diff options
Diffstat (limited to 'llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp')
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp b/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp index f727eb0..1ba548b 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp @@ -2164,10 +2164,14 @@ Value *InstCombinerImpl::OptimizePointerDifference(Value *LHS, Value *RHS, // If this is a single inbounds GEP and the original sub was nuw, // then the final multiplication is also nuw. - if (auto *I = dyn_cast<Instruction>(Result)) + if (auto *I = dyn_cast<OverflowingBinaryOperator>(Result)) if (IsNUW && match(Offset2, m_Zero()) && Base.LHSNW.isInBounds() && - I->getOpcode() == Instruction::Mul) - I->setHasNoUnsignedWrap(); + (I->use_empty() || I->hasOneUse()) && I->hasNoSignedWrap() && + !I->hasNoUnsignedWrap() && + ((I->getOpcode() == Instruction::Mul && + match(I->getOperand(1), m_NonNegative())) || + I->getOpcode() == Instruction::Shl)) + cast<Instruction>(I)->setHasNoUnsignedWrap(); // If we have a 2nd GEP of the same base pointer, subtract the offsets. // If both GEPs are inbounds, then the subtract does not have signed overflow. |