1 files changed, 4 insertions, 0 deletions
diff --git a/llvm/lib/Analysis/InstructionSimplify.cpp b/llvm/lib/Analysis/InstructionSimplify.cpp
index 12a3193e6375..c4c174977c47 100644
--- a/llvm/lib/Analysis/InstructionSimplify.cpp
+++ b/llvm/lib/Analysis/InstructionSimplify.cpp
@@ -5181,6 +5181,10 @@ Value *llvm::simplifyInsertElementInst(Value *Vec, Value *Val, Value *Idx,
       (Q.isUndefValue(Val) && isGuaranteedNotToBePoison(Vec)))
     return Vec;
 
+  // Inserting the splatted value into a constant splat does nothing.
+  if (VecC && ValC && VecC->getSplatValue() == ValC)
+    return Vec;
+
   // If we are extracting a value from a vector, then inserting it into the same
   // place, that's the input vector:
   // insertelt Vec, (extractelt Vec, Idx), Idx --> Vec