[llvm] [VPlan] Use DL index type consistently for GEPs (PR #169396)

[Ramkumar Ramachandra via llvm-commits]

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@@ -2593,22 +2593,12 @@ void VPWidenGEPRecipe::printRecipe(raw_ostream &O, const Twine &Indent,
 }
 #endif
 
-static Type *getGEPIndexTy(bool IsScalable, bool IsReverse, bool IsUnitStride,
-                           unsigned CurrentPart, IRBuilderBase &Builder) {
-  // Use i32 for the gep index type when the value is constant,
-  // or query DataLayout for a more suitable index type otherwise.
-  const DataLayout &DL = Builder.GetInsertBlock()->getDataLayout();
-  return !IsUnitStride || (IsScalable && (IsReverse || CurrentPart > 0))
-             ? DL.getIndexType(Builder.getPtrTy(0))
-             : Builder.getInt32Ty();
-}
-
 void VPVectorEndPointerRecipe::execute(VPTransformState &State) {
   auto &Builder = State.Builder;
   unsigned CurrentPart = getUnrollPart(*this);
-  bool IsUnitStride = Stride == 1 || Stride == -1;
-  Type *IndexTy = getGEPIndexTy(State.VF.isScalable(), /*IsReverse*/ true,
-                                IsