1 files changed, 6 insertions, 0 deletions
diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 535b272f793..50cad23a00a 100644
--- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -13572,6 +13572,12 @@ SDValue DAGCombiner::visitINSERT_VECTOR_ELT(SDNode *N) {
 
   EVT VT = InVec.getValueType();
 
+  // Remove redundant insertions:
+  // (insert_vector_elt x (extract_vector_elt x idx) idx) -> x
+  if (InVal.getOpcode() == ISD::EXTRACT_VECTOR_ELT &&
+      InVec == InVal->getOperand(0) && EltNo == InVal->getOperand(1))
+    return InVec;
+
   // Check that we know which element is being inserted
   if (!isa<ConstantSDNode>(EltNo))
     return SDValue();