Replace the #definition check with isa<>.

Author: Mel-Chen

llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp

@@ -1494,15 +1494,15 @@ bool VPlanTransforms::tryAddExplicitVectorLength(VPlan &Plan) {
       }
 
       if (NewRecipe) {
-        unsigned NumDefVal = NewRecipe->getNumDefinedValues();
+        [[maybe_unused]] unsigned NumDefVal = NewRecipe->getNumDefinedValues();
         assert(NumDefVal == CurRecipe->getNumDefinedValues() &&
                "New recipe must define the same number of values as the "
                "original.");
         assert(
             NumDefVal <= 1 &&
             "Only supports recipes with a single definition or without users.");
         NewRecipe->insertBefore(CurRecipe);
-        if (NumDefVal > 0) {
+        if (isa<VPSingleDefRecipe, VPWidenLoadEVLRecipe>(NewRecipe)) {
           VPValue *CurVPV = CurRecipe->getVPSingleValue();
           CurVPV->replaceAllUsesWith(NewRecipe->getVPSingleValue());
         }