[llvm] [SLP] More OOP to simplify vectorizeStores() (NFC) (PR #134605)

[Alexey Bataev via llvm-commits]

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@@ -20358,12 +20364,54 @@ struct RelatedStoreInsts {
     return Inserted ? std::nullopt : std::optional<unsigned>(It->second);
   }
 
+  StoreInst &getBaseStore() const { return *AllStores[BaseInstrIdx]; }
+  using DistToInstMap = std::map<int, unsigned>;
+  const DistToInstMap &getStores() const { return Instrs; }
+
+  /// Recompute the pointer distances to be based on \p NewBaseInstIdx.
+  /// Stores whose index is less than \p MinSafeIdx will be dropped.
+  void rebase(unsigned MinSafeIdx, unsigned NewBaseInstIdx,
+              int DistFromCurBase) {
+    DistToInstMap PrevSet = std::move(Instrs);
+    reset(NewBaseInstIdx);
+
+    // Re-insert stores that come after MinSafeIdx to try and vectorize them
+    // again. Their distance will be "rebased" to use NewBaseInstIdx as
+    // reference.
+    for (auto [Dist, InstIdx] : PrevSet) {
+      if (InstIdx >= MinSafeIdx) {
+        insertOrLookup(InstIdx, Dist - DistFromCurBase);
+      }
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alexey-bataev wrote:

https://llvm.org/docs/CodingStandards.html#don-t-use-braces-on-simple-single-statement-bodies-of-if-else-loop-statements

https://github.com/llvm/llvm-project/pull/134605