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path: root/lib/Transforms/InstCombine/InstCombineCasts.cpp
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-rw-r--r--lib/Transforms/InstCombine/InstCombineCasts.cpp129
1 files changed, 52 insertions, 77 deletions
diff --git a/lib/Transforms/InstCombine/InstCombineCasts.cpp b/lib/Transforms/InstCombine/InstCombineCasts.cpp
index ff083d7..aba77bb 100644
--- a/lib/Transforms/InstCombine/InstCombineCasts.cpp
+++ b/lib/Transforms/InstCombine/InstCombineCasts.cpp
@@ -335,7 +335,8 @@ Instruction *InstCombiner::commonCastTransforms(CastInst &CI) {
///
/// This function works on both vectors and scalars.
///
-static bool CanEvaluateTruncated(Value *V, Type *Ty) {
+static bool CanEvaluateTruncated(Value *V, Type *Ty, InstCombiner &IC,
+ Instruction *CxtI) {
// We can always evaluate constants in another type.
if (isa<Constant>(V))
return true;
@@ -364,8 +365,8 @@ static bool CanEvaluateTruncated(Value *V, Type *Ty) {
case Instruction::Or:
case Instruction::Xor:
// These operators can all arbitrarily be extended or truncated.
- return CanEvaluateTruncated(I->getOperand(0), Ty) &&
- CanEvaluateTruncated(I->getOperand(1), Ty);
+ return CanEvaluateTruncated(I->getOperand(0), Ty, IC, CxtI) &&
+ CanEvaluateTruncated(I->getOperand(1), Ty, IC, CxtI);
case Instruction::UDiv:
case Instruction::URem: {
@@ -374,10 +375,10 @@ static bool CanEvaluateTruncated(Value *V, Type *Ty) {
uint32_t BitWidth = Ty->getScalarSizeInBits();
if (BitWidth < OrigBitWidth) {
APInt Mask = APInt::getHighBitsSet(OrigBitWidth, OrigBitWidth-BitWidth);
- if (MaskedValueIsZero(I->getOperand(0), Mask) &&
- MaskedValueIsZero(I->getOperand(1), Mask)) {
- return CanEvaluateTruncated(I->getOperand(0), Ty) &&
- CanEvaluateTruncated(I->getOperand(1), Ty);
+ if (IC.MaskedValueIsZero(I->getOperand(0), Mask, 0, CxtI) &&
+ IC.MaskedValueIsZero(I->getOperand(1), Mask, 0, CxtI)) {
+ return CanEvaluateTruncated(I->getOperand(0), Ty, IC, CxtI) &&
+ CanEvaluateTruncated(I->getOperand(1), Ty, IC, CxtI);
}
}
break;
@@ -388,7 +389,7 @@ static bool CanEvaluateTruncated(Value *V, Type *Ty) {
if (ConstantInt *CI = dyn_cast<ConstantInt>(I->getOperand(1))) {
uint32_t BitWidth = Ty->getScalarSizeInBits();
if (CI->getLimitedValue(BitWidth) < BitWidth)
- return CanEvaluateTruncated(I->getOperand(0), Ty);
+ return CanEvaluateTruncated(I->getOperand(0), Ty, IC, CxtI);
}
break;
case Instruction::LShr:
@@ -398,10 +399,10 @@ static bool CanEvaluateTruncated(Value *V, Type *Ty) {
if (ConstantInt *CI = dyn_cast<ConstantInt>(I->getOperand(1))) {
uint32_t OrigBitWidth = OrigTy->getScalarSizeInBits();
uint32_t BitWidth = Ty->getScalarSizeInBits();
- if (MaskedValueIsZero(I->getOperand(0),
- APInt::getHighBitsSet(OrigBitWidth, OrigBitWidth-BitWidth)) &&
+ if (IC.MaskedValueIsZero(I->getOperand(0),
+ APInt::getHighBitsSet(OrigBitWidth, OrigBitWidth-BitWidth), 0, CxtI) &&
CI->getLimitedValue(BitWidth) < BitWidth) {
- return CanEvaluateTruncated(I->getOperand(0), Ty);
+ return CanEvaluateTruncated(I->getOperand(0), Ty, IC, CxtI);
}
}
break;
@@ -415,8 +416,8 @@ static bool CanEvaluateTruncated(Value *V, Type *Ty) {
return true;
case Instruction::Select: {
SelectInst *SI = cast<SelectInst>(I);
- return CanEvaluateTruncated(SI->getTrueValue(), Ty) &&
- CanEvaluateTruncated(SI->getFalseValue(), Ty);
+ return CanEvaluateTruncated(SI->getTrueValue(), Ty, IC, CxtI) &&
+ CanEvaluateTruncated(SI->getFalseValue(), Ty, IC, CxtI);
}
case Instruction::PHI: {
// We can change a phi if we can change all operands. Note that we never
@@ -424,7 +425,7 @@ static bool CanEvaluateTruncated(Value *V, Type *Ty) {
// instructions with a single use.
