//===----------------------------------------------------------------------===//
#include "llvm/CodeGen/SelectionDAG.h"
+#include "llvm/ADT/SmallBitVector.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SetVector.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetLowering.h"
-#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetOptions.h"
#include "llvm/Target/TargetRegisterInfo.h"
#include "llvm/Target/TargetSubtargetInfo.h"
"slicing"),
cl::init(false));
+ static cl::opt<bool>
+ MaySplitLoadIndex("combiner-split-load-index", cl::Hidden, cl::init(true),
+ cl::desc("DAG combiner may split indexing from loads"));
+
//------------------------------ DAGCombiner ---------------------------------//
class DAGCombiner {
// AA - Used for DAG load/store alias analysis.
AliasAnalysis &AA;
- /// AddUsersToWorklist - When an instruction is simplified, add all users of
- /// the instruction to the work lists because they might get more simplified
- /// now.
- ///
+ /// When an instruction is simplified, add all users of the instruction to
+ /// the work lists because they might get more simplified now.
void AddUsersToWorklist(SDNode *N) {
for (SDNode *Node : N->uses())
AddToWorklist(Node);
}
- /// visit - call the node-specific routine that knows how to fold each
- /// particular type of node.
+ /// Call the node-specific routine that folds each particular type of node.
SDValue visit(SDNode *N);
public:
- /// AddToWorklist - Add to the work list making sure its instance is at the
- /// back (next to be processed.)
+ /// Add to the worklist making sure its instance is at the back (next to be
+ /// processed.)
void AddToWorklist(SDNode *N) {
// Skip handle nodes as they can't usefully be combined and confuse the
// zero-use deletion strategy.
Worklist.push_back(N);
}
- /// removeFromWorklist - remove all instances of N from the worklist.
- ///
+ /// Remove all instances of N from the worklist.
void removeFromWorklist(SDNode *N) {
CombinedNodes.erase(N);
private:
- /// SimplifyDemandedBits - Check the specified integer node value to see if
- /// it can be simplified or if things it uses can be simplified by bit
- /// propagation. If so, return true.
+ /// Check the specified integer node value to see if it can be simplified or
+ /// if things it uses can be simplified by bit propagation.
+ /// If so, return true.
bool SimplifyDemandedBits(SDValue Op) {
unsigned BitWidth = Op.getValueType().getScalarType().getSizeInBits();
APInt Demanded = APInt::getAllOnesValue(BitWidth);
bool CombineToPreIndexedLoadStore(SDNode *N);
bool CombineToPostIndexedLoadStore(SDNode *N);
+ SDValue SplitIndexingFromLoad(LoadSDNode *LD);
bool SliceUpLoad(SDNode *N);
/// \brief Replace an ISD::EXTRACT_VECTOR_ELT of a load with a narrowed
SDValue Trunc, SDValue ExtLoad, SDLoc DL,
ISD::NodeType ExtType);
- /// combine - call the node-specific routine that knows how to fold each
+ /// Call the node-specific routine that knows how to fold each
/// particular type of node. If that doesn't do anything, try the
/// target-specific DAG combines.
SDValue combine(SDNode *N);
SDValue visitFMA(SDNode *N);
SDValue visitFDIV(SDNode *N);
SDValue visitFREM(SDNode *N);
+ SDValue visitFSQRT(SDNode *N);
SDValue visitFCOPYSIGN(SDNode *N);
SDValue visitSINT_TO_FP(SDNode *N);
SDValue visitUINT_TO_FP(SDNode *N);
SDValue visitFCEIL(SDNode *N);
SDValue visitFTRUNC(SDNode *N);
SDValue visitFFLOOR(SDNode *N);
+ SDValue visitFMINNUM(SDNode *N);
+ SDValue visitFMAXNUM(SDNode *N);
SDValue visitBRCOND(SDNode *N);
SDValue visitBR_CC(SDNode *N);
SDValue visitLOAD(SDNode *N);
SDValue visitEXTRACT_SUBVECTOR(SDNode *N);
SDValue visitVECTOR_SHUFFLE(SDNode *N);
SDValue visitINSERT_SUBVECTOR(SDNode *N);
+ SDValue visitMLOAD(SDNode *N);
+ SDValue visitMSTORE(SDNode *N);
SDValue XformToShuffleWithZero(SDNode *N);
SDValue ReassociateOps(unsigned Opc, SDLoc DL, SDValue LHS, SDValue RHS);
SDValue BuildSDIV(SDNode *N);
SDValue BuildSDIVPow2(SDNode *N);
SDValue BuildUDIV(SDNode *N);
+ SDValue BuildReciprocalEstimate(SDValue Op);
+ SDValue BuildRsqrtEstimate(SDValue Op);
+ SDValue BuildRsqrtNROneConst(SDValue Op, SDValue Est, unsigned Iterations);
+ SDValue BuildRsqrtNRTwoConst(SDValue Op, SDValue Est, unsigned Iterations);
SDValue MatchBSwapHWordLow(SDNode *N, SDValue N0, SDValue N1,
bool DemandHighBits = true);
SDValue MatchBSwapHWord(SDNode *N, SDValue N0, SDValue N1);
SDValue GetDemandedBits(SDValue V, const APInt &Mask);
- /// GatherAllAliases - Walk up chain skipping non-aliasing memory nodes,
+ /// Walk up chain skipping non-aliasing memory nodes,
/// looking for aliasing nodes and adding them to the Aliases vector.
void GatherAllAliases(SDNode *N, SDValue OriginalChain,
SmallVectorImpl<SDValue> &Aliases);
- /// isAlias - Return true if there is any possibility that the two addresses
- /// overlap.
+ /// Return true if there is any possibility that the two addresses overlap.
bool isAlias(LSBaseSDNode *Op0, LSBaseSDNode *Op1) const;
- /// FindBetterChain - Walk up chain skipping non-aliasing memory nodes,
- /// looking for a better chain (aliasing node.)
+ /// Walk up chain skipping non-aliasing memory nodes, looking for a better
+ /// chain (aliasing node.)
SDValue FindBetterChain(SDNode *N, SDValue Chain);
/// Merge consecutive store operations into a wide store.
FnAttrs.hasAttribute(AttributeSet::FunctionIndex, Attribute::MinSize);
}
- /// Run - runs the dag combiner on all nodes in the work list
+ /// Runs the dag combiner on all nodes in the work list
void Run(CombineLevel AtLevel);
SelectionDAG &getDAG() const { return DAG; }
- /// getShiftAmountTy - Returns a type large enough to hold any valid
- /// shift amount - before type legalization these can be huge.
+ /// Returns a type large enough to hold any valid shift amount - before type
+ /// legalization these can be huge.
EVT getShiftAmountTy(EVT LHSTy) {
assert(LHSTy.isInteger() && "Shift amount is not an integer type!");
if (LHSTy.isVector())
: TLI.getPointerTy();
}
- /// isTypeLegal - This method returns true if we are running before type
- /// legalization or if the specified VT is legal.
+ /// This method returns true if we are running before type legalization or
+ /// if the specified VT is legal.
bool isTypeLegal(const EVT &VT) {
if (!LegalTypes) return true;
return TLI.isTypeLegal(VT);
}
- /// getSetCCResultType - Convenience wrapper around
- /// TargetLowering::getSetCCResultType
+ /// Convenience wrapper around TargetLowering::getSetCCResultType
EVT getSetCCResultType(EVT VT) const {
return TLI.getSetCCResultType(*DAG.getContext(), VT);
}
namespace {
-/// WorklistRemover - This class is a DAGUpdateListener that removes any deleted
+/// This class is a DAGUpdateListener that removes any deleted
/// nodes from the worklist.
class WorklistRemover : public SelectionDAG::DAGUpdateListener {
DAGCombiner &DC;
// If the operands of this node are only used by the node, they will now be
// dead. Make sure to re-visit them and recursively delete dead nodes.
for (const SDValue &Op : N->ops())
- if (Op->hasOneUse())
+ // For an operand generating multiple values, one of the values may
+ // become dead allowing further simplification (e.g. split index
+ // arithmetic from an indexed load).
+ if (Op->hasOneUse() || Op->getNumValues() > 1)
AddToWorklist(Op.getNode());
DAG.DeleteNode(N);
}
-/// isNegatibleForFree - Return 1 if we can compute the negated form of the
-/// specified expression for the same cost as the expression itself, or 2 if we
-/// can compute the negated form more cheaply than the expression itself.
+/// Return 1 if we can compute the negated form of the specified expression for
+/// the same cost as the expression itself, or 2 if we can compute the negated
+/// form more cheaply than the expression itself.
static char isNegatibleForFree(SDValue Op, bool LegalOperations,
const TargetLowering &TLI,
const TargetOptions *Options,
}
}
-/// GetNegatedExpression - If isNegatibleForFree returns true, this function
-/// returns the newly negated expression.
+/// If isNegatibleForFree returns true, return the newly negated expression.
static SDValue GetNegatedExpression(SDValue Op, SelectionDAG &DAG,
bool LegalOperations, unsigned Depth = 0) {
+ const TargetOptions &Options = DAG.getTarget().Options;
// fneg is removable even if it has multiple uses.
if (Op.getOpcode() == ISD::FNEG) return Op.getOperand(0);
}
case ISD::FADD:
// FIXME: determine better conditions for this xform.
- assert(DAG.getTarget().Options.UnsafeFPMath);
+ assert(Options.UnsafeFPMath);
// fold (fneg (fadd A, B)) -> (fsub (fneg A), B)
if (isNegatibleForFree(Op.getOperand(0), LegalOperations,
- DAG.getTargetLoweringInfo(),
- &DAG.getTarget().Options, Depth+1))
+ DAG.getTargetLoweringInfo(), &Options, Depth+1))
return DAG.getNode(ISD::FSUB, SDLoc(Op), Op.getValueType(),
GetNegatedExpression(Op.getOperand(0), DAG,
LegalOperations, Depth+1),
Op.getOperand(0));
case ISD::FSUB:
// We can't turn -(A-B) into B-A when we honor signed zeros.
- assert(DAG.getTarget().Options.UnsafeFPMath);
+ assert(Options.UnsafeFPMath);
// fold (fneg (fsub 0, B)) -> B
if (ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(Op.getOperand(0)))
case ISD::FMUL:
case ISD::FDIV:
- assert(!DAG.getTarget().Options.HonorSignDependentRoundingFPMath());
+ assert(!Options.HonorSignDependentRoundingFPMath());
// fold (fneg (fmul X, Y)) -> (fmul (fneg X), Y)
if (isNegatibleForFree(Op.getOperand(0), LegalOperations,
- DAG.getTargetLoweringInfo(),
- &DAG.getTarget().Options, Depth+1))
+ DAG.getTargetLoweringInfo(), &Options, Depth+1))
return DAG.getNode(Op.getOpcode(), SDLoc(Op), Op.getValueType(),
GetNegatedExpression(Op.getOperand(0), DAG,
LegalOperations, Depth+1),
}
}
-// isSetCCEquivalent - Return true if this node is a setcc, or is a select_cc
+// Return true if this node is a setcc, or is a select_cc
// that selects between the target values used for true and false, making it
// equivalent to a setcc. Also, set the incoming LHS, RHS, and CC references to
// the appropriate nodes based on the type of node we are checking. This
!TLI.isConstFalseVal(N.getOperand(3).getNode()))
return false;
+ if (TLI.getBooleanContents(N.getValueType()) ==
+ TargetLowering::UndefinedBooleanContent)
+ return false;
+
LHS = N.getOperand(0);
RHS = N.getOperand(1);
CC = N.getOperand(4);
return true;
}
-// isOneUseSetCC - Return true if this is a SetCC-equivalent operation with only
-// one use. If this is true, it allows the users to invert the operation for
-// free when it is profitable to do so.
+/// Return true if this is a SetCC-equivalent operation with only one use.
+/// If this is true, it allows the users to invert the operation for free when
+/// it is profitable to do so.
bool DAGCombiner::isOneUseSetCC(SDValue N) const {
SDValue N0, N1, N2;
if (isSetCCEquivalent(N, N0, N1, N2) && N.getNode()->hasOneUse())
return false;
}
-/// isConstantSplatVector - Returns true if N is a BUILD_VECTOR node whose
+/// Returns true if N is a BUILD_VECTOR node whose
/// elements are all the same constant or undefined.
static bool isConstantSplatVector(SDNode *N, APInt& SplatValue) {
BuildVectorSDNode *C = dyn_cast<BuildVectorSDNode>(N);
if (isa<ConstantSDNode>(N))
return N.getNode();
BuildVectorSDNode *BV = dyn_cast<BuildVectorSDNode>(N);
- if(BV && BV->isConstant())
+ if (BV && BV->isConstant())
return BV;
return nullptr;
}
BitVector UndefElements;
ConstantFPSDNode *CN = BV->getConstantFPSplatNode(&UndefElements);
- // BuildVectors can truncate their operands. Ignore that case here.
- // FIXME: We blindly ignore splats which include undef which is overly
- // pessimistic.
- if (CN && UndefElements.none() &&
- CN->getValueType(0) == N.getValueType().getScalarType())
+ if (CN && UndefElements.none())
return CN;
}
deleteAndRecombine(TLO.Old.getNode());
}
-/// SimplifyDemandedBits - Check the specified integer node value to see if
-/// it can be simplified or if things it uses can be simplified by bit
-/// propagation. If so, return true.
+/// Check the specified integer node value to see if it can be simplified or if
+/// things it uses can be simplified by bit propagation. If so, return true.
bool DAGCombiner::SimplifyDemandedBits(SDValue Op, const APInt &Demanded) {
TargetLowering::TargetLoweringOpt TLO(DAG, LegalTypes, LegalOperations);
APInt KnownZero, KnownOne;
return DAG.getZeroExtendInReg(NewOp, dl, OldVT);
}
-/// PromoteIntBinOp - Promote the specified integer binary operation if the
-/// target indicates it is beneficial. e.g. On x86, it's usually better to
-/// promote i16 operations to i32 since i16 instructions are longer.
+/// Promote the specified integer binary operation if the target indicates it is
+/// beneficial. e.g. On x86, it's usually better to promote i16 operations to
+/// i32 since i16 instructions are longer.
SDValue DAGCombiner::PromoteIntBinOp(SDValue Op) {
if (!LegalOperations)
return SDValue();
return SDValue();
}
-/// PromoteIntShiftOp - Promote the specified integer shift operation if the
-/// target indicates it is beneficial. e.g. On x86, it's usually better to
-/// promote i16 operations to i32 since i16 instructions are longer.
+/// Promote the specified integer shift operation if the target indicates it is
+/// beneficial. e.g. On x86, it's usually better to promote i16 operations to
+/// i32 since i16 instructions are longer.
SDValue DAGCombiner::PromoteIntShiftOp(SDValue Op) {
if (!LegalOperations)
return SDValue();
LegalOperations = Level >= AfterLegalizeVectorOps;
LegalTypes = Level >= AfterLegalizeTypes;
+ // Early exit if this basic block is in an optnone function.
+ AttributeSet FnAttrs =
+ DAG.getMachineFunction().getFunction()->getAttributes();
+ if (FnAttrs.hasAttribute(AttributeSet::FunctionIndex,
+ Attribute::OptimizeNone))
+ return;
+
// Add all the dag nodes to the worklist.
for (SelectionDAG::allnodes_iterator I = DAG.allnodes_begin(),
E = DAG.allnodes_end(); I != E; ++I)
case ISD::FMA: return visitFMA(N);
case ISD::FDIV: return visitFDIV(N);
case ISD::FREM: return visitFREM(N);
+ case ISD::FSQRT: return visitFSQRT(N);
case ISD::FCOPYSIGN: return visitFCOPYSIGN(N);
case ISD::SINT_TO_FP: return visitSINT_TO_FP(N);
case ISD::UINT_TO_FP: return visitUINT_TO_FP(N);
case ISD::FNEG: return visitFNEG(N);
case ISD::FABS: return visitFABS(N);
case ISD::FFLOOR: return visitFFLOOR(N);
+ case ISD::FMINNUM: return visitFMINNUM(N);
+ case ISD::FMAXNUM: return visitFMAXNUM(N);
case ISD::FCEIL: return visitFCEIL(N);
case ISD::FTRUNC: return visitFTRUNC(N);
case ISD::BRCOND: return visitBRCOND(N);
case ISD::EXTRACT_SUBVECTOR: return visitEXTRACT_SUBVECTOR(N);
case ISD::VECTOR_SHUFFLE: return visitVECTOR_SHUFFLE(N);
case ISD::INSERT_SUBVECTOR: return visitINSERT_SUBVECTOR(N);
+ case ISD::MLOAD: return visitMLOAD(N);
+ case ISD::MSTORE: return visitMSTORE(N);
}
return SDValue();
}
return RV;
}
-/// getInputChainForNode - Given a node, return its input chain if it has one,
-/// otherwise return a null sd operand.
+/// Given a node, return its input chain if it has one, otherwise return a null
+/// sd operand.
static SDValue getInputChainForNode(SDNode *N) {
if (unsigned NumOps = N->getNumOperands()) {
if (N->getOperand(0).getValueType() == MVT::Other)
default:
// Only add if it isn't already in the list.
- if (SeenOps.insert(Op.getNode()))
+ if (SeenOps.insert(Op.getNode()).second)
Ops.push_back(Op);
else
Changed = true;
return SDValue(N, 0); // Return N so it doesn't get rechecked!
}
-static
-SDValue combineShlAddConstant(SDLoc DL, SDValue N0, SDValue N1,
- SelectionDAG &DAG) {
- EVT VT = N0.getValueType();
- SDValue N00 = N0.getOperand(0);
- SDValue N01 = N0.getOperand(1);
- ConstantSDNode *N01C = dyn_cast<ConstantSDNode>(N01);
-
- if (N01C && N00.getOpcode() == ISD::ADD && N00.getNode()->hasOneUse() &&
- isa<ConstantSDNode>(N00.getOperand(1))) {
- // fold (add (shl (add x, c1), c2), ) -> (add (add (shl x, c2), c1<<c2), )
- N0 = DAG.getNode(ISD::ADD, SDLoc(N0), VT,
- DAG.getNode(ISD::SHL, SDLoc(N00), VT,
- N00.getOperand(0), N01),
- DAG.getNode(ISD::SHL, SDLoc(N01), VT,
- N00.getOperand(1), N01));
- return DAG.getNode(ISD::ADD, DL, VT, N0, N1);
- }
-
- return SDValue();
-}
-
SDValue DAGCombiner::visitADD(SDNode *N) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
}
}
- // fold (add (shl (add x, c1), c2), ) -> (add (add (shl x, c2), c1<<c2), )
- if (N0.getOpcode() == ISD::SHL && N0.getNode()->hasOneUse()) {
- SDValue Result = combineShlAddConstant(SDLoc(N), N0, N1, DAG);
- if (Result.getNode()) return Result;
- }
- if (N1.getOpcode() == ISD::SHL && N1.getNode()->hasOneUse()) {
- SDValue Result = combineShlAddConstant(SDLoc(N), N1, N0, DAG);
- if (Result.getNode()) return Result;
- }
-
// fold (add x, shl(0 - y, n)) -> sub(x, shl(y, n))
if (N1.getOpcode() == ISD::SHL &&
N1.getOperand(0).getOpcode() == ISD::SUB)
return DAG.getNode(ISD::SUB, DL, VT, N1, ZExt);
}
+ // add X, (sextinreg Y i1) -> sub X, (and Y 1)
+ if (N1.getOpcode() == ISD::SIGN_EXTEND_INREG) {
+ VTSDNode *TN = cast<VTSDNode>(N1.getOperand(1));
+ if (TN->getVT() == MVT::i1) {
+ SDLoc DL(N);
+ SDValue ZExt = DAG.getNode(ISD::AND, DL, VT, N1.getOperand(0),
+ DAG.getConstant(1, VT));
+ return DAG.getNode(ISD::SUB, DL, VT, N0, ZExt);
+ }
+ }
+
return SDValue();
}
VT);
}
+ // sub X, (sextinreg Y i1) -> add X, (and Y 1)
+ if (N1.getOpcode() == ISD::SIGN_EXTEND_INREG) {
+ VTSDNode *TN = cast<VTSDNode>(N1.getOperand(1));
+ if (TN->getVT() == MVT::i1) {
+ SDLoc DL(N);
+ SDValue ZExt = DAG.getNode(ISD::AND, DL, VT, N1.getOperand(0),
+ DAG.getConstant(1, VT));
+ return DAG.getNode(ISD::ADD, DL, VT, N0, ZExt);
+ }
+ }
+
return SDValue();
}
return SDValue();
}
-/// SimplifyNodeWithTwoResults - Perform optimizations common to nodes that
-/// compute two values. LoOp and HiOp give the opcodes for the two computations
-/// that are being performed. Return true if a simplification was made.
-///
+/// Perform optimizations common to nodes that compute two values. LoOp and HiOp
+/// give the opcodes for the two computations that are being performed. Return
+/// true if a simplification was made.
SDValue DAGCombiner::SimplifyNodeWithTwoResults(SDNode *N, unsigned LoOp,
unsigned HiOp) {
// If the high half is not needed, just compute the low half.
return SDValue();
}
-/// SimplifyBinOpWithSameOpcodeHands - If this is a binary operator with
-/// two operands of the same opcode, try to simplify it.
+/// If this is a binary operator with two operands of the same opcode, try to
+/// simplify it.
SDValue DAGCombiner::SimplifyBinOpWithSameOpcodeHands(SDNode *N) {
SDValue N0 = N->getOperand(0), N1 = N->getOperand(1);
EVT VT = N0.getValueType();
// fold (and x, 0) -> 0, vector edition
if (ISD::isBuildVectorAllZeros(N0.getNode()))
- return N0;
+ // do not return N0, because undef node may exist in N0
+ return DAG.getConstant(
+ APInt::getNullValue(
+ N0.getValueType().getScalarType().getSizeInBits()),
+ N0.getValueType());
if (ISD::isBuildVectorAllZeros(N1.getNode()))
- return N1;
+ // do not return N1, because undef node may exist in N1
+ return DAG.getConstant(
+ APInt::getNullValue(
+ N1.getValueType().getScalarType().getSizeInBits()),
+ N1.getValueType());
// fold (and x, -1) -> x, vector edition
if (ISD::isBuildVectorAllOnes(N0.getNode()))
return SDValue();
}
-/// MatchBSwapHWord - Match (a >> 8) | (a << 8) as (bswap a) >> 16
-///
+/// Match (a >> 8) | (a << 8) as (bswap a) >> 16.
SDValue DAGCombiner::MatchBSwapHWordLow(SDNode *N, SDValue N0, SDValue N1,
bool DemandHighBits) {
if (!LegalOperations)
return Res;
}
-/// isBSwapHWordElement - Return true if the specified node is an element
-/// that makes up a 32-bit packed halfword byteswap. i.e.
-/// ((x&0xff)<<8)|((x&0xff00)>>8)|((x&0x00ff0000)<<8)|((x&0xff000000)>>8)
-static bool isBSwapHWordElement(SDValue N, SmallVectorImpl<SDNode *> &Parts) {
+/// Return true if the specified node is an element that makes up a 32-bit
+/// packed halfword byteswap.
+/// ((x & 0x000000ff) << 8) |
+/// ((x & 0x0000ff00) >> 8) |
+/// ((x & 0x00ff0000) << 8) |
+/// ((x & 0xff000000) >> 8)
+static bool isBSwapHWordElement(SDValue N, MutableArrayRef<SDNode *> Parts) {
if (!N.getNode()->hasOneUse())
return false;
return true;
}
-/// MatchBSwapHWord - Match a 32-bit packed halfword bswap. That is
-/// ((x&0xff)<<8)|((x&0xff00)>>8)|((x&0x00ff0000)<<8)|((x&0xff000000)>>8)
+/// Match a 32-bit packed halfword bswap. That is
+/// ((x & 0x000000ff) << 8) |
+/// ((x & 0x0000ff00) >> 8) |
+/// ((x & 0x00ff0000) << 8) |
+/// ((x & 0xff000000) >> 8)
/// => (rotl (bswap x), 16)
SDValue DAGCombiner::MatchBSwapHWord(SDNode *N, SDValue N0, SDValue N1) {
if (!LegalOperations)
if (!TLI.isOperationLegal(ISD::BSWAP, VT))
return SDValue();
- SmallVector<SDNode*,4> Parts(4, (SDNode*)nullptr);
// Look for either
// (or (or (and), (and)), (or (and), (and)))
// (or (or (or (and), (and)), (and)), (and))
return SDValue();
SDValue N00 = N0.getOperand(0);
SDValue N01 = N0.getOperand(1);
+ SDNode *Parts[4] = {};
if (N1.getOpcode() == ISD::OR &&
N00.getNumOperands() == 2 && N01.getNumOperands() == 2) {
// fold (or x, -1) -> -1, vector edition
if (ISD::isBuildVectorAllOnes(N0.getNode()))
- return N0;
+ // do not return N0, because undef node may exist in N0
+ return DAG.getConstant(
+ APInt::getAllOnesValue(
+ N0.getValueType().getScalarType().getSizeInBits()),
+ N0.getValueType());
if (ISD::isBuildVectorAllOnes(N1.getNode()))
- return N1;
+ // do not return N1, because undef node may exist in N1
+ return DAG.getConstant(
+ APInt::getAllOnesValue(
+ N1.getValueType().getScalarType().getSizeInBits()),
+ N1.getValueType());
// fold (or (shuf A, V_0, MA), (shuf B, V_0, MB)) -> (shuf A, B, Mask1)
// fold (or (shuf A, V_0, MA), (shuf B, V_0, MB)) -> (shuf B, A, Mask2)
return SDValue();
}
-/// MatchRotateHalf - Match "(X shl/srl V1) & V2" where V2 may not be present.
+/// Match "(X shl/srl V1) & V2" where V2 may not be present.
static bool MatchRotateHalf(SDValue Op, SDValue &Shift, SDValue &Mask) {
if (Op.getOpcode() == ISD::AND) {
if (isa<ConstantSDNode>(Op.getOperand(1))) {
return RXOR;
// fold !(x cc y) -> (x !cc y)
- if (N1C && N1C->getAPIntValue() == 1 && isSetCCEquivalent(N0, LHS, RHS, CC)) {
+ if (TLI.isConstTrueVal(N1.getNode()) && isSetCCEquivalent(N0, LHS, RHS, CC)) {
bool isInt = LHS.getValueType().isInteger();
ISD::CondCode NotCC = ISD::getSetCCInverse(cast<CondCodeSDNode>(CC)->get(),
isInt);
return SDValue();
}
-/// visitShiftByConstant - Handle transforms common to the three shifts, when
-/// the shift amount is a constant.
+/// Handle transforms common to the three shifts, when the shift amount is a
+/// constant.
SDValue DAGCombiner::visitShiftByConstant(SDNode *N, ConstantSDNode *Amt) {
// We can't and shouldn't fold opaque constants.
if (Amt->isOpaque())
HiBitsMask);
}
+ // fold (shl (add x, c1), c2) -> (add (shl x, c2), c1 << c2)
+ // Variant of version done on multiply, except mul by a power of 2 is turned
+ // into a shift.
+ APInt Val;
+ if (N1C && N0.getOpcode() == ISD::ADD && N0.getNode()->hasOneUse() &&
+ (isa<ConstantSDNode>(N0.getOperand(1)) ||
+ isConstantSplatVector(N0.getOperand(1).getNode(), Val))) {
+ SDValue Shl0 = DAG.getNode(ISD::SHL, SDLoc(N0), VT, N0.getOperand(0), N1);
+ SDValue Shl1 = DAG.getNode(ISD::SHL, SDLoc(N1), VT, N0.getOperand(1), N1);
+ return DAG.getNode(ISD::ADD, SDLoc(N), VT, Shl0, Shl1);
+ }
+
if (N1C) {
SDValue NewSHL = visitShiftByConstant(N, N1C);
if (NewSHL.getNode())
if (N0.getOpcode() == ISD::SETCC) {
if ((!LegalOperations &&
TLI.isOperationLegalOrCustom(ISD::SELECT_CC, VT)) ||
- TLI.isOperationLegal(ISD::SELECT_CC, VT))
+ TLI.isOperationLegal(ISD::SELECT_CC, VT))
return DAG.getNode(ISD::SELECT_CC, SDLoc(N), VT,
N0.getOperand(0), N0.getOperand(1),
N1, N2, N0.getOperand(2));
TopHalf->isNullValue() ? RHS->getOperand(1) : LHS->getOperand(1));
}
+SDValue DAGCombiner::visitMSTORE(SDNode *N) {
+
+ if (Level >= AfterLegalizeTypes)
+ return SDValue();
+
+ MaskedStoreSDNode *MST = dyn_cast<MaskedStoreSDNode>(N);
+ SDValue Mask = MST->getMask();
+ SDValue Data = MST->getData();
+ SDLoc DL(N);
+
+ // If the MSTORE data type requires splitting and the mask is provided by a
+ // SETCC, then split both nodes and its operands before legalization. This
+ // prevents the type legalizer from unrolling SETCC into scalar comparisons
+ // and enables future optimizations (e.g. min/max pattern matching on X86).
+ if (Mask.getOpcode() == ISD::SETCC) {
+
+ // Check if any splitting is required.
+ if (TLI.getTypeAction(*DAG.getContext(), Data.getValueType()) !=
+ TargetLowering::TypeSplitVector)
+ return SDValue();
+
+ SDValue MaskLo, MaskHi, Lo, Hi;
+ std::tie(MaskLo, MaskHi) = SplitVSETCC(Mask.getNode(), DAG);
+
+ EVT LoVT, HiVT;
+ std::tie(LoVT, HiVT) = DAG.GetSplitDestVTs(MST->getValueType(0));
+
+ SDValue Chain = MST->getChain();
+ SDValue Ptr = MST->getBasePtr();
+
+ EVT MemoryVT = MST->getMemoryVT();
+ unsigned Alignment = MST->getOriginalAlignment();
+
+ // if Alignment is equal to the vector size,
+ // take the half of it for the second part
+ unsigned SecondHalfAlignment =
+ (Alignment == Data->getValueType(0).getSizeInBits()/8) ?
+ Alignment/2 : Alignment;
+
+ EVT LoMemVT, HiMemVT;
+ std::tie(LoMemVT, HiMemVT) = DAG.GetSplitDestVTs(MemoryVT);
+
+ SDValue DataLo, DataHi;
+ std::tie(DataLo, DataHi) = DAG.SplitVector(Data, DL);
+
+ MachineMemOperand *MMO = DAG.getMachineFunction().
+ getMachineMemOperand(MST->getPointerInfo(),
+ MachineMemOperand::MOStore, LoMemVT.getStoreSize(),
+ Alignment, MST->getAAInfo(), MST->getRanges());
+
+ Lo = DAG.getMaskedStore(Chain, DL, DataLo, Ptr, MaskLo, MMO);
+
+ unsigned IncrementSize = LoMemVT.getSizeInBits()/8;
+ Ptr = DAG.getNode(ISD::ADD, DL, Ptr.getValueType(), Ptr,
+ DAG.getConstant(IncrementSize, Ptr.getValueType()));
+
+ MMO = DAG.getMachineFunction().
+ getMachineMemOperand(MST->getPointerInfo(),
+ MachineMemOperand::MOStore, HiMemVT.getStoreSize(),
+ SecondHalfAlignment, MST->getAAInfo(),
+ MST->getRanges());
+
+ Hi = DAG.getMaskedStore(Chain, DL, DataHi, Ptr, MaskHi, MMO);
+
+ AddToWorklist(Lo.getNode());
+ AddToWorklist(Hi.getNode());
+
+ return DAG.getNode(ISD::TokenFactor, DL, MVT::Other, Lo, Hi);
+ }
+ return SDValue();
+}
+
+SDValue DAGCombiner::visitMLOAD(SDNode *N) {
+
+ if (Level >= AfterLegalizeTypes)
+ return SDValue();
+
+ MaskedLoadSDNode *MLD = dyn_cast<MaskedLoadSDNode>(N);
+ SDValue Mask = MLD->getMask();
+ SDLoc DL(N);
+
+ // If the MLOAD result requires splitting and the mask is provided by a
+ // SETCC, then split both nodes and its operands before legalization. This
+ // prevents the type legalizer from unrolling SETCC into scalar comparisons
+ // and enables future optimizations (e.g. min/max pattern matching on X86).
