#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"
#include <algorithm>
using namespace llvm;
STATISTIC(PostIndexedNodes, "Number of post-indexed nodes created");
STATISTIC(OpsNarrowed , "Number of load/op/store narrowed");
STATISTIC(LdStFP2Int , "Number of fp load/store pairs transformed to int");
+STATISTIC(SlicedLoads, "Number of load sliced");
namespace {
static cl::opt<bool>
CombinerAA("combiner-alias-analysis", cl::Hidden,
- cl::desc("Turn on alias analysis during testing"));
+ cl::desc("Enable DAG combiner alias-analysis heuristics"));
static cl::opt<bool>
CombinerGlobalAA("combiner-global-alias-analysis", cl::Hidden,
- cl::desc("Include global information in alias analysis"));
+ cl::desc("Enable DAG combiner's use of IR alias analysis"));
+
+// FIXME: Enable the use of TBAA. There are two known issues preventing this:
+// 1. Stack coloring does not update TBAA when merging allocas
+// 2. CGP inserts ptrtoint/inttoptr pairs when sinking address computations.
+// Because BasicAA does not handle inttoptr, we'll often miss basic type
+// punning idioms that we need to catch so we don't miscompile real-world
+// code.
+ static cl::opt<bool>
+ UseTBAA("combiner-use-tbaa", cl::Hidden, cl::init(false),
+ cl::desc("Enable DAG combiner's use of TBAA"));
+
+#ifndef NDEBUG
+ static cl::opt<std::string>
+ CombinerAAOnlyFunc("combiner-aa-only-func", cl::Hidden,
+ cl::desc("Only use DAG-combiner alias analysis in this"
+ " function"));
+#endif
+
+ /// Hidden option to stress test load slicing, i.e., when this option
+ /// is enabled, load slicing bypasses most of its profitability guards.
+ static cl::opt<bool>
+ StressLoadSlicing("combiner-stress-load-slicing", cl::Hidden,
+ cl::desc("Bypass the profitability model of load "
+ "slicing"),
+ cl::init(false));
//------------------------------ DAGCombiner ---------------------------------//
CodeGenOpt::Level OptLevel;
bool LegalOperations;
bool LegalTypes;
+ bool ForCodeSize;
// Worklist of all of the nodes that need to be simplified.
//
bool CombineToPreIndexedLoadStore(SDNode *N);
bool CombineToPostIndexedLoadStore(SDNode *N);
+ bool SliceUpLoad(SDNode *N);
void ReplaceLoadWithPromotedLoad(SDNode *Load, SDNode *ExtLoad);
SDValue PromoteOperand(SDValue Op, EVT PVT, bool &Replace);
SDValue PromoteExtend(SDValue Op);
bool PromoteLoad(SDValue Op);
- void ExtendSetCCUses(SmallVector<SDNode*, 4> SetCCs,
+ void ExtendSetCCUses(const SmallVectorImpl<SDNode *> &SetCCs,
SDValue Trunc, SDValue ExtLoad, SDLoc DL,
ISD::NodeType ExtType);
SDValue visitCONCAT_VECTORS(SDNode *N);
SDValue visitEXTRACT_SUBVECTOR(SDNode *N);
SDValue visitVECTOR_SHUFFLE(SDNode *N);
+ SDValue visitINSERT_SUBVECTOR(SDNode *N);
SDValue XformToShuffleWithZero(SDNode *N);
SDValue ReassociateOps(unsigned Opc, SDLoc DL, SDValue LHS, SDValue RHS);
SDValue MatchBSwapHWordLow(SDNode *N, SDValue N0, SDValue N1,
bool DemandHighBits = true);
SDValue MatchBSwapHWord(SDNode *N, SDValue N0, SDValue N1);
+ SDNode *MatchRotatePosNeg(SDValue Shifted, SDValue Pos, SDValue Neg,
+ SDValue InnerPos, SDValue InnerNeg,
+ unsigned PosOpcode, unsigned NegOpcode,
+ SDLoc DL);
SDNode *MatchRotate(SDValue LHS, SDValue RHS, SDLoc DL);
SDValue ReduceLoadWidth(SDNode *N);
SDValue ReduceLoadOpStoreWidth(SDNode *N);
/// GatherAllAliases - 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,
- SmallVector<SDValue, 8> &Aliases);
+ SmallVectorImpl<SDValue> &Aliases);
/// isAlias - Return true if there is any possibility that the two addresses
/// overlap.
- bool isAlias(SDValue Ptr1, int64_t Size1,
+ bool isAlias(SDValue Ptr1, int64_t Size1, bool IsVolatile1,
const Value *SrcValue1, int SrcValueOffset1,
unsigned SrcValueAlign1,
const MDNode *TBAAInfo1,
- SDValue Ptr2, int64_t Size2,
+ SDValue Ptr2, int64_t Size2, bool IsVolatile2,
const Value *SrcValue2, int SrcValueOffset2,
unsigned SrcValueAlign2,
const MDNode *TBAAInfo2) const;
/// FindAliasInfo - Extracts the relevant alias information from the memory
/// node. Returns true if the operand was a load.
bool FindAliasInfo(SDNode *N,
- SDValue &Ptr, int64_t &Size,
+ SDValue &Ptr, int64_t &Size, bool &IsVolatile,
const Value *&SrcValue, int &SrcValueOffset,
unsigned &SrcValueAlignment,
const MDNode *&TBAAInfo) const;
public:
DAGCombiner(SelectionDAG &D, AliasAnalysis &A, CodeGenOpt::Level OL)
- : DAG(D), TLI(D.getTargetLoweringInfo()), Level(BeforeLegalizeTypes),
- OptLevel(OL), LegalOperations(false), LegalTypes(false), AA(A) {}
+ : DAG(D), TLI(D.getTargetLoweringInfo()), Level(BeforeLegalizeTypes),
+ OptLevel(OL), LegalOperations(false), LegalTypes(false), AA(A) {
+ AttributeSet FnAttrs =
+ DAG.getMachineFunction().getFunction()->getAttributes();
+ ForCodeSize =
+ FnAttrs.hasAttribute(AttributeSet::FunctionIndex,
+ Attribute::OptimizeForSize) ||
+ FnAttrs.hasAttribute(AttributeSet::FunctionIndex, Attribute::MinSize);
+ }
/// Run - runs the dag combiner on all nodes in the work list
void Run(CombineLevel AtLevel);
assert(LHSTy.isInteger() && "Shift amount is not an integer type!");
if (LHSTy.isVector())
return LHSTy;
- return LegalTypes ? TLI.getScalarShiftAmountTy(LHSTy) : TLI.getPointerTy();
+ return LegalTypes ? TLI.getScalarShiftAmountTy(LHSTy)
+ : TLI.getPointerTy();
}
/// isTypeLegal - This method returns true if we are running before type
return false;
}
+// \brief Returns the SDNode if it is a constant BuildVector or constant int.
+static SDNode *isConstantBuildVectorOrConstantInt(SDValue N) {
+ if (isa<ConstantSDNode>(N))
+ return N.getNode();
+ BuildVectorSDNode *BV = dyn_cast<BuildVectorSDNode>(N);
+ if(BV && BV->isConstant())
+ return BV;
+ return NULL;
+}
+
SDValue DAGCombiner::ReassociateOps(unsigned Opc, SDLoc DL,
SDValue N0, SDValue N1) {
EVT VT = N0.getValueType();
- if (N0.getOpcode() == Opc && isa<ConstantSDNode>(N0.getOperand(1))) {
- if (isa<ConstantSDNode>(N1)) {
- // reassoc. (op (op x, c1), c2) -> (op x, (op c1, c2))
- SDValue OpNode =
- DAG.FoldConstantArithmetic(Opc, VT,
- cast<ConstantSDNode>(N0.getOperand(1)),
- cast<ConstantSDNode>(N1));
- return DAG.getNode(Opc, DL, VT, N0.getOperand(0), OpNode);
- }
- if (N0.hasOneUse()) {
- // reassoc. (op (op x, c1), y) -> (op (op x, y), c1) iff x+c1 has one use
- SDValue OpNode = DAG.getNode(Opc, SDLoc(N0), VT,
- N0.getOperand(0), N1);
- AddToWorkList(OpNode.getNode());
- return DAG.getNode(Opc, DL, VT, OpNode, N0.getOperand(1));
- }
- }
-
- if (N1.getOpcode() == Opc && isa<ConstantSDNode>(N1.getOperand(1))) {
- if (isa<ConstantSDNode>(N0)) {
- // reassoc. (op c2, (op x, c1)) -> (op x, (op c1, c2))
- SDValue OpNode =
- DAG.FoldConstantArithmetic(Opc, VT,
- cast<ConstantSDNode>(N1.getOperand(1)),
- cast<ConstantSDNode>(N0));
- return DAG.getNode(Opc, DL, VT, N1.getOperand(0), OpNode);
- }
- if (N1.hasOneUse()) {
- // reassoc. (op y, (op x, c1)) -> (op (op x, y), c1) iff x+c1 has one use
- SDValue OpNode = DAG.getNode(Opc, SDLoc(N0), VT,
- N1.getOperand(0), N0);
- AddToWorkList(OpNode.getNode());
- return DAG.getNode(Opc, DL, VT, OpNode, N1.getOperand(1));
+ if (N0.getOpcode() == Opc) {
+ if (SDNode *L = isConstantBuildVectorOrConstantInt(N0.getOperand(1))) {
+ if (SDNode *R = isConstantBuildVectorOrConstantInt(N1)) {
+ // reassoc. (op (op x, c1), c2) -> (op x, (op c1, c2))
+ SDValue OpNode = DAG.FoldConstantArithmetic(Opc, VT, L, R);
+ if (!OpNode.getNode())
+ return SDValue();
+ return DAG.getNode(Opc, DL, VT, N0.getOperand(0), OpNode);
+ }
+ if (N0.hasOneUse()) {
+ // reassoc. (op (op x, c1), y) -> (op (op x, y), c1) iff x+c1 has one
+ // use
+ SDValue OpNode = DAG.getNode(Opc, SDLoc(N0), VT, N0.getOperand(0), N1);
+ if (!OpNode.getNode())
+ return SDValue();
+ AddToWorkList(OpNode.getNode());
+ return DAG.getNode(Opc, DL, VT, OpNode, N0.getOperand(1));
+ }
+ }
+ }
+
+ if (N1.getOpcode() == Opc) {
+ if (SDNode *R = isConstantBuildVectorOrConstantInt(N1.getOperand(1))) {
+ if (SDNode *L = isConstantBuildVectorOrConstantInt(N0)) {
+ // reassoc. (op c2, (op x, c1)) -> (op x, (op c1, c2))
+ SDValue OpNode = DAG.FoldConstantArithmetic(Opc, VT, R, L);
+ if (!OpNode.getNode())
+ return SDValue();
+ return DAG.getNode(Opc, DL, VT, N1.getOperand(0), OpNode);
+ }
+ if (N1.hasOneUse()) {
+ // reassoc. (op y, (op x, c1)) -> (op (op x, y), c1) iff x+c1 has one
+ // use
+ SDValue OpNode = DAG.getNode(Opc, SDLoc(N0), VT, N1.getOperand(0), N0);
+ if (!OpNode.getNode())
+ return SDValue();
+ AddToWorkList(OpNode.getNode());
+ return DAG.getNode(Opc, DL, VT, OpNode, N1.getOperand(1));
+ }
}
}
Replace = true;
return DAG.getExtLoad(ExtType, dl, PVT,
LD->getChain(), LD->getBasePtr(),
- LD->getPointerInfo(),
- MemVT, LD->isVolatile(),
- LD->isNonTemporal(), LD->getAlignment());
+ MemVT, LD->getMemOperand());
}
unsigned Opc = Op.getOpcode();
: LD->getExtensionType();
SDValue NewLD = DAG.getExtLoad(ExtType, dl, PVT,
LD->getChain(), LD->getBasePtr(),
- LD->getPointerInfo(),
- MemVT, LD->isVolatile(),
- LD->isNonTemporal(), LD->getAlignment());
+ MemVT, LD->getMemOperand());
SDValue Result = DAG.getNode(ISD::TRUNCATE, dl, VT, NewLD);
DEBUG(dbgs() << "\nPromoting ";
// try and combine it.
while (!WorkListContents.empty()) {
SDNode *N;
- // The WorkListOrder holds the SDNodes in order, but it may contain duplicates.
+ // The WorkListOrder holds the SDNodes in order, but it may contain
+ // duplicates.
// In order to avoid a linear scan, we use a set (O(log N)) to hold what the
// worklist *should* contain, and check the node we want to visit is should
// actually be visited.
case ISD::CONCAT_VECTORS: return visitCONCAT_VECTORS(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);
}
return SDValue();
}
// If all possibly-set bits on the LHS are clear on the RHS, return an OR.
// If all possibly-set bits on the RHS are clear on the LHS, return an OR.
- if ((RHSZero & ~LHSZero) == ~LHSZero || (LHSZero & ~RHSZero) == ~RHSZero)
- return DAG.getNode(ISD::OR, SDLoc(N), VT, N0, N1);
+ if ((RHSZero & ~LHSZero) == ~LHSZero || (LHSZero & ~RHSZero) == ~RHSZero){
+ if (!LegalOperations || TLI.isOperationLegal(ISD::OR, VT))
+ return DAG.getNode(ISD::OR, SDLoc(N), VT, N0, N1);
+ }
}
}
// Since it may not be valid to emit a fold to zero for vector initializers
// check if we can before folding.
static SDValue tryFoldToZero(SDLoc DL, const TargetLowering &TLI, EVT VT,
- SelectionDAG &DAG, bool LegalOperations) {
+ SelectionDAG &DAG,
+ bool LegalOperations, bool LegalTypes) {
if (!VT.isVector())
return DAG.getConstant(0, VT);
- if (!LegalOperations || TLI.isOperationLegal(ISD::BUILD_VECTOR, VT)) {
- // Produce a vector of zeros.
- SDValue El = DAG.getConstant(0, VT.getVectorElementType());
- std::vector<SDValue> Ops(VT.getVectorNumElements(), El);
- return DAG.getNode(ISD::BUILD_VECTOR, DL, VT,
- &Ops[0], Ops.size());
- }
+ if (!LegalOperations || TLI.isOperationLegal(ISD::BUILD_VECTOR, VT))
+ return DAG.getConstant(0, VT);
return SDValue();
}
// fold (sub x, x) -> 0
// FIXME: Refactor this and xor and other similar operations together.
if (N0 == N1)
- return tryFoldToZero(SDLoc(N), TLI, VT, DAG, LegalOperations);
+ return tryFoldToZero(SDLoc(N), TLI, VT, DAG, LegalOperations, LegalTypes);
// fold (sub c1, c2) -> c1-c2
if (N0C && N1C)
return DAG.FoldConstantArithmetic(ISD::SUB, VT, N0C, N1C);
return SDValue();
}
-/// isConstantSplatVector - Returns true if N is a BUILD_VECTOR node whose elements are
-/// all the same constant or undefined.
