diff options
Diffstat (limited to 'llvm/lib/Transforms/Utils/LoopUtils.cpp')
| -rw-r--r-- | llvm/lib/Transforms/Utils/LoopUtils.cpp | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/llvm/lib/Transforms/Utils/LoopUtils.cpp b/llvm/lib/Transforms/Utils/LoopUtils.cpp index b1d0c83..472be10 100644 --- a/llvm/lib/Transforms/Utils/LoopUtils.cpp +++ b/llvm/lib/Transforms/Utils/LoopUtils.cpp @@ -937,6 +937,11 @@ llvm::getShuffleReduction(IRBuilder<> &Builder, Value *Src, unsigned Op, } if (!RedOps.empty()) propagateIRFlags(TmpVec, RedOps); + + // We may compute the reassociated scalar ops in a way that does not + // preserve nsw/nuw etc. Conservatively, drop those flags. + if (auto *ReductionInst = dyn_cast<Instruction>(TmpVec)) + ReductionInst->dropPoisonGeneratingFlags(); } // The result is in the first element of the vector. return Builder.CreateExtractElement(TmpVec, Builder.getInt32(0)); |