[llvm] [LV] Convert gather loads with invariant stride into strided loads (PR #147297)

[Mel Chen via llvm-commits]

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@@ -1805,6 +1802,29 @@ class LLVM_ABI_FOR_TEST VPWidenGEPRecipe : public VPRecipeWithIRFlags {
   /// This recipe generates a GEP instruction.
   unsigned getOpcode() const { return Instruction::GetElementPtr; }
 
+  bool isPointerLoopInvariant() const {
+    return getOperand(0)->isDefinedOutsideLoopRegions();
+  }
+
+  std::optional<unsigned> getUniqueVariantIndex() const {
+    std::optional<unsigned> VarIdx;
+    for (unsigned I = 0, E = getNumOperands() - 1; I < E; ++I) {
+      if (isIndexLoopInvariant(I))
+        continue;
+
+      if (VarIdx)
+        return std::nullopt;
+      VarIdx = I;
+    }
+    return VarIdx;
+  }
+
+  Type *getIndexedType(unsigned I) const {
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Mel-Chen wrote:

a3f18ae86936c2f422dac57501b5df332528593d

https://github.com/llvm/llvm-project/pull/147297