+/// isConstantSplatVector - 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 (!C)
N1IsConst = isConstantSplatVector(N1.getNode(), ConstValue1);
} else {
N0IsConst = dyn_cast<ConstantSDNode>(N0) != 0;
- ConstValue0 = N0IsConst? (dyn_cast<ConstantSDNode>(N0))->getAPIntValue() : APInt();
+ ConstValue0 = N0IsConst ? (dyn_cast<ConstantSDNode>(N0))->getAPIntValue()
+ : APInt();
N1IsConst = dyn_cast<ConstantSDNode>(N1) != 0;
- ConstValue1 = N1IsConst? (dyn_cast<ConstantSDNode>(N1))->getAPIntValue() : APInt();
+ ConstValue1 = N1IsConst ? (dyn_cast<ConstantSDNode>(N1))->getAPIntValue()
+ : APInt();
}
// fold (mul c1, c2) -> c1*c2
// fold (mul x, 0) -> 0
if (N1IsConst && ConstValue1 == 0)
return N1;
+ // We require a splat of the entire scalar bit width for non-contiguous
+ // bit patterns.
+ bool IsFullSplat =
+ ConstValue1.getBitWidth() == VT.getScalarType().getSizeInBits();
// fold (mul x, 1) -> x
- if (N1IsConst && ConstValue1 == 1)
+ if (N1IsConst && ConstValue1 == 1 && IsFullSplat)
return N0;
// fold (mul x, -1) -> 0-x
if (N1IsConst && ConstValue1.isAllOnesValue())
return DAG.getNode(ISD::SUB, SDLoc(N), VT,
DAG.getConstant(0, VT), N0);
// fold (mul x, (1 << c)) -> x << c
- if (N1IsConst && ConstValue1.isPowerOf2())
+ if (N1IsConst && ConstValue1.isPowerOf2() && IsFullSplat)
return DAG.getNode(ISD::SHL, SDLoc(N), VT, N0,
DAG.getConstant(ConstValue1.logBase2(),
getShiftAmountTy(N0.getValueType())));
// fold (mul x, -(1 << c)) -> -(x << c) or (-x) << c
- if (N1IsConst && (-ConstValue1).isPowerOf2()) {
+ if (N1IsConst && (-ConstValue1).isPowerOf2() && IsFullSplat) {
unsigned Log2Val = (-ConstValue1).logBase2();
// FIXME: If the input is something that is easily negated (e.g. a
// single-use add), we should put the negate there.
bool HiExists = N->hasAnyUseOfValue(1);
if (!HiExists &&
(!LegalOperations ||
- TLI.isOperationLegal(LoOp, N->getValueType(0)))) {
+ TLI.isOperationLegalOrCustom(LoOp, N->getValueType(0)))) {
SDValue Res = DAG.getNode(LoOp, SDLoc(N), N->getValueType(0),
N->op_begin(), N->getNumOperands());
return CombineTo(N, Res, Res);
return DAG.getSetCC(SDLoc(N), VT, ORNode, LR, Op1);
}
}
+ // Simplify (and (setne X, 0), (setne X, -1)) -> (setuge (add X, 1), 2)
+ if (LL == RL && isa<ConstantSDNode>(LR) && isa<ConstantSDNode>(RR) &&
+ Op0 == Op1 && LL.getValueType().isInteger() &&
+ Op0 == ISD::SETNE && ((cast<ConstantSDNode>(LR)->isNullValue() &&
+ cast<ConstantSDNode>(RR)->isAllOnesValue()) ||
+ (cast<ConstantSDNode>(LR)->isAllOnesValue() &&
+ cast<ConstantSDNode>(RR)->isNullValue()))) {
+ SDValue ADDNode = DAG.getNode(ISD::ADD, SDLoc(N0), LL.getValueType(),
+ LL, DAG.getConstant(1, LL.getValueType()));
+ AddToWorkList(ADDNode.getNode());
+ return DAG.getSetCC(SDLoc(N), VT, ADDNode,
+ DAG.getConstant(2, LL.getValueType()), ISD::SETUGE);
+ }
// canonicalize equivalent to ll == rl
if (LL == RR && LR == RL) {
Op1 = ISD::getSetCCSwappedOperands(Op1);
TLI.isLoadExtLegal(ISD::ZEXTLOAD, MemVT))) {
SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, SDLoc(N0), VT,
LN0->getChain(), LN0->getBasePtr(),
- LN0->getPointerInfo(), MemVT,
- LN0->isVolatile(), LN0->isNonTemporal(),
- LN0->getAlignment());
+ MemVT, LN0->getMemOperand());
AddToWorkList(N);
CombineTo(N0.getNode(), ExtLoad, ExtLoad.getValue(1));
return SDValue(N, 0); // Return N so it doesn't get rechecked!
((!LegalOperations && !LN0->isVolatile()) ||
TLI.isLoadExtLegal(ISD::ZEXTLOAD, MemVT))) {
SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, SDLoc(N0), VT,
- LN0->getChain(),
- LN0->getBasePtr(), LN0->getPointerInfo(),
- MemVT,
- LN0->isVolatile(), LN0->isNonTemporal(),
- LN0->getAlignment());
+ LN0->getChain(), LN0->getBasePtr(),
+ MemVT, LN0->getMemOperand());
AddToWorkList(N);
CombineTo(N0.getNode(), ExtLoad, ExtLoad.getValue(1));
return SDValue(N, 0); // Return N so it doesn't get rechecked!
SDValue NewLoad =
DAG.getExtLoad(ISD::ZEXTLOAD, SDLoc(LN0), LoadResultTy,
- LN0->getChain(), LN0->getBasePtr(),
- LN0->getPointerInfo(),
- ExtVT, LN0->isVolatile(), LN0->isNonTemporal(),
- LN0->getAlignment());
+ LN0->getChain(), LN0->getBasePtr(), ExtVT,
+ LN0->getMemOperand());
AddToWorkList(N);
CombineTo(LN0, NewLoad, NewLoad.getValue(1));
return SDValue(N, 0); // Return N so it doesn't get rechecked!
LN0->getChain(), NewPtr,
LN0->getPointerInfo(),
ExtVT, LN0->isVolatile(), LN0->isNonTemporal(),
- Alignment);
+ Alignment, LN0->getTBAAInfo());
AddToWorkList(N);
CombineTo(LN0, Load, Load.getValue(1));
return SDValue(N, 0); // Return N so it doesn't get rechecked!
}
}
+ // fold (and (or (srl N, 8), (shl N, 8)), 0xffff) -> (srl (bswap N), const)
+ if (N1C && N1C->getAPIntValue() == 0xffff && N0.getOpcode() == ISD::OR) {
+ SDValue BSwap = MatchBSwapHWordLow(N0.getNode(), N0.getOperand(0),
+ N0.getOperand(1), false);
+ if (BSwap.getNode())
+ return BSwap;
+ }
+
return SDValue();
}
if (N00 != N10)
return SDValue();
- // Make sure everything beyond the low halfword is zero since the SRL 16
- // will clear the top bits.
+ // Make sure everything beyond the low halfword gets set to zero since the SRL
+ // 16 will clear the top bits.
unsigned OpSizeInBits = VT.getSizeInBits();
- if (DemandHighBits && OpSizeInBits > 16 &&
- (!LookPassAnd0 || !LookPassAnd1) &&
- !DAG.MaskedValueIsZero(N10, APInt::getHighBitsSet(OpSizeInBits, 16)))
- return SDValue();
+ if (DemandHighBits && OpSizeInBits > 16) {
+ // If the left-shift isn't masked out then the only way this is a bswap is
+ // if all bits beyond the low 8 are 0. In that case the entire pattern
+ // reduces to a left shift anyway: leave it for other parts of the combiner.
+ if (!LookPassAnd0)
+ return SDValue();
+
+ // However, if the right shift isn't masked out then it might be because
+ // it's not needed. See if we can spot that too.
+ if (!LookPassAnd1 &&
+ !DAG.MaskedValueIsZero(
+ N10, APInt::getHighBitsSet(OpSizeInBits, OpSizeInBits - 16)))
+ return SDValue();
+ }
SDValue Res = DAG.getNode(ISD::BSWAP, SDLoc(N), VT, N00);
if (OpSizeInBits > 16)
/// 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, SmallVector<SDNode*,4> &Parts) {
+static bool isBSwapHWordElement(SDValue N, SmallVectorImpl<SDNode *> &Parts) {
if (!N.getNode()->hasOneUse())
return false;
SDValue BSwap = DAG.getNode(ISD::BSWAP, SDLoc(N), VT,
SDValue(Parts[0],0));
- // Result of the bswap should be rotated by 16. If it's not legal, than
+ // Result of the bswap should be rotated by 16. If it's not legal, then
// do (x << 16) | (x >> 16).
SDValue ShAmt = DAG.getConstant(16, getShiftAmountTy(VT));
if (TLI.isOperationLegalOrCustom(ISD::ROTL, VT))
if (N1C && N0.getOpcode() == ISD::AND && N0.getNode()->hasOneUse() &&
isa<ConstantSDNode>(N0.getOperand(1))) {
ConstantSDNode *C1 = cast<ConstantSDNode>(N0.getOperand(1));
- if ((C1->getAPIntValue() & N1C->getAPIntValue()) != 0)
+ if ((C1->getAPIntValue() & N1C->getAPIntValue()) != 0) {
+ SDValue COR = DAG.FoldConstantArithmetic(ISD::OR, VT, N1C, C1);
+ if (!COR.getNode())
+ return SDValue();
return DAG.getNode(ISD::AND, SDLoc(N), VT,
DAG.getNode(ISD::OR, SDLoc(N0), VT,
- N0.getOperand(0), N1),
- DAG.FoldConstantArithmetic(ISD::OR, VT, N1C, C1));
+ N0.getOperand(0), N1), COR);
+ }
}
// fold (or (setcc x), (setcc y)) -> (setcc (or x, y))
if (isSetCCEquivalent(N0, LL, LR, CC0) && isSetCCEquivalent(N1, RL, RR, CC1)){
return false;
}
+// Return true if we can prove that, whenever Neg and Pos are both in the
+// range [0, OpSize), Neg == (Pos == 0 ? 0 : OpSize - Pos). This means that
+// for two opposing shifts shift1 and shift2 and a value X with OpBits bits:
+//
+// (or (shift1 X, Neg), (shift2 X, Pos))
+//
+// reduces to a rotate in direction shift2 by Pos and a rotate in direction
+// shift1 by Neg. The range [0, OpSize) means that we only need to consider
+// shift amounts with defined behavior.
+static bool matchRotateSub(SDValue Pos, SDValue Neg, unsigned OpSize) {
+ // If OpSize is a power of 2 then:
+ //
+ // (a) (Pos == 0 ? 0 : OpSize - Pos) == (OpSize - Pos) & (OpSize - 1)
+ // (b) Neg == Neg & (OpSize - 1) whenever Neg is in [0, OpSize).
+ //
+ // So if OpSize is a power of 2 and Neg is (and Neg', OpSize-1), we check
+ // for the stronger condition:
+ //
+ // Neg & (OpSize - 1) == (OpSize - Pos) & (OpSize - 1) [A]
+ //
+ // for all Neg and Pos. Since Neg & (OpSize - 1) == Neg' & (OpSize - 1)
+ // we can just replace Neg with Neg' for the rest of the function.
+ //
+ // In other cases we check for the even stronger condition:
+ //
+ // Neg == OpSize - Pos [B]
+ //
+ // for all Neg and Pos. Note that the (or ...) then invokes undefined
+ // behavior if Pos == 0 (and consequently Neg == OpSize).
+ //
+ // We could actually use [A] whenever OpSize is a power of 2, but the
+ // only extra cases that it would match are those uninteresting ones
+ // where Neg and Pos are never in range at the same time. E.g. for
+ // OpSize == 32, using [A] would allow a Neg of the form (sub 64, Pos)
+ // as well as (sub 32, Pos), but:
+ //
+ // (or (shift1 X, (sub 64, Pos)), (shift2 X, Pos))
+ //
+ // always invokes undefined behavior for 32-bit X.
+ //
+ // Below, Mask == OpSize - 1 when using [A] and is all-ones otherwise.
+ unsigned LoBits = 0;
+ if (Neg.getOpcode() == ISD::AND &&
+ isPowerOf2_64(OpSize) &&
+ Neg.getOperand(1).getOpcode() == ISD::Constant &&
+ cast<ConstantSDNode>(Neg.getOperand(1))->getAPIntValue() == OpSize - 1) {
+ Neg = Neg.getOperand(0);
+ LoBits = Log2_64(OpSize);
+ }
+
+ // Check whether Neg has the form (sub NegC, NegOp1) for some NegC and NegOp1.
+ if (Neg.getOpcode() != ISD::SUB)
+ return 0;
+ ConstantSDNode *NegC = dyn_cast<ConstantSDNode>(Neg.getOperand(0));
+ if (!NegC)
+ return 0;
+ SDValue NegOp1 = Neg.getOperand(1);
+
+ // The condition we need is now:
+ //
+ // (NegC - NegOp1) & Mask == (OpSize - Pos) & Mask
+ //
+ // If NegOp1 == Pos then we need:
+ //
+ // OpSize & Mask == NegC & Mask
+ //
+ // (because "x & Mask" is a truncation and distributes through subtraction).
+ APInt Width;
+ if (Pos == NegOp1)
+ Width = NegC->getAPIntValue();
+ // Check for cases where Pos has the form (add NegOp1, PosC) for some PosC.
+ // Then the condition we want to prove becomes:
+ //
+ // (NegC - NegOp1) & Mask == (OpSize - (NegOp1 + PosC)) & Mask
+ //
+ // which, again because "x & Mask" is a truncation, becomes:
+ //
+ // NegC & Mask == (OpSize - PosC) & Mask
+ // OpSize & Mask == (NegC + PosC) & Mask
+ else if (Pos.getOpcode() == ISD::ADD &&
+ Pos.getOperand(0) == NegOp1 &&
+ Pos.getOperand(1).getOpcode() == ISD::Constant)
+ Width = (cast<ConstantSDNode>(Pos.getOperand(1))->getAPIntValue() +
+ NegC->getAPIntValue());
+ else
+ return false;
+
+ // Now we just need to check that OpSize & Mask == Width & Mask.
+ if (LoBits)
+ return Width.getLoBits(LoBits) == 0;
+ return Width == OpSize;
+}
+
+// A subroutine of MatchRotate used once we have found an OR of two opposite
+// shifts of Shifted. If Neg == <operand size> - Pos then the OR reduces
+// to both (PosOpcode Shifted, Pos) and (NegOpcode Shifted, Neg), with the
+// former being preferred if supported. InnerPos and InnerNeg are Pos and
+// Neg with outer conversions stripped away.
