[SLP][REVEC] Make vectorizeOperand support vector instructions.

Author: HanKuanChen

llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp

@@ -12212,7 +12212,8 @@ Value *BoUpSLP::vectorizeOperand(TreeEntry *E, unsigned NodeIdx,
         return ShuffleBuilder.finalize(std::nullopt);
       };
       Value *V = vectorizeTree(VE, PostponedPHIs);
-      if (VF != cast<FixedVectorType>(V->getType())->getNumElements()) {
+      if (VF * getNumElements(VL[0]->getType()) !=
+          cast<FixedVectorType>(V->getType())->getNumElements()) {
         if (!VE->ReuseShuffleIndices.empty()) {
           // Reshuffle to get only unique values.
           // If some of the scalars are duplicated in the vectorization