "~{fpsr}")) {

      if (AsmPieces.size() == 3)
        return true;
      else if (std::count(AsmPieces.begin(), AsmPieces.end(), "~{dirflag}"))
        return true;
    }
  }
  return false;
}

bool X86TargetLowering::ExpandInlineAsm(CallInst *CI) const {
  InlineAsm *IA = cast<InlineAsm>(CI->getCalledValue());

  std::string AsmStr = IA->getAsmString();

  IntegerType *Ty = dyn_cast<IntegerType>(CI->getType());
  if (!Ty || Ty->getBitWidth() % 16 != 0)
    return false;

  // TODO: should remove alternatives from the asmstring: "foo {a|b}" -> "foo a"
  SmallVector<StringRef, 4> AsmPieces;
  SplitString(AsmStr, AsmPieces, ";\n");

  switch (AsmPieces.size()) {
  default: return false;
  case 1:
    // FIXME: this should verify that we are targeting a 486 or better.  If not,
    // we will turn this bswap into something that will be lowered to logical
    // ops instead of emitting the bswap asm.  For now, we don't support 486 or
    // lower so don't worry about this.
    // bswap $0
    if (matchAsm(AsmPieces[0], "bswap", "$0") ||
        matchAsm(AsmPieces[0], "bswapl", "$0") ||
        matchAsm(AsmPieces[0], "bswapq", "$0") ||
        matchAsm(AsmPieces[0], "bswap", "${0:q}") ||
        matchAsm(AsmPieces[0], "bswapl", "${0:q}") ||
        matchAsm(AsmPieces[0], "bswapq", "${0:q}")) {
      // No need to check constraints, nothing other than the equivalent of
      // "=r,0" would be valid here.
      return IntrinsicLowering::LowerToByteSwap(CI);
    }

    // rorw $$8, ${0:w}  -->  llvm.bswap.i16
    if (CI->getType()->isIntegerTy(16) &&
        IA->getConstraintString().compare(0, 5, "=r,0,") == 0 &&
        (matchAsm(AsmPieces[0], "rorw", "$$8,", "${0:w}") ||
         matchAsm(AsmPieces[0], "rolw", "$$8,", "${0:w}"))) {
      AsmPieces.clear();
      const std::string &ConstraintsStr = IA->getConstraintString();
      SplitString(StringRef(ConstraintsStr).substr(5), AsmPieces, ",");
      array_pod_sort(AsmPieces.begin(), AsmPieces.end());
      if (clobbersFlagRegisters(AsmPieces))
        return IntrinsicLowering::LowerToByteSwap(CI);
    }
    break;
  case 3:
    if (CI->getType()->isIntegerTy(32) &&
        IA->getConstraintString().compare(0, 5, "=r,0,") == 0 &&
        matchAsm(AsmPieces[0], "rorw", "$$8,", "${0:w}") &&
        matchAsm(AsmPieces[1], "rorl", "$$16,", "$0") &&
        matchAsm(AsmPieces[2], "rorw", "$$8,", "${0:w}")) {
      AsmPieces.clear();
      const std::string &ConstraintsStr = IA->getConstraintString();
      SplitString(StringRef(ConstraintsStr).substr(5), AsmPieces, ",");
      array_pod_sort(AsmPieces.begin(), AsmPieces.end());
      if (clobbersFlagRegisters(AsmPieces))
        return IntrinsicLowering::LowerToByteSwap(CI);
    }

    if (CI->getType()->isIntegerTy(64)) {
      InlineAsm::ConstraintInfoVector Constraints = IA->ParseConstraints();
      if (Constraints.size() >= 2 &&
          Constraints[0].Codes.size() == 1 && Constraints[0].Codes[0] == "A" &&
          Constraints[1].Codes.size() == 1 && Constraints[1].Codes[0] == "0") {
        // bswap %eax / bswap %edx / xchgl %eax, %edx  -> llvm.bswap.i64
        if (matchAsm(AsmPieces[0], "bswap", "%eax") &&
            matchAsm(AsmPieces[1], "bswap", "%edx") &&
            matchAsm(AsmPieces[2], "xchgl", "%eax,", "%edx"))
          return IntrinsicLowering::LowerToByteSwap(CI);
      }
    }
    break;
  }
  return false;
}

