diff options
Diffstat (limited to 'llvm/lib/Transforms')
| -rw-r--r-- | llvm/lib/Transforms/Scalar/InstructionCombining.cpp | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/llvm/lib/Transforms/Scalar/InstructionCombining.cpp b/llvm/lib/Transforms/Scalar/InstructionCombining.cpp index 9b75ee13cb6..4247d8a6e29 100644 --- a/llvm/lib/Transforms/Scalar/InstructionCombining.cpp +++ b/llvm/lib/Transforms/Scalar/InstructionCombining.cpp @@ -939,20 +939,26 @@ bool InstCombiner::SimplifyDemandedBits(Value *V, uint64_t DemandedMask, // Compute the new bits that are at the top now. uint64_t HighBits = (1ULL << ShAmt)-1; HighBits <<= I->getType()->getPrimitiveSizeInBits() - ShAmt; - + uint64_t TypeMask = I->getType()->getIntegralTypeMask(); if (I->getType()->isUnsigned()) { // Unsigned shift right. - if (SimplifyDemandedBits(I->getOperand(0), DemandedMask << ShAmt, + if (SimplifyDemandedBits(I->getOperand(0), + (DemandedMask << ShAmt) & TypeMask, KnownZero, KnownOne, Depth+1)) return true; assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?"); + KnownZero &= TypeMask; + KnownOne &= TypeMask; KnownZero >>= ShAmt; KnownOne >>= ShAmt; KnownZero |= HighBits; // high bits known zero. } else { // Signed shift right. - if (SimplifyDemandedBits(I->getOperand(0), DemandedMask << ShAmt, + if (SimplifyDemandedBits(I->getOperand(0), + (DemandedMask << ShAmt) & TypeMask, KnownZero, KnownOne, Depth+1)) return true; assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?"); + KnownZero &= TypeMask; + KnownOne &= TypeMask; KnownZero >>= SA->getValue(); KnownOne >>= SA->getValue(); |
