diff options
Diffstat (limited to 'llvm/lib')
| -rw-r--r-- | llvm/lib/IR/Instruction.cpp | 6 | ||||
| -rw-r--r-- | llvm/lib/Transforms/Vectorize/LoopVectorize.cpp | 6 |
2 files changed, 8 insertions, 4 deletions
diff --git a/llvm/lib/IR/Instruction.cpp b/llvm/lib/IR/Instruction.cpp index 000661073b1..3dd653d2d04 100644 --- a/llvm/lib/IR/Instruction.cpp +++ b/llvm/lib/IR/Instruction.cpp @@ -216,10 +216,10 @@ void Instruction::copyFastMathFlags(const Instruction *I) { copyFastMathFlags(I->getFastMathFlags()); } -void Instruction::copyIRFlags(const Value *V) { +void Instruction::copyIRFlags(const Value *V, bool IncludeWrapFlags) { // Copy the wrapping flags. - if (auto *OB = dyn_cast<OverflowingBinaryOperator>(V)) { - if (isa<OverflowingBinaryOperator>(this)) { + if (IncludeWrapFlags && isa<OverflowingBinaryOperator>(this)) { + if (auto *OB = dyn_cast<OverflowingBinaryOperator>(V)) { setHasNoSignedWrap(OB->hasNoSignedWrap()); setHasNoUnsignedWrap(OB->hasNoUnsignedWrap()); } diff --git a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp index 4040be10a14..1abdb248485 100644 --- a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp +++ b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp @@ -3814,7 +3814,11 @@ void InnerLoopVectorizer::truncateToMinimalBitwidths() { if (auto *BO = dyn_cast<BinaryOperator>(I)) { NewI = B.CreateBinOp(BO->getOpcode(), ShrinkOperand(BO->getOperand(0)), ShrinkOperand(BO->getOperand(1))); - cast<BinaryOperator>(NewI)->copyIRFlags(I); + + // Any wrapping introduced by shrinking this operation shouldn't be + // considered undefined behavior. So, we can't unconditionally copy + // arithmetic wrapping flags to NewI. + cast<BinaryOperator>(NewI)->copyIRFlags(I, /*IncludeWrapFlags=*/false); } else if (auto *CI = dyn_cast<ICmpInst>(I)) { NewI = B.CreateICmp(CI->getPredicate(), ShrinkOperand(CI->getOperand(0)), |