/// getConstraintType - Given a constraint letter, return the type of
/// constraint it is for this target.
X86TargetLowering::ConstraintType
X86TargetLowering::getConstraintType(const std::string &Constraint) const {
  if (Constraint.size() == 1) {
    switch (Constraint[0]) {
    case 'R':
    case 'q':
    case 'Q':
    case 'f':
    case 't':
    case 'u':
    case 'y':
    case 'x':
    case 'Y':
    case 'l':
      return C_RegisterClass;
    case 'a':
    case 'b':
    case 'c':
    case 'd':
    case 'S':
    case 'D':
    case 'A':
      return C_Register;
    case 'I':
    case 'J':
    case 'K':
    case 'L':
    case 'M':
    case 'N':
    case 'G':
    case 'C':
    case 'e':
    case 'Z':
      return C_Other;
    default:
      break;
    }
  }
  return TargetLowering::getConstraintType(Constraint);
}

/// Examine constraint type and operand type and determine a weight value.
/// This object must already have been set up with the operand type
/// and the current alternative constraint selected.
TargetLowering::ConstraintWeight
  X86TargetLowering::getSingleConstraintMatchWeight(
    AsmOperandInfo &info, const char *constraint) const {
  ConstraintWeight weight = CW_Invalid;
  Value *CallOperandVal = info.CallOperandVal;
    // If we don't have a value, we can't do a match,
    // but allow it at the lowest weight.
  if (!CallOperandVal)
    return CW_Default;
  Type *type = CallOperandVal->getType();
  // Look at the constraint type.
  switch (*constraint) {
  default:
    weight = TargetLowering::getSingleConstraintMatchWeight(info, constraint);
  case 'R':
  case 'q':
  case 'Q':
  case 'a':
  case 'b':
  case 'c':
  case 'd':
  case 'S':
  case 'D':
  case 'A':
    if (CallOperandVal->getType()->isIntegerTy())
      weight = CW_SpecificReg;
    break;
  case 'f':
  case 't':
  case 'u':
    if (type->isFloatingPointTy())
      weight = CW_SpecificReg;
    break;
  case 'y':
    if (type->isX86_MMXTy() && Subtarget->hasMMX())
      weight = CW_SpecificReg;
    break;
  case 'x':
  case 'Y':
    if (((type->getPrimitiveSizeInBits() == 128) && Subtarget->hasSSE1()) ||
        ((type->getPrimitiveSizeInBits() == 256) && Subtarget->hasFp256()))
      weight = CW_Register;
    break;
  case 'I':
    if (ConstantInt *C = dyn_cast<ConstantInt>(info.CallOperandVal)) {
      if (C->getZExtValue() <= 31)
        weight = CW_Constant;
    }
    break;
  case 'J':
    if (ConstantInt *C = dyn_cast<ConstantInt>(CallOperandVal)) {
      if (C->getZExtValue() <= 63)
        weight = CW_Constant;
    }
    break;
  case 'K':
    if (ConstantInt *C = dyn_cast<ConstantInt>(CallOperandVal)) {
      if ((C->getSExtValue() >= -0x80) && (C->getSExtValue() <= 0x7f))
        weight = CW_Constant;
    }
    break;
  case 'L':
    if (ConstantInt *C = dyn_cast<ConstantInt>(CallOperandVal)) {
      if ((C->getZExtValue() == 0xff) || (C->getZExtValue() == 0xffff))
        weight = CW_Constant;
    }
    break;
  case 'M':
    if (ConstantInt *C = dyn_cast<ConstantInt>(CallOperandVal)) {
      if (C->getZExtValue() <= 3)
        weight = CW_Constant;
    }
    break;
  case 'N':
    if (ConstantInt *C = dyn_cast<ConstantInt>(CallOperandVal)) {
      if (C->getZExtValue() <= 0xff)
        weight = CW_Constant;
    }
    break;
  case 'G':
  case 'C':
    if (dyn_cast<ConstantFP>(CallOperandVal)) {
      weight = CW_Constant;
    }
    break;
  case 'e':
    if (ConstantInt *C = dyn_cast<ConstantInt>(CallOperandVal)) {
      if ((C->getSExtValue() >= -0x80000000LL) &&
          (C->getSExtValue() <= 0x7fffffffLL))
        weight = CW_Constant;
    }
    break;
  case 'Z':
    if (ConstantInt *C = dyn_cast<ConstantInt>(CallOperandVal)) {
      if (C->getZExtValue() <= 0xffffffff)
        weight = CW_Constant;
    }
    break;
  }
  return weight;
}