PHINode *PN = cast<PHINode>(I);
for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i)
- if (!CanEvaluateTruncated(PN->getIncomingValue(i), Ty))
+ if (!CanEvaluateTruncated(PN->getIncomingValue(i), Ty, IC, CxtI))
return false;
return true;
}
@@ -453,7 +454,7 @@ Instruction *InstCombiner::visitTrunc(TruncInst &CI) {
// expression tree to something weird like i93 unless the source is also
// strange.
if ((DestTy->isVectorTy() || ShouldChangeType(SrcTy, DestTy)) &&
- CanEvaluateTruncated(Src, DestTy)) {
+ CanEvaluateTruncated(Src, DestTy, *this, &CI)) {
// If this cast is a truncate, evaluting in a different type always
// eliminates the cast, so it is always a win.
@@ -553,7 +554,7 @@ Instruction *InstCombiner::transformZExtICmp(ICmpInst *ICI, Instruction &CI,
// If Op1C some other power of two, convert:
uint32_t BitWidth = Op1C->getType()->getBitWidth();
APInt KnownZero(BitWidth, 0), KnownOne(BitWidth, 0);
- computeKnownBits(ICI->getOperand(0), KnownZero, KnownOne);
+ computeKnownBits(ICI->getOperand(0), KnownZero, KnownOne, 0, &CI);
APInt KnownZeroMask(~KnownZero);
if (KnownZeroMask.isPowerOf2()) { // Exactly 1 possible 1?
@@ -601,8 +602,8 @@ Instruction *InstCombiner::transformZExtICmp(ICmpInst *ICI, Instruction &CI,
APInt KnownZeroLHS(BitWidth, 0), KnownOneLHS(BitWidth, 0);
APInt KnownZeroRHS(BitWidth, 0), KnownOneRHS(BitWidth, 0);
- computeKnownBits(LHS, KnownZeroLHS, KnownOneLHS);
- computeKnownBits(RHS, KnownZeroRHS, KnownOneRHS);
+ computeKnownBits(LHS, KnownZeroLHS, KnownOneLHS, 0, &CI);
+ computeKnownBits(RHS, KnownZeroRHS, KnownOneRHS, 0, &CI);
if (KnownZeroLHS == KnownZeroRHS && KnownOneLHS == KnownOneRHS) {
APInt KnownBits = KnownZeroLHS | KnownOneLHS;
@@ -651,7 +652,8 @@ Instruction *InstCombiner::transformZExtICmp(ICmpInst *ICI, Instruction &CI,
/// clear the top bits anyway, doing this has no extra cost.
///
/// This function works on both vectors and scalars.