+SDNode *DAGCombiner::MatchRotatePosNeg(SDValue Shifted, SDValue Pos,
+ SDValue Neg, SDValue InnerPos,
+ SDValue InnerNeg, unsigned PosOpcode,
+ unsigned NegOpcode, SDLoc DL) {
+ // fold (or (shl x, (*ext y)),
+ // (srl x, (*ext (sub 32, y)))) ->
+ // (rotl x, y) or (rotr x, (sub 32, y))
+ //
+ // fold (or (shl x, (*ext (sub 32, y))),
+ // (srl x, (*ext y))) ->
+ // (rotr x, y) or (rotl x, (sub 32, y))
+ EVT VT = Shifted.getValueType();
+ if (matchRotateSub(InnerPos, InnerNeg, VT.getSizeInBits())) {
+ bool HasPos = TLI.isOperationLegalOrCustom(PosOpcode, VT);
+ return DAG.getNode(HasPos ? PosOpcode : NegOpcode, DL, VT, Shifted,
+ HasPos ? Pos : Neg).getNode();
+ }
+
+ // fold (or (shl (*ext x), (*ext y)),
+ // (srl (*ext x), (*ext (sub 32, y)))) ->
+ // (*ext (rotl x, y)) or (*ext (rotr x, (sub 32, y)))
+ //
+ // fold (or (shl (*ext x), (*ext (sub 32, y))),
+ // (srl (*ext x), (*ext y))) ->
+ // (*ext (rotr x, y)) or (*ext (rotl x, (sub 32, y)))
+ if (Shifted.getOpcode() == ISD::ZERO_EXTEND ||
+ Shifted.getOpcode() == ISD::ANY_EXTEND) {
+ SDValue InnerShifted = Shifted.getOperand(0);
+ EVT InnerVT = InnerShifted.getValueType();
+ bool HasPosInner = TLI.isOperationLegalOrCustom(PosOpcode, InnerVT);
+ if (HasPosInner || TLI.isOperationLegalOrCustom(NegOpcode, InnerVT)) {
+ if (matchRotateSub(InnerPos, InnerNeg, InnerVT.getSizeInBits())) {
+ SDValue V = DAG.getNode(HasPosInner ? PosOpcode : NegOpcode, DL,
+ InnerVT, InnerShifted, HasPosInner ? Pos : Neg);
+ return DAG.getNode(Shifted.getOpcode(), DL, VT, V).getNode();
+ }
+ }
+ }
+
+ return 0;
+}
+
// MatchRotate - Handle an 'or' of two operands. If this is one of the many
// idioms for rotate, and if the target supports rotation instructions, generate
// a rot[lr].
unsigned OpSizeInBits = VT.getSizeInBits();
SDValue LHSShiftArg = LHSShift.getOperand(0);
SDValue LHSShiftAmt = LHSShift.getOperand(1);
+ SDValue RHSShiftArg = RHSShift.getOperand(0);
SDValue RHSShiftAmt = RHSShift.getOperand(1);
// fold (or (shl x, C1), (srl x, C2)) -> (rotl x, C1)
if (LHSMask.getNode() || RHSMask.getNode())
return 0;
- // fold (or (shl x, y), (srl x, (sub 32, y))) -> (rotl x, y)
- // fold (or (shl x, y), (srl x, (sub 32, y))) -> (rotr x, (sub 32, y))
- if (RHSShiftAmt.getOpcode() == ISD::SUB &&
- LHSShiftAmt == RHSShiftAmt.getOperand(1)) {
- if (ConstantSDNode *SUBC =
- dyn_cast<ConstantSDNode>(RHSShiftAmt.getOperand(0))) {
- if (SUBC->getAPIntValue() == OpSizeInBits)
- return DAG.getNode(HasROTL ? ISD::ROTL : ISD::ROTR, DL, VT, LHSShiftArg,
- HasROTL ? LHSShiftAmt : RHSShiftAmt).getNode();
- }
- }
-
- // fold (or (shl x, (sub 32, y)), (srl x, r)) -> (rotr x, y)
- // fold (or (shl x, (sub 32, y)), (srl x, r)) -> (rotl x, (sub 32, y))
- if (LHSShiftAmt.getOpcode() == ISD::SUB &&
- RHSShiftAmt == LHSShiftAmt.getOperand(1))
- if (ConstantSDNode *SUBC =
- dyn_cast<ConstantSDNode>(LHSShiftAmt.getOperand(0)))
- if (SUBC->getAPIntValue() == OpSizeInBits)
- return DAG.getNode(HasROTR ? ISD::ROTR : ISD::ROTL, DL, VT, LHSShiftArg,
- HasROTR ? RHSShiftAmt : LHSShiftAmt).getNode();
-
- // Look for sign/zext/any-extended or truncate cases:
+ // If the shift amount is sign/zext/any-extended just peel it off.
+ SDValue LExtOp0 = LHSShiftAmt;
+ SDValue RExtOp0 = RHSShiftAmt;
if ((LHSShiftAmt.getOpcode() == ISD::SIGN_EXTEND ||
LHSShiftAmt.getOpcode() == ISD::ZERO_EXTEND ||
LHSShiftAmt.getOpcode() == ISD::ANY_EXTEND ||
RHSShiftAmt.getOpcode() == ISD::ZERO_EXTEND ||
RHSShiftAmt.getOpcode() == ISD::ANY_EXTEND ||
RHSShiftAmt.getOpcode() == ISD::TRUNCATE)) {
- SDValue LExtOp0 = LHSShiftAmt.getOperand(0);
- SDValue RExtOp0 = RHSShiftAmt.getOperand(0);
- if (RExtOp0.getOpcode() == ISD::SUB &&
- RExtOp0.getOperand(1) == LExtOp0) {
- // fold (or (shl x, (*ext y)), (srl x, (*ext (sub 32, y)))) ->
- // (rotl x, y)
- // fold (or (shl x, (*ext y)), (srl x, (*ext (sub 32, y)))) ->
- // (rotr x, (sub 32, y))
- if (ConstantSDNode *SUBC =
- dyn_cast<ConstantSDNode>(RExtOp0.getOperand(0)))
- if (SUBC->getAPIntValue() == OpSizeInBits)
- return DAG.getNode(HasROTL ? ISD::ROTL : ISD::ROTR, DL, VT,
- LHSShiftArg,
- HasROTL ? LHSShiftAmt : RHSShiftAmt).getNode();
- } else if (LExtOp0.getOpcode() == ISD::SUB &&
- RExtOp0 == LExtOp0.getOperand(1)) {
- // fold (or (shl x, (*ext (sub 32, y))), (srl x, (*ext y))) ->
- // (rotr x, y)
- // fold (or (shl x, (*ext (sub 32, y))), (srl x, (*ext y))) ->
- // (rotl x, (sub 32, y))
- if (ConstantSDNode *SUBC =
- dyn_cast<ConstantSDNode>(LExtOp0.getOperand(0)))
- if (SUBC->getAPIntValue() == OpSizeInBits)
- return DAG.getNode(HasROTR ? ISD::ROTR : ISD::ROTL, DL, VT,
- LHSShiftArg,
- HasROTR ? RHSShiftAmt : LHSShiftAmt).getNode();
- }
+ LExtOp0 = LHSShiftAmt.getOperand(0);
+ RExtOp0 = RHSShiftAmt.getOperand(0);
}
+ SDNode *TryL = MatchRotatePosNeg(LHSShiftArg, LHSShiftAmt, RHSShiftAmt,
+ LExtOp0, RExtOp0, ISD::ROTL, ISD::ROTR, DL);
+ if (TryL)
+ return TryL;
+
+ SDNode *TryR = MatchRotatePosNeg(RHSShiftArg, RHSShiftAmt, LHSShiftAmt,
+ RExtOp0, LExtOp0, ISD::ROTR, ISD::ROTL, DL);
+ if (TryR)
+ return TryR;
+
return 0;
}
}
// fold (xor x, x) -> 0
if (N0 == N1)
- return tryFoldToZero(SDLoc(N), TLI, VT, DAG, LegalOperations);
+ return tryFoldToZero(SDLoc(N), TLI, VT, DAG, LegalOperations, LegalTypes);
// Simplify: xor (op x...), (op y...) -> (op (xor x, y))
if (N0.getOpcode() == N1.getOpcode()) {
/// visitShiftByConstant - Handle transforms common to the three shifts, when
/// the shift amount is a constant.
SDValue DAGCombiner::visitShiftByConstant(SDNode *N, unsigned Amt) {
+ assert(isa<ConstantSDNode>(N->getOperand(1)) &&
+ "Expected an ConstantSDNode operand.");
+ // We can't and shouldn't fold opaque constants.
+ if (cast<ConstantSDNode>(N->getOperand(1))->isOpaque())
+ return SDValue();
+
SDNode *LHS = N->getOperand(0).getNode();
if (!LHS->hasOneUse()) return SDValue();
break;
}
- // We require the RHS of the binop to be a constant as well.
+ // We require the RHS of the binop to be a constant and not opaque as well.
ConstantSDNode *BinOpCst = dyn_cast<ConstantSDNode>(LHS->getOperand(1));
- if (!BinOpCst) return SDValue();
+ if (!BinOpCst || BinOpCst->isOpaque()) return SDValue();
// FIXME: disable this unless the input to the binop is a shift by a constant.
// If it is not a shift, it pessimizes some common cases like:
SDValue NewRHS = DAG.getNode(N->getOpcode(), SDLoc(LHS->getOperand(1)),
N->getValueType(0),
LHS->getOperand(1), N->getOperand(1));
+ assert(isa<ConstantSDNode>(NewRHS) && "Folding was not successful!");
// Create the new shift.
SDValue NewShift = DAG.getNode(N->getOpcode(),
EVT VT = N0.getValueType();
unsigned OpSizeInBits = VT.getScalarType().getSizeInBits();
+ // fold vector ops
+ if (VT.isVector()) {
+ SDValue FoldedVOp = SimplifyVBinOp(N);
+ if (FoldedVOp.getNode()) return FoldedVOp;
+ }
+
// fold (shl c1, c2) -> c1<<c2
if (N0C && N1C)
return DAG.FoldConstantArithmetic(ISD::SHL, VT, N0C, N1C);
}
}
+ // fold (shl (zext (srl x, C)), C) -> (zext (shl (srl x, C), C))
+ // Only fold this if the inner zext has no other uses to avoid increasing
+ // the total number of instructions.
+ if (N1C && N0.getOpcode() == ISD::ZERO_EXTEND && N0.hasOneUse() &&
+ N0.getOperand(0).getOpcode() == ISD::SRL &&
+ isa<ConstantSDNode>(N0.getOperand(0)->getOperand(1))) {
+ uint64_t c1 =
+ cast<ConstantSDNode>(N0.getOperand(0)->getOperand(1))->getZExtValue();
+ if (c1 < VT.getSizeInBits()) {
+ uint64_t c2 = N1C->getZExtValue();
+ if (c1 == c2) {
+ SDValue NewOp0 = N0.getOperand(0);
+ EVT CountVT = NewOp0.getOperand(1).getValueType();
+ SDValue NewSHL = DAG.getNode(ISD::SHL, SDLoc(N), NewOp0.getValueType(),
+ NewOp0, DAG.getConstant(c2, CountVT));
+ AddToWorkList(NewSHL.getNode());
+ return DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N0), VT, NewSHL);
+ }
+ }
+ }
+
// fold (shl (srl x, c1), c2) -> (and (shl x, (sub c2, c1), MASK) or
// (and (srl x, (sub c1, c2), MASK)
// Only fold this if the inner shift has no other uses -- if it does, folding
EVT VT = N0.getValueType();
unsigned OpSizeInBits = VT.getScalarType().getSizeInBits();
+ // fold vector ops
+ if (VT.isVector()) {
+ SDValue FoldedVOp = SimplifyVBinOp(N);
+ if (FoldedVOp.getNode()) return FoldedVOp;
+ }
+
// fold (sra c1, c2) -> (sra c1, c2)
if (N0C && N1C)
return DAG.FoldConstantArithmetic(ISD::SRA, VT, N0C, N1C);
EVT VT = N0.getValueType();
unsigned OpSizeInBits = VT.getScalarType().getSizeInBits();
+ // fold vector ops
+ if (VT.isVector()) {
+ SDValue FoldedVOp = SimplifyVBinOp(N);
+ if (FoldedVOp.getNode()) return FoldedVOp;
+ }
+
// fold (srl c1, c2) -> c1 >>u c2
if (N0C && N1C)
return DAG.FoldConstantArithmetic(ISD::SRL, VT, N0C, N1C);
return SDValue();
}
+static
+std::pair<SDValue, SDValue> SplitVSETCC(const SDNode *N, SelectionDAG &DAG) {
+ SDLoc DL(N);
+ EVT LoVT, HiVT;
+ llvm::tie(LoVT, HiVT) = DAG.GetSplitDestVTs(N->getValueType(0));
+
+ // Split the inputs.
+ SDValue Lo, Hi, LL, LH, RL, RH;
+ llvm::tie(LL, LH) = DAG.SplitVectorOperand(N, 0);
+ llvm::tie(RL, RH) = DAG.SplitVectorOperand(N, 1);
+
+ Lo = DAG.getNode(N->getOpcode(), DL, LoVT, LL, RL, N->getOperand(2));
+ Hi = DAG.getNode(N->getOpcode(), DL, HiVT, LH, RH, N->getOperand(2));
+
+ return std::make_pair(Lo, Hi);
+}
+
SDValue DAGCombiner::visitVSELECT(SDNode *N) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
}
}
+ // If the VSELECT 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 (N0.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 Lo, Hi, CCLo, CCHi, LL, LH, RL, RH;
+ llvm::tie(CCLo, CCHi) = SplitVSETCC(N0.getNode(), DAG);
+ llvm::tie(LL, LH) = DAG.SplitVectorOperand(N, 1);
+ llvm::tie(RL, RH) = DAG.SplitVectorOperand(N, 2);
+
+ Lo = DAG.getNode(N->getOpcode(), DL, LL.getValueType(), CCLo, LL, RL);
+ Hi = DAG.getNode(N->getOpcode(), DL, LH.getValueType(), CCHi, LH, RH);
+
+ // Add the new VSELECT nodes to the work list in case they need to be split
+ // again.
+ AddToWorkList(Lo.getNode());
+ AddToWorkList(Hi.getNode());
+
+ return DAG.getNode(ISD::CONCAT_VECTORS, DL, VT, Lo, Hi);
+ }
+
+ // Fold (vselect (build_vector all_ones), N1, N2) -> N1
+ if (ISD::isBuildVectorAllOnes(N0.getNode()))
+ return N1;
+ // Fold (vselect (build_vector all_zeros), N1, N2) -> N2
+ if (ISD::isBuildVectorAllZeros(N0.getNode()))
+ return N2;
+
return SDValue();
}
SDLoc(N));
}
+// tryToFoldExtendOfConstant - Try to fold a sext/zext/aext
+// dag node into a ConstantSDNode or a build_vector of constants.
+// This function is called by the DAGCombiner when visiting sext/zext/aext
+// dag nodes (see for example method DAGCombiner::visitSIGN_EXTEND).
+// Vector extends are not folded if operations are legal; this is to
+// avoid introducing illegal build_vector dag nodes.