+
+ if (Mask.getOpcode() == ISD::SETCC) {
+ EVT VT = N->getValueType(0);
+
+ // Check if any splitting is required.
+ if (TLI.getTypeAction(*DAG.getContext(), VT) !=
+ TargetLowering::TypeSplitVector)
+ return SDValue();
+
+ SDValue MaskLo, MaskHi, Lo, Hi;
+ std::tie(MaskLo, MaskHi) = SplitVSETCC(Mask.getNode(), DAG);
+
+ SDValue Src0 = MLD->getSrc0();
+ SDValue Src0Lo, Src0Hi;
+ std::tie(Src0Lo, Src0Hi) = DAG.SplitVector(Src0, DL);
+
+ EVT LoVT, HiVT;
+ std::tie(LoVT, HiVT) = DAG.GetSplitDestVTs(MLD->getValueType(0));
+
+ SDValue Chain = MLD->getChain();
+ SDValue Ptr = MLD->getBasePtr();
+ EVT MemoryVT = MLD->getMemoryVT();
+ unsigned Alignment = MLD->getOriginalAlignment();
+
+ // if Alignment is equal to the vector size,
+ // take the half of it for the second part
+ unsigned SecondHalfAlignment =
+ (Alignment == MLD->getValueType(0).getSizeInBits()/8) ?
+ Alignment/2 : Alignment;
+
+ EVT LoMemVT, HiMemVT;
+ std::tie(LoMemVT, HiMemVT) = DAG.GetSplitDestVTs(MemoryVT);
+
+ MachineMemOperand *MMO = DAG.getMachineFunction().
+ getMachineMemOperand(MLD->getPointerInfo(),
+ MachineMemOperand::MOLoad, LoMemVT.getStoreSize(),
+ Alignment, MLD->getAAInfo(), MLD->getRanges());
+
+ Lo = DAG.getMaskedLoad(LoVT, DL, Chain, Ptr, MaskLo, Src0Lo, MMO);
+
+ unsigned IncrementSize = LoMemVT.getSizeInBits()/8;
+ Ptr = DAG.getNode(ISD::ADD, DL, Ptr.getValueType(), Ptr,
+ DAG.getConstant(IncrementSize, Ptr.getValueType()));
+
+ MMO = DAG.getMachineFunction().
+ getMachineMemOperand(MLD->getPointerInfo(),
+ MachineMemOperand::MOLoad, HiMemVT.getStoreSize(),
+ SecondHalfAlignment, MLD->getAAInfo(), MLD->getRanges());
+
+ Hi = DAG.getMaskedLoad(HiVT, DL, Chain, Ptr, MaskHi, Src0Hi, MMO);
+
+ AddToWorklist(Lo.getNode());
+ AddToWorklist(Hi.getNode());
+
+ // Build a factor node to remember that this load is independent of the
+ // other one.
+ Chain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, Lo.getValue(1),
+ Hi.getValue(1));
+
+ // Legalized the chain result - switch anything that used the old chain to
+ // use the new one.
+ DAG.ReplaceAllUsesOfValueWith(SDValue(MLD, 1), Chain);
+
+ SDValue LoadRes = DAG.getNode(ISD::CONCAT_VECTORS, DL, VT, Lo, Hi);
+
+ SDValue RetOps[] = { LoadRes, Chain };
+ return DAG.getMergeValues(RetOps, DL);
+ }
+ return SDValue();
+}
+
SDValue DAGCombiner::visitVSELECT(SDNode *N) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
if (!LegalOperations || TLI.isOperationLegal(ISD::SETCC, SetCCVT)) {
SDLoc DL(N);
ISD::CondCode CC = cast<CondCodeSDNode>(N0.getOperand(2))->get();
- SDValue SetCC = DAG.getSetCC(DL,
- SetCCVT,
+ SDValue SetCC = DAG.getSetCC(DL, SetCCVT,
N0.getOperand(0), N0.getOperand(1), CC);
- EVT SelectVT = getSetCCResultType(VT);
- return DAG.getSelect(DL, VT,
- DAG.getSExtOrTrunc(SetCC, DL, SelectVT),
+ return DAG.getSelect(DL, VT, SetCC,
NegOne, DAG.getConstant(0, VT));
-
}
}
}
return SDValue();
}
-/// GetDemandedBits - See if the specified operand can be simplified with the
-/// knowledge that only the bits specified by Mask are used. If so, return the
-/// simpler operand, otherwise return a null SDValue.
+/// See if the specified operand can be simplified with the knowledge that only
+/// the bits specified by Mask are used. If so, return the simpler operand,
+/// otherwise return a null SDValue.
SDValue DAGCombiner::GetDemandedBits(SDValue V, const APInt &Mask) {
switch (V.getOpcode()) {
default: break;
return SDValue();
}
-/// ReduceLoadWidth - If the result of a wider load is shifted to right of N
-/// bits and then truncated to a narrower type and where N is a multiple
-/// of number of bits of the narrower type, transform it to a narrower load
-/// from address + N / num of bits of new type. If the result is to be
-/// extended, also fold the extension to form a extending load.
+/// If the result of a wider load is shifted to right of N bits and then
+/// truncated to a narrower type and where N is a multiple of number of bits of
+/// the narrower type, transform it to a narrower load from address + N / num of
+/// bits of new type. If the result is to be extended, also fold the extension
+/// to form a extending load.
SDValue DAGCombiner::ReduceLoadWidth(SDNode *N) {
unsigned Opc = N->getOpcode();
return Elt.getOperand(Elt.getResNo()).getNode();
}
-/// CombineConsecutiveLoads - build_pair (load, load) -> load
+/// build_pair (load, load) -> load
/// if load locations are consecutive.
SDValue DAGCombiner::CombineConsecutiveLoads(SDNode *N, EVT VT) {
assert(N->getOpcode() == ISD::BUILD_PAIR);
return CombineConsecutiveLoads(N, VT);
}
-/// ConstantFoldBITCASTofBUILD_VECTOR - We know that BV is a build_vector
-/// node with Constant, ConstantFP or Undef operands. DstEltVT indicates the
-/// destination element value type.
+/// We know that BV is a build_vector node with Constant, ConstantFP or Undef
+/// operands. DstEltVT indicates the destination element value type.
SDValue DAGCombiner::
ConstantFoldBITCASTofBUILD_VECTOR(SDNode *BV, EVT DstEltVT) {
EVT SrcEltVT = BV->getValueType(0).getVectorElementType();
ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
EVT VT = N->getValueType(0);
+ const TargetOptions &Options = DAG.getTarget().Options;
// fold vector ops
if (VT.isVector()) {
// fold (fadd c1, c2) -> c1 + c2
if (N0CFP && N1CFP)
return DAG.getNode(ISD::FADD, SDLoc(N), VT, N0, N1);
+
// canonicalize constant to RHS
if (N0CFP && !N1CFP)
return DAG.getNode(ISD::FADD, SDLoc(N), VT, N1, N0);
- // fold (fadd A, 0) -> A
- if (DAG.getTarget().Options.UnsafeFPMath && N1CFP &&
- N1CFP->getValueAPF().isZero())
- return N0;
+
// fold (fadd A, (fneg B)) -> (fsub A, B)
if ((!LegalOperations || TLI.isOperationLegalOrCustom(ISD::FSUB, VT)) &&
- isNegatibleForFree(N1, LegalOperations, TLI, &DAG.getTarget().Options) == 2)
+ isNegatibleForFree(N1, LegalOperations, TLI, &Options) == 2)
return DAG.getNode(ISD::FSUB, SDLoc(N), VT, N0,
GetNegatedExpression(N1, DAG, LegalOperations));
+
// fold (fadd (fneg A), B) -> (fsub B, A)
if ((!LegalOperations || TLI.isOperationLegalOrCustom(ISD::FSUB, VT)) &&
- isNegatibleForFree(N0, LegalOperations, TLI, &DAG.getTarget().Options) == 2)
+ isNegatibleForFree(N0, LegalOperations, TLI, &Options) == 2)
return DAG.getNode(ISD::FSUB, SDLoc(N), VT, N1,
GetNegatedExpression(N0, DAG, LegalOperations));
- // If allowed, fold (fadd (fadd x, c1), c2) -> (fadd x, (fadd c1, c2))
- if (DAG.getTarget().Options.UnsafeFPMath && N1CFP &&
- N0.getOpcode() == ISD::FADD && N0.getNode()->hasOneUse() &&
- isa<ConstantFPSDNode>(N0.getOperand(1)))
- return DAG.getNode(ISD::FADD, SDLoc(N), VT, N0.getOperand(0),
- DAG.getNode(ISD::FADD, SDLoc(N), VT,
- N0.getOperand(1), N1));
+ // If 'unsafe math' is enabled, fold lots of things.
+ if (Options.UnsafeFPMath) {
+ // No FP constant should be created after legalization as Instruction
+ // Selection pass has a hard time dealing with FP constants.
+ bool AllowNewConst = (Level < AfterLegalizeDAG);
- // No FP constant should be created after legalization as Instruction
- // Selection pass has hard time in dealing with FP constant.
- //
- // We don't need test this condition for transformation like following, as
- // the DAG being transformed implies it is legal to take FP constant as
- // operand.
- //
- // (fadd (fmul c, x), x) -> (fmul c+1, x)
- //
- bool AllowNewFpConst = (Level < AfterLegalizeDAG);
-
- // If allow, fold (fadd (fneg x), x) -> 0.0
- if (AllowNewFpConst && DAG.getTarget().Options.UnsafeFPMath &&
- N0.getOpcode() == ISD::FNEG && N0.getOperand(0) == N1)
- return DAG.getConstantFP(0.0, VT);
-
- // If allow, fold (fadd x, (fneg x)) -> 0.0
- if (AllowNewFpConst && DAG.getTarget().Options.UnsafeFPMath &&
- N1.getOpcode() == ISD::FNEG && N1.getOperand(0) == N0)
- return DAG.getConstantFP(0.0, VT);
-
- // In unsafe math mode, we can fold chains of FADD's of the same value
- // into multiplications. This transform is not safe in general because
- // we are reducing the number of rounding steps.
- if (DAG.getTarget().Options.UnsafeFPMath &&
- TLI.isOperationLegalOrCustom(ISD::FMUL, VT) &&
- !N0CFP && !N1CFP) {
- if (N0.getOpcode() == ISD::FMUL) {
- ConstantFPSDNode *CFP00 = dyn_cast<ConstantFPSDNode>(N0.getOperand(0));
- ConstantFPSDNode *CFP01 = dyn_cast<ConstantFPSDNode>(N0.getOperand(1));
-
- // (fadd (fmul c, x), x) -> (fmul x, c+1)
- if (CFP00 && !CFP01 && N0.getOperand(1) == N1) {
- SDValue NewCFP = DAG.getNode(ISD::FADD, SDLoc(N), VT,
- SDValue(CFP00, 0),
- DAG.getConstantFP(1.0, VT));
- return DAG.getNode(ISD::FMUL, SDLoc(N), VT,
- N1, NewCFP);
- }
+ // fold (fadd A, 0) -> A
+ if (N1CFP && N1CFP->getValueAPF().isZero())
+ return N0;
- // (fadd (fmul x, c), x) -> (fmul x, c+1)
- if (CFP01 && !CFP00 && N0.getOperand(0) == N1) {
- SDValue NewCFP = DAG.getNode(ISD::FADD, SDLoc(N), VT,
- SDValue(CFP01, 0),
- DAG.getConstantFP(1.0, VT));
- return DAG.getNode(ISD::FMUL, SDLoc(N), VT,
- N1, NewCFP);
- }
+ // fold (fadd (fadd x, c1), c2) -> (fadd x, (fadd c1, c2))
+ if (N1CFP && N0.getOpcode() == ISD::FADD && N0.getNode()->hasOneUse() &&
+ isa<ConstantFPSDNode>(N0.getOperand(1)))
+ return DAG.getNode(ISD::FADD, SDLoc(N), VT, N0.getOperand(0),
+ DAG.getNode(ISD::FADD, SDLoc(N), VT,
+ N0.getOperand(1), N1));
+
+ // If allowed, fold (fadd (fneg x), x) -> 0.0
+ if (AllowNewConst && N0.getOpcode() == ISD::FNEG && N0.getOperand(0) == N1)
+ return DAG.getConstantFP(0.0, VT);
+
+ // If allowed, fold (fadd x, (fneg x)) -> 0.0
+ if (AllowNewConst && N1.getOpcode() == ISD::FNEG && N1.getOperand(0) == N0)
+ return DAG.getConstantFP(0.0, VT);
+
+ // We can fold chains of FADD's of the same value into multiplications.
+ // This transform is not safe in general because we are reducing the number
+ // of rounding steps.
+ if (TLI.isOperationLegalOrCustom(ISD::FMUL, VT) && !N0CFP && !N1CFP) {
+ if (N0.getOpcode() == ISD::FMUL) {
+ ConstantFPSDNode *CFP00 = dyn_cast<ConstantFPSDNode>(N0.getOperand(0));
+ ConstantFPSDNode *CFP01 = dyn_cast<ConstantFPSDNode>(N0.getOperand(1));
+
+ // (fadd (fmul x, c), x) -> (fmul x, c+1)
+ if (CFP01 && !CFP00 && N0.getOperand(0) == N1) {
+ SDValue NewCFP = DAG.getNode(ISD::FADD, SDLoc(N), VT,
+ SDValue(CFP01, 0),
+ DAG.getConstantFP(1.0, VT));
+ return DAG.getNode(ISD::FMUL, SDLoc(N), VT, N1, NewCFP);
+ }
- // (fadd (fmul c, x), (fadd x, x)) -> (fmul x, c+2)
- if (CFP00 && !CFP01 && N1.getOpcode() == ISD::FADD &&
- N1.getOperand(0) == N1.getOperand(1) &&
- N0.getOperand(1) == N1.getOperand(0)) {
- SDValue NewCFP = DAG.getNode(ISD::FADD, SDLoc(N), VT,
- SDValue(CFP00, 0),
- DAG.getConstantFP(2.0, VT));
- return DAG.getNode(ISD::FMUL, SDLoc(N), VT,
- N0.getOperand(1), NewCFP);
+ // (fadd (fmul x, c), (fadd x, x)) -> (fmul x, c+2)
+ if (CFP01 && !CFP00 && N1.getOpcode() == ISD::FADD &&
+ N1.getOperand(0) == N1.getOperand(1) &&
+ N0.getOperand(0) == N1.getOperand(0)) {
+ SDValue NewCFP = DAG.getNode(ISD::FADD, SDLoc(N), VT,
+ SDValue(CFP01, 0),
+ DAG.getConstantFP(2.0, VT));
+ return DAG.getNode(ISD::FMUL, SDLoc(N), VT,
+ N0.getOperand(0), NewCFP);
+ }
}
- // (fadd (fmul x, c), (fadd x, x)) -> (fmul x, c+2)
- if (CFP01 && !CFP00 && N1.getOpcode() == ISD::FADD &&
- N1.getOperand(0) == N1.getOperand(1) &&
- N0.getOperand(0) == N1.getOperand(0)) {
- SDValue NewCFP = DAG.getNode(ISD::FADD, SDLoc(N), VT,
- SDValue(CFP01, 0),
- DAG.getConstantFP(2.0, VT));
- return DAG.getNode(ISD::FMUL, SDLoc(N), VT,
- N0.getOperand(0), NewCFP);
- }
- }
+ if (N1.getOpcode() == ISD::FMUL) {
+ ConstantFPSDNode *CFP10 = dyn_cast<ConstantFPSDNode>(N1.getOperand(0));
+ ConstantFPSDNode *CFP11 = dyn_cast<ConstantFPSDNode>(N1.getOperand(1));
- if (N1.getOpcode() == ISD::FMUL) {
- ConstantFPSDNode *CFP10 = dyn_cast<ConstantFPSDNode>(N1.getOperand(0));
- ConstantFPSDNode *CFP11 = dyn_cast<ConstantFPSDNode>(N1.getOperand(1));
+ // (fadd x, (fmul x, c)) -> (fmul x, c+1)
+ if (CFP11 && !CFP10 && N1.getOperand(0) == N0) {
+ SDValue NewCFP = DAG.getNode(ISD::FADD, SDLoc(N), VT,
+ SDValue(CFP11, 0),
+ DAG.getConstantFP(1.0, VT));
+ return DAG.getNode(ISD::FMUL, SDLoc(N), VT, N0, NewCFP);
+ }
- // (fadd x, (fmul c, x)) -> (fmul x, c+1)
- if (CFP10 && !CFP11 && N1.getOperand(1) == N0) {
- SDValue NewCFP = DAG.getNode(ISD::FADD, SDLoc(N), VT,
- SDValue(CFP10, 0),
- DAG.getConstantFP(1.0, VT));
- return DAG.getNode(ISD::FMUL, SDLoc(N), VT,
- N0, NewCFP);
+ // (fadd (fadd x, x), (fmul x, c)) -> (fmul x, c+2)
+ if (CFP11 && !CFP10 && N0.getOpcode() == ISD::FADD &&
+ N0.getOperand(0) == N0.getOperand(1) &&
+ N1.getOperand(0) == N0.getOperand(0)) {
+ SDValue NewCFP = DAG.getNode(ISD::FADD, SDLoc(N), VT,
+ SDValue(CFP11, 0),
+ DAG.getConstantFP(2.0, VT));
+ return DAG.getNode(ISD::FMUL, SDLoc(N), VT, N1.getOperand(0), NewCFP);
+ }
}
- // (fadd x, (fmul x, c)) -> (fmul x, c+1)
- if (CFP11 && !CFP10 && N1.getOperand(0) == N0) {
- SDValue NewCFP = DAG.getNode(ISD::FADD, SDLoc(N), VT,
- SDValue(CFP11, 0),
- DAG.getConstantFP(1.0, VT));
- return DAG.getNode(ISD::FMUL, SDLoc(N), VT,
- N0, NewCFP);
+ if (N0.getOpcode() == ISD::FADD && AllowNewConst) {
+ ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(N0.getOperand(0));
+ // (fadd (fadd x, x), x) -> (fmul x, 3.0)
+ if (!CFP && N0.getOperand(0) == N0.getOperand(1) &&
+ (N0.getOperand(0) == N1))
+ return DAG.getNode(ISD::FMUL, SDLoc(N), VT,
+ N1, DAG.getConstantFP(3.0, VT));
}
-
- // (fadd (fadd x, x), (fmul c, x)) -> (fmul x, c+2)
- if (CFP10 && !CFP11 && N0.getOpcode() == ISD::FADD &&
- N0.getOperand(0) == N0.getOperand(1) &&
- N1.getOperand(1) == N0.getOperand(0)) {
- SDValue NewCFP = DAG.getNode(ISD::FADD, SDLoc(N), VT,
- SDValue(CFP10, 0),
- DAG.getConstantFP(2.0, VT));
- return DAG.getNode(ISD::FMUL, SDLoc(N), VT,
- N1.getOperand(1), NewCFP);
+ if (N1.getOpcode() == ISD::FADD && AllowNewConst) {
+ ConstantFPSDNode *CFP10 = dyn_cast<ConstantFPSDNode>(N1.getOperand(0));
+ // (fadd x, (fadd x, x)) -> (fmul x, 3.0)
+ if (!CFP10 && N1.getOperand(0) == N1.getOperand(1) &&
+ N1.getOperand(0) == N0)
+ return DAG.getNode(ISD::FMUL, SDLoc(N), VT,
+ N0, DAG.getConstantFP(3.0, VT));
}
- // (fadd (fadd x, x), (fmul x, c)) -> (fmul x, c+2)
- if (CFP11 && !CFP10 && N0.getOpcode() == ISD::FADD &&
+ // (fadd (fadd x, x), (fadd x, x)) -> (fmul x, 4.0)
+ if (AllowNewConst &&
+ N0.getOpcode() == ISD::FADD && N1.getOpcode() == ISD::FADD &&
N0.getOperand(0) == N0.getOperand(1) &&
- N1.getOperand(0) == N0.getOperand(0)) {
- SDValue NewCFP = DAG.getNode(ISD::FADD, SDLoc(N), VT,
- SDValue(CFP11, 0),
- DAG.getConstantFP(2.0, VT));
- return DAG.getNode(ISD::FMUL, SDLoc(N), VT,
- N1.getOperand(0), NewCFP);
- }
- }
-
- if (N0.getOpcode() == ISD::FADD && AllowNewFpConst) {
- ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(N0.getOperand(0));
- // (fadd (fadd x, x), x) -> (fmul x, 3.0)
- if (!CFP && N0.getOperand(0) == N0.getOperand(1) &&
- (N0.getOperand(0) == N1))
- return DAG.getNode(ISD::FMUL, SDLoc(N), VT,
- N1, DAG.getConstantFP(3.0, VT));
- }
-
- if (N1.getOpcode() == ISD::FADD && AllowNewFpConst) {
- ConstantFPSDNode *CFP10 = dyn_cast<ConstantFPSDNode>(N1.getOperand(0));
- // (fadd x, (fadd x, x)) -> (fmul x, 3.0)
- if (!CFP10 && N1.getOperand(0) == N1.getOperand(1) &&
- N1.getOperand(0) == N0)
+ N1.getOperand(0) == N1.getOperand(1) &&
+ N0.getOperand(0) == N1.getOperand(0))
return DAG.getNode(ISD::FMUL, SDLoc(N), VT,
- N0, DAG.getConstantFP(3.0, VT));
+ N0.getOperand(0), DAG.getConstantFP(4.0, VT));
}
-
- // (fadd (fadd x, x), (fadd x, x)) -> (fmul x, 4.0)
- if (AllowNewFpConst &&
- N0.getOpcode() == ISD::FADD && N1.getOpcode() == ISD::FADD &&
- N0.getOperand(0) == N0.getOperand(1) &&
- N1.getOperand(0) == N1.getOperand(1) &&
- N0.getOperand(0) == N1.getOperand(0))
- return DAG.getNode(ISD::FMUL, SDLoc(N), VT,
- N0.getOperand(0),
- DAG.getConstantFP(4.0, VT));
- }
+ } // enable-unsafe-fp-math
// FADD -> FMA combines:
- if ((DAG.getTarget().Options.AllowFPOpFusion == FPOpFusion::Fast ||
- DAG.getTarget().Options.UnsafeFPMath) &&
- DAG.getTarget()
- .getSubtargetImpl()
- ->getTargetLowering()
- ->isFMAFasterThanFMulAndFAdd(VT) &&
+ if ((Options.AllowFPOpFusion == FPOpFusion::Fast || Options.UnsafeFPMath) &&
+ TLI.isFMAFasterThanFMulAndFAdd(VT) &&
(!LegalOperations || TLI.isOperationLegalOrCustom(ISD::FMA, VT))) {
// fold (fadd (fmul x, y), z) -> (fma x, y, z)
- if (N0.getOpcode() == ISD::FMUL && N0->hasOneUse())
+ if (N0.getOpcode() == ISD::FMUL &&
+ (N0->hasOneUse() || TLI.enableAggressiveFMAFusion(VT)))
return DAG.getNode(ISD::FMA, SDLoc(N), VT,
N0.getOperand(0), N0.getOperand(1), N1);
// fold (fadd x, (fmul y, z)) -> (fma y, z, x)
// Note: Commutes FADD operands.
- if (N1.getOpcode() == ISD::FMUL && N1->hasOneUse())
+ if (N1.getOpcode() == ISD::FMUL &&
+ (N1->hasOneUse() || TLI.enableAggressiveFMAFusion(VT)))
return DAG.getNode(ISD::FMA, SDLoc(N), VT,
N1.getOperand(0), N1.getOperand(1), N0);
}
SDValue DAGCombiner::visitFSUB(SDNode *N) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
- ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
- ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
+ ConstantFPSDNode *N0CFP = isConstOrConstSplatFP(N0);
+ ConstantFPSDNode *N1CFP = isConstOrConstSplatFP(N1);
EVT VT = N->getValueType(0);
SDLoc dl(N);
- const TargetOptions *Options = &DAG.getTarget().Options;
+ const TargetOptions &Options = DAG.getTarget().Options;
// fold vector ops
if (VT.isVector()) {
return DAG.getNode(ISD::FSUB, SDLoc(N), VT, N0, N1);
// fold (fsub A, (fneg B)) -> (fadd A, B)
- if (isNegatibleForFree(N1, LegalOperations, TLI, Options))
+ if (isNegatibleForFree(N1, LegalOperations, TLI, &Options))
return DAG.getNode(ISD::FADD, dl, VT, N0,
GetNegatedExpression(N1, DAG, LegalOperations));
// If 'unsafe math' is enabled, fold lots of things.
- if (Options->UnsafeFPMath) {
+ if (Options.UnsafeFPMath) {
// (fsub A, 0) -> A
if (N1CFP && N1CFP->getValueAPF().isZero())
return N0;
// (fsub 0, B) -> -B
if (N0CFP && N0CFP->getValueAPF().isZero()) {
- if (isNegatibleForFree(N1, LegalOperations, TLI, Options))
+ if (isNegatibleForFree(N1, LegalOperations, TLI, &Options))
return GetNegatedExpression(N1, DAG, LegalOperations);
if (!LegalOperations || TLI.isOperationLegal(ISD::FNEG, VT))
return DAG.getNode(ISD::FNEG, dl, VT, N1);
SDValue N10 = N1->getOperand(0);
SDValue N11 = N1->getOperand(1);
- if (N10 == N0 && isNegatibleForFree(N11, LegalOperations, TLI, Options))
+ if (N10 == N0 && isNegatibleForFree(N11, LegalOperations, TLI, &Options))
return GetNegatedExpression(N11, DAG, LegalOperations);
- if (N11 == N0 && isNegatibleForFree(N10, LegalOperations, TLI, Options))
+ if (N11 == N0 && isNegatibleForFree(N10, LegalOperations, TLI, &Options))
return GetNegatedExpression(N10, DAG, LegalOperations);
}
}
// FSUB -> FMA combines:
- if ((Options->AllowFPOpFusion == FPOpFusion::Fast || Options->UnsafeFPMath) &&
- DAG.getTarget().getSubtargetImpl()
- ->getTargetLowering()
- ->isFMAFasterThanFMulAndFAdd(VT) &&
+ if ((Options.AllowFPOpFusion == FPOpFusion::Fast || Options.UnsafeFPMath) &&
+ TLI.isFMAFasterThanFMulAndFAdd(VT) &&
(!LegalOperations || TLI.isOperationLegalOrCustom(ISD::FMA, VT))) {
// fold (fsub (fmul x, y), z) -> (fma x, y, (fneg z))
- if (N0.getOpcode() == ISD::FMUL && N0->hasOneUse())
+ if (N0.getOpcode() == ISD::FMUL &&
+ (N0->hasOneUse() || TLI.enableAggressiveFMAFusion(VT)))
return DAG.getNode(ISD::FMA, dl, VT,
N0.getOperand(0), N0.getOperand(1),
DAG.getNode(ISD::FNEG, dl, VT, N1));
// fold (fsub x, (fmul y, z)) -> (fma (fneg y), z, x)
// Note: Commutes FSUB operands.
- if (N1.getOpcode() == ISD::FMUL && N1->hasOneUse())
+ if (N1.getOpcode() == ISD::FMUL &&
+ (N1->hasOneUse() || TLI.enableAggressiveFMAFusion(VT)))
return DAG.getNode(ISD::FMA, dl, VT,
DAG.getNode(ISD::FNEG, dl, VT,
N1.getOperand(0)),
// fold (fsub (fneg (fmul, x, y)), z) -> (fma (fneg x), y, (fneg z))
if (N0.getOpcode() == ISD::FNEG &&
N0.getOperand(0).getOpcode() == ISD::FMUL &&
- N0->hasOneUse() && N0.getOperand(0).hasOneUse()) {
+ ((N0->hasOneUse() && N0.getOperand(0).hasOneUse()) ||
+ TLI.enableAggressiveFMAFusion(VT))) {
SDValue N00 = N0.getOperand(0).getOperand(0);
SDValue N01 = N0.getOperand(0).getOperand(1);
return DAG.getNode(ISD::FMA, dl, VT,
ConstantFPSDNode *N0CFP = isConstOrConstSplatFP(N0);
ConstantFPSDNode *N1CFP = isConstOrConstSplatFP(N1);
EVT VT = N->getValueType(0);
- const TargetLowering &TLI = DAG.getTargetLoweringInfo();
+ const TargetOptions &Options = DAG.getTarget().Options;
// fold vector ops
if (VT.isVector()) {
+ // This just handles C1 * C2 for vectors. Other vector folds are below.
SDValue FoldedVOp = SimplifyVBinOp(N);
- if (FoldedVOp.getNode()) return FoldedVOp;
+ if (FoldedVOp.getNode())
+ return FoldedVOp;
+ // Canonicalize vector constant to RHS.
+ if (N0.getOpcode() == ISD::BUILD_VECTOR &&
+ N1.getOpcode() != ISD::BUILD_VECTOR)
+ if (auto *BV0 = dyn_cast<BuildVectorSDNode>(N0))
+ if (BV0->isConstant())
+ return DAG.getNode(N->getOpcode(), SDLoc(N), VT, N1, N0);
}
// fold (fmul c1, c2) -> c1*c2
if (N0CFP && N1CFP)
return DAG.getNode(ISD::FMUL, SDLoc(N), VT, N0, N1);
+
// canonicalize constant to RHS
if (N0CFP && !N1CFP)
return DAG.getNode(ISD::FMUL, SDLoc(N), VT, N1, N0);
- // fold (fmul A, 0) -> 0
- if (DAG.getTarget().Options.UnsafeFPMath &&
- N1CFP && N1CFP->getValueAPF().isZero())
- return N1;
+
// fold (fmul A, 1.0) -> A
if (N1CFP && N1CFP->isExactlyValue(1.0))
return N0;
+ if (Options.UnsafeFPMath) {
+ // fold (fmul A, 0) -> 0
+ if (N1CFP && N1CFP->getValueAPF().isZero())
+ return N1;
+
+ // fold (fmul (fmul x, c1), c2) -> (fmul x, (fmul c1, c2))
+ if (N0.getOpcode() == ISD::FMUL) {
+ // Fold scalars or any vector constants (not just splats).
+ // This fold is done in general by InstCombine, but extra fmul insts
+ // may have been generated during lowering.
+ SDValue N01 = N0.getOperand(1);
+ auto *BV1 = dyn_cast<BuildVectorSDNode>(N1);
+ auto *BV01 = dyn_cast<BuildVectorSDNode>(N01);
+ if ((N1CFP && isConstOrConstSplatFP(N01)) ||
+ (BV1 && BV01 && BV1->isConstant() && BV01->isConstant())) {
+ SDLoc SL(N);
+ SDValue MulConsts = DAG.getNode(ISD::FMUL, SL, VT, N01, N1);
+ return DAG.getNode(ISD::FMUL, SL, VT, N0.getOperand(0), MulConsts);
+ }
+ }
+
+ // fold (fmul (fadd x, x), c) -> (fmul x, (fmul 2.0, c))
+ // Undo the fmul 2.0, x -> fadd x, x transformation, since if it occurs
+ // during an early run of DAGCombiner can prevent folding with fmuls
+ // inserted during lowering.
+ if (N0.getOpcode() == ISD::FADD && N0.getOperand(0) == N0.getOperand(1)) {
+ SDLoc SL(N);
+ const SDValue Two = DAG.getConstantFP(2.0, VT);
+ SDValue MulConsts = DAG.getNode(ISD::FMUL, SL, VT, Two, N1);
+ return DAG.getNode(ISD::FMUL, SDLoc(N), VT, N0.getOperand(0), MulConsts);
+ }
+ }
+
// fold (fmul X, 2.0) -> (fadd X, X)
if (N1CFP && N1CFP->isExactlyValue(+2.0))
return DAG.getNode(ISD::FADD, SDLoc(N), VT, N0, N0);
+
// fold (fmul X, -1.0) -> (fneg X)
if (N1CFP && N1CFP->isExactlyValue(-1.0))
if (!LegalOperations || TLI.isOperationLegal(ISD::FNEG, VT))
return DAG.getNode(ISD::FNEG, SDLoc(N), VT, N0);
// fold (fmul (fneg X), (fneg Y)) -> (fmul X, Y)
- if (char LHSNeg = isNegatibleForFree(N0, LegalOperations, TLI,
- &DAG.getTarget().Options)) {
- if (char RHSNeg = isNegatibleForFree(N1, LegalOperations, TLI,
- &DAG.getTarget().Options)) {
+ if (char LHSNeg = isNegatibleForFree(N0, LegalOperations, TLI, &Options)) {
+ if (char RHSNeg = isNegatibleForFree(N1, LegalOperations, TLI, &Options)) {
// Both can be negated for free, check to see if at least one is cheaper
// negated.
if (LHSNeg == 2 || RHSNeg == 2)
}
}
- // If allowed, fold (fmul (fmul x, c1), c2) -> (fmul x, (fmul c1, c2))
- if (DAG.getTarget().Options.UnsafeFPMath &&
- N1CFP && N0.getOpcode() == ISD::FMUL &&
- N0.getNode()->hasOneUse() && isConstOrConstSplatFP(N0.getOperand(1))) {
- return DAG.getNode(ISD::FMUL, SDLoc(N), VT, N0.getOperand(0),
- DAG.getNode(ISD::FMUL, SDLoc(N), VT,
- N0.getOperand(1), N1));
- }
-
return SDValue();
}
ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
EVT VT = N->getValueType(0);
SDLoc dl(N);
-
+ const TargetOptions &Options = DAG.getTarget().Options;
// Constant fold FMA.
if (isa<ConstantFPSDNode>(N0) &&
return DAG.getNode(ISD::FMA, dl, VT, N0, N1, N2);
}
- if (DAG.getTarget().Options.UnsafeFPMath) {
+ if (Options.UnsafeFPMath) {
if (N0CFP && N0CFP->isZero())
return N2;
if (N1CFP && N1CFP->isZero())
return DAG.getNode(ISD::FMA, SDLoc(N), VT, N1, N0, N2);
// (fma x, c1, (fmul x, c2)) -> (fmul x, c1+c2)
- if (DAG.getTarget().Options.UnsafeFPMath && N1CFP &&
+ if (Options.UnsafeFPMath && N1CFP &&
N2.getOpcode() == ISD::FMUL &&
N0 == N2.getOperand(0) &&
N2.getOperand(1).getOpcode() == ISD::ConstantFP) {
// (fma (fmul x, c1), c2, y) -> (fma x, c1*c2, y)
- if (DAG.getTarget().Options.UnsafeFPMath &&
+ if (Options.UnsafeFPMath &&
N0.getOpcode() == ISD::FMUL && N1CFP &&
N0.getOperand(1).getOpcode() == ISD::ConstantFP) {
return DAG.getNode(ISD::FMA, dl, VT,
}
// (fma x, c, x) -> (fmul x, (c+1))
- if (DAG.getTarget().Options.UnsafeFPMath && N1CFP && N0 == N2)
+ if (Options.UnsafeFPMath && N1CFP && N0 == N2)
return DAG.getNode(ISD::FMUL, dl, VT, N0,
DAG.getNode(ISD::FADD, dl, VT,
N1, DAG.getConstantFP(1.0, VT)));
// (fma x, c, (fneg x)) -> (fmul x, (c-1))
- if (DAG.getTarget().Options.UnsafeFPMath && N1CFP &&
+ if (Options.UnsafeFPMath && N1CFP &&
N2.getOpcode() == ISD::FNEG && N2.getOperand(0) == N0)
return DAG.getNode(ISD::FMUL, dl, VT, N0,
DAG.getNode(ISD::FADD, dl, VT,
ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
EVT VT = N->getValueType(0);
- const TargetLowering &TLI = DAG.getTargetLoweringInfo();
+ SDLoc DL(N);
+ const TargetOptions &Options = DAG.getTarget().Options;
// fold vector ops
if (VT.isVector()) {
if (N0CFP && N1CFP)
return DAG.getNode(ISD::FDIV, SDLoc(N), VT, N0, N1);
- // fold (fdiv X, c2) -> fmul X, 1/c2 if losing precision is acceptable.
- if (N1CFP && DAG.getTarget().Options.UnsafeFPMath) {
- // Compute the reciprocal 1.0 / c2.
- APFloat N1APF = N1CFP->getValueAPF();
- APFloat Recip(N1APF.getSemantics(), 1); // 1.0
- APFloat::opStatus st = Recip.divide(N1APF, APFloat::rmNearestTiesToEven);
- // Only do the transform if the reciprocal is a legal fp immediate that
- // isn't too nasty (eg NaN, denormal, ...).
- if ((st == APFloat::opOK || st == APFloat::opInexact) && // Not too nasty
- (!LegalOperations ||
- // FIXME: custom lowering of ConstantFP might fail (see e.g. ARM
- // backend)... we should handle this gracefully after Legalize.
- // TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT) ||
- TLI.isOperationLegal(llvm::ISD::ConstantFP, VT) ||
- TLI.isFPImmLegal(Recip, VT)))
- return DAG.getNode(ISD::FMUL, SDLoc(N), VT, N0,
- DAG.getConstantFP(Recip, VT));
+ if (Options.UnsafeFPMath) {
+ // fold (fdiv X, c2) -> fmul X, 1/c2 if losing precision is acceptable.
+ if (N1CFP) {
+ // Compute the reciprocal 1.0 / c2.
+ APFloat N1APF = N1CFP->getValueAPF();
+ APFloat Recip(N1APF.getSemantics(), 1); // 1.0
+ APFloat::opStatus st = Recip.divide(N1APF, APFloat::rmNearestTiesToEven);
+ // Only do the transform if the reciprocal is a legal fp immediate that
+ // isn't too nasty (eg NaN, denormal, ...).
+ if ((st == APFloat::opOK || st == APFloat::opInexact) && // Not too nasty
+ (!LegalOperations ||
+ // FIXME: custom lowering of ConstantFP might fail (see e.g. ARM
+ // backend)... we should handle this gracefully after Legalize.
+ // TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT) ||
+ TLI.isOperationLegal(llvm::ISD::ConstantFP, VT) ||
+ TLI.isFPImmLegal(Recip, VT)))
+ return DAG.getNode(ISD::FMUL, SDLoc(N), VT, N0,
+ DAG.getConstantFP(Recip, VT));
+ }
+
+ // If this FDIV is part of a reciprocal square root, it may be folded
+ // into a target-specific square root estimate instruction.
+ if (N1.getOpcode() == ISD::FSQRT) {
+ if (SDValue RV = BuildRsqrtEstimate(N1.getOperand(0))) {
+ return DAG.getNode(ISD::FMUL, DL, VT, N0, RV);
+ }
+ } else if (N1.getOpcode() == ISD::FP_EXTEND &&
+ N1.getOperand(0).getOpcode() == ISD::FSQRT) {
+ if (SDValue RV = BuildRsqrtEstimate(N1.getOperand(0).getOperand(0))) {
+ RV = DAG.getNode(ISD::FP_EXTEND, SDLoc(N1), VT, RV);
+ AddToWorklist(RV.getNode());
+ return DAG.getNode(ISD::FMUL, DL, VT, N0, RV);
+ }
+ } else if (N1.getOpcode() == ISD::FP_ROUND &&
+ N1.getOperand(0).getOpcode() == ISD::FSQRT) {
+ if (SDValue RV = BuildRsqrtEstimate(N1.getOperand(0).getOperand(0))) {
+ RV = DAG.getNode(ISD::FP_ROUND, SDLoc(N1), VT, RV, N1.getOperand(1));
+ AddToWorklist(RV.getNode());
+ return DAG.getNode(ISD::FMUL, DL, VT, N0, RV);
+ }
+ } else if (N1.getOpcode() == ISD::FMUL) {
+ // Look through an FMUL. Even though this won't remove the FDIV directly,
+ // it's still worthwhile to get rid of the FSQRT if possible.
+ SDValue SqrtOp;
+ SDValue OtherOp;
+ if (N1.getOperand(0).getOpcode() == ISD::FSQRT) {
+ SqrtOp = N1.getOperand(0);
+ OtherOp = N1.getOperand(1);
+ } else if (N1.getOperand(1).getOpcode() == ISD::FSQRT) {
+ SqrtOp = N1.getOperand(1);
+ OtherOp = N1.getOperand(0);
+ }
+ if (SqrtOp.getNode()) {
+ // We found a FSQRT, so try to make this fold:
+ // x / (y * sqrt(z)) -> x * (rsqrt(z) / y)
+ if (SDValue RV = BuildRsqrtEstimate(SqrtOp.getOperand(0))) {
+ RV = DAG.getNode(ISD::FDIV, SDLoc(N1), VT, RV, OtherOp);
+ AddToWorklist(RV.getNode());
+ return DAG.getNode(ISD::FMUL, DL, VT, N0, RV);
+ }
+ }
+ }
+
+ // Fold into a reciprocal estimate and multiply instead of a real divide.
+ if (SDValue RV = BuildReciprocalEstimate(N1)) {
+ AddToWorklist(RV.getNode());
+ return DAG.getNode(ISD::FMUL, DL, VT, N0, RV);
+ }
}
// (fdiv (fneg X), (fneg Y)) -> (fdiv X, Y)
- if (char LHSNeg = isNegatibleForFree(N0, LegalOperations, TLI,
- &DAG.getTarget().Options)) {
- if (char RHSNeg = isNegatibleForFree(N1, LegalOperations, TLI,
- &DAG.getTarget().Options)) {
+ if (char LHSNeg = isNegatibleForFree(N0, LegalOperations, TLI, &Options)) {
+ if (char RHSNeg = isNegatibleForFree(N1, LegalOperations, TLI, &Options)) {
// Both can be negated for free, check to see if at least one is cheaper
// negated.
if (LHSNeg == 2 || RHSNeg == 2)
}
}
+ // Combine multiple FDIVs with the same divisor into multiple FMULs by the
+ // reciprocal.
+ // E.g., (a / D; b / D;) -> (recip = 1.0 / D; a * recip; b * recip)
+ // Notice that this is not always beneficial. One reason is different target
+ // may have different costs for FDIV and FMUL, so sometimes the cost of two
+ // FDIVs may be lower than the cost of one FDIV and two FMULs. Another reason
+ // is the critical path is increased from "one FDIV" to "one FDIV + one FMUL".
+ if (Options.UnsafeFPMath) {
+ // Skip if current node is a reciprocal.
+ if (N0CFP && N0CFP->isExactlyValue(1.0))
+ return SDValue();
+
+ SmallVector<SDNode *, 4> Users;
+ // Find all FDIV users of the same divisor.
+ for (SDNode::use_iterator UI = N1.getNode()->use_begin(),
+ UE = N1.getNode()->use_end();
+ UI != UE; ++UI) {
+ SDNode *User = UI.getUse().getUser();
+ if (User->getOpcode() == ISD::FDIV && User->getOperand(1) == N1)
+ Users.push_back(User);
+ }
+
+ if (TLI.combineRepeatedFPDivisors(Users.size())) {
+ SDValue FPOne = DAG.getConstantFP(1.0, VT); // floating point 1.0
+ SDValue Reciprocal = DAG.getNode(ISD::FDIV, SDLoc(N), VT, FPOne, N1);
+
+ // Dividend / Divisor -> Dividend * Reciprocal
+ for (auto I = Users.begin(), E = Users.end(); I != E; ++I) {
+ if ((*I)->getOperand(0) != FPOne) {
+ SDValue NewNode = DAG.getNode(ISD::FMUL, SDLoc(*I), VT,
+ (*I)->getOperand(0), Reciprocal);
+ DAG.ReplaceAllUsesWith(*I, NewNode.getNode());
+ }
+ }
+ return SDValue();
+ }
+ }
+
return SDValue();
}
return SDValue();
}
+SDValue DAGCombiner::visitFSQRT(SDNode *N) {
+ if (DAG.getTarget().Options.UnsafeFPMath) {
+ // Compute this as X * (1/sqrt(X)) = X * (X ** -0.5)
+ if (SDValue RV = BuildRsqrtEstimate(N->getOperand(0))) {
+ EVT VT = RV.getValueType();
+ RV = DAG.getNode(ISD::FMUL, SDLoc(N), VT, N->getOperand(0), RV);
+ AddToWorklist(RV.getNode());
+
+ // Unfortunately, RV is now NaN if the input was exactly 0.
+ // Select out this case and force the answer to 0.
+ SDValue Zero = DAG.getConstantFP(0.0, VT);
+ SDValue ZeroCmp =
+ DAG.getSetCC(SDLoc(N), TLI.getSetCCResultType(*DAG.getContext(), VT),
+ N->getOperand(0), Zero, ISD::SETEQ);
+ AddToWorklist(ZeroCmp.getNode());
+ AddToWorklist(RV.getNode());
+
+ RV = DAG.getNode(VT.isVector() ? ISD::VSELECT : ISD::SELECT,
+ SDLoc(N), VT, ZeroCmp, Zero, RV);
+ return RV;
+ }
+ }
+ return SDValue();
+}
+
SDValue DAGCombiner::visitFCOPYSIGN(SDNode *N) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
return SDValue();
}
-SDValue DAGCombiner::visitFNEG(SDNode *N) {
+SDValue DAGCombiner::visitFCEIL(SDNode *N) {
SDValue N0 = N->getOperand(0);
+ ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
EVT VT = N->getValueType(0);
- // Constant fold FNEG.
- if (isa<ConstantFPSDNode>(N0))
- return DAG.getNode(ISD::FNEG, SDLoc(N), VT, N->getOperand(0));
+ // fold (fceil c1) -> fceil(c1)
+ if (N0CFP)
+ return DAG.getNode(ISD::FCEIL, SDLoc(N), VT, N0);
+
+ return SDValue();
+}
+
+SDValue DAGCombiner::visitFTRUNC(SDNode *N) {
+ SDValue N0 = N->getOperand(0);
+ ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
+ EVT VT = N->getValueType(0);
+
+ // fold (ftrunc c1) -> ftrunc(c1)
+ if (N0CFP)
+ return DAG.getNode(ISD::FTRUNC, SDLoc(N), VT, N0);
+
+ return SDValue();
+}
+
+SDValue DAGCombiner::visitFFLOOR(SDNode *N) {
+ SDValue N0 = N->getOperand(0);
+ ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
+ EVT VT = N->getValueType(0);
+
+ // fold (ffloor c1) -> ffloor(c1)
+ if (N0CFP)
+ return DAG.getNode(ISD::FFLOOR, SDLoc(N), VT, N0);
+
+ return SDValue();
+}
+
+// FIXME: FNEG and FABS have a lot in common; refactor.
+SDValue DAGCombiner::visitFNEG(SDNode *N) {
+ SDValue N0 = N->getOperand(0);
+ EVT VT = N->getValueType(0);
if (VT.isVector()) {
SDValue FoldedVOp = SimplifyVUnaryOp(N);
if (FoldedVOp.getNode()) return FoldedVOp;
}
+ // Constant fold FNEG.
+ if (isa<ConstantFPSDNode>(N0))
+ return DAG.getNode(ISD::FNEG, SDLoc(N), VT, N->getOperand(0));
+
if (isNegatibleForFree(N0, LegalOperations, DAG.getTargetLoweringInfo(),
&DAG.getTarget().Options))
return GetNegatedExpression(N0, DAG, LegalOperations);
// Transform fneg(bitconvert(x)) -> bitconvert(x ^ sign) to avoid loading
// constant pool values.
- if (!TLI.isFNegFree(VT) && N0.getOpcode() == ISD::BITCAST &&
+ if (!TLI.isFNegFree(VT) &&
+ N0.getOpcode() == ISD::BITCAST &&
N0.getNode()->hasOneUse()) {
SDValue Int = N0.getOperand(0);
EVT IntVT = Int.getValueType();
return SDValue();
}
-SDValue DAGCombiner::visitFCEIL(SDNode *N) {
+SDValue DAGCombiner::visitFMINNUM(SDNode *N) {
SDValue N0 = N->getOperand(0);
- ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
- EVT VT = N->getValueType(0);
-
- // fold (fceil c1) -> fceil(c1)
- if (N0CFP)
- return DAG.getNode(ISD::FCEIL, SDLoc(N), VT, N0);
-
- return SDValue();
-}
+ SDValue N1 = N->getOperand(1);
+ const ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
+ const ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
-SDValue DAGCombiner::visitFTRUNC(SDNode *N) {
- SDValue N0 = N->getOperand(0);
- ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
- EVT VT = N->getValueType(0);
+ if (N0CFP && N1CFP) {
+ const APFloat &C0 = N0CFP->getValueAPF();
+ const APFloat &C1 = N1CFP->getValueAPF();
+ return DAG.getConstantFP(minnum(C0, C1), N->getValueType(0));
+ }
- // fold (ftrunc c1) -> ftrunc(c1)
- if (N0CFP)
- return DAG.getNode(ISD::FTRUNC, SDLoc(N), VT, N0);
+ if (N0CFP) {
+ EVT VT = N->getValueType(0);
+ // Canonicalize to constant on RHS.
+ return DAG.getNode(ISD::FMINNUM, SDLoc(N), VT, N1, N0);
+ }
return SDValue();
}
-SDValue DAGCombiner::visitFFLOOR(SDNode *N) {
+SDValue DAGCombiner::visitFMAXNUM(SDNode *N) {
SDValue N0 = N->getOperand(0);
- ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
- EVT VT = N->getValueType(0);
+ SDValue N1 = N->getOperand(1);
+ const ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
+ const ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
- // fold (ffloor c1) -> ffloor(c1)
- if (N0CFP)
- return DAG.getNode(ISD::FFLOOR, SDLoc(N), VT, N0);
+ if (N0CFP && N1CFP) {
+ const APFloat &C0 = N0CFP->getValueAPF();
+ const APFloat &C1 = N1CFP->getValueAPF();
+ return DAG.getConstantFP(maxnum(C0, C1), N->getValueType(0));
+ }
+
+ if (N0CFP) {
+ EVT VT = N->getValueType(0);
+ // Canonicalize to constant on RHS.
+ return DAG.getNode(ISD::FMAXNUM, SDLoc(N), VT, N1, N0);
+ }
return SDValue();
}
SDValue DAGCombiner::visitFABS(SDNode *N) {
SDValue N0 = N->getOperand(0);
- ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
EVT VT = N->getValueType(0);
if (VT.isVector()) {
}
// fold (fabs c1) -> fabs(c1)
- if (N0CFP)
+ if (isa<ConstantFPSDNode>(N0))
return DAG.getNode(ISD::FABS, SDLoc(N), VT, N0);
+
// fold (fabs (fabs x)) -> (fabs x)
if (N0.getOpcode() == ISD::FABS)
return N->getOperand(0);
+
// fold (fabs (fneg x)) -> (fabs x)
// fold (fabs (fcopysign x, y)) -> (fabs x)
if (N0.getOpcode() == ISD::FNEG || N0.getOpcode() == ISD::FCOPYSIGN)
return SDValue();
}
-/// canFoldInAddressingMode - Return true if 'Use' is a load or a store that
-/// uses N as its base pointer and that N may be folded in the load / store
-/// addressing mode.
+/// Return true if 'Use' is a load or a store that uses N as its base pointer
+/// and that N may be folded in the load / store addressing mode.
static bool canFoldInAddressingMode(SDNode *N, SDNode *Use,
SelectionDAG &DAG,
const TargetLowering &TLI) {
return TLI.isLegalAddressingMode(AM, VT.getTypeForEVT(*DAG.getContext()));
}
-/// CombineToPreIndexedLoadStore - Try turning a load / store into a
-/// pre-indexed load / store when the base pointer is an add or subtract
-/// and it has other uses besides the load / store. After the
-/// transformation, the new indexed load / store has effectively folded
-/// the add / subtract in and all of its other uses are redirected to the
-/// new load / store.
+/// Try turning a load/store into a pre-indexed load/store when the base
+/// pointer is an add or subtract and it has other uses besides the load/store.
+/// After the transformation, the new indexed load/store has effectively folded
+/// the add/subtract in and all of its other uses are redirected to the
+/// new load/store.
bool DAGCombiner::CombineToPreIndexedLoadStore(SDNode *N) {
if (Level < AfterLegalizeDAG)
return false;
return true;
}
-/// CombineToPostIndexedLoadStore - Try to combine a load / store with a
-/// add / sub of the base pointer node into a post-indexed load / store.
-/// The transformation folded the add / subtract into the new indexed
-/// load / store effectively and all of its uses are redirected to the
-/// new load / store.
+/// Try to combine a load/store with a add/sub of the base pointer node into a
+/// post-indexed load/store. The transformation folded the add/subtract into the
+/// new indexed load/store effectively and all of its uses are redirected to the
+/// new load/store.
bool DAGCombiner::CombineToPostIndexedLoadStore(SDNode *N) {
if (Level < AfterLegalizeDAG)
return false;
return false;
}
+/// \brief Return the base-pointer arithmetic from an indexed \p LD.
+SDValue DAGCombiner::SplitIndexingFromLoad(LoadSDNode *LD) {
+ ISD::MemIndexedMode AM = LD->getAddressingMode();
+ assert(AM != ISD::UNINDEXED);
+ SDValue BP = LD->getOperand(1);
+ SDValue Inc = LD->getOperand(2);
+
+ // Some backends use TargetConstants for load offsets, but don't expect
+ // TargetConstants in general ADD nodes. We can convert these constants into
+ // regular Constants (if the constant is not opaque).
+ assert((Inc.getOpcode() != ISD::TargetConstant ||
+ !cast<ConstantSDNode>(Inc)->isOpaque()) &&
+ "Cannot split out indexing using opaque target constants");
+ if (Inc.getOpcode() == ISD::TargetConstant) {
+ ConstantSDNode *ConstInc = cast<ConstantSDNode>(Inc);
+ Inc = DAG.getConstant(*ConstInc->getConstantIntValue(),
+ ConstInc->getValueType(0));
+ }
+
+ unsigned Opc =
+ (AM == ISD::PRE_INC || AM == ISD::POST_INC ? ISD::ADD : ISD::SUB);
+ return DAG.getNode(Opc, SDLoc(LD), BP.getSimpleValueType(), BP, Inc);
+}
+
SDValue DAGCombiner::visitLOAD(SDNode *N) {
LoadSDNode *LD = cast<LoadSDNode>(N);
SDValue Chain = LD->getChain();
} else {
// Indexed loads.
assert(N->getValueType(2) == MVT::Other && "Malformed indexed loads?");
- if (!N->hasAnyUseOfValue(0) && !N->hasAnyUseOfValue(1)) {
+
+ // If this load has an opaque TargetConstant offset, then we cannot split
+ // the indexing into an add/sub directly (that TargetConstant may not be
+ // valid for a different type of node, and we cannot convert an opaque
+ // target constant into a regular constant).
+ bool HasOTCInc = LD->getOperand(2).getOpcode() == ISD::TargetConstant &&
+ cast<ConstantSDNode>(LD->getOperand(2))->isOpaque();
+
+ if (!N->hasAnyUseOfValue(0) &&
+ ((MaySplitLoadIndex && !HasOTCInc) || !N->hasAnyUseOfValue(1))) {
SDValue Undef = DAG.getUNDEF(N->getValueType(0));
+ SDValue Index;
+ if (N->hasAnyUseOfValue(1) && MaySplitLoadIndex && !HasOTCInc) {
+ Index = SplitIndexingFromLoad(LD);
+ // Try to fold the base pointer arithmetic into subsequent loads and
+ // stores.
+ AddUsersToWorklist(N);
+ } else
+ Index = DAG.getUNDEF(N->getValueType(1));
DEBUG(dbgs() << "\nReplacing.7 ";
N->dump(&DAG);
dbgs() << "\nWith: ";
dbgs() << " and 2 other values\n");
WorklistRemover DeadNodes(*this);
DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Undef);
- DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1),
- DAG.getUNDEF(N->getValueType(1)));
+ DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), Index);
DAG.ReplaceAllUsesOfValueWith(SDValue(N, 2), Chain);
deleteAndRecombine(N);
return SDValue(N, 0); // Return N so it doesn't get rechecked!
}
}
- bool UseAA = CombinerAA.getNumOccurrences() > 0 ? CombinerAA :
- TLI.getTargetMachine().getSubtarget<TargetSubtargetInfo>().useAA();
+ bool UseAA = CombinerAA.getNumOccurrences() > 0 ? CombinerAA
+ : DAG.getSubtarget().useAA();
#ifndef NDEBUG
if (CombinerAAOnlyFunc.getNumOccurrences() &&
CombinerAAOnlyFunc != DAG.getMachineFunction().getName())
// At this point, we know that we perform a cross-register-bank copy.
// Check if it is expensive.
- const TargetRegisterInfo *TRI =
- TLI.getTargetMachine().getSubtargetImpl()->getRegisterInfo();
+ const TargetRegisterInfo *TRI = DAG->getSubtarget().getRegisterInfo();
// Assume bitcasts are cheap, unless both register classes do not
// explicitly share a common sub class.
if (!TRI || TRI->getCommonSubClass(ArgRC, ResRC))
return true;
}
-/// CheckForMaskedLoad - Check to see if V is (and load (ptr), imm), where the
-/// load is having specific bytes cleared out. If so, return the byte size
-/// being masked out and the shift amount.
+/// Check to see if V is (and load (ptr), imm), where the load is having
+/// specific bytes cleared out. If so, return the byte size being masked out
+/// and the shift amount.
static std::pair<unsigned, unsigned>
CheckForMaskedLoad(SDValue V, SDValue Ptr, SDValue Chain) {
std::pair<unsigned, unsigned> Result(0, 0);
}
-/// ShrinkLoadReplaceStoreWithStore - Check to see if IVal is something that
-/// provides a value as specified by MaskInfo. If so, replace the specified
-/// store with a narrower store of truncated IVal.
+/// Check to see if IVal is something that provides a value as specified by
+/// MaskInfo. If so, replace the specified store with a narrower store of
+/// truncated IVal.
static SDNode *
ShrinkLoadReplaceStoreWithStore(const std::pair<unsigned, unsigned> &MaskInfo,
SDValue IVal, StoreSDNode *St,
}
-/// ReduceLoadOpStoreWidth - Look for sequence of load / op / store where op is
-/// one of 'or', 'xor', and 'and' of immediates. If 'op' is only touching some
-/// of the loaded bits, try narrowing the load and store if it would end up
-/// being a win for performance or code size.
+/// Look for sequence of load / op / store where op is one of 'or', 'xor', and
+/// 'and' of immediates. If 'op' is only touching some of the loaded bits, try
+/// narrowing the load and store if it would end up being a win for performance
+/// or code size.
SDValue DAGCombiner::ReduceLoadOpStoreWidth(SDNode *N) {
StoreSDNode *ST = cast<StoreSDNode>(N);
if (ST->isVolatile())
return SDValue();
}
-/// TransformFPLoadStorePair - For a given floating point load / store pair,
-/// if the load value isn't used by any other operations, then consider
-/// transforming the pair to integer load / store operations if the target
-/// deems the transformation profitable.
+/// For a given floating point load / store pair, if the load value isn't used
+/// by any other operations, then consider transforming the pair to integer
+/// load / store operations if the target deems the transformation profitable.
SDValue DAGCombiner::TransformFPLoadStorePair(SDNode *N) {
StoreSDNode *ST = cast<StoreSDNode>(N);
SDValue Chain = ST->getChain();
if (NewST.getNode())
return NewST;
- bool UseAA = CombinerAA.getNumOccurrences() > 0 ? CombinerAA :
- TLI.getTargetMachine().getSubtarget<TargetSubtargetInfo>().useAA();
+ bool UseAA = CombinerAA.getNumOccurrences() > 0 ? CombinerAA
+ : DAG.getSubtarget().useAA();
#ifndef NDEBUG
if (CombinerAAOnlyFunc.getNumOccurrences() &&
CombinerAAOnlyFunc != DAG.getMachineFunction().getName())
}
}
+ // If this is a store followed by a store with the same value to the same
+ // location, then the store is dead/noop.
+ if (StoreSDNode *ST1 = dyn_cast<StoreSDNode>(Chain)) {
+ if (ST1->getBasePtr() == Ptr && ST->getMemoryVT() == ST1->getMemoryVT() &&
+ ST1->getValue() == Value && ST->isUnindexed() && !ST->isVolatile() &&
+ ST1->isUnindexed() && !ST1->isVolatile()) {
+ // The store is dead, remove it.
+ return Chain;
+ }
+ }
+
// If this is an FP_ROUND or TRUNC followed by a store, fold this into a
// truncating store. We can do this even if this is already a truncstore.
if ((Value.getOpcode() == ISD::FP_ROUND || Value.getOpcode() == ISD::TRUNCATE)
// operations. If so, and if the EXTRACT_VECTOR_ELT vector inputs come from
// at most two distinct vectors, turn this into a shuffle node.
+ // Only type-legal BUILD_VECTOR nodes are converted to shuffle nodes.
+ if (!isTypeLegal(VT))
+ return SDValue();
+
// May only combine to shuffle after legalize if shuffle is legal.
- if (LegalOperations &&
- !TLI.isOperationLegalOrCustom(ISD::VECTOR_SHUFFLE, VT))
+ if (LegalOperations && !TLI.isOperationLegal(ISD::VECTOR_SHUFFLE, VT))
return SDValue();
SDValue VecIn1, VecIn2;
+ bool UsesZeroVector = false;
for (unsigned i = 0; i != NumInScalars; ++i) {
+ SDValue Op = N->getOperand(i);
// Ignore undef inputs.
- if (N->getOperand(i).getOpcode() == ISD::UNDEF) continue;
+ if (Op.getOpcode() == ISD::UNDEF) continue;
+
+ // See if we can combine this build_vector into a blend with a zero vector.
+ if (!VecIn2.getNode() && ((Op.getOpcode() == ISD::Constant &&
+ cast<ConstantSDNode>(Op.getNode())->isNullValue()) ||
+ (Op.getOpcode() == ISD::ConstantFP &&
+ cast<ConstantFPSDNode>(Op.getNode())->getValueAPF().isZero()))) {
+ UsesZeroVector = true;
+ continue;
+ }
// If this input is something other than a EXTRACT_VECTOR_ELT with a
// constant index, bail out.
- if (N->getOperand(i).getOpcode() != ISD::EXTRACT_VECTOR_ELT ||
- !isa<ConstantSDNode>(N->getOperand(i).getOperand(1))) {
+ if (Op.getOpcode() != ISD::EXTRACT_VECTOR_ELT ||
+ !isa<ConstantSDNode>(Op.getOperand(1))) {
VecIn1 = VecIn2 = SDValue(nullptr, 0);
break;
}
// We allow up to two distinct input vectors.
- SDValue ExtractedFromVec = N->getOperand(i).getOperand(0);
+ SDValue ExtractedFromVec = Op.getOperand(0);
if (ExtractedFromVec == VecIn1 || ExtractedFromVec == VecIn2)
continue;
if (!VecIn1.getNode()) {
VecIn1 = ExtractedFromVec;
- } else if (!VecIn2.getNode()) {
+ } else if (!VecIn2.getNode() && !UsesZeroVector) {
VecIn2 = ExtractedFromVec;
} else {
// Too many inputs.
if (VecIn1.getNode()) {
SmallVector<int, 8> Mask;
for (unsigned i = 0; i != NumInScalars; ++i) {
- if (N->getOperand(i).getOpcode() == ISD::UNDEF) {
+ unsigned Opcode = N->getOperand(i).getOpcode();
+ if (Opcode == ISD::UNDEF) {
Mask.push_back(-1);
continue;
}
+ // Operands can also be zero.
+ if (Opcode != ISD::EXTRACT_VECTOR_ELT) {
+ assert(UsesZeroVector &&
+ (Opcode == ISD::Constant || Opcode == ISD::ConstantFP) &&
+ "Unexpected node found!");
+ Mask.push_back(NumInScalars+i);
+ continue;
+ }
+
// If extracting from the first vector, just use the index directly.
SDValue Extract = N->getOperand(i);
SDValue ExtVal = Extract.getOperand(1);
+ unsigned ExtIndex = cast<ConstantSDNode>(ExtVal)->getZExtValue();
if (Extract.getOperand(0) == VecIn1) {
- unsigned ExtIndex = cast<ConstantSDNode>(ExtVal)->getZExtValue();
if (ExtIndex > VT.getVectorNumElements())
return SDValue();
}
// Otherwise, use InIdx + VecSize
- unsigned Idx = cast<ConstantSDNode>(ExtVal)->getZExtValue();
- Mask.push_back(Idx+NumInScalars);
+ Mask.push_back(NumInScalars+ExtIndex);
}
+ // Avoid introducing illegal shuffles with zero.
+ if (UsesZeroVector && !TLI.isVectorClearMaskLegal(Mask, VT))
+ return SDValue();
+
// We can't generate a shuffle node with mismatched input and output types.
// Attempt to transform a single input vector to the correct type.
if ((VT != VecIn1.getValueType())) {
VecIn1, DAG.getUNDEF(VecIn1.getValueType()));
}
- // If VecIn2 is unused then change it to undef.
- VecIn2 = VecIn2.getNode() ? VecIn2 : DAG.getUNDEF(VT);
+ if (UsesZeroVector)
+ VecIn2 = VT.isInteger() ? DAG.getConstant(0, VT) :
+ DAG.getConstantFP(0.0, VT);
+ else
+ // If VecIn2 is unused then change it to undef.
+ VecIn2 = VecIn2.getNode() ? VecIn2 : DAG.getUNDEF(VT);
// Check that we were able to transform all incoming values to the same
// type.
VecIn1.getValueType() != VT)
return SDValue();
- // Only type-legal BUILD_VECTOR nodes are converted to shuffle nodes.
- if (!isTypeLegal(VT))
- return SDValue();
-
// Return the new VECTOR_SHUFFLE node.
SDValue Ops[2];
Ops[0] = VecIn1;
return SDValue();
}
+static SDValue simplifyShuffleOperandRecursively(SmallBitVector &UsedElements,
+ SDValue V, SelectionDAG &DAG) {
+ SDLoc DL(V);
+ EVT VT = V.getValueType();
+
+ switch (V.getOpcode()) {
+ default:
+ return V;
+
+ case ISD::CONCAT_VECTORS: {
+ EVT OpVT = V->getOperand(0).getValueType();
+ int OpSize = OpVT.getVectorNumElements();
+ SmallBitVector OpUsedElements(OpSize, false);
+ bool FoundSimplification = false;
+ SmallVector<SDValue, 4> NewOps;
+ NewOps.reserve(V->getNumOperands());
+ for (int i = 0, NumOps = V->getNumOperands(); i < NumOps; ++i) {
+ SDValue Op = V->getOperand(i);
+ bool OpUsed = false;
+ for (int j = 0; j < OpSize; ++j)
+ if (UsedElements[i * OpSize + j]) {
+ OpUsedElements[j] = true;
+ OpUsed = true;
+ }
+ NewOps.push_back(
+ OpUsed ? simplifyShuffleOperandRecursively(OpUsedElements, Op, DAG)
+ : DAG.getUNDEF(OpVT));
+ FoundSimplification |= Op == NewOps.back();
+ OpUsedElements.reset();
+ }
+ if (FoundSimplification)
+ V = DAG.getNode(ISD::CONCAT_VECTORS, DL, VT, NewOps);
+ return V;
+ }
+
+ case ISD::INSERT_SUBVECTOR: {
+ SDValue BaseV = V->getOperand(0);
+ SDValue SubV = V->getOperand(1);
+ auto *IdxN = dyn_cast<ConstantSDNode>(V->getOperand(2));
+ if (!IdxN)
+ return V;
+
+ int SubSize = SubV.getValueType().getVectorNumElements();
+ int Idx = IdxN->getZExtValue();
+ bool SubVectorUsed = false;
+ SmallBitVector SubUsedElements(SubSize, false);
+ for (int i = 0; i < SubSize; ++i)
+ if (UsedElements[i + Idx]) {
+ SubVectorUsed = true;
+ SubUsedElements[i] = true;
+ UsedElements[i + Idx] = false;
+ }
+
+ // Now recurse on both the base and sub vectors.
+ SDValue SimplifiedSubV =
+ SubVectorUsed
+ ? simplifyShuffleOperandRecursively(SubUsedElements, SubV, DAG)
+ : DAG.getUNDEF(SubV.getValueType());
+ SDValue SimplifiedBaseV = simplifyShuffleOperandRecursively(UsedElements, BaseV, DAG);
+ if (SimplifiedSubV != SubV || SimplifiedBaseV != BaseV)
+ V = DAG.getNode(ISD::INSERT_SUBVECTOR, DL, VT,
+ SimplifiedBaseV, SimplifiedSubV, V->getOperand(2));
+ return V;
+ }
+ }
+}
+
+static SDValue simplifyShuffleOperands(ShuffleVectorSDNode *SVN, SDValue N0,
+ SDValue N1, SelectionDAG &DAG) {
+ EVT VT = SVN->getValueType(0);
+ int NumElts = VT.getVectorNumElements();
+ SmallBitVector N0UsedElements(NumElts, false), N1UsedElements(NumElts, false);
+ for (int M : SVN->getMask())
+ if (M >= 0 && M < NumElts)
+ N0UsedElements[M] = true;
+ else if (M >= NumElts)
+ N1UsedElements[M - NumElts] = true;
+
+ SDValue S0 = simplifyShuffleOperandRecursively(N0UsedElements, N0, DAG);
+ SDValue S1 = simplifyShuffleOperandRecursively(N1UsedElements, N1, DAG);
+ if (S0 == N0 && S1 == N1)
+ return SDValue();
+
+ return DAG.getVectorShuffle(VT, SDLoc(SVN), S0, S1, SVN->getMask());
+}
+
// Tries to turn a shuffle of two CONCAT_VECTORS into a single concat.
static SDValue partitionShuffleOfConcats(SDNode *N, SelectionDAG &DAG) {
EVT VT = N->getValueType(0);
}
}
+ // There are various patterns used to build up a vector from smaller vectors,
+ // subvectors, or elements. Scan chains of these and replace unused insertions
+ // or components with undef.
+ if (SDValue S = simplifyShuffleOperands(SVN, N0, N1, DAG))
+ return S;
+
if (N0.getOpcode() == ISD::CONCAT_VECTORS &&
Level < AfterLegalizeVectorOps &&
(N1.getOpcode() == ISD::UNDEF ||
return V;
}
- // If this shuffle node is simply a swizzle of another shuffle node,
- // then try to simplify it.
- if (N0.getOpcode() == ISD::VECTOR_SHUFFLE && Level < AfterLegalizeDAG &&
- N1.getOpcode() == ISD::UNDEF) {
-
- ShuffleVectorSDNode *OtherSV = cast<ShuffleVectorSDNode>(N0);
-
- // The incoming shuffle must be of the same type as the result of the
- // current shuffle.
- assert(OtherSV->getOperand(0).getValueType() == VT &&
- "Shuffle types don't match");
-
- SmallVector<int, 4> Mask;
- // Compute the combined shuffle mask.
- for (unsigned i = 0; i != NumElts; ++i) {
- int Idx = SVN->getMaskElt(i);
- assert(Idx < (int)NumElts && "Index references undef operand");
- // Next, this index comes from the first value, which is the incoming
- // shuffle. Adopt the incoming index.
- if (Idx >= 0)
- Idx = OtherSV->getMaskElt(Idx);
- Mask.push_back(Idx);
- }
-
- // Check if all indices in Mask are Undef. In case, propagate Undef.
- bool isUndefMask = true;
- for (unsigned i = 0; i != NumElts && isUndefMask; ++i)
- isUndefMask &= Mask[i] < 0;
-
- if (isUndefMask)
- return DAG.getUNDEF(VT);
-
- bool CommuteOperands = false;
- if (N0.getOperand(1).getOpcode() != ISD::UNDEF) {
- // To be valid, the combine shuffle mask should only reference elements
- // from one of the two vectors in input to the inner shufflevector.
- bool IsValidMask = true;
- for (unsigned i = 0; i != NumElts && IsValidMask; ++i)
- // See if the combined mask only reference undefs or elements coming
- // from the first shufflevector operand.
- IsValidMask = Mask[i] < 0 || (unsigned)Mask[i] < NumElts;
-
- if (!IsValidMask) {
- IsValidMask = true;
- for (unsigned i = 0; i != NumElts && IsValidMask; ++i)
- // Check that all the elements come from the second shuffle operand.
- IsValidMask = Mask[i] < 0 || (unsigned)Mask[i] >= NumElts;
- CommuteOperands = IsValidMask;
- }
-
- // Early exit if the combined shuffle mask is not valid.
- if (!IsValidMask)
- return SDValue();
- }
-
- // See if this pair of shuffles can be safely folded according to either
- // of the following rules:
- // shuffle(shuffle(x, y), undef) -> x
- // shuffle(shuffle(x, undef), undef) -> x
- // shuffle(shuffle(x, y), undef) -> y
- bool IsIdentityMask = true;
- unsigned BaseMaskIndex = CommuteOperands ? NumElts : 0;
- for (unsigned i = 0; i != NumElts && IsIdentityMask; ++i) {
- // Skip Undefs.
- if (Mask[i] < 0)
- continue;
-
- // The combined shuffle must map each index to itself.
- IsIdentityMask = (unsigned)Mask[i] == i + BaseMaskIndex;
- }
-
- if (IsIdentityMask) {
- if (CommuteOperands)
- // optimize shuffle(shuffle(x, y), undef) -> y.
- return OtherSV->getOperand(1);
-
- // optimize shuffle(shuffle(x, undef), undef) -> x
- // optimize shuffle(shuffle(x, y), undef) -> x
- return OtherSV->getOperand(0);
- }
-
- // It may still be beneficial to combine the two shuffles if the
- // resulting shuffle is legal.
- if (TLI.isTypeLegal(VT)) {
- if (!CommuteOperands) {
- if (TLI.isShuffleMaskLegal(Mask, VT))
- // shuffle(shuffle(x, undef, M1), undef, M2) -> shuffle(x, undef, M3).
- // shuffle(shuffle(x, y, M1), undef, M2) -> shuffle(x, undef, M3)
- return DAG.getVectorShuffle(VT, SDLoc(N), N0->getOperand(0), N1,
- &Mask[0]);
- } else {
- // Compute the commuted shuffle mask.
- for (unsigned i = 0; i != NumElts; ++i) {
- int idx = Mask[i];
- if (idx < 0)
- continue;
- else if (idx < (int)NumElts)
- Mask[i] = idx + NumElts;
- else
- Mask[i] = idx - NumElts;
- }
-
- if (TLI.isShuffleMaskLegal(Mask, VT))
- // shuffle(shuffle(x, y, M1), undef, M2) -> shuffle(y, undef, M3)
- return DAG.getVectorShuffle(VT, SDLoc(N), N0->getOperand(1), N1,
- &Mask[0]);
- }
- }
- }
-
// Canonicalize shuffles according to rules:
// shuffle(A, shuffle(A, B)) -> shuffle(shuffle(A,B), A)
// shuffle(B, shuffle(A, B)) -> shuffle(shuffle(A,B), B)
// shuffle(B, shuffle(A, Undef)) -> shuffle(shuffle(A, Undef), B)
- if (N1.getOpcode() == ISD::VECTOR_SHUFFLE && N0.getOpcode() != ISD::UNDEF &&
+ if (N1.getOpcode() == ISD::VECTOR_SHUFFLE &&
N0.getOpcode() != ISD::VECTOR_SHUFFLE && Level < AfterLegalizeDAG &&
TLI.isTypeLegal(VT)) {
// The incoming shuffle must be of the same type as the result of the
}
// Try to fold according to rules:
- // shuffle(shuffle(A, B, M0), B, M1) -> shuffle(A, B, M2)
- // shuffle(shuffle(A, B, M0), A, M1) -> shuffle(A, B, M2)
- // shuffle(shuffle(A, Undef, M0), B, M1) -> shuffle(A, B, M2)
- // shuffle(shuffle(A, Undef, M0), A, M1) -> shuffle(A, Undef, M2)
+ // shuffle(shuffle(A, B, M0), C, M1) -> shuffle(A, B, M2)
+ // shuffle(shuffle(A, B, M0), C, M1) -> shuffle(A, C, M2)
+ // shuffle(shuffle(A, B, M0), C, M1) -> shuffle(B, C, M2)
// Don't try to fold shuffles with illegal type.
if (N0.getOpcode() == ISD::VECTOR_SHUFFLE && Level < AfterLegalizeDAG &&
- N1.getOpcode() != ISD::UNDEF && TLI.isTypeLegal(VT)) {
+ TLI.isTypeLegal(VT)) {
ShuffleVectorSDNode *OtherSV = cast<ShuffleVectorSDNode>(N0);
// The incoming shuffle must be of the same type as the result of the
assert(OtherSV->getOperand(0).getValueType() == VT &&
"Shuffle types don't match");
- SDValue SV0 = OtherSV->getOperand(0);
- SDValue SV1 = OtherSV->getOperand(1);
- bool HasSameOp0 = N1 == SV0;
- bool IsSV1Undef = SV1.getOpcode() == ISD::UNDEF;
- if (!HasSameOp0 && !IsSV1Undef && N1 != SV1)
- // Early exit.
- return SDValue();
-
+ SDValue SV0, SV1;
SmallVector<int, 4> Mask;
// Compute the combined shuffle mask for a shuffle with SV0 as the first
// operand, and SV1 as the second operand.
continue;
}
+ SDValue CurrentVec;
if (Idx < (int)NumElts) {
+ // This shuffle index refers to the inner shuffle N0. Lookup the inner
+ // shuffle mask to identify which vector is actually referenced.
Idx = OtherSV->getMaskElt(Idx);
- if (IsSV1Undef && Idx >= (int) NumElts)
- Idx = -1; // Propagate Undef.
- } else
- Idx = HasSameOp0 ? Idx - NumElts : Idx;
+ if (Idx < 0) {
+ // Propagate Undef.
+ Mask.push_back(Idx);
+ continue;
+ }
- Mask.push_back(Idx);
+ CurrentVec = (Idx < (int) NumElts) ? OtherSV->getOperand(0)
+ : OtherSV->getOperand(1);
+ } else {
+ // This shuffle index references an element within N1.
+ CurrentVec = N1;
+ }
+
+ // Simple case where 'CurrentVec' is UNDEF.
+ if (CurrentVec.getOpcode() == ISD::UNDEF) {
+ Mask.push_back(-1);
+ continue;
+ }
+
+ // Canonicalize the shuffle index. We don't know yet if CurrentVec
+ // will be the first or second operand of the combined shuffle.
+ Idx = Idx % NumElts;
+ if (!SV0.getNode() || SV0 == CurrentVec) {
+ // Ok. CurrentVec is the left hand side.
+ // Update the mask accordingly.
+ SV0 = CurrentVec;
+ Mask.push_back(Idx);
+ continue;
+ }
+
+ // Bail out if we cannot convert the shuffle pair into a single shuffle.
+ if (SV1.getNode() && SV1 != CurrentVec)
+ return SDValue();
+
+ // Ok. CurrentVec is the right hand side.
+ // Update the mask accordingly.
+ SV1 = CurrentVec;
+ Mask.push_back(Idx + NumElts);
}
// Check if all indices in Mask are Undef. In case, propagate Undef.
if (isUndefMask)
return DAG.getUNDEF(VT);
+ if (!SV0.getNode())
+ SV0 = DAG.getUNDEF(VT);
+ if (!SV1.getNode())
+ SV1 = DAG.getUNDEF(VT);
+
// Avoid introducing shuffles with illegal mask.
- if (TLI.isShuffleMaskLegal(Mask, VT)) {
- if (IsSV1Undef)
- // shuffle(shuffle(A, Undef, M0), B, M1) -> shuffle(A, B, M2)
- // shuffle(shuffle(A, Undef, M0), A, M1) -> shuffle(A, Undef, M2)
- return DAG.getVectorShuffle(VT, SDLoc(N), SV0, N1, &Mask[0]);
- return DAG.getVectorShuffle(VT, SDLoc(N), SV0, SV1, &Mask[0]);
+ if (!TLI.isShuffleMaskLegal(Mask, VT)) {
+ // Compute the commuted shuffle mask and test again.
+ for (unsigned i = 0; i != NumElts; ++i) {
+ int idx = Mask[i];
+ if (idx < 0)
+ continue;
+ else if (idx < (int)NumElts)
+ Mask[i] = idx + NumElts;
+ else
+ Mask[i] = idx - NumElts;
+ }
+
+ if (!TLI.isShuffleMaskLegal(Mask, VT))
+ return SDValue();
+
+ // shuffle(shuffle(A, B, M0), C, M1) -> shuffle(B, A, M2)
+ // shuffle(shuffle(A, B, M0), C, M1) -> shuffle(C, A, M2)
+ // shuffle(shuffle(A, B, M0), C, M1) -> shuffle(C, B, M2)
+ std::swap(SV0, SV1);
}
+
+ // shuffle(shuffle(A, B, M0), C, M1) -> shuffle(A, B, M2)
+ // shuffle(shuffle(A, B, M0), C, M1) -> shuffle(A, C, M2)
+ // shuffle(shuffle(A, B, M0), C, M1) -> shuffle(B, C, M2)
+ return DAG.getVectorShuffle(VT, SDLoc(N), SV0, SV1, &Mask[0]);
}
return SDValue();
return SDValue();
}
-/// XformToShuffleWithZero - Returns a vector_shuffle if it able to transform
-/// an AND to a vector_shuffle with the destination vector and a zero vector.
+/// Returns a vector_shuffle if it able to transform an AND to a vector_shuffle
+/// with the destination vector and a zero vector.
/// e.g. AND V, <0xffffffff, 0, 0xffffffff, 0>. ==>
/// vector_shuffle V, Zero, <0, 4, 2, 4>
SDValue DAGCombiner::XformToShuffleWithZero(SDNode *N) {
if (cast<ConstantSDNode>(Elt)->isAllOnesValue())
Indices.push_back(i);
else if (cast<ConstantSDNode>(Elt)->isNullValue())
- Indices.push_back(NumElts);
+ Indices.push_back(NumElts+i);
else
return SDValue();
}
return SDValue();
}
-/// SimplifyVBinOp - Visit a binary vector operation, like ADD.
+/// Visit a binary vector operation, like ADD.
SDValue DAGCombiner::SimplifyVBinOp(SDNode *N) {
assert(N->getValueType(0).isVector() &&
"SimplifyVBinOp only works on vectors!");
return SDValue();
}
-/// SimplifyVUnaryOp - Visit a binary vector operation, like FABS/FNEG.
+/// Visit a binary vector operation, like FABS/FNEG.
SDValue DAGCombiner::SimplifyVUnaryOp(SDNode *N) {
assert(N->getValueType(0).isVector() &&
"SimplifyVUnaryOp only works on vectors!");
return SDValue();
}
-/// SimplifySelectOps - Given a SELECT or a SELECT_CC node, where LHS and RHS
-/// are the two values being selected between, see if we can simplify the
-/// select. Callers of this should assume that TheSelect is deleted if this
-/// returns true. As such, they should return the appropriate thing (e.g. the
-/// node) back to the top-level of the DAG combiner loop to avoid it being
-/// looked at.
+/// Given a SELECT or a SELECT_CC node, where LHS and RHS are the two values
+/// being selected between, see if we can simplify the select. Callers of this
+/// should assume that TheSelect is deleted if this returns true. As such, they
+/// should return the appropriate thing (e.g. the node) back to the top-level of
+/// the DAG combiner loop to avoid it being looked at.
bool DAGCombiner::SimplifySelectOps(SDNode *TheSelect, SDValue LHS,
SDValue RHS) {
// It is safe to replace the two loads if they have different alignments,
// but the new load must be the minimum (most restrictive) alignment of the
// inputs.
- bool isInvariant = LLD->getAlignment() & RLD->getAlignment();
+ bool isInvariant = LLD->isInvariant() & RLD->isInvariant();
unsigned Alignment = std::min(LLD->getAlignment(), RLD->getAlignment());
if (LLD->getExtensionType() == ISD::NON_EXTLOAD) {
Load = DAG.getLoad(TheSelect->getValueType(0),
return false;
}
-/// SimplifySelectCC - Simplify an expression of the form (N0 cond N1) ? N2 : N3
+/// Simplify an expression of the form (N0 cond N1) ? N2 : N3
/// where 'cond' is the comparison specified by CC.
SDValue DAGCombiner::SimplifySelectCC(SDLoc DL, SDValue N0, SDValue N1,
SDValue N2, SDValue N3,
return SDValue();
}
-/// SimplifySetCC - This is a stub for TargetLowering::SimplifySetCC.
+/// This is a stub for TargetLowering::SimplifySetCC.
SDValue DAGCombiner::SimplifySetCC(EVT VT, SDValue N0,
SDValue N1, ISD::CondCode Cond,
SDLoc DL, bool foldBooleans) {
return TLI.SimplifySetCC(VT, N0, N1, Cond, foldBooleans, DagCombineInfo, DL);
}
-/// BuildSDIV - Given an ISD::SDIV node expressing a divide by constant, return
+/// Given an ISD::SDIV node expressing a divide by constant, return
/// a DAG expression to select that will generate the same value by multiplying
-/// by a magic number. See:
-/// <http://the.wall.riscom.net/books/proc/ppc/cwg/code2.html>
+/// by a magic number.
+/// Ref: "Hacker's Delight" or "The PowerPC Compiler Writer's Guide".
SDValue DAGCombiner::BuildSDIV(SDNode *N) {
ConstantSDNode *C = isConstOrConstSplat(N->getOperand(1));
if (!C)
return S;
}
-/// BuildSDIVPow2 - Given an ISD::SDIV node expressing a divide by constant
-/// power of 2, return a DAG expression to select that will generate the same
-/// value by right shifting.
+/// Given an ISD::SDIV node expressing a divide by constant power of 2, return a
+/// DAG expression that will generate the same value by right shifting.
SDValue DAGCombiner::BuildSDIVPow2(SDNode *N) {
ConstantSDNode *C = isConstOrConstSplat(N->getOperand(1));
if (!C)
return S;
}
-/// BuildUDIV - Given an ISD::UDIV node expressing a divide by constant,
-/// return a DAG expression to select that will generate the same value by
-/// multiplying by a magic number. See:
-/// <http://the.wall.riscom.net/books/proc/ppc/cwg/code2.html>
+/// Given an ISD::UDIV node expressing a divide by constant, return a DAG
+/// expression that will generate the same value by multiplying by a magic
+/// number.
+/// Ref: "Hacker's Delight" or "The PowerPC Compiler Writer's Guide".
SDValue DAGCombiner::BuildUDIV(SDNode *N) {
ConstantSDNode *C = isConstOrConstSplat(N->getOperand(1));
if (!C)
return S;
}
-/// FindBaseOffset - Return true if base is a frame index, which is known not
-// to alias with anything but itself. Provides base object and offset as
-// results.
+SDValue DAGCombiner::BuildReciprocalEstimate(SDValue Op) {
+ if (Level >= AfterLegalizeDAG)
+ return SDValue();
+
+ // Expose the DAG combiner to the target combiner implementations.
+ TargetLowering::DAGCombinerInfo DCI(DAG, Level, false, this);
+
+ unsigned Iterations = 0;
+ if (SDValue Est = TLI.getRecipEstimate(Op, DCI, Iterations)) {
+ if (Iterations) {
+ // Newton iteration for a function: F(X) is X_{i+1} = X_i - F(X_i)/F'(X_i)
+ // For the reciprocal, we need to find the zero of the function:
+ // F(X) = A X - 1 [which has a zero at X = 1/A]
+ // =>
+ // X_{i+1} = X_i (2 - A X_i) = X_i + X_i (1 - A X_i) [this second form
+ // does not require additional intermediate precision]
+ EVT VT = Op.getValueType();
+ SDLoc DL(Op);
+ SDValue FPOne = DAG.getConstantFP(1.0, VT);
+
+ AddToWorklist(Est.getNode());
+
+ // Newton iterations: Est = Est + Est (1 - Arg * Est)
+ for (unsigned i = 0; i < Iterations; ++i) {
+ SDValue NewEst = DAG.getNode(ISD::FMUL, DL, VT, Op, Est);
+ AddToWorklist(NewEst.getNode());
+
+ NewEst = DAG.getNode(ISD::FSUB, DL, VT, FPOne, NewEst);
+ AddToWorklist(NewEst.getNode());
+
+ NewEst = DAG.getNode(ISD::FMUL, DL, VT, Est, NewEst);
+ AddToWorklist(NewEst.getNode());
+
+ Est = DAG.getNode(ISD::FADD, DL, VT, Est, NewEst);
+ AddToWorklist(Est.getNode());
+ }
+ }
+ return Est;
+ }
+
+ return SDValue();
+}
+
+/// Newton iteration for a function: F(X) is X_{i+1} = X_i - F(X_i)/F'(X_i)
+/// For the reciprocal sqrt, we need to find the zero of the function:
+/// F(X) = 1/X^2 - A [which has a zero at X = 1/sqrt(A)]
+/// =>
+/// X_{i+1} = X_i (1.5 - A X_i^2 / 2)
+/// As a result, we precompute A/2 prior to the iteration loop.
+SDValue DAGCombiner::BuildRsqrtNROneConst(SDValue Arg, SDValue Est,
+ unsigned Iterations) {
+ EVT VT = Arg.getValueType();
+ SDLoc DL(Arg);
+ SDValue ThreeHalves = DAG.getConstantFP(1.5, VT);
+
+ // We now need 0.5 * Arg which we can write as (1.5 * Arg - Arg) so that
+ // this entire sequence requires only one FP constant.
+ SDValue HalfArg = DAG.getNode(ISD::FMUL, DL, VT, ThreeHalves, Arg);
+ AddToWorklist(HalfArg.getNode());
+
+ HalfArg = DAG.getNode(ISD::FSUB, DL, VT, HalfArg, Arg);
+ AddToWorklist(HalfArg.getNode());
+
+ // Newton iterations: Est = Est * (1.5 - HalfArg * Est * Est)
+ for (unsigned i = 0; i < Iterations; ++i) {
+ SDValue NewEst = DAG.getNode(ISD::FMUL, DL, VT, Est, Est);
+ AddToWorklist(NewEst.getNode());
+
+ NewEst = DAG.getNode(ISD::FMUL, DL, VT, HalfArg, NewEst);
+ AddToWorklist(NewEst.getNode());
+
+ NewEst = DAG.getNode(ISD::FSUB, DL, VT, ThreeHalves, NewEst);
+ AddToWorklist(NewEst.getNode());
+
+ Est = DAG.getNode(ISD::FMUL, DL, VT, Est, NewEst);
+ AddToWorklist(Est.getNode());
+ }
+ return Est;
+}
+
+/// Newton iteration for a function: F(X) is X_{i+1} = X_i - F(X_i)/F'(X_i)
+/// For the reciprocal sqrt, we need to find the zero of the function:
+/// F(X) = 1/X^2 - A [which has a zero at X = 1/sqrt(A)]
+/// =>
+/// X_{i+1} = (-0.5 * X_i) * (A * X_i * X_i + (-3.0))
+SDValue DAGCombiner::BuildRsqrtNRTwoConst(SDValue Arg, SDValue Est,
+ unsigned Iterations) {
+ EVT VT = Arg.getValueType();
+ SDLoc DL(Arg);
+ SDValue MinusThree = DAG.getConstantFP(-3.0, VT);
+ SDValue MinusHalf = DAG.getConstantFP(-0.5, VT);
+
+ // Newton iterations: Est = -0.5 * Est * (-3.0 + Arg * Est * Est)
+ for (unsigned i = 0; i < Iterations; ++i) {
+ SDValue HalfEst = DAG.getNode(ISD::FMUL, DL, VT, Est, MinusHalf);
+ AddToWorklist(HalfEst.getNode());
+
+ Est = DAG.getNode(ISD::FMUL, DL, VT, Est, Est);
+ AddToWorklist(Est.getNode());
+
+ Est = DAG.getNode(ISD::FMUL, DL, VT, Est, Arg);
+ AddToWorklist(Est.getNode());
+
+ Est = DAG.getNode(ISD::FADD, DL, VT, Est, MinusThree);
+ AddToWorklist(Est.getNode());
+
+ Est = DAG.getNode(ISD::FMUL, DL, VT, Est, HalfEst);
+ AddToWorklist(Est.getNode());
+ }
+ return Est;
+}
+
+SDValue DAGCombiner::BuildRsqrtEstimate(SDValue Op) {
+ if (Level >= AfterLegalizeDAG)
+ return SDValue();
+
+ // Expose the DAG combiner to the target combiner implementations.
+ TargetLowering::DAGCombinerInfo DCI(DAG, Level, false, this);
+ unsigned Iterations = 0;
+ bool UseOneConstNR = false;
+ if (SDValue Est = TLI.getRsqrtEstimate(Op, DCI, Iterations, UseOneConstNR)) {
+ AddToWorklist(Est.getNode());
+ if (Iterations) {
+ Est = UseOneConstNR ?
+ BuildRsqrtNROneConst(Op, Est, Iterations) :
+ BuildRsqrtNRTwoConst(Op, Est, Iterations);
+ }
+ return Est;
+ }
+
+ return SDValue();
+}
+
+/// Return true if base is a frame index, which is known not to alias with
+/// anything but itself. Provides base object and offset as results.
static bool FindBaseOffset(SDValue Ptr, SDValue &Base, int64_t &Offset,
const GlobalValue *&GV, const void *&CV) {
// Assume it is a primitive operation.
return isa<FrameIndexSDNode>(Base);
}
-/// isAlias - Return true if there is any possibility that the two addresses
-/// overlap.
+/// Return true if there is any possibility that the two addresses overlap.
bool DAGCombiner::isAlias(LSBaseSDNode *Op0, LSBaseSDNode *Op1) const {
// If they are the same then they must be aliases.
if (Op0->getBasePtr() == Op1->getBasePtr()) return true;
return false;
}
- bool UseAA = CombinerGlobalAA.getNumOccurrences() > 0 ? CombinerGlobalAA :
- TLI.getTargetMachine().getSubtarget<TargetSubtargetInfo>().useAA();
+ bool UseAA = CombinerGlobalAA.getNumOccurrences() > 0
+ ? CombinerGlobalAA
+ : DAG.getSubtarget().useAA();
#ifndef NDEBUG
if (CombinerAAOnlyFunc.getNumOccurrences() &&
CombinerAAOnlyFunc != DAG.getMachineFunction().getName())
return true;
}
-/// GatherAllAliases - Walk up chain skipping non-aliasing memory nodes,
+/// Walk up chain skipping non-aliasing memory nodes,
/// looking for aliasing nodes and adding them to the Aliases vector.
void DAGCombiner::GatherAllAliases(SDNode *N, SDValue OriginalChain,
SmallVectorImpl<SDValue> &Aliases) {
}
// Don't bother if we've been before.
- if (!Visited.insert(Chain.getNode()))
+ if (!Visited.insert(Chain.getNode()).second)
continue;
switch (Chain.getOpcode()) {
for (SDNode::use_iterator UI = M->use_begin(),
UIE = M->use_end(); UI != UIE; ++UI)
- if (UI.getUse().getValueType() == MVT::Other && Visited.insert(*UI)) {
+ if (UI.getUse().getValueType() == MVT::Other &&
+ Visited.insert(*UI).second) {
if (isa<MemIntrinsicSDNode>(*UI) || isa<MemSDNode>(*UI)) {
// We've not visited this use, and we care about it (it could have an
// ordering dependency with the original node).
}
}
-/// FindBetterChain - Walk up chain skipping non-aliasing memory nodes, looking
-/// for a better chain (aliasing node.)
+/// Walk up chain skipping non-aliasing memory nodes, looking for a better chain
+/// (aliasing node.)
SDValue DAGCombiner::FindBetterChain(SDNode *N, SDValue OldChain) {
SmallVector<SDValue, 8> Aliases; // Ops for replacing token factor.
return DAG.getNode(ISD::TokenFactor, SDLoc(N), MVT::Other, Aliases);
}
-// SelectionDAG::Combine - This is the entry point for the file.
-//
+/// This is the entry point for the file.
void SelectionDAG::Combine(CombineLevel Level, AliasAnalysis &AA,
CodeGenOpt::Level OptLevel) {
- /// run - This is the main entry point to this class.
- ///
+ /// This is the main entry point to this class.
DAGCombiner(*this, AA, OptLevel).Run(Level);
}
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