[llvm] Re-land [Transform][LoadStoreVectorizer] allow redundant in Chain (PR #168135)

[Drew Kersnar via llvm-commits]

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@@ -626,26 +626,35 @@ std::vector<Chain> Vectorizer::splitChainByContiguity(Chain &C) {
   std::vector<Chain> Ret;
   Ret.push_back({C.front()});
 
+  unsigned ElemBytes = DL.getTypeStoreSize(getChainElemTy(C));
+  APInt PrevReadEnd = C[0].OffsetFromLeader +
+                      DL.getTypeStoreSize(getLoadStoreType(&*C[0].Inst));
   for (auto It = std::next(C.begin()), End = C.end(); It != End; ++It) {
     // `prev` accesses offsets [PrevDistFromBase, PrevReadEnd).
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dakersnar wrote:

nit: update comment

https://github.com/llvm/llvm-project/pull/168135