+static SDNode *tryToFoldExtendOfConstant(SDNode *N, const TargetLowering &TLI,
+ SelectionDAG &DAG, bool LegalTypes,
+ bool LegalOperations) {
+ unsigned Opcode = N->getOpcode();
+ SDValue N0 = N->getOperand(0);
+ EVT VT = N->getValueType(0);
+
+ assert((Opcode == ISD::SIGN_EXTEND || Opcode == ISD::ZERO_EXTEND ||
+ Opcode == ISD::ANY_EXTEND) && "Expected EXTEND dag node in input!");
+
+ // fold (sext c1) -> c1
+ // fold (zext c1) -> c1
+ // fold (aext c1) -> c1
+ if (isa<ConstantSDNode>(N0))
+ return DAG.getNode(Opcode, SDLoc(N), VT, N0).getNode();
+
+ // fold (sext (build_vector AllConstants) -> (build_vector AllConstants)
+ // fold (zext (build_vector AllConstants) -> (build_vector AllConstants)
+ // fold (aext (build_vector AllConstants) -> (build_vector AllConstants)
+ EVT SVT = VT.getScalarType();
+ if (!(VT.isVector() &&
+ (!LegalTypes || (!LegalOperations && TLI.isTypeLegal(SVT))) &&
+ ISD::isBuildVectorOfConstantSDNodes(N0.getNode())))
+ return 0;
+
+ // We can fold this node into a build_vector.
+ unsigned VTBits = SVT.getSizeInBits();
+ unsigned EVTBits = N0->getValueType(0).getScalarType().getSizeInBits();
+ unsigned ShAmt = VTBits - EVTBits;
+ SmallVector<SDValue, 8> Elts;
+ unsigned NumElts = N0->getNumOperands();
+ SDLoc DL(N);
+
+ for (unsigned i=0; i != NumElts; ++i) {
+ SDValue Op = N0->getOperand(i);
+ if (Op->getOpcode() == ISD::UNDEF) {
+ Elts.push_back(DAG.getUNDEF(SVT));
+ continue;
+ }
+
+ ConstantSDNode *CurrentND = cast<ConstantSDNode>(Op);
+ const APInt &C = APInt(VTBits, CurrentND->getAPIntValue().getZExtValue());
+ if (Opcode == ISD::SIGN_EXTEND)
+ Elts.push_back(DAG.getConstant(C.shl(ShAmt).ashr(ShAmt).getZExtValue(),
+ SVT));
+ else
+ Elts.push_back(DAG.getConstant(C.shl(ShAmt).lshr(ShAmt).getZExtValue(),
+ SVT));
+ }
+
+ return DAG.getNode(ISD::BUILD_VECTOR, DL, VT, &Elts[0], NumElts).getNode();
+}
+
// ExtendUsesToFormExtLoad - Trying to extend uses of a load to enable this:
// "fold ({s|z|a}ext (load x)) -> ({s|z|a}ext (truncate ({s|z|a}extload x)))"
// transformation. Returns true if extension are possible and the above
// mentioned transformation is profitable.
static bool ExtendUsesToFormExtLoad(SDNode *N, SDValue N0,
unsigned ExtOpc,
- SmallVector<SDNode*, 4> &ExtendNodes,
+ SmallVectorImpl<SDNode *> &ExtendNodes,
const TargetLowering &TLI) {
bool HasCopyToRegUses = false;
bool isTruncFree = TLI.isTruncateFree(N->getValueType(0), N0.getValueType());
return true;
}
-void DAGCombiner::ExtendSetCCUses(SmallVector<SDNode*, 4> SetCCs,
+void DAGCombiner::ExtendSetCCUses(const SmallVectorImpl<SDNode *> &SetCCs,
SDValue Trunc, SDValue ExtLoad, SDLoc DL,
ISD::NodeType ExtType) {
// Extend SetCC uses if necessary.
SDValue N0 = N->getOperand(0);
EVT VT = N->getValueType(0);
- // fold (sext c1) -> c1
- if (isa<ConstantSDNode>(N0))
- return DAG.getNode(ISD::SIGN_EXTEND, SDLoc(N), VT, N0);
+ if (SDNode *Res = tryToFoldExtendOfConstant(N, TLI, DAG, LegalTypes,
+ LegalOperations))
+ return SDValue(Res, 0);
// fold (sext (sext x)) -> (sext x)
// fold (sext (aext x)) -> (sext x)
LoadSDNode *LN0 = cast<LoadSDNode>(N0);
SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, SDLoc(N), VT,
LN0->getChain(),
- LN0->getBasePtr(), LN0->getPointerInfo(),
- N0.getValueType(),
- LN0->isVolatile(), LN0->isNonTemporal(),
- LN0->getAlignment());
+ LN0->getBasePtr(), N0.getValueType(),
+ LN0->getMemOperand());
CombineTo(N, ExtLoad);
SDValue Trunc = DAG.getNode(ISD::TRUNCATE, SDLoc(N0),
N0.getValueType(), ExtLoad);
TLI.isLoadExtLegal(ISD::SEXTLOAD, MemVT)) {
SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, SDLoc(N), VT,
LN0->getChain(),
- LN0->getBasePtr(), LN0->getPointerInfo(),
- MemVT,
- LN0->isVolatile(), LN0->isNonTemporal(),
- LN0->getAlignment());
+ LN0->getBasePtr(), MemVT,
+ LN0->getMemOperand());
CombineTo(N, ExtLoad);
CombineTo(N0.getNode(),
DAG.getNode(ISD::TRUNCATE, SDLoc(N0),
if (DoXform) {
SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, SDLoc(LN0), VT,
LN0->getChain(), LN0->getBasePtr(),
- LN0->getPointerInfo(),
LN0->getMemoryVT(),
- LN0->isVolatile(),
- LN0->isNonTemporal(),
- LN0->getAlignment());
+ LN0->getMemOperand());
APInt Mask = cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
Mask = Mask.sext(VT.getSizeInBits());
SDValue And = DAG.getNode(N0.getOpcode(), SDLoc(N), VT,
}
}
- // sext(setcc x, y, cc) -> (select_cc x, y, -1, 0, cc)
+ // sext(setcc x, y, cc) -> (select (setcc x, y, cc), -1, 0)
unsigned ElementWidth = VT.getScalarType().getSizeInBits();
SDValue NegOne =
DAG.getConstant(APInt::getAllOnesValue(ElementWidth), VT);
NegOne, DAG.getConstant(0, VT),
cast<CondCodeSDNode>(N0.getOperand(2))->get(), true);
if (SCC.getNode()) return SCC;
- if (!VT.isVector() &&
- (!LegalOperations ||
- TLI.isOperationLegal(ISD::SETCC, getSetCCResultType(VT)))) {
- return DAG.getSelect(SDLoc(N), VT,
- DAG.getSetCC(SDLoc(N),
- getSetCCResultType(VT),
- N0.getOperand(0), N0.getOperand(1),
- cast<CondCodeSDNode>(N0.getOperand(2))->get()),
- NegOne, DAG.getConstant(0, VT));
+
+ if (!VT.isVector()) {
+ EVT SetCCVT = getSetCCResultType(N0.getOperand(0).getValueType());
+ 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,
+ N0.getOperand(0), N0.getOperand(1), CC);
+ EVT SelectVT = getSetCCResultType(VT);
+ return DAG.getSelect(DL, VT,
+ DAG.getSExtOrTrunc(SetCC, DL, SelectVT),
+ NegOne, DAG.getConstant(0, VT));
+
+ }
}
}
SDValue N0 = N->getOperand(0);
EVT VT = N->getValueType(0);
- // fold (zext c1) -> c1
- if (isa<ConstantSDNode>(N0))
- return DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N), VT, N0);
+ if (SDNode *Res = tryToFoldExtendOfConstant(N, TLI, DAG, LegalTypes,
+ LegalOperations))
+ return SDValue(Res, 0);
+
// fold (zext (zext x)) -> (zext x)
// fold (zext (aext x)) -> (zext x)
if (N0.getOpcode() == ISD::ZERO_EXTEND || N0.getOpcode() == ISD::ANY_EXTEND)
LoadSDNode *LN0 = cast<LoadSDNode>(N0);
SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, SDLoc(N), VT,
LN0->getChain(),
- LN0->getBasePtr(), LN0->getPointerInfo(),
- N0.getValueType(),
- LN0->isVolatile(), LN0->isNonTemporal(),
- LN0->getAlignment());
+ LN0->getBasePtr(), N0.getValueType(),
+ LN0->getMemOperand());
CombineTo(N, ExtLoad);
SDValue Trunc = DAG.getNode(ISD::TRUNCATE, SDLoc(N0),
N0.getValueType(), ExtLoad);
if (DoXform) {
SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, SDLoc(LN0), VT,
LN0->getChain(), LN0->getBasePtr(),
- LN0->getPointerInfo(),
LN0->getMemoryVT(),
- LN0->isVolatile(),
- LN0->isNonTemporal(),
- LN0->getAlignment());
+ LN0->getMemOperand());
APInt Mask = cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
Mask = Mask.zext(VT.getSizeInBits());
SDValue And = DAG.getNode(N0.getOpcode(), SDLoc(N), VT,
TLI.isLoadExtLegal(ISD::ZEXTLOAD, MemVT)) {
SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, SDLoc(N), VT,
LN0->getChain(),
- LN0->getBasePtr(), LN0->getPointerInfo(),
- MemVT,
- LN0->isVolatile(), LN0->isNonTemporal(),
- LN0->getAlignment());
+ LN0->getBasePtr(), MemVT,
+ LN0->getMemOperand());
CombineTo(N, ExtLoad);
CombineTo(N0.getNode(),
DAG.getNode(ISD::TRUNCATE, SDLoc(N0), N0.getValueType(),
}
if (N0.getOpcode() == ISD::SETCC) {
- if (!LegalOperations && VT.isVector()) {
+ if (!LegalOperations && VT.isVector() &&
+ N0.getValueType().getVectorElementType() == MVT::i1) {
+ EVT N0VT = N0.getOperand(0).getValueType();
+ if (getSetCCResultType(N0VT) == N0.getValueType())
+ return SDValue();
+
// zext(setcc) -> (and (vsetcc), (1, 1, ...) for vectors.
// Only do this before legalize for now.
- EVT N0VT = N0.getOperand(0).getValueType();
EVT EltVT = VT.getVectorElementType();
SmallVector<SDValue,8> OneOps(VT.getVectorNumElements(),
DAG.getConstant(1, EltVT));
SDValue N0 = N->getOperand(0);
EVT VT = N->getValueType(0);
- // fold (aext c1) -> c1
- if (isa<ConstantSDNode>(N0))
- return DAG.getNode(ISD::ANY_EXTEND, SDLoc(N), VT, N0);
+ if (SDNode *Res = tryToFoldExtendOfConstant(N, TLI, DAG, LegalTypes,
+ LegalOperations))
+ return SDValue(Res, 0);
+
// fold (aext (aext x)) -> (aext x)
// fold (aext (zext x)) -> (zext x)
// fold (aext (sext x)) -> (sext x)
LoadSDNode *LN0 = cast<LoadSDNode>(N0);
SDValue ExtLoad = DAG.getExtLoad(ISD::EXTLOAD, SDLoc(N), VT,
LN0->getChain(),
- LN0->getBasePtr(), LN0->getPointerInfo(),
- N0.getValueType(),
- LN0->isVolatile(), LN0->isNonTemporal(),
- LN0->getAlignment());
+ LN0->getBasePtr(), N0.getValueType(),
+ LN0->getMemOperand());
CombineTo(N, ExtLoad);
SDValue Trunc = DAG.getNode(ISD::TRUNCATE, SDLoc(N0),
N0.getValueType(), ExtLoad);
EVT MemVT = LN0->getMemoryVT();
SDValue ExtLoad = DAG.getExtLoad(LN0->getExtensionType(), SDLoc(N),
VT, LN0->getChain(), LN0->getBasePtr(),
- LN0->getPointerInfo(), MemVT,
- LN0->isVolatile(), LN0->isNonTemporal(),
- LN0->getAlignment());
+ MemVT, LN0->getMemOperand());
CombineTo(N, ExtLoad);
CombineTo(N0.getNode(),
DAG.getNode(ISD::TRUNCATE, SDLoc(N0),
Load = DAG.getLoad(VT, SDLoc(N0), LN0->getChain(), NewPtr,
LN0->getPointerInfo().getWithOffset(PtrOff),
LN0->isVolatile(), LN0->isNonTemporal(),
- LN0->isInvariant(), NewAlign);
+ LN0->isInvariant(), NewAlign, LN0->getTBAAInfo());
else
Load = DAG.getExtLoad(ExtType, SDLoc(N0), VT, LN0->getChain(),NewPtr,
LN0->getPointerInfo().getWithOffset(PtrOff),
ExtVT, LN0->isVolatile(), LN0->isNonTemporal(),
- NewAlign);
+ NewAlign, LN0->getTBAAInfo());
// Replace the old load's chain with the new load's chain.
WorkListRemover DeadNodes(*this);
LoadSDNode *LN0 = cast<LoadSDNode>(N0);
SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, SDLoc(N), VT,
LN0->getChain(),
- LN0->getBasePtr(), LN0->getPointerInfo(),
- EVT,
- LN0->isVolatile(), LN0->isNonTemporal(),
- LN0->getAlignment());
+ LN0->getBasePtr(), EVT,
+ LN0->getMemOperand());
CombineTo(N, ExtLoad);
CombineTo(N0.getNode(), ExtLoad, ExtLoad.getValue(1));
AddToWorkList(ExtLoad.getNode());
LoadSDNode *LN0 = cast<LoadSDNode>(N0);
SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, SDLoc(N), VT,
LN0->getChain(),
- LN0->getBasePtr(), LN0->getPointerInfo(),
- EVT,
- LN0->isVolatile(), LN0->isNonTemporal(),
- LN0->getAlignment());
+ LN0->getBasePtr(), EVT,
+ LN0->getMemOperand());
CombineTo(N, ExtLoad);
CombineTo(N0.getNode(), ExtLoad, ExtLoad.getValue(1));
return SDValue(N, 0); // Return N so it doesn't get rechecked!
BSwap, N1);
}
+ // Fold a sext_inreg of a build_vector of ConstantSDNodes or undefs
+ // into a build_vector.
+ if (ISD::isBuildVectorOfConstantSDNodes(N0.getNode())) {
+ SmallVector<SDValue, 8> Elts;
+ unsigned NumElts = N0->getNumOperands();
+ unsigned ShAmt = VTBits - EVTBits;
+
+ for (unsigned i = 0; i != NumElts; ++i) {
+ SDValue Op = N0->getOperand(i);
+ if (Op->getOpcode() == ISD::UNDEF) {
+ Elts.push_back(Op);
+ continue;
+ }
+
+ ConstantSDNode *CurrentND = cast<ConstantSDNode>(Op);
+ const APInt &C = APInt(VTBits, CurrentND->getAPIntValue().getZExtValue());
+ Elts.push_back(DAG.getConstant(C.shl(ShAmt).ashr(ShAmt).getZExtValue(),
+ Op.getValueType()));
+ }
+
+ return DAG.getNode(ISD::BUILD_VECTOR, SDLoc(N), VT, &Elts[0], NumElts);
+ }
+
return SDValue();
}
SDValue EltNo = N0->getOperand(1);
if (isa<ConstantSDNode>(EltNo) && isTypeLegal(NVT)) {
int Elt = cast<ConstantSDNode>(EltNo)->getZExtValue();
- EVT IndexTy = N0->getOperand(1).getValueType();
+ EVT IndexTy = TLI.getVectorIdxTy();
int Index = isLE ? (Elt*SizeRatio) : (Elt*SizeRatio + (SizeRatio-1));
SDValue V = DAG.getNode(ISD::BITCAST, SDLoc(N),
SDValue Reduced = ReduceLoadWidth(N);
if (Reduced.getNode())
return Reduced;
+ // Handle the case where the load remains an extending load even
+ // after truncation.
+ if (N0.hasOneUse() && ISD::isUNINDEXEDLoad(N0.getNode())) {
+ LoadSDNode *LN0 = cast<LoadSDNode>(N0);
+ if (!LN0->isVolatile() &&
+ LN0->getMemoryVT().getStoreSizeInBits() < VT.getSizeInBits()) {
+ SDValue NewLoad = DAG.getExtLoad(LN0->getExtensionType(), SDLoc(LN0),
+ VT, LN0->getChain(), LN0->getBasePtr(),
+ LN0->getMemoryVT(),
+ LN0->getMemOperand());
+ DAG.ReplaceAllUsesOfValueWith(N0.getValue(1), NewLoad.getValue(1));
+ return NewLoad;
+ }
+ }
}
// fold (trunc (concat ... x ...)) -> (concat ..., (trunc x), ...)),
// where ... are all 'undef'.
if (!LegalTypes &&
N0.getOpcode() == ISD::BUILD_VECTOR && N0.getNode()->hasOneUse() &&
VT.isVector()) {
- bool isSimple = true;
- for (unsigned i = 0, e = N0.getNumOperands(); i != e; ++i)
- if (N0.getOperand(i).getOpcode() != ISD::UNDEF &&
- N0.getOperand(i).getOpcode() != ISD::Constant &&
- N0.getOperand(i).getOpcode() != ISD::ConstantFP) {
- isSimple = false;
- break;
- }
+ bool isSimple = cast<BuildVectorSDNode>(N0)->isConstant();
EVT DestEltVT = N->getValueType(0).getVectorElementType();
assert(!DestEltVT.isVector() &&
if (ISD::isNormalLoad(N0.getNode()) && N0.hasOneUse() &&
// Do not change the width of a volatile load.
!cast<LoadSDNode>(N0)->isVolatile() &&
- (!LegalOperations || TLI.isOperationLegal(ISD::LOAD, VT))) {
+ (!LegalOperations || TLI.isOperationLegal(ISD::LOAD, VT)) &&
+ TLI.isLoadBitCastBeneficial(N0.getValueType(), VT)) {
LoadSDNode *LN0 = cast<LoadSDNode>(N0);
unsigned Align = TLI.getDataLayout()->
getABITypeAlignment(VT.getTypeForEVT(*DAG.getContext()));
SDValue Load = DAG.getLoad(VT, SDLoc(N), LN0->getChain(),
LN0->getBasePtr(), LN0->getPointerInfo(),
LN0->isVolatile(), LN0->isNonTemporal(),
- LN0->isInvariant(), OrigAlign);
+ LN0->isInvariant(), OrigAlign,
+ LN0->getTBAAInfo());
AddToWorkList(N);
CombineTo(N0.getNode(),
DAG.getNode(ISD::BITCAST, SDLoc(N0),
// fold (bitconvert (fneg x)) -> (xor (bitconvert x), signbit)
// fold (bitconvert (fabs x)) -> (and (bitconvert x), (not signbit))
// This often reduces constant pool loads.
- if (((N0.getOpcode() == ISD::FNEG && !TLI.isFNegFree(VT)) ||
- (N0.getOpcode() == ISD::FABS && !TLI.isFAbsFree(VT))) &&
+ if (((N0.getOpcode() == ISD::FNEG && !TLI.isFNegFree(N0.getValueType())) ||
+ (N0.getOpcode() == ISD::FABS && !TLI.isFAbsFree(N0.getValueType()))) &&
N0.getNode()->hasOneUse() && VT.isInteger() &&
!VT.isVector() && !N0.getValueType().isVector()) {
SDValue NewConv = DAG.getNode(ISD::BITCAST, SDLoc(N0), VT,
// FADD -> FMA combines:
if ((DAG.getTarget().Options.AllowFPOpFusion == FPOpFusion::Fast ||
DAG.getTarget().Options.UnsafeFPMath) &&
- DAG.getTarget().getTargetLowering()->isFMAFasterThanMulAndAdd(VT) &&
- TLI.isOperationLegalOrCustom(ISD::FMA, VT)) {
+ DAG.getTarget().getTargetLowering()->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 (N10 == N0 && isNegatibleForFree(N11, LegalOperations, TLI,
&DAG.getTarget().Options))
return GetNegatedExpression(N11, DAG, LegalOperations);
-
+
if (N11 == N0 && isNegatibleForFree(N10, LegalOperations, TLI,
&DAG.getTarget().Options))
return GetNegatedExpression(N10, DAG, LegalOperations);
// FSUB -> FMA combines:
if ((DAG.getTarget().Options.AllowFPOpFusion == FPOpFusion::Fast ||
DAG.getTarget().Options.UnsafeFPMath) &&
- DAG.getTarget().getTargetLowering()->isFMAFasterThanMulAndAdd(VT) &&
- TLI.isOperationLegalOrCustom(ISD::FMA, VT)) {
+ DAG.getTarget().getTargetLowering()->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())
// 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())
return DAG.getNode(ISD::FMA, dl, VT,
DAG.getNode(ISD::FNEG, dl, VT,
N1.getOperand(0)),
return DAG.getNode(ISD::UINT_TO_FP, SDLoc(N), VT, N0);
}
- // The next optimizations are desireable only if SELECT_CC can be lowered.
+ // The next optimizations are desirable only if SELECT_CC can be lowered.
// Check against MVT::Other for SELECT_CC, which is a workaround for targets
// having to say they don't support SELECT_CC on every type the DAG knows
// about, since there is no way to mark an opcode illegal at all value types
return DAG.getNode(ISD::SINT_TO_FP, SDLoc(N), VT, N0);
}
- // The next optimizations are desireable only if SELECT_CC can be lowered.
+ // The next optimizations are desirable only if SELECT_CC can be lowered.
// Check against MVT::Other for SELECT_CC, which is a workaround for targets
// having to say they don't support SELECT_CC on every type the DAG knows
// about, since there is no way to mark an opcode illegal at all value types
}
// fold (fpext (load x)) -> (fpext (fptrunc (extload x)))
- if (ISD::isNON_EXTLoad(N0.getNode()) && N0.hasOneUse() &&
+ if (ISD::isNormalLoad(N0.getNode()) && N0.hasOneUse() &&
((!LegalOperations && !cast<LoadSDNode>(N0)->isVolatile()) ||
TLI.isLoadExtLegal(ISD::EXTLOAD, N0.getValueType()))) {
LoadSDNode *LN0 = cast<LoadSDNode>(N0);
SDValue ExtLoad = DAG.getExtLoad(ISD::EXTLOAD, SDLoc(N), VT,
LN0->getChain(),
- LN0->getBasePtr(), LN0->getPointerInfo(),
- N0.getValueType(),
- LN0->isVolatile(), LN0->isNonTemporal(),
- LN0->getAlignment());
+ LN0->getBasePtr(), N0.getValueType(),
+ LN0->getMemOperand());
CombineTo(N, ExtLoad);
CombineTo(N0.getNode(),
DAG.getNode(ISD::FP_ROUND, SDLoc(N0),
LD->getValueType(0),
Chain, Ptr, LD->getPointerInfo(),
LD->getMemoryVT(),
- LD->isVolatile(), LD->isNonTemporal(), Align);
+ LD->isVolatile(), LD->isNonTemporal(), Align,
+ LD->getTBAAInfo());
return CombineTo(N, NewLoad, SDValue(NewLoad.getNode(), 1), true);
}
}
}
- if (CombinerAA) {
+ bool UseAA = CombinerAA.getNumOccurrences() > 0 ? CombinerAA :
+ TLI.getTargetMachine().getSubtarget<TargetSubtargetInfo>().useAA();
+#ifndef NDEBUG
+ if (CombinerAAOnlyFunc.getNumOccurrences() &&
+ CombinerAAOnlyFunc != DAG.getMachineFunction().getName())
+ UseAA = false;
+#endif
+ if (UseAA && LD->isUnindexed()) {
// Walk up chain skipping non-aliasing memory nodes.
SDValue BetterChain = FindBetterChain(N, Chain);
// Replace the chain to void dependency.
if (LD->getExtensionType() == ISD::NON_EXTLOAD) {
ReplLoad = DAG.getLoad(N->getValueType(0), SDLoc(LD),
- BetterChain, Ptr, LD->getPointerInfo(),
- LD->isVolatile(), LD->isNonTemporal(),
- LD->isInvariant(), LD->getAlignment());
+ BetterChain, Ptr, LD->getMemOperand());
} else {
ReplLoad = DAG.getExtLoad(LD->getExtensionType(), SDLoc(LD),
LD->getValueType(0),
- BetterChain, Ptr, LD->getPointerInfo(),
- LD->getMemoryVT(),
- LD->isVolatile(),
- LD->isNonTemporal(),
- LD->getAlignment());
+ BetterChain, Ptr, LD->getMemoryVT(),
+ LD->getMemOperand());
}
// Create token factor to keep old chain connected.
if (CombineToPreIndexedLoadStore(N) || CombineToPostIndexedLoadStore(N))
return SDValue(N, 0);
+ // Try to slice up N to more direct loads if the slices are mapped to
+ // different register banks or pairing can take place.
+ if (SliceUpLoad(N))
+ return SDValue(N, 0);
+
return SDValue();
}
+namespace {
+/// \brief Helper structure used to slice a load in smaller loads.
+/// Basically a slice is obtained from the following sequence:
+/// Origin = load Ty1, Base
+/// Shift = srl Ty1 Origin, CstTy Amount
+/// Inst = trunc Shift to Ty2
+///
+/// Then, it will be rewriten into:
+/// Slice = load SliceTy, Base + SliceOffset
+/// [Inst = zext Slice to Ty2], only if SliceTy <> Ty2
+///
+/// SliceTy is deduced from the number of bits that are actually used to
+/// build Inst.
+struct LoadedSlice {
+ /// \brief Helper structure used to compute the cost of a slice.
+ struct Cost {
+ /// Are we optimizing for code size.
+ bool ForCodeSize;
+ /// Various cost.
+ unsigned Loads;
+ unsigned Truncates;
+ unsigned CrossRegisterBanksCopies;
+ unsigned ZExts;
+ unsigned Shift;
+
+ Cost(bool ForCodeSize = false)
+ : ForCodeSize(ForCodeSize), Loads(0), Truncates(0),
+ CrossRegisterBanksCopies(0), ZExts(0), Shift(0) {}
+
+ /// \brief Get the cost of one isolated slice.
+ Cost(const LoadedSlice &LS, bool ForCodeSize = false)
+ : ForCodeSize(ForCodeSize), Loads(1), Truncates(0),
+ CrossRegisterBanksCopies(0), ZExts(0), Shift(0) {
+ EVT TruncType = LS.Inst->getValueType(0);
+ EVT LoadedType = LS.getLoadedType();
+ if (TruncType != LoadedType &&
+ !LS.DAG->getTargetLoweringInfo().isZExtFree(LoadedType, TruncType))
+ ZExts = 1;
+ }
+
+ /// \brief Account for slicing gain in the current cost.
+ /// Slicing provide a few gains like removing a shift or a
+ /// truncate. This method allows to grow the cost of the original
+ /// load with the gain from this slice.
+ void addSliceGain(const LoadedSlice &LS) {
+ // Each slice saves a truncate.
+ const TargetLowering &TLI = LS.DAG->getTargetLoweringInfo();
+ if (!TLI.isTruncateFree(LS.Inst->getValueType(0),
+ LS.Inst->getOperand(0).getValueType()))
+ ++Truncates;
+ // If there is a shift amount, this slice gets rid of it.
+ if (LS.Shift)
+ ++Shift;
+ // If this slice can merge a cross register bank copy, account for it.
+ if (LS.canMergeExpensiveCrossRegisterBankCopy())
+ ++CrossRegisterBanksCopies;
+ }
+
+ Cost &operator+=(const Cost &RHS) {
+ Loads += RHS.Loads;
+ Truncates += RHS.Truncates;
+ CrossRegisterBanksCopies += RHS.CrossRegisterBanksCopies;
+ ZExts += RHS.ZExts;
+ Shift += RHS.Shift;
+ return *this;
+ }
+
+ bool operator==(const Cost &RHS) const {
+ return Loads == RHS.Loads && Truncates == RHS.Truncates &&
+ CrossRegisterBanksCopies == RHS.CrossRegisterBanksCopies &&
+ ZExts == RHS.ZExts && Shift == RHS.Shift;
+ }
+
+ bool operator!=(const Cost &RHS) const { return !(*this == RHS); }
+
+ bool operator<(const Cost &RHS) const {
+ // Assume cross register banks copies are as expensive as loads.
+ // FIXME: Do we want some more target hooks?
+ unsigned ExpensiveOpsLHS = Loads + CrossRegisterBanksCopies;
+ unsigned ExpensiveOpsRHS = RHS.Loads + RHS.CrossRegisterBanksCopies;
+ // Unless we are optimizing for code size, consider the
+ // expensive operation first.
+ if (!ForCodeSize && ExpensiveOpsLHS != ExpensiveOpsRHS)
+ return ExpensiveOpsLHS < ExpensiveOpsRHS;
+ return (Truncates + ZExts + Shift + ExpensiveOpsLHS) <
+ (RHS.Truncates + RHS.ZExts + RHS.Shift + ExpensiveOpsRHS);
+ }
+
+ bool operator>(const Cost &RHS) const { return RHS < *this; }
+
+ bool operator<=(const Cost &RHS) const { return !(RHS < *this); }
+
+ bool operator>=(const Cost &RHS) const { return !(*this < RHS); }
+ };
+ // The last instruction that represent the slice. This should be a
+ // truncate instruction.
+ SDNode *Inst;
+ // The original load instruction.
+ LoadSDNode *Origin;
+ // The right shift amount in bits from the original load.
+ unsigned Shift;
+ // The DAG from which Origin came from.
+ // This is used to get some contextual information about legal types, etc.
+ SelectionDAG *DAG;
+
+ LoadedSlice(SDNode *Inst = NULL, LoadSDNode *Origin = NULL,
+ unsigned Shift = 0, SelectionDAG *DAG = NULL)
+ : Inst(Inst), Origin(Origin), Shift(Shift), DAG(DAG) {}
+
+ LoadedSlice(const LoadedSlice &LS)
+ : Inst(LS.Inst), Origin(LS.Origin), Shift(LS.Shift), DAG(LS.DAG) {}
+
+ /// \brief Get the bits used in a chunk of bits \p BitWidth large.