/// LowerXConstraint - try to replace an X constraint, which matches anything,
/// with another that has more specific requirements based on the type of the
/// corresponding operand.
const char *X86TargetLowering::
LowerXConstraint(EVT ConstraintVT) const {
  // FP X constraints get lowered to SSE1/2 registers if available, otherwise
  // 'f' like normal targets.
  if (ConstraintVT.isFloatingPoint()) {
    if (Subtarget->hasSSE2())
      return "Y";
    if (Subtarget->hasSSE1())
      return "x";
  }

  return TargetLowering::LowerXConstraint(ConstraintVT);
}

/// LowerAsmOperandForConstraint - Lower the specified operand into the Ops
/// vector.  If it is invalid, don't add anything to Ops.
void X86TargetLowering::LowerAsmOperandForConstraint(SDValue Op,
                                                     std::string &Constraint,
                                                     std::vector<SDValue>&Ops,
                                                     SelectionDAG &DAG) const {
  SDValue Result;

  // Only support length 1 constraints for now.
  if (Constraint.length() > 1) return;

  char ConstraintLetter = Constraint[0];
  switch (ConstraintLetter) {
  default: break;
  case 'I':
    if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
      if (C->getZExtValue() <= 31) {
        Result = DAG.getTargetConstant(C->getZExtValue(), Op.getValueType());
        break;
      }
    }
    return;
  case 'J':
    if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
      if (C->getZExtValue() <= 63) {
        Result = DAG.getTargetConstant(C->getZExtValue(), Op.getValueType());
        break;
      }
    }
    return;
  case 'K':
    if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
      if (isInt<8>(C->getSExtValue())) {
        Result = DAG.getTargetConstant(C->getZExtValue(), Op.getValueType());
        break;
      }
    }
    return;
  case 'L':
    if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
      if (C->getZExtValue() == 0xff || C->getZExtValue() == 0xffff ||
          (Subtarget->is64Bit() && C->getZExtValue() == 0xffffffff)) {
        Result = DAG.getTargetConstant(C->getSExtValue(), Op.getValueType());
        break;
      }
    }
    return;
  case 'M':
    if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
      if (C->getZExtValue() <= 3) {
        Result = DAG.getTargetConstant(C->getZExtValue(), Op.getValueType());
        break;
      }
    }
    return;
  case 'N':
    if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
      if (C->getZExtValue() <= 255) {
        Result = DAG.getTargetConstant(C->getZExtValue(), Op.getValueType());
        break;
      }
    }
    return;
  case 'O':
    if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
      if (C->getZExtValue() <= 127) {
        Result = DAG.getTargetConstant(C->getZExtValue(), Op.getValueType());
        break;
      }
    }
    return;
  case 'e': {
    // 32-bit signed value
    if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
      if (ConstantInt::isValueValidForType(Type::getInt32Ty(*DAG.getContext()),
                                           C->getSExtValue())) {
        // Widen to 64 bits here to get it sign extended.
        Result = DAG.getTargetConstant(C->getSExtValue(), MVT::i64);
        break;
      }
    // FIXME gcc accepts some relocatable values here too, but only in certain
    // memory models; it's complicated.
    }
    return;
  }
  case 'Z': {
    // 32-bit unsigned value
    if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
      if (ConstantInt::isValueValidForType(Type::getInt32Ty(*DAG.getContext()),
                                           C->getZExtValue())) {
        Result = DAG.getTargetConstant(C->getZExtValue(), Op.getValueType());
        break;
      }
    }
    // FIXME gcc accepts some relocatable values here too, but only in certain
    // memory models; it's complicated.
    return;
  }
  case 'i': {
    // Literal immediates are always ok.
    if (ConstantSDNode *CST = dyn_cast<ConstantSDNode>(Op)) {
      // Widen to 64 bits here to get it sign extended.
      Result = DAG.getTargetConstant(CST->getSExtValue(), MVT::i64);
      break;
    }

    // In any sort of PIC mode addresses need to be computed at runtime by
    // adding in a register or some sort of table lookup.  These can't
    // be used as immediates.
    if (Subtarget->isPICStyleGOT() || Subtarget->isPICStyleStubPIC())
      return;

