diff options
Diffstat (limited to 'contrib/llvm/lib/Transforms')
| -rw-r--r-- | contrib/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp | 25 |
1 files changed, 15 insertions, 10 deletions
diff --git a/contrib/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp b/contrib/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp index 8add1ea..60d672b 100644 --- a/contrib/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp +++ b/contrib/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp @@ -845,21 +845,26 @@ Value *InstCombiner::SimplifyDemandedUseBits(Value *V, APInt DemandedMask, Value *InstCombiner::SimplifyShrShlDemandedBits(Instruction *Shr, Instruction *Shl, APInt DemandedMask, APInt &KnownZero, APInt &KnownOne) { - unsigned ShlAmt = cast<ConstantInt>(Shl->getOperand(1))->getZExtValue(); - unsigned ShrAmt = cast<ConstantInt>(Shr->getOperand(1))->getZExtValue(); + const APInt &ShlOp1 = cast<ConstantInt>(Shl->getOperand(1))->getValue(); + const APInt &ShrOp1 = cast<ConstantInt>(Shr->getOperand(1))->getValue(); + if (!ShlOp1 || !ShrOp1) + return 0; // Noop. + + Value *VarX = Shr->getOperand(0); + Type *Ty = VarX->getType(); + unsigned BitWidth = Ty->getIntegerBitWidth(); + if (ShlOp1.uge(BitWidth) || ShrOp1.uge(BitWidth)) + return 0; // Undef. + + unsigned ShlAmt = ShlOp1.getZExtValue(); + unsigned ShrAmt = ShrOp1.getZExtValue(); KnownOne.clearAllBits(); KnownZero = APInt::getBitsSet(KnownZero.getBitWidth(), 0, ShlAmt-1); KnownZero &= DemandedMask; - if (ShlAmt == 0 || ShrAmt == 0) - return 0; - - Value *VarX = Shr->getOperand(0); - Type *Ty = VarX->getType(); - - APInt BitMask1(APInt::getAllOnesValue(Ty->getIntegerBitWidth())); - APInt BitMask2(APInt::getAllOnesValue(Ty->getIntegerBitWidth())); + APInt BitMask1(APInt::getAllOnesValue(BitWidth)); + APInt BitMask2(APInt::getAllOnesValue(BitWidth)); bool isLshr = (Shr->getOpcode() == Instruction::LShr); BitMask1 = isLshr ? (BitMask1.lshr(ShrAmt) << ShlAmt) : |