+ /// \return Result is \p BitWidth and has used bits set to 1 and
+ /// not used bits set to 0.
+ APInt getUsedBits() const {
+ // Reproduce the trunc(lshr) sequence:
+ // - Start from the truncated value.
+ // - Zero extend to the desired bit width.
+ // - Shift left.
+ assert(Origin && "No original load to compare against.");
+ unsigned BitWidth = Origin->getValueSizeInBits(0);
+ assert(Inst && "This slice is not bound to an instruction");
+ assert(Inst->getValueSizeInBits(0) <= BitWidth &&
+ "Extracted slice is bigger than the whole type!");
+ APInt UsedBits(Inst->getValueSizeInBits(0), 0);
+ UsedBits.setAllBits();
+ UsedBits = UsedBits.zext(BitWidth);
+ UsedBits <<= Shift;
+ return UsedBits;
+ }
+
+ /// \brief Get the size of the slice to be loaded in bytes.
+ unsigned getLoadedSize() const {
+ unsigned SliceSize = getUsedBits().countPopulation();
+ assert(!(SliceSize & 0x7) && "Size is not a multiple of a byte.");
+ return SliceSize / 8;
+ }
+
+ /// \brief Get the type that will be loaded for this slice.
+ /// Note: This may not be the final type for the slice.
+ EVT getLoadedType() const {
+ assert(DAG && "Missing context");
+ LLVMContext &Ctxt = *DAG->getContext();
+ return EVT::getIntegerVT(Ctxt, getLoadedSize() * 8);
+ }
+
+ /// \brief Get the alignment of the load used for this slice.
+ unsigned getAlignment() const {
+ unsigned Alignment = Origin->getAlignment();
+ unsigned Offset = getOffsetFromBase();
+ if (Offset != 0)
+ Alignment = MinAlign(Alignment, Alignment + Offset);
+ return Alignment;
+ }
+
+ /// \brief Check if this slice can be rewritten with legal operations.
+ bool isLegal() const {
+ // An invalid slice is not legal.
+ if (!Origin || !Inst || !DAG)
+ return false;
+
+ // Offsets are for indexed load only, we do not handle that.
+ if (Origin->getOffset().getOpcode() != ISD::UNDEF)
+ return false;
+
+ const TargetLowering &TLI = DAG->getTargetLoweringInfo();
+
+ // Check that the type is legal.
+ EVT SliceType = getLoadedType();
+ if (!TLI.isTypeLegal(SliceType))
+ return false;
+
+ // Check that the load is legal for this type.
+ if (!TLI.isOperationLegal(ISD::LOAD, SliceType))
+ return false;
+
+ // Check that the offset can be computed.
+ // 1. Check its type.
+ EVT PtrType = Origin->getBasePtr().getValueType();
+ if (PtrType == MVT::Untyped || PtrType.isExtended())
+ return false;
+
+ // 2. Check that it fits in the immediate.
+ if (!TLI.isLegalAddImmediate(getOffsetFromBase()))
+ return false;
+
+ // 3. Check that the computation is legal.
+ if (!TLI.isOperationLegal(ISD::ADD, PtrType))
+ return false;
+
+ // Check that the zext is legal if it needs one.
+ EVT TruncateType = Inst->getValueType(0);
+ if (TruncateType != SliceType &&
+ !TLI.isOperationLegal(ISD::ZERO_EXTEND, TruncateType))
+ return false;
+
+ return true;
+ }
+
+ /// \brief Get the offset in bytes of this slice in the original chunk of
+ /// bits.
+ /// \pre DAG != NULL.
+ uint64_t getOffsetFromBase() const {
+ assert(DAG && "Missing context.");
+ bool IsBigEndian =
+ DAG->getTargetLoweringInfo().getDataLayout()->isBigEndian();
+ assert(!(Shift & 0x7) && "Shifts not aligned on Bytes are not supported.");
+ uint64_t Offset = Shift / 8;
+ unsigned TySizeInBytes = Origin->getValueSizeInBits(0) / 8;
+ assert(!(Origin->getValueSizeInBits(0) & 0x7) &&
+ "The size of the original loaded type is not a multiple of a"
+ " byte.");
+ // If Offset is bigger than TySizeInBytes, it means we are loading all
+ // zeros. This should have been optimized before in the process.
+ assert(TySizeInBytes > Offset &&
+ "Invalid shift amount for given loaded size");
+ if (IsBigEndian)
+ Offset = TySizeInBytes - Offset - getLoadedSize();
+ return Offset;
+ }
+
+ /// \brief Generate the sequence of instructions to load the slice
+ /// represented by this object and redirect the uses of this slice to
+ /// this new sequence of instructions.
+ /// \pre this->Inst && this->Origin are valid Instructions and this
+ /// object passed the legal check: LoadedSlice::isLegal returned true.
+ /// \return The last instruction of the sequence used to load the slice.
+ SDValue loadSlice() const {
+ assert(Inst && Origin && "Unable to replace a non-existing slice.");
+ const SDValue &OldBaseAddr = Origin->getBasePtr();
+ SDValue BaseAddr = OldBaseAddr;
+ // Get the offset in that chunk of bytes w.r.t. the endianess.
+ int64_t Offset = static_cast<int64_t>(getOffsetFromBase());
+ assert(Offset >= 0 && "Offset too big to fit in int64_t!");
+ if (Offset) {
+ // BaseAddr = BaseAddr + Offset.
+ EVT ArithType = BaseAddr.getValueType();
+ BaseAddr = DAG->getNode(ISD::ADD, SDLoc(Origin), ArithType, BaseAddr,
+ DAG->getConstant(Offset, ArithType));
+ }
+
+ // Create the type of the loaded slice according to its size.
+ EVT SliceType = getLoadedType();
+
+ // Create the load for the slice.
+ SDValue LastInst = DAG->getLoad(
+ SliceType, SDLoc(Origin), Origin->getChain(), BaseAddr,
+ Origin->getPointerInfo().getWithOffset(Offset), Origin->isVolatile(),
+ Origin->isNonTemporal(), Origin->isInvariant(), getAlignment());
+ // If the final type is not the same as the loaded type, this means that
+ // we have to pad with zero. Create a zero extend for that.
+ EVT FinalType = Inst->getValueType(0);
+ if (SliceType != FinalType)
+ LastInst =
+ DAG->getNode(ISD::ZERO_EXTEND, SDLoc(LastInst), FinalType, LastInst);
+ return LastInst;
+ }
+
+ /// \brief Check if this slice can be merged with an expensive cross register
+ /// bank copy. E.g.,
+ /// i = load i32
+ /// f = bitcast i32 i to float
+ bool canMergeExpensiveCrossRegisterBankCopy() const {
+ if (!Inst || !Inst->hasOneUse())
+ return false;
+ SDNode *Use = *Inst->use_begin();
+ if (Use->getOpcode() != ISD::BITCAST)
+ return false;
+ assert(DAG && "Missing context");
+ const TargetLowering &TLI = DAG->getTargetLoweringInfo();
+ EVT ResVT = Use->getValueType(0);
+ const TargetRegisterClass *ResRC = TLI.getRegClassFor(ResVT.getSimpleVT());
+ const TargetRegisterClass *ArgRC =
+ TLI.getRegClassFor(Use->getOperand(0).getValueType().getSimpleVT());
+ if (ArgRC == ResRC || !TLI.isOperationLegal(ISD::LOAD, ResVT))
+ return false;
+
+ // At this point, we know that we perform a cross-register-bank copy.
+ // Check if it is expensive.
+ const TargetRegisterInfo *TRI = TLI.getTargetMachine().getRegisterInfo();
+ // Assume bitcasts are cheap, unless both register classes do not
+ // explicitly share a common sub class.
+ if (!TRI || TRI->getCommonSubClass(ArgRC, ResRC))
+ return false;
+
+ // Check if it will be merged with the load.
+ // 1. Check the alignment constraint.
+ unsigned RequiredAlignment = TLI.getDataLayout()->getABITypeAlignment(
+ ResVT.getTypeForEVT(*DAG->getContext()));
+
+ if (RequiredAlignment > getAlignment())
+ return false;
+
+ // 2. Check that the load is a legal operation for that type.
+ if (!TLI.isOperationLegal(ISD::LOAD, ResVT))
+ return false;
+
+ // 3. Check that we do not have a zext in the way.
+ if (Inst->getValueType(0) != getLoadedType())
+ return false;
+
+ return true;
+ }
+};
+}
+
+/// \brief Sorts LoadedSlice according to their offset.
+struct LoadedSliceSorter {
+ bool operator()(const LoadedSlice &LHS, const LoadedSlice &RHS) {
+ assert(LHS.Origin == RHS.Origin && "Different bases not implemented.");
+ return LHS.getOffsetFromBase() < RHS.getOffsetFromBase();
+ }
+};
+
+/// \brief Check that all bits set in \p UsedBits form a dense region, i.e.,
+/// \p UsedBits looks like 0..0 1..1 0..0.
+static bool areUsedBitsDense(const APInt &UsedBits) {
+ // If all the bits are one, this is dense!
+ if (UsedBits.isAllOnesValue())
+ return true;
+
+ // Get rid of the unused bits on the right.
+ APInt NarrowedUsedBits = UsedBits.lshr(UsedBits.countTrailingZeros());
+ // Get rid of the unused bits on the left.
+ if (NarrowedUsedBits.countLeadingZeros())
+ NarrowedUsedBits = NarrowedUsedBits.trunc(NarrowedUsedBits.getActiveBits());
+ // Check that the chunk of bits is completely used.
+ return NarrowedUsedBits.isAllOnesValue();
+}
+
+/// \brief Check whether or not \p First and \p Second are next to each other
+/// in memory. This means that there is no hole between the bits loaded
+/// by \p First and the bits loaded by \p Second.
+static bool areSlicesNextToEachOther(const LoadedSlice &First,
+ const LoadedSlice &Second) {
+ assert(First.Origin == Second.Origin && First.Origin &&
+ "Unable to match different memory origins.");
+ APInt UsedBits = First.getUsedBits();
+ assert((UsedBits & Second.getUsedBits()) == 0 &&
+ "Slices are not supposed to overlap.");
+ UsedBits |= Second.getUsedBits();
+ return areUsedBitsDense(UsedBits);
+}
+
+/// \brief Adjust the \p GlobalLSCost according to the target
+/// paring capabilities and the layout of the slices.
+/// \pre \p GlobalLSCost should account for at least as many loads as
+/// there is in the slices in \p LoadedSlices.
+static void adjustCostForPairing(SmallVectorImpl<LoadedSlice> &LoadedSlices,
+ LoadedSlice::Cost &GlobalLSCost) {
+ unsigned NumberOfSlices = LoadedSlices.size();
+ // If there is less than 2 elements, no pairing is possible.
+ if (NumberOfSlices < 2)
+ return;
+
+ // Sort the slices so that elements that are likely to be next to each
+ // other in memory are next to each other in the list.
+ std::sort(LoadedSlices.begin(), LoadedSlices.end(), LoadedSliceSorter());
+ const TargetLowering &TLI = LoadedSlices[0].DAG->getTargetLoweringInfo();
+ // First (resp. Second) is the first (resp. Second) potentially candidate
+ // to be placed in a paired load.
+ const LoadedSlice *First = NULL;
+ const LoadedSlice *Second = NULL;
+ for (unsigned CurrSlice = 0; CurrSlice < NumberOfSlices; ++CurrSlice,
+ // Set the beginning of the pair.
+ First = Second) {
+
+ Second = &LoadedSlices[CurrSlice];
+
+ // If First is NULL, it means we start a new pair.
+ // Get to the next slice.
+ if (!First)
+ continue;
+
+ EVT LoadedType = First->getLoadedType();
+
+ // If the types of the slices are different, we cannot pair them.
+ if (LoadedType != Second->getLoadedType())
+ continue;
+
+ // Check if the target supplies paired loads for this type.
+ unsigned RequiredAlignment = 0;
+ if (!TLI.hasPairedLoad(LoadedType, RequiredAlignment)) {
+ // move to the next pair, this type is hopeless.
+ Second = NULL;
+ continue;
+ }
+ // Check if we meet the alignment requirement.
+ if (RequiredAlignment > First->getAlignment())
+ continue;
+
+ // Check that both loads are next to each other in memory.
+ if (!areSlicesNextToEachOther(*First, *Second))
+ continue;
+
+ assert(GlobalLSCost.Loads > 0 && "We save more loads than we created!");
+ --GlobalLSCost.Loads;
+ // Move to the next pair.
+ Second = NULL;
+ }
+}
+
+/// \brief Check the profitability of all involved LoadedSlice.
+/// Currently, it is considered profitable if there is exactly two
+/// involved slices (1) which are (2) next to each other in memory, and
+/// whose cost (\see LoadedSlice::Cost) is smaller than the original load (3).
+///
+/// Note: The order of the elements in \p LoadedSlices may be modified, but not
+/// the elements themselves.
+///
+/// FIXME: When the cost model will be mature enough, we can relax
+/// constraints (1) and (2).
+static bool isSlicingProfitable(SmallVectorImpl<LoadedSlice> &LoadedSlices,
+ const APInt &UsedBits, bool ForCodeSize) {
+ unsigned NumberOfSlices = LoadedSlices.size();
+ if (StressLoadSlicing)
+ return NumberOfSlices > 1;
+
+ // Check (1).
+ if (NumberOfSlices != 2)
+ return false;
+
+ // Check (2).
+ if (!areUsedBitsDense(UsedBits))
+ return false;
+
+ // Check (3).
+ LoadedSlice::Cost OrigCost(ForCodeSize), GlobalSlicingCost(ForCodeSize);
+ // The original code has one big load.
+ OrigCost.Loads = 1;
+ for (unsigned CurrSlice = 0; CurrSlice < NumberOfSlices; ++CurrSlice) {
+ const LoadedSlice &LS = LoadedSlices[CurrSlice];
+ // Accumulate the cost of all the slices.
+ LoadedSlice::Cost SliceCost(LS, ForCodeSize);
+ GlobalSlicingCost += SliceCost;
+
+ // Account as cost in the original configuration the gain obtained
+ // with the current slices.
+ OrigCost.addSliceGain(LS);
+ }
+
+ // If the target supports paired load, adjust the cost accordingly.
+ adjustCostForPairing(LoadedSlices, GlobalSlicingCost);
+ return OrigCost > GlobalSlicingCost;
+}
+
+/// \brief If the given load, \p LI, is used only by trunc or trunc(lshr)
+/// operations, split it in the various pieces being extracted.
+///
+/// This sort of thing is introduced by SROA.
+/// This slicing takes care not to insert overlapping loads.
+/// \pre LI is a simple load (i.e., not an atomic or volatile load).
+bool DAGCombiner::SliceUpLoad(SDNode *N) {
+ if (Level < AfterLegalizeDAG)
+ return false;
+
+ LoadSDNode *LD = cast<LoadSDNode>(N);
+ if (LD->isVolatile() || !ISD::isNormalLoad(LD) ||
+ !LD->getValueType(0).isInteger())
+ return false;
+
+ // Keep track of already used bits to detect overlapping values.