    // If we are in non-pic codegen mode, we allow the address of a global (with
    // an optional displacement) to be used with 'i'.
    GlobalAddressSDNode *GA = nullptr;
    int64_t Offset = 0;

    // Match either (GA), (GA+C), (GA+C1+C2), etc.
    while (1) {
      if ((GA = dyn_cast<GlobalAddressSDNode>(Op))) {
        Offset += GA->getOffset();
        break;
      } else if (Op.getOpcode() == ISD::ADD) {
        if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op.getOperand(1))) {
          Offset += C->getZExtValue();
          Op = Op.getOperand(0);
          continue;
        }
      } else if (Op.getOpcode() == ISD::SUB) {
        if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op.getOperand(1))) {
          Offset += -C->getZExtValue();
          Op = Op.getOperand(0);
          continue;
        }
      }

      // Otherwise, this isn't something we can handle, reject it.
      return;
    }

    const GlobalValue *GV = GA->getGlobal();
    // If we require an extra load to get this address, as in PIC mode, we
    // can't accept it.
    if (isGlobalStubReference(
            Subtarget->ClassifyGlobalReference(GV, DAG.getTarget())))
      return;

    Result = DAG.getTargetGlobalAddress(GV, SDLoc(Op),
                                        GA->getValueType(0), Offset);
    break;
  }
  }

  if (Result.getNode()) {
    Ops.push_back(Result);
    return;
  }
  return TargetLowering::LowerAsmOperandForConstraint(Op, Constraint, Ops, DAG);
}

std::pair<unsigned, const TargetRegisterClass*>
X86TargetLowering::getRegForInlineAsmConstraint(const std::string &Constraint,
                                                MVT VT) const {
  // First, see if this is a constraint that directly corresponds to an LLVM
  // register class.
  if (Constraint.size() == 1) {
    // GCC Constraint Letters
    switch (Constraint[0]) {
    default: break;
      // TODO: Slight differences here in allocation order and leaving
      // RIP in the class. Do they matter any more here than they do
      // in the normal allocation?
    case 'q':   // GENERAL_REGS in 64-bit mode, Q_REGS in 32-bit mode.
      if (Subtarget->is64Bit()) {
        if (VT == MVT::i32 || VT == MVT::f32)
          return std::make_pair(0U, &X86::GR32RegClass);
        if (VT == MVT::i16)
          return std::make_pair(0U, &X86::GR16RegClass);
        if (VT == MVT::i8 || VT == MVT::i1)
          return std::make_pair(0U, &X86::GR8RegClass);
        if (VT == MVT::i64 || VT == MVT::f64)
          return std::make_pair(0U, &X86::GR64RegClass);
        break;
      }
      // 32-bit fallthrough
    case 'Q':   // Q_REGS
      if (VT == MVT::i32 || VT == MVT::f32)
        return std::make_pair(0U, &X86::GR32_ABCDRegClass);
      if (VT == MVT::i16)
        return std::make_pair(0U, &X86::GR16_ABCDRegClass);
      if (VT == MVT::i8 || VT == MVT::i1)
        return std::make_pair(0U, &X86::GR8_ABCD_LRegClass);
      if (VT == MVT::i64)
        return std::make_pair(0U, &X86::GR64_ABCDRegClass);
      break;
    case 'r':   // GENERAL_REGS
    case 'l':   // INDEX_REGS
      if (VT == MVT::i8 || VT == MVT::i1)
        return std::make_pair(0U, &X86::GR8RegClass);
      if (VT == MVT::i16)
        return std::make_pair(0U, &X86::GR16RegClass);
      if (VT == MVT::i32 || VT == MVT::f32 || !Subtarget->is64Bit())
        return std::make_pair(0U, &X86::GR32RegClass);
      return std::make_pair(0U, &X86::GR64RegClass);
    case 'R':   // LEGACY_REGS
      if (VT == MVT::i8 || VT == MVT::i1)
        return std::make_pair(0U, &X86::GR8_NOREXRegClass);
      if (VT == MVT::i16)
        return std::make_pair(0U, &X86::GR16_NOREXRegClass);
      if (VT == MVT::i32 || !Subtarget->is64Bit())
        return std::make_pair(0U, &X86::GR32_NOREXRegClass);
      return std::make_pair(0U, &X86::GR64_NOREXRegClass);
    case 'f':  // FP Stack registers.
      // If SSE is enabled for this VT, use f80 to ensure the isel moves the
      // value to the correct fpstack register class.
      if (VT == MVT::f32 && !isScalarFPTypeInSSEReg(VT))
        return std::make_pair(0U, &X86::RFP32RegClass);
      if (VT == MVT::f64 && !isScalarFPTypeInSSEReg(VT))
        return std::make_pair(0U, &X86::RFP64RegClass);
      return std::make_pair(0U, &X86::RFP80RegClass);
    case 'y':   // MMX_REGS if MMX allowed.
      if (!Subtarget->hasMMX()) break;
      return std::make_pair(0U, &X86::VR64RegClass);
    case 'Y':   // SSE_REGS if SSE2 allowed
      if (!Subtarget->hasSSE2()) break;
      // FALL THROUGH.
    case 'x':   // SSE_REGS if SSE1 allowed or AVX_REGS if AVX allowed
      if (!Subtarget->hasSSE1()) break;