-static bool CanEvaluateZExtd(Value *V, Type *Ty, unsigned &BitsToClear) {
+static bool CanEvaluateZExtd(Value *V, Type *Ty, unsigned &BitsToClear,
+ InstCombiner &IC, Instruction *CxtI) {
BitsToClear = 0;
if (isa<Constant>(V))
return true;
@@ -680,8 +682,8 @@ static bool CanEvaluateZExtd(Value *V, Type *Ty, unsigned &BitsToClear) {
case Instruction::Add:
case Instruction::Sub:
case Instruction::Mul:
- if (!CanEvaluateZExtd(I->getOperand(0), Ty, BitsToClear) ||
- !CanEvaluateZExtd(I->getOperand(1), Ty, Tmp))
+ if (!CanEvaluateZExtd(I->getOperand(0), Ty, BitsToClear, IC, CxtI) ||
+ !CanEvaluateZExtd(I->getOperand(1), Ty, Tmp, IC, CxtI))
return false;
// These can all be promoted if neither operand has 'bits to clear'.
if (BitsToClear == 0 && Tmp == 0)
@@ -695,8 +697,9 @@ static bool CanEvaluateZExtd(Value *V, Type *Ty, unsigned &BitsToClear) {
// We use MaskedValueIsZero here for generality, but the case we care
// about the most is constant RHS.
unsigned VSize = V->getType()->getScalarSizeInBits();
- if (MaskedValueIsZero(I->getOperand(1),
- APInt::getHighBitsSet(VSize, BitsToClear)))
+ if (IC.MaskedValueIsZero(I->getOperand(1),
+ APInt::getHighBitsSet(VSize, BitsToClear),
+ 0, CxtI))
return true;
}
@@ -707,7 +710,7 @@ static bool CanEvaluateZExtd(Value *V, Type *Ty, unsigned &BitsToClear) {
// We can promote shl(x, cst) if we can promote x. Since shl overwrites the
// upper bits we can reduce BitsToClear by the shift amount.
if (ConstantInt *Amt = dyn_cast<ConstantInt>(I->getOperand(1))) {
- if (!CanEvaluateZExtd(I->getOperand(0), Ty, BitsToClear))
+ if (!CanEvaluateZExtd(I->getOperand(0), Ty, BitsToClear, IC, CxtI))
return false;
uint64_t ShiftAmt = Amt->getZExtValue();
BitsToClear = ShiftAmt < BitsToClear ? BitsToClear - ShiftAmt : 0;
@@ -718,7 +721,7 @@ static bool CanEvaluateZExtd(Value *V, Type *Ty, unsigned &BitsToClear) {
// We can promote lshr(x, cst) if we can promote x. This requires the
// ultimate 'and' to clear out the high zero bits we're clearing out though.
if (ConstantInt *Amt = dyn_cast<ConstantInt>(I->getOperand(1))) {
- if (!CanEvaluateZExtd(I->getOperand(0), Ty, BitsToClear))
+ if (!CanEvaluateZExtd(I->getOperand(0), Ty, BitsToClear, IC, CxtI))
return false;
BitsToClear += Amt->getZExtValue();
if (BitsToClear > V->getType()->getScalarSizeInBits())
@@ -728,8 +731,8 @@ static bool CanEvaluateZExtd(Value *V, Type *Ty, unsigned &BitsToClear) {
// Cannot promote variable LSHR.
return false;
case Instruction::Select:
- if (!CanEvaluateZExtd(I->getOperand(1), Ty, Tmp) ||
- !CanEvaluateZExtd(I->getOperand(2), Ty, BitsToClear) ||
+ if (!CanEvaluateZExtd(I->getOperand(1), Ty, Tmp, IC, CxtI) ||
+ !CanEvaluateZExtd(I->getOperand(2), Ty, BitsToClear, IC, CxtI) ||
// TODO: If important, we could handle the case when the BitsToClear are
// known zero in the disagreeing side.
Tmp != BitsToClear)
@@ -741,10 +744,10 @@ static bool CanEvaluateZExtd(Value *V, Type *Ty, unsigned &BitsToClear) {
// get into trouble with cyclic PHIs here because we only consider
// instructions with a single use.
