diff --git a/llvm/include/llvm/Support/TypeSize.h b/llvm/include/llvm/Support/TypeSize.h
--- a/llvm/include/llvm/Support/TypeSize.h
+++ b/llvm/include/llvm/Support/TypeSize.h
@@ -79,6 +79,10 @@
     return {(unsigned)llvm::NextPowerOf2(Min), Scalable};
   }
 
+  bool isKnownMultipleOf(unsigned RHS) const {
+    return Min % RHS == 0;
+  }
+
   static ElementCount getFixed(unsigned Min) { return {Min, false}; }
   static ElementCount getScalable(unsigned Min) { return {Min, true}; }
   static ElementCount get(unsigned Min, bool Scalable) {
diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
--- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -20620,7 +20620,7 @@
       SDLoc DL(N);
       SDValue NewIdx;
       LLVMContext &Ctx = *DAG.getContext();
-      unsigned NumElts = VT.getVectorNumElements();
+      ElementCount NumElts = VT.getVectorElementCount();
       unsigned EltSizeInBits = VT.getScalarSizeInBits();
       if ((EltSizeInBits % N1SrcSVT.getSizeInBits()) == 0) {
         unsigned Scale = EltSizeInBits / N1SrcSVT.getSizeInBits();
@@ -20628,7 +20628,7 @@
         NewIdx = DAG.getVectorIdxConstant(InsIdx * Scale, DL);
       } else if ((N1SrcSVT.getSizeInBits() % EltSizeInBits) == 0) {
         unsigned Scale = N1SrcSVT.getSizeInBits() / EltSizeInBits;
-        if ((NumElts % Scale) == 0 && (InsIdx % Scale) == 0) {
+        if (NumElts.isKnownMultipleOf(Scale) && (InsIdx % Scale) == 0) {
           NewVT = EVT::getVectorVT(Ctx, N1SrcSVT, NumElts / Scale);
           NewIdx = DAG.getVectorIdxConstant(InsIdx / Scale, DL);
         }