1 files changed, 7 insertions, 0 deletions
diff --git a/llvm/lib/Transforms/Utils/Local.cpp b/llvm/lib/Transforms/Utils/Local.cpp
index 69dcd30..fe1391a 100644
--- a/llvm/lib/Transforms/Utils/Local.cpp
+++ b/llvm/lib/Transforms/Utils/Local.cpp
@@ -4364,6 +4364,13 @@ bool llvm::inferAttributesFromOthers(Function &F) {
 }
 
 void OverflowTracking::mergeFlags(Instruction &I) {
+#ifndef NDEBUG
+  if (Opcode)
+    assert(Opcode == I.getOpcode() &&
+           "can only use mergeFlags on instructions with matching opcodes");
+  else
+    Opcode = I.getOpcode();
+#endif
   if (isa<OverflowingBinaryOperator>(&I)) {
     HasNUW &= I.hasNoUnsignedWrap();
     HasNSW &= I.hasNoSignedWrap();