[SLP] NFC. ShuffleInstructionBuilder::add V1->getType() is always a FixedVectorType. (#99842)

castToScalarTyElem has a cast<VectorType>(V->getType()).

Author: HanKuanChen

llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp

@@ -12043,6 +12043,9 @@ class BoUpSLP::ShuffleInstructionBuilder final : public BaseShuffleAnalysis {
   /// Adds 2 input vectors and the mask for their shuffling.
   void add(Value *V1, Value *V2, ArrayRef<int> Mask) {
     assert(V1 && V2 && !Mask.empty() && "Expected non-empty input vectors.");
+    assert(isa<FixedVectorType>(V1->getType()) &&
+           isa<FixedVectorType>(V2->getType()) &&
+           "castToScalarTyElem expects V1 and V2 to be FixedVectorType");
     V1 = castToScalarTyElem(V1);
     V2 = castToScalarTyElem(V2);
     if (InVectors.empty()) {
@@ -12072,22 +12075,18 @@ class BoUpSLP::ShuffleInstructionBuilder final : public BaseShuffleAnalysis {
   }
   /// Adds another one input vector and the mask for the shuffling.
   void add(Value *V1, ArrayRef<int> Mask, bool = false) {
+    assert(isa<FixedVectorType>(V1->getType()) &&
+           "castToScalarTyElem expects V1 to be FixedVectorType");
     V1 = castToScalarTyElem(V1);
     if (InVectors.empty()) {
-      if (!isa<FixedVectorType>(V1->getType())) {
-        V1 = createShuffle(V1, nullptr, CommonMask);
-        CommonMask.assign(Mask.size(), PoisonMaskElem);
-        transformMaskAfterShuffle(CommonMask, Mask);
-      }
       InVectors.push_back(V1);
       CommonMask.assign(Mask.begin(), Mask.end());
       return;
     }
     const auto *It = find(InVectors, V1);
     if (It == InVectors.end()) {
       if (InVectors.size() == 2 ||
-          InVectors.front()->getType() != V1->getType() ||
-          !isa<FixedVectorType>(V1->getType())) {
+          InVectors.front()->getType() != V1->getType()) {
         Value *V = InVectors.front();
         if (InVectors.size() == 2) {
           V = createShuffle(InVectors.front(), InVectors.back(), CommonMask);
@@ -12121,9 +12120,7 @@ class BoUpSLP::ShuffleInstructionBuilder final : public BaseShuffleAnalysis {
           break;
         }
     }
-    int VF = CommonMask.size();
-    if (auto *FTy = dyn_cast<FixedVectorType>(V1->getType()))
-      VF = FTy->getNumElements();
+    int VF = cast<FixedVectorType>(V1->getType())->getNumElements();
     for (unsigned Idx = 0, Sz = CommonMask.size(); Idx < Sz; ++Idx)
       if (Mask[Idx] != PoisonMaskElem && CommonMask[Idx] == PoisonMaskElem)
         CommonMask[Idx] = Mask[Idx] + (It == InVectors.begin() ? 0 : VF);