      switch (VT.SimpleTy) {
      default: break;
      // Scalar SSE types.
      case MVT::f32:
      case MVT::i32:
        return std::make_pair(0U, &X86::FR32RegClass);
      case MVT::f64:
      case MVT::i64:
        return std::make_pair(0U, &X86::FR64RegClass);
      // Vector types.
      case MVT::v16i8:
      case MVT::v8i16:
      case MVT::v4i32:
      case MVT::v2i64:
      case MVT::v4f32:
      case MVT::v2f64:
        return std::make_pair(0U, &X86::VR128RegClass);
      // AVX types.
      case MVT::v32i8:
      case MVT::v16i16:
      case MVT::v8i32:
      case MVT::v4i64:
      case MVT::v8f32:
      case MVT::v4f64:
        return std::make_pair(0U, &X86::VR256RegClass);
      case MVT::v8f64:
      case MVT::v16f32:
      case MVT::v16i32:
      case MVT::v8i64:
        return std::make_pair(0U, &X86::VR512RegClass);
      }
      break;
    }
  }

  // Use the default implementation in TargetLowering to convert the register
  // constraint into a member of a register class.
  std::pair<unsigned, const TargetRegisterClass*> Res;
  Res = TargetLowering::getRegForInlineAsmConstraint(Constraint, VT);

  // Not found as a standard register?
  if (!Res.second) {
    // Map st(0) -> st(7) -> ST0
    if (Constraint.size() == 7 && Constraint[0] == '{' &&
        tolower(Constraint[1]) == 's' &&
        tolower(Constraint[2]) == 't' &&
        Constraint[3] == '(' &&
        (Constraint[4] >= '0' && Constraint[4] <= '7') &&
        Constraint[5] == ')' &&
        Constraint[6] == '}') {

      Res.first = X86::FP0+Constraint[4]-'0';
      Res.second = &X86::RFP80RegClass;
      return Res;
    }

    // GCC allows "st(0)" to be called just plain "st".
    if (StringRef("{st}").equals_lower(Constraint)) {
      Res.first = X86::FP0;
      Res.second = &X86::RFP80RegClass;
      return Res;
    }

    // flags -> EFLAGS
    if (StringRef("{flags}").equals_lower(Constraint)) {
      Res.first = X86::EFLAGS;
      Res.second = &X86::CCRRegClass;
      return Res;
    }

    // 'A' means EAX + EDX.
    if (Constraint == "A") {
      Res.first = X86::EAX;
      Res.second = &X86::GR32_ADRegClass;
      return Res;
    }
    return Res;
  }

  // Otherwise, check to see if this is a register class of the wrong value
  // type.  For example, we want to map "{ax},i32" -> {eax}, we don't want it to
  // turn into {ax},{dx}.
  if (Res.second->hasType(VT))
    return Res;   // Correct type already, nothing to do.