PHINode *PN = cast<PHINode>(I);
- if (!CanEvaluateZExtd(PN->getIncomingValue(0), Ty, BitsToClear))
+ if (!CanEvaluateZExtd(PN->getIncomingValue(0), Ty, BitsToClear, IC, CxtI))
return false;
for (unsigned i = 1, e = PN->getNumIncomingValues(); i != e; ++i)
- if (!CanEvaluateZExtd(PN->getIncomingValue(i), Ty, Tmp) ||
+ if (!CanEvaluateZExtd(PN->getIncomingValue(i), Ty, Tmp, IC, CxtI) ||
// TODO: If important, we could handle the case when the BitsToClear
// are known zero in the disagreeing input.
Tmp != BitsToClear)
@@ -781,7 +784,7 @@ Instruction *InstCombiner::visitZExt(ZExtInst &CI) {
// strange.
unsigned BitsToClear;
if ((DestTy->isVectorTy() || ShouldChangeType(SrcTy, DestTy)) &&
- CanEvaluateZExtd(Src, DestTy, BitsToClear)) {
+ CanEvaluateZExtd(Src, DestTy, BitsToClear, *this, &CI)) {
assert(BitsToClear < SrcTy->getScalarSizeInBits() &&
"Unreasonable BitsToClear");
@@ -796,8 +799,10 @@ Instruction *InstCombiner::visitZExt(ZExtInst &CI) {
// If the high bits are already filled with zeros, just replace this
// cast with the result.
- if (MaskedValueIsZero(Res, APInt::getHighBitsSet(DestBitSize,
- DestBitSize-SrcBitsKept)))
+ if (MaskedValueIsZero(Res,
+ APInt::getHighBitsSet(DestBitSize,
+ DestBitSize-SrcBitsKept),
+ 0, &CI))
return ReplaceInstUsesWith(CI, Res);
// We need to emit an AND to clear the high bits.
@@ -895,6 +900,10 @@ Instruction *InstCombiner::transformSExtICmp(ICmpInst *ICI, Instruction &CI) {
Value *Op0 = ICI->getOperand(0), *Op1 = ICI->getOperand(1);
ICmpInst::Predicate Pred = ICI->getPredicate();
+ // Don't bother if Op1 isn't of vector or integer type.
+ if (!Op1->getType()->isIntOrIntVectorTy())
+ return nullptr;
+
if (Constant *Op1C = dyn_cast<Constant>(Op1)) {
// (x <s 0) ? -1 : 0 -> ashr x, 31 -> all ones if negative
// (x >s -1) ? -1 : 0 -> not (ashr x, 31) -> all ones if positive
@@ -921,7 +930,7 @@ Instruction *InstCombiner::transformSExtICmp(ICmpInst *ICI, Instruction &CI) {
ICI->isEquality() && (Op1C->isZero() || Op1C->getValue().isPowerOf2())){
unsigned BitWidth = Op1C->getType()->getBitWidth();
APInt KnownZero(BitWidth, 0), KnownOne(BitWidth, 0);
- computeKnownBits(Op0, KnownZero, KnownOne);
+ computeKnownBits(Op0, KnownZero, KnownOne, 0, &CI);
APInt KnownZeroMask(~KnownZero);
if (KnownZeroMask.isPowerOf2()) {
@@ -1072,7 +1081,7 @@ Instruction *InstCombiner::visitSExt(SExtInst &CI) {
// If the high bits are already filled with sign bit, just replace this
// cast with the result.
- if (ComputeNumSignBits(Res) > DestBitSize - SrcBitSize)
+ if (ComputeNumSignBits(Res, 0, &CI) > DestBitSize - SrcBitSize)
return ReplaceInstUsesWith(CI, Res);
// We need to emit a shl + ashr to do the sign extend.
@@ -1264,10 +1273,12 @@ Instruction *InstCombiner::visitFPTrunc(FPTruncInst &CI) {
LHSOrig = Builder->CreateFPExt(LHSOrig, RHSOrig->getType());
else if (RHSWidth <= SrcWidth)
RHSOrig = Builder->CreateFPExt(RHSOrig, LHSOrig->getType());
- Value *ExactResult = Builder->CreateFRem(LHSOrig, RHSOrig);
- if (Instruction *RI = dyn_cast<Instruction>(ExactResult))
- RI->copyFastMathFlags(OpI);
- return CastInst::CreateFPCast(ExactResult, CI.getType());
+ if (LHSOrig != OpI->getOperand(0) || RHSOrig != OpI->getOperand(1)) {
+ Value *ExactResult = Builder->CreateFRem(LHSOrig, RHSOrig);
+ if (Instruction *RI = dyn_cast<Instruction>(ExactResult))
+ RI->copyFastMathFlags(OpI);
+ return CastInst::CreateFPCast(ExactResult, CI.getType());
+ }
}
// (fptrunc (fneg x)) -> (fneg (fptrunc x))
@@ -1312,42 +1323,6 @@ Instruction *InstCombiner::visitFPTrunc(FPTruncInst &CI) {
}
}
- // Fold (fptrunc (sqrt (fpext x))) -> (sqrtf x)
- // Note that we restrict this transformation based on
- // TLI->has(LibFunc::sqrtf), even for the sqrt intrinsic, because
- // TLI->has(LibFunc::sqrtf) is sufficient to guarantee that the
- // single-precision intrinsic can be expanded in the backend.
- CallInst *Call = dyn_cast<CallInst>(CI.getOperand(0));
- if (Call && Call->getCalledFunction() && TLI->has(LibFunc::sqrtf) &&
- (Call->getCalledFunction()->getName() == TLI->getName(LibFunc::sqrt) ||
- Call->getCalledFunction()->getIntrinsicID() == Intrinsic::sqrt) &&
- Call->getNumArgOperands() == 1 &&
- Call->hasOneUse()) {
- CastInst *Arg = dyn_cast<CastInst>(Call->getArgOperand(0));
- if (Arg && Arg->getOpcode() == Instruction::FPExt &&
- CI.getType()->isFloatTy() &&
- Call->getType()->isDoubleTy() &&
- Arg->getType()->isDoubleTy() &&
- Arg->getOperand(0)->getType()->isFloatTy()) {
- Function *Callee = Call->getCalledFunction();
- Module *M = CI.getParent()->getParent()->getParent();
- Constant *SqrtfFunc = (Callee->getIntrinsicID() == Intrinsic::sqrt) ?
- Intrinsic::getDeclaration(M, Intrinsic::sqrt, Builder->getFloatTy()) :
- M->getOrInsertFunction("sqrtf", Callee->getAttributes(),
- Builder->getFloatTy(), Builder->getFloatTy(),
- NULL);
- CallInst *ret = CallInst::Create(SqrtfFunc, Arg->getOperand(0),
- "sqrtfcall");
- ret->setAttributes(Callee->getAttributes());
-
-
- // Remove the old Call. With -fmath-errno, it won't get marked readnone.
- ReplaceInstUsesWith(*Call, UndefValue::get(Call->getType()));
- EraseInstFromFunction(*Call);
- return ret;
- }
- }
-
return nullptr;
}
@@ -1909,9 +1884,9 @@ Instruction *InstCombiner::visitBitCast(BitCastInst &CI) {
}
Instruction *InstCombiner::visitAddrSpaceCast(AddrSpaceCastInst &CI) {
- // If the destination pointer element type is not the the same as the source's
- // do the addrspacecast to the same type, and then the bitcast in the new
- // address space. This allows the cast to be exposed to other transforms.
+ // If the destination pointer element type is not the same as the source's
+ // first do a bitcast to the destination type, and then the addrspacecast.
+ // This allows the cast to be exposed to other transforms.
Value *Src = CI.getOperand(0);
PointerType *SrcTy = cast<PointerType>(Src->getType()->getScalarType());
PointerType *DestTy = cast<PointerType>(CI.getType()->getScalarType());