[llvm] [SLPVectorizer] Widen strided loads. (PR #153074)

[Mikhail Gudim via llvm-commits]

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@@ -1918,6 +1918,21 @@ class BoUpSLP {
   class ShuffleCostEstimator;
   class ShuffleInstructionBuilder;
 
+  // If we decide to generate strided load / store, this struct contains all the
+  // necessary info. It's fields are calculated by analyzeRtStrideCandidate and
+  // analyzeConstantStrideCandidate. Note that Stride can be given either as a
+  // SCEV or as a Value if it already exists.
+  // To get the stride in bytes, StrideVal (or value obtained from StrideSCEV)
+  // has to by multiplied by the size of element of FixedVectorType.
+  struct StridedPtrInfo {
+    Value *StrideVal = nullptr;
+    const SCEV *StrideSCEV = nullptr;
+    // Represents the ammount which needs to be added to the base pointer of
+    // strided load.
+    FixedVectorType *Ty = nullptr;
+  };
+  DenseMap<TreeEntry *, StridedPtrInfo> TreeEntryToStridedPtrInfoMap;
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mgudim wrote:

By using the map we avoid adding extra field to each node.

https://github.com/llvm/llvm-project/pull/153074