+ // In that case, we will just abort the transformation.
+ APInt UsedBits(LD->getValueSizeInBits(0), 0);
+
+ SmallVector<LoadedSlice, 4> LoadedSlices;
+
+ // Check if this load is used as several smaller chunks of bits.
+ // Basically, look for uses in trunc or trunc(lshr) and record a new chain
+ // of computation for each trunc.
+ for (SDNode::use_iterator UI = LD->use_begin(), UIEnd = LD->use_end();
+ UI != UIEnd; ++UI) {
+ // Skip the uses of the chain.
+ if (UI.getUse().getResNo() != 0)
+ continue;
+
+ SDNode *User = *UI;
+ unsigned Shift = 0;
+
+ // Check if this is a trunc(lshr).
+ if (User->getOpcode() == ISD::SRL && User->hasOneUse() &&
+ isa<ConstantSDNode>(User->getOperand(1))) {
+ Shift = cast<ConstantSDNode>(User->getOperand(1))->getZExtValue();
+ User = *User->use_begin();
+ }
+
+ // At this point, User is a Truncate, iff we encountered, trunc or
+ // trunc(lshr).
+ if (User->getOpcode() != ISD::TRUNCATE)
+ return false;
+
+ // The width of the type must be a power of 2 and greater than 8-bits.
+ // Otherwise the load cannot be represented in LLVM IR.
+ // Moreover, if we shifted with a non-8-bits multiple, the slice
+ // will be across several bytes. We do not support that.
+ unsigned Width = User->getValueSizeInBits(0);
+ if (Width < 8 || !isPowerOf2_32(Width) || (Shift & 0x7))
+ return 0;
+
+ // Build the slice for this chain of computations.
+ LoadedSlice LS(User, LD, Shift, &DAG);
+ APInt CurrentUsedBits = LS.getUsedBits();
+
+ // Check if this slice overlaps with another.
+ if ((CurrentUsedBits & UsedBits) != 0)
+ return false;
+ // Update the bits used globally.
+ UsedBits |= CurrentUsedBits;
+
+ // Check if the new slice would be legal.
+ if (!LS.isLegal())
+ return false;
+
+ // Record the slice.
+ LoadedSlices.push_back(LS);
+ }
+
+ // Abort slicing if it does not seem to be profitable.
+ if (!isSlicingProfitable(LoadedSlices, UsedBits, ForCodeSize))
+ return false;
+
+ ++SlicedLoads;
+
+ // Rewrite each chain to use an independent load.
+ // By construction, each chain can be represented by a unique load.
+
+ // Prepare the argument for the new token factor for all the slices.
+ SmallVector<SDValue, 8> ArgChains;
+ for (SmallVectorImpl<LoadedSlice>::const_iterator
+ LSIt = LoadedSlices.begin(),
+ LSItEnd = LoadedSlices.end();
+ LSIt != LSItEnd; ++LSIt) {
+ SDValue SliceInst = LSIt->loadSlice();
+ CombineTo(LSIt->Inst, SliceInst, true);
+ if (SliceInst.getNode()->getOpcode() != ISD::LOAD)
+ SliceInst = SliceInst.getOperand(0);
+ assert(SliceInst->getOpcode() == ISD::LOAD &&
+ "It takes more than a zext to get to the loaded slice!!");
+ ArgChains.push_back(SliceInst.getValue(1));
+ }
+
+ SDValue Chain = DAG.getNode(ISD::TokenFactor, SDLoc(LD), MVT::Other,
+ &ArgChains[0], ArgChains.size());
+ DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), Chain);
+ 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.
LD->getChain(), NewPtr,
LD->getPointerInfo().getWithOffset(PtrOff),
LD->isVolatile(), LD->isNonTemporal(),
- LD->isInvariant(), NewAlign);
+ LD->isInvariant(), NewAlign,
+ LD->getTBAAInfo());
SDValue NewVal = DAG.getNode(Opc, SDLoc(Value), NewVT, NewLD,
DAG.getConstant(NewImm, NewVT));
SDValue NewST = DAG.getStore(Chain, SDLoc(N),
static BaseIndexOffset match(SDValue Ptr) {
bool IsIndexSignExt = false;
- // Just Base or possibly anything else.
+ // We only can pattern match BASE + INDEX + OFFSET. If Ptr is not an ADD
+ // instruction, then it could be just the BASE or everything else we don't
+ // know how to handle. Just use Ptr as BASE and give up.
if (Ptr->getOpcode() != ISD::ADD)
return BaseIndexOffset(Ptr, SDValue(), 0, IsIndexSignExt);
- // Base + offset.
+ // We know that we have at least an ADD instruction. Try to pattern match
+ // the simple case of BASE + OFFSET.
if (isa<ConstantSDNode>(Ptr->getOperand(1))) {
int64_t Offset = cast<ConstantSDNode>(Ptr->getOperand(1))->getSExtValue();
return BaseIndexOffset(Ptr->getOperand(0), SDValue(), Offset,
IsIndexSignExt);
}
+ // Inside a loop the current BASE pointer is calculated using an ADD and a
+ // MUL instruction. In this case Ptr is the actual BASE pointer.
+ // (i64 add (i64 %array_ptr)
+ // (i64 mul (i64 %induction_var)
+ // (i64 %element_size)))
+ if (Ptr->getOperand(1)->getOpcode() == ISD::MUL)
+ return BaseIndexOffset(Ptr, SDValue(), 0, IsIndexSignExt);
+
// Look at Base + Index + Offset cases.
SDValue Base = Ptr->getOperand(0);
SDValue IndexOffset = Ptr->getOperand(1);
// base ptr.
struct ConsecutiveMemoryChainSorter {
bool operator()(MemOpLink LHS, MemOpLink RHS) {
- return LHS.OffsetFromBase < RHS.OffsetFromBase;
+ return
+ LHS.OffsetFromBase < RHS.OffsetFromBase ||
+ (LHS.OffsetFromBase == RHS.OffsetFromBase &&
+ LHS.SequenceNum > RHS.SequenceNum);
}
};
Index = STn;
break;
} else if (LoadSDNode *Ldn = dyn_cast<LoadSDNode>(NextInChain)) {
+ if (Ldn->isVolatile()) {
+ Index = NULL;
+ break;
+ }
+
// Save the load node for later. Continue the scan.
AliasLoadNodes.push_back(Ldn);
NextInChain = Ldn->getChain().getNode();
} else if (ConstantFPSDNode *C = dyn_cast<ConstantFPSDNode>(StoredVal)) {
NonZero |= !C->getConstantFPValue()->isNullValue();
} else {
- // Non constant.
+ // Non-constant.
break;
}
TLI.isOperationLegalOrCustom(ISD::STORE, SVT)))
return DAG.getStore(Chain, SDLoc(N), Value.getOperand(0),
Ptr, ST->getPointerInfo(), ST->isVolatile(),
- ST->isNonTemporal(), OrigAlign);
+ ST->isNonTemporal(), OrigAlign,
+ ST->getTBAAInfo());
}
// Turn 'store undef, Ptr' -> nothing.
// transform should not be done in this case.
if (Value.getOpcode() != ISD::TargetConstantFP) {
SDValue Tmp;
- switch (CFP->getValueType(0).getSimpleVT().SimpleTy) {
+ switch (CFP->getSimpleValueType(0).SimpleTy) {
default: llvm_unreachable("Unknown FP type");
case MVT::f16: // We don't do this for these yet.
case MVT::f80:
Tmp = DAG.getConstant((uint32_t)CFP->getValueAPF().
bitcastToAPInt().getZExtValue(), MVT::i32);
return DAG.getStore(Chain, SDLoc(N), Tmp,
- Ptr, ST->getPointerInfo(), ST->isVolatile(),
- ST->isNonTemporal(), ST->getAlignment());
+ Ptr, ST->getMemOperand());
}
break;
case MVT::f64:
Tmp = DAG.getConstant(CFP->getValueAPF().bitcastToAPInt().
getZExtValue(), MVT::i64);
return DAG.getStore(Chain, SDLoc(N), Tmp,
- Ptr, ST->getPointerInfo(), ST->isVolatile(),
- ST->isNonTemporal(), ST->getAlignment());
+ Ptr, ST->getMemOperand());
}
if (!ST->isVolatile() &&
unsigned Alignment = ST->getAlignment();
bool isVolatile = ST->isVolatile();
bool isNonTemporal = ST->isNonTemporal();
+ const MDNode *TBAAInfo = ST->getTBAAInfo();
SDValue St0 = DAG.getStore(Chain, SDLoc(ST), Lo,
Ptr, ST->getPointerInfo(),
isVolatile, isNonTemporal,
- ST->getAlignment());
+ ST->getAlignment(), TBAAInfo);
Ptr = DAG.getNode(ISD::ADD, SDLoc(N), Ptr.getValueType(), Ptr,
DAG.getConstant(4, Ptr.getValueType()));
Alignment = MinAlign(Alignment, 4U);
SDValue St1 = DAG.getStore(Chain, SDLoc(ST), Hi,
Ptr, ST->getPointerInfo().getWithOffset(4),
isVolatile, isNonTemporal,
- Alignment);
+ Alignment, TBAAInfo);
return DAG.getNode(ISD::TokenFactor, SDLoc(N), MVT::Other,
St0, St1);
}
if (Align > ST->getAlignment())
return DAG.getTruncStore(Chain, SDLoc(N), Value,
Ptr, ST->getPointerInfo(), ST->getMemoryVT(),
- ST->isVolatile(), ST->isNonTemporal(), Align);
+ ST->isVolatile(), ST->isNonTemporal(), Align,
+ ST->getTBAAInfo());
}
}
if (NewST.getNode())
return NewST;
- if (CombinerAA) {
+ bool UseAA = CombinerAA.getNumOccurrences() > 0 ? CombinerAA :
+ TLI.getTargetMachine().getSubtarget<TargetSubtargetInfo>().useAA();
+#ifndef NDEBUG
+ if (CombinerAAOnlyFunc.getNumOccurrences() &&
+ CombinerAAOnlyFunc != DAG.getMachineFunction().getName())
+ UseAA = false;
+#endif
+ if (UseAA && ST->isUnindexed()) {
// Walk up chain skipping non-aliasing memory nodes.
SDValue BetterChain = FindBetterChain(N, Chain);
// Replace the chain to avoid dependency.
if (ST->isTruncatingStore()) {
ReplStore = DAG.getTruncStore(BetterChain, SDLoc(N), Value, Ptr,
- ST->getPointerInfo(),
- ST->getMemoryVT(), ST->isVolatile(),
- ST->isNonTemporal(), ST->getAlignment());
+ ST->getMemoryVT(), ST->getMemOperand());
} else {
ReplStore = DAG.getStore(BetterChain, SDLoc(N), Value, Ptr,
- ST->getPointerInfo(),
- ST->isVolatile(), ST->isNonTemporal(),
- ST->getAlignment());
+ ST->getMemOperand());
}
// Create token to keep both nodes around.
AddToWorkList(Value.getNode());
if (Shorter.getNode())
return DAG.getTruncStore(Chain, SDLoc(N), Shorter,
- Ptr, ST->getPointerInfo(), ST->getMemoryVT(),
- ST->isVolatile(), ST->isNonTemporal(),
- ST->getAlignment());
+ Ptr, ST->getMemoryVT(), ST->getMemOperand());
// Otherwise, see if we can simplify the operation with
// SimplifyDemandedBits, which only works if the value has a single use.
TLI.isTruncStoreLegal(Value.getOperand(0).getValueType(),
ST->getMemoryVT())) {
return DAG.getTruncStore(Chain, SDLoc(N), Value.getOperand(0),
- Ptr, ST->getPointerInfo(), ST->getMemoryVT(),
- ST->isVolatile(), ST->isNonTemporal(),
- ST->getAlignment());
+ Ptr, ST->getMemoryVT(), ST->getMemOperand());
}
// Only perform this optimization before the types are legal, because we
// be converted to a BUILD_VECTOR). Fill in the Ops vector with the
// vector elements.
SmallVector<SDValue, 8> Ops;
- if (InVec.getOpcode() == ISD::BUILD_VECTOR) {
+ // Do not combine these two vectors if the output vector will not replace
+ // the input vector.
+ if (InVec.getOpcode() == ISD::BUILD_VECTOR && InVec.hasOneUse()) {
Ops.append(InVec.getNode()->op_begin(),
InVec.getNode()->op_end());
} else if (InVec.getOpcode() == ISD::UNDEF) {
OrigElt -= NumElem;
}
- EVT IndexTy = N->getOperand(1).getValueType();
+ EVT IndexTy = TLI.getVectorIdxTy();
return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SDLoc(N), NVT,
InVec, DAG.getConstant(OrigElt, IndexTy));
}
? ISD::ZEXTLOAD : ISD::EXTLOAD;
Load = DAG.getExtLoad(ExtType, SDLoc(N), NVT, LN0->getChain(),
NewPtr, LN0->getPointerInfo().getWithOffset(PtrOff),
- LVT, LN0->isVolatile(), LN0->isNonTemporal(),Align);
+ LVT, LN0->isVolatile(), LN0->isNonTemporal(),
+ Align, LN0->getTBAAInfo());
Chain = Load.getValue(1);
} else {
Load = DAG.getLoad(LVT, SDLoc(N), LN0->getChain(), NewPtr,
LN0->getPointerInfo().getWithOffset(PtrOff),
LN0->isVolatile(), LN0->isNonTemporal(),
- LN0->isInvariant(), Align);
+ LN0->isInvariant(), Align, LN0->getTBAAInfo());
Chain = Load.getValue(1);
if (NVT.bitsLT(LVT))
Load = DAG.getNode(ISD::TRUNCATE, SDLoc(N), NVT, Load);
return N->getOperand(0);
// Check if all of the operands are undefs.
+ EVT VT = N->getValueType(0);
if (ISD::allOperandsUndef(N))
- return DAG.getUNDEF(N->getValueType(0));
+ return DAG.getUNDEF(VT);
+
+ // Optimize concat_vectors where one of the vectors is undef.
+ if (N->getNumOperands() == 2 &&
+ N->getOperand(1)->getOpcode() == ISD::UNDEF) {
+ SDValue In = N->getOperand(0);
+ assert(In.getValueType().isVector() && "Must concat vectors");
+
+ // Transform: concat_vectors(scalar, undef) -> scalar_to_vector(sclr).
+ if (In->getOpcode() == ISD::BITCAST &&
+ !In->getOperand(0)->getValueType(0).isVector()) {
+ SDValue Scalar = In->getOperand(0);
+ EVT SclTy = Scalar->getValueType(0);
+
+ if (!SclTy.isFloatingPoint() && !SclTy.isInteger())
+ return SDValue();
+
+ EVT NVT = EVT::getVectorVT(*DAG.getContext(), SclTy,
+ VT.getSizeInBits() / SclTy.getSizeInBits());
+ if (!TLI.isTypeLegal(NVT) || !TLI.isTypeLegal(Scalar.getValueType()))
+ return SDValue();
+
+ SDLoc dl = SDLoc(N);
+ SDValue Res = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, NVT, Scalar);
+ return DAG.getNode(ISD::BITCAST, dl, VT, Res);
+ }
+ }
// Type legalization of vectors and DAG canonicalization of SHUFFLE_VECTOR
// nodes often generate nop CONCAT_VECTOR nodes.