  // All of the single-register GCC register classes map their values onto
  // 16-bit register pieces "ax","dx","cx","bx","si","di","bp","sp".  If we
  // really want an 8-bit or 32-bit register, map to the appropriate register
  // class and return the appropriate register.
  if (Res.second == &X86::GR16RegClass) {
    if (VT == MVT::i8 || VT == MVT::i1) {
      unsigned DestReg = 0;
      switch (Res.first) {
      default: break;
      case X86::AX: DestReg = X86::AL; break;
      case X86::DX: DestReg = X86::DL; break;
      case X86::CX: DestReg = X86::CL; break;
      case X86::BX: DestReg = X86::BL; break;
      }
      if (DestReg) {
        Res.first = DestReg;
        Res.second = &X86::GR8RegClass;
      }
    } else if (VT == MVT::i32 || VT == MVT::f32) {
      unsigned DestReg = 0;
      switch (Res.first) {
      default: break;
      case X86::AX: DestReg = X86::EAX; break;
      case X86::DX: DestReg = X86::EDX; break;
      case X86::CX: DestReg = X86::ECX; break;
      case X86::BX: DestReg = X86::EBX; break;
      case X86::SI: DestReg = X86::ESI; break;
      case X86::DI: DestReg = X86::EDI; break;
      case X86::BP: DestReg = X86::EBP; break;
      case X86::SP: DestReg = X86::ESP; break;
      }
      if (DestReg) {
        Res.first = DestReg;
        Res.second = &X86::GR32RegClass;
      }
    } else if (VT == MVT::i64 || VT == MVT::f64) {
      unsigned DestReg = 0;
      switch (Res.first) {
      default: break;
      case X86::AX: DestReg = X86::RAX; break;
      case X86::DX: DestReg = X86::RDX; break;
      case X86::CX: DestReg = X86::RCX; break;
      case X86::BX: DestReg = X86::RBX; break;
      case X86::SI: DestReg = X86::RSI; break;
      case X86::DI: DestReg = X86::RDI; break;
      case X86::BP: DestReg = X86::RBP; break;
      case X86::SP: DestReg = X86::RSP; break;
      }
      if (DestReg) {
        Res.first = DestReg;
        Res.second = &X86::GR64RegClass;
      }
    }
  } else if (Res.second == &X86::FR32RegClass ||
             Res.second == &X86::FR64RegClass ||
             Res.second == &X86::VR128RegClass ||
             Res.second == &X86::VR256RegClass ||
             Res.second == &X86::FR32XRegClass ||
             Res.second == &X86::FR64XRegClass ||
             Res.second == &X86::VR128XRegClass ||
             Res.second == &X86::VR256XRegClass ||
             Res.second == &X86::VR512RegClass) {
    // Handle references to XMM physical registers that got mapped into the
    // wrong class.  This can happen with constraints like {xmm0} where the
    // target independent register mapper will just pick the first match it can
    // find, ignoring the required type.

    if (VT == MVT::f32 || VT == MVT::i32)
      Res.second = &X86::FR32RegClass;
    else if (VT == MVT::f64 || VT == MVT::i64)
      Res.second = &X86::FR64RegClass;
    else if (X86::VR128RegClass.hasType(VT))
      Res.second = &X86::VR128RegClass;
    else if (X86::VR256RegClass.hasType(VT))
      Res.second = &X86::VR256RegClass;
    else if (X86::VR512RegClass.hasType(VT))
      Res.second = &X86::VR512RegClass;
  }

  return Res;
}

int X86TargetLowering::getScalingFactorCost(const AddrMode &AM,
                                            Type *Ty) const {
  // Scaling factors are not free at all.
  // An indexed folded instruction, i.e., inst (reg1, reg2, scale),
  // will take 2 allocations in the out of order engine instead of 1
  // for plain addressing mode, i.e. inst (reg1).
  // E.g.,
  // vaddps (%rsi,%drx), %ymm0, %ymm1
  // Requires two allocations (one for the load, one for the computation)
  // whereas:
  // vaddps (%rsi), %ymm0, %ymm1
  // Requires just 1 allocation, i.e., freeing allocations for other operations
  // and having less micro operations to execute.
  //
  // For some X86 architectures, this is even worse because for instance for
  // stores, the complex addressing mode forces the instruction to use the
  // "load" ports instead of the dedicated "store" port.
  // E.g., on Haswell:
  // vmovaps %ymm1, (%r8, %rdi) can use port 2 or 3.
  // vmovaps %ymm1, (%r8) can use port 2, 3, or 7.
  if (isLegalAddressingMode(AM, Ty))
    // Scale represents reg2 * scale, thus account for 1
    // as soon as we use a second register.
    return AM.Scale != 0;
  return -1;
}

bool X86TargetLowering::isTargetFTOL() const {
  return Subtarget->isTargetKnownWindowsMSVC() && !Subtarget->is64Bit();
}