1 files changed, 11 insertions, 0 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineNegator.cpp b/llvm/lib/Transforms/InstCombine/InstCombineNegator.cpp
index e4895b59f4b4..cb052da79bb3 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineNegator.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineNegator.cpp
@@ -334,6 +334,17 @@ std::array<Value *, 2> Negator::getSortedOperandsOfBinOp(Instruction *I) {
       NewSelect->swapValues();
       // Don't swap prof metadata, we didn't change the branch behavior.
       NewSelect->setName(I->getName() + ".neg");
+      // Poison-generating flags should be dropped
+      Value *TV = NewSelect->getTrueValue();
+      Value *FV = NewSelect->getFalseValue();
+      if (match(TV, m_Neg(m_Specific(FV))))
+        cast<Instruction>(TV)->dropPoisonGeneratingFlags();
+      else if (match(FV, m_Neg(m_Specific(TV))))
+        cast<Instruction>(FV)->dropPoisonGeneratingFlags();
+      else {
+        cast<Instruction>(TV)->dropPoisonGeneratingFlags();
+        cast<Instruction>(FV)->dropPoisonGeneratingFlags();
+      }
       Builder.Insert(NewSelect);
       return NewSelect;
     }