// (extract_subvec (concat V1, V2, ...), i)
// Into:
// Vi if possible
- // Only operand 0 is checked as 'concat' assumes all inputs of the same type.
+ // Only operand 0 is checked as 'concat' assumes all inputs of the same
+ // type.
if (V->getOperand(0).getValueType() != NVT)
return SDValue();
unsigned Idx = dyn_cast<ConstantSDNode>(N->getOperand(1))->getZExtValue();
for (unsigned i = 0; i != NumElts; ++i) {
int Idx = SVN->getMaskElt(i);
if (Idx >= 0) {
- if (Idx < (int)NumElts)
- Idx += NumElts;
- else
+ if (Idx >= (int)NumElts)
Idx -= NumElts;
+ else
+ Idx = -1; // remove reference to lhs
}
NewMask.push_back(Idx);
}
return SDValue();
}
+SDValue DAGCombiner::visitINSERT_SUBVECTOR(SDNode *N) {
+ SDValue N0 = N->getOperand(0);
+ SDValue N2 = N->getOperand(2);
+
+ // If the input vector is a concatenation, and the insert replaces
+ // one of the halves, we can optimize into a single concat_vectors.
+ if (N0.getOpcode() == ISD::CONCAT_VECTORS &&
+ N0->getNumOperands() == 2 && N2.getOpcode() == ISD::Constant) {
+ APInt InsIdx = cast<ConstantSDNode>(N2)->getAPIntValue();
+ EVT VT = N->getValueType(0);
+
+ // Lower half: fold (insert_subvector (concat_vectors X, Y), Z) ->
+ // (concat_vectors Z, Y)
+ if (InsIdx == 0)
+ return DAG.getNode(ISD::CONCAT_VECTORS, SDLoc(N), VT,
+ N->getOperand(1), N0.getOperand(1));
+
+ // Upper half: fold (insert_subvector (concat_vectors X, Y), Z) ->
+ // (concat_vectors X, Z)
+ if (InsIdx == VT.getVectorNumElements()/2)
+ return DAG.getNode(ISD::CONCAT_VECTORS, SDLoc(N), VT,
+ N0.getOperand(0), N->getOperand(1));
+ }
+
+ 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.
/// e.g. AND V, <0xffffffff, 0, 0xffffffff, 0>. ==>
// this operation.
if (LHS.getOpcode() == ISD::BUILD_VECTOR &&
RHS.getOpcode() == ISD::BUILD_VECTOR) {
+ // Check if both vectors are constants. If not bail out.
+ if (!(cast<BuildVectorSDNode>(LHS)->isConstant() &&
+ cast<BuildVectorSDNode>(RHS)->isConstant()))
+ return SDValue();
+
SmallVector<SDValue, 8> Ops;
for (unsigned i = 0, e = LHS.getNumOperands(); i != e; ++i) {
SDValue LHSOp = LHS.getOperand(i);
SDValue RHSOp = RHS.getOperand(i);
- // If these two elements can't be folded, bail out.
- if ((LHSOp.getOpcode() != ISD::UNDEF &&
- LHSOp.getOpcode() != ISD::Constant &&
- LHSOp.getOpcode() != ISD::ConstantFP) ||
- (RHSOp.getOpcode() != ISD::UNDEF &&
- RHSOp.getOpcode() != ISD::Constant &&
- RHSOp.getOpcode() != ISD::ConstantFP))
- break;
// Can't fold divide by zero.
if (N->getOpcode() == ISD::SDIV || N->getOpcode() == ISD::UDIV ||
if (LLD->getExtensionType() == ISD::NON_EXTLOAD) {
Load = DAG.getLoad(TheSelect->getValueType(0),
SDLoc(TheSelect),
- // FIXME: Discards pointer info.
+ // FIXME: Discards pointer and TBAA info.
LLD->getChain(), Addr, MachinePointerInfo(),
LLD->isVolatile(), LLD->isNonTemporal(),
LLD->isInvariant(), LLD->getAlignment());
RLD->getExtensionType() : LLD->getExtensionType(),
SDLoc(TheSelect),
TheSelect->getValueType(0),
- // FIXME: Discards pointer info.
+ // FIXME: Discards pointer and TBAA info.
LLD->getChain(), Addr, MachinePointerInfo(),
LLD->getMemoryVT(), LLD->isVolatile(),
LLD->isNonTemporal(), LLD->getAlignment());
SDValue CstOffset = DAG.getSelect(DL, Zero.getValueType(),
Cond, One, Zero);
AddToWorkList(CstOffset.getNode());
- CPIdx = DAG.getNode(ISD::ADD, DL, TLI.getPointerTy(), CPIdx,
+ CPIdx = DAG.getNode(ISD::ADD, DL, CPIdx.getValueType(), CPIdx,
CstOffset);
AddToWorkList(CPIdx.getNode());
return DAG.getLoad(TV->getValueType(0), DL, DAG.getEntryNode(), CPIdx,
return Temp;
// shl setcc result by log2 n2c
- return DAG.getNode(ISD::SHL, DL, N2.getValueType(), Temp,
- DAG.getConstant(N2C->getAPIntValue().logBase2(),
- getShiftAmountTy(Temp.getValueType())));
+ return DAG.getNode(
+ ISD::SHL, DL, N2.getValueType(), Temp,
+ DAG.getConstant(N2C->getAPIntValue().logBase2(),
+ getShiftAmountTy(Temp.getValueType())));
}
}
/// isAlias - Return true if there is any possibility that the two addresses
/// overlap.
-bool DAGCombiner::isAlias(SDValue Ptr1, int64_t Size1,
+bool DAGCombiner::isAlias(SDValue Ptr1, int64_t Size1, bool IsVolatile1,
const Value *SrcValue1, int SrcValueOffset1,
unsigned SrcValueAlign1,
const MDNode *TBAAInfo1,
- SDValue Ptr2, int64_t Size2,
+ SDValue Ptr2, int64_t Size2, bool IsVolatile2,
const Value *SrcValue2, int SrcValueOffset2,
unsigned SrcValueAlign2,
const MDNode *TBAAInfo2) const {
// If they are the same then they must be aliases.
if (Ptr1 == Ptr2) return true;
+ // If they are both volatile then they cannot be reordered.
+ if (IsVolatile1 && IsVolatile2) return true;
+
// Gather base node and offset information.
SDValue Base1, Base2;
int64_t Offset1, Offset2;
return false;
}
- if (CombinerGlobalAA) {
+ bool UseAA = CombinerGlobalAA.getNumOccurrences() > 0 ? CombinerGlobalAA :
+ TLI.getTargetMachine().getSubtarget<TargetSubtargetInfo>().useAA();
+#ifndef NDEBUG
+ if (CombinerAAOnlyFunc.getNumOccurrences() &&
+ CombinerAAOnlyFunc != DAG.getMachineFunction().getName())
+ UseAA = false;
+#endif
+ if (UseAA && SrcValue1 && SrcValue2) {
// Use alias analysis information.
int64_t MinOffset = std::min(SrcValueOffset1, SrcValueOffset2);
int64_t Overlap1 = Size1 + SrcValueOffset1 - MinOffset;
int64_t Overlap2 = Size2 + SrcValueOffset2 - MinOffset;
AliasAnalysis::AliasResult AAResult =
- AA.alias(AliasAnalysis::Location(SrcValue1, Overlap1, TBAAInfo1),
- AliasAnalysis::Location(SrcValue2, Overlap2, TBAAInfo2));
+ AA.alias(AliasAnalysis::Location(SrcValue1, Overlap1,
+ UseTBAA ? TBAAInfo1 : 0),
+ AliasAnalysis::Location(SrcValue2, Overlap2,
+ UseTBAA ? TBAAInfo2 : 0));
if (AAResult == AliasAnalysis::NoAlias)
return false;
}
bool DAGCombiner::isAlias(LSBaseSDNode *Op0, LSBaseSDNode *Op1) {
SDValue Ptr0, Ptr1;
int64_t Size0, Size1;
+ bool IsVolatile0, IsVolatile1;
const Value *SrcValue0, *SrcValue1;
int SrcValueOffset0, SrcValueOffset1;
unsigned SrcValueAlign0, SrcValueAlign1;
const MDNode *SrcTBAAInfo0, *SrcTBAAInfo1;
- FindAliasInfo(Op0, Ptr0, Size0, SrcValue0, SrcValueOffset0,
+ FindAliasInfo(Op0, Ptr0, Size0, IsVolatile0, SrcValue0, SrcValueOffset0,
SrcValueAlign0, SrcTBAAInfo0);
- FindAliasInfo(Op1, Ptr1, Size1, SrcValue1, SrcValueOffset1,
+ FindAliasInfo(Op1, Ptr1, Size1, IsVolatile1, SrcValue1, SrcValueOffset1,
SrcValueAlign1, SrcTBAAInfo1);
- return isAlias(Ptr0, Size0, SrcValue0, SrcValueOffset0,
+ return isAlias(Ptr0, Size0, IsVolatile0, SrcValue0, SrcValueOffset0,
SrcValueAlign0, SrcTBAAInfo0,
- Ptr1, Size1, SrcValue1, SrcValueOffset1,
+ Ptr1, Size1, IsVolatile1, SrcValue1, SrcValueOffset1,
SrcValueAlign1, SrcTBAAInfo1);
}
/// FindAliasInfo - Extracts the relevant alias information from the memory
-/// node. Returns true if the operand was a load.
+/// node. Returns true if the operand was a nonvolatile load.
bool DAGCombiner::FindAliasInfo(SDNode *N,
- SDValue &Ptr, int64_t &Size,
+ SDValue &Ptr, int64_t &Size, bool &IsVolatile,
const Value *&SrcValue,
int &SrcValueOffset,
unsigned &SrcValueAlign,
Ptr = LS->getBasePtr();
Size = LS->getMemoryVT().getSizeInBits() >> 3;
+ IsVolatile = LS->isVolatile();
SrcValue = LS->getSrcValue();
SrcValueOffset = LS->getSrcValueOffset();
SrcValueAlign = LS->getOriginalAlignment();
TBAAInfo = LS->getTBAAInfo();
- return isa<LoadSDNode>(LS);
+ return isa<LoadSDNode>(LS) && !IsVolatile;
}
/// GatherAllAliases - 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,
- SmallVector<SDValue, 8> &Aliases) {
+ SmallVectorImpl<SDValue> &Aliases) {
SmallVector<SDValue, 8> Chains; // List of chains to visit.
SmallPtrSet<SDNode *, 16> Visited; // Visited node set.
// Get alias information for node.
SDValue Ptr;
int64_t Size;
+ bool IsVolatile;
const Value *SrcValue;
int SrcValueOffset;
unsigned SrcValueAlign;
const MDNode *SrcTBAAInfo;
- bool IsLoad = FindAliasInfo(N, Ptr, Size, SrcValue, SrcValueOffset,
- SrcValueAlign, SrcTBAAInfo);
+ bool IsLoad = FindAliasInfo(N, Ptr, Size, IsVolatile, SrcValue,
+ SrcValueOffset, SrcValueAlign, SrcTBAAInfo);
// Starting off.
Chains.push_back(OriginalChain);
if (Depth > 6 || Aliases.size() == 2) {
Aliases.clear();
Aliases.push_back(OriginalChain);
- break;
+ return;
}
// Don't bother if we've been before.
// Get alias information for Chain.
SDValue OpPtr;
int64_t OpSize;
+ bool OpIsVolatile;
const Value *OpSrcValue;
int OpSrcValueOffset;
unsigned OpSrcValueAlign;
const MDNode *OpSrcTBAAInfo;
bool IsOpLoad = FindAliasInfo(Chain.getNode(), OpPtr, OpSize,
- OpSrcValue, OpSrcValueOffset,
+ OpIsVolatile, OpSrcValue, OpSrcValueOffset,
OpSrcValueAlign,
OpSrcTBAAInfo);
// If chain is alias then stop here.
if (!(IsLoad && IsOpLoad) &&
- isAlias(Ptr, Size, SrcValue, SrcValueOffset, SrcValueAlign,
- SrcTBAAInfo,
- OpPtr, OpSize, OpSrcValue, OpSrcValueOffset,
+ isAlias(Ptr, Size, IsVolatile, SrcValue, SrcValueOffset,
+ SrcValueAlign, SrcTBAAInfo,
+ OpPtr, OpSize, OpIsVolatile, OpSrcValue, OpSrcValueOffset,
OpSrcValueAlign, OpSrcTBAAInfo)) {
Aliases.push_back(Chain);
} else {
break;
}
}
+
+ // We need to be careful here to also search for aliases through the
+ // value operand of a store, etc. Consider the following situation:
+ // Token1 = ...
+ // L1 = load Token1, %52
+ // S1 = store Token1, L1, %51
+ // L2 = load Token1, %52+8
+ // S2 = store Token1, L2, %51+8
+ // Token2 = Token(S1, S2)
+ // L3 = load Token2, %53
+ // S3 = store Token2, L3, %52
+ // L4 = load Token2, %53+8
+ // S4 = store Token2, L4, %52+8
+ // If we search for aliases of S3 (which loads address %52), and we look
+ // only through the chain, then we'll miss the trivial dependence on L1
+ // (which also loads from %52). We then might change all loads and
+ // stores to use Token1 as their chain operand, which could result in
+ // copying %53 into %52 before copying %52 into %51 (which should
+ // happen first).
+ //
+ // The problem is, however, that searching for such data dependencies
+ // can become expensive, and the cost is not directly related to the
+ // chain depth. Instead, we'll rule out such configurations here by
+ // insisting that we've visited all chain users (except for users
+ // of the original chain, which is not necessary). When doing this,
+ // we need to look through nodes we don't care about (otherwise, things
+ // like register copies will interfere with trivial cases).
+
+ SmallVector<const SDNode *, 16> Worklist;
+ for (SmallPtrSet<SDNode *, 16>::iterator I = Visited.begin(),
+ IE = Visited.end(); I != IE; ++I)
+ if (*I != OriginalChain.getNode())
+ Worklist.push_back(*I);
+
+ while (!Worklist.empty()) {
+ const SDNode *M = Worklist.pop_back_val();
+
+ // We have already visited M, and want to make sure we've visited any uses
+ // of M that we care about. For uses that we've not visisted, and don't
+ // care about, queue them to the worklist.
+
+ 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 (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).
+ Aliases.clear();
+ Aliases.push_back(OriginalChain);
+ return;
+ }
+
+ // We've not visited this use, but we don't care about it. Mark it as
+ // visited and enqueue it to the worklist.
+ Worklist.push_back(*UI);
+ }
+ }
}
/// FindBetterChain - Walk up chain skipping non-aliasing memory nodes, looking
projects / oota-llvm.git / blobdiff