[llvm] [LoadStoreVectorizer] Fix one-element vector handling (PR #169671)

[Drew Kersnar via llvm-commits]

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@@ -953,15 +953,15 @@ bool Vectorizer::vectorizeChain(Chain &C) {
       unsigned EOffset =
           (E.OffsetFromLeader - C[0].OffsetFromLeader).getZExtValue();
       unsigned VecIdx = 8 * EOffset / DL.getTypeSizeInBits(VecElemTy);
-      if (auto *VT = dyn_cast<FixedVectorType>(T)) {
+      if (VecTy == VecElemTy) {
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dakersnar wrote:

`VecElemTy` comes from `getChainElemTy` which has to return a scalar type, right? So for the special case we are handling here where NumElem == 1, VecElemTy and therefore VecTy should always be a scalar type.

https://github.com/llvm/llvm-project/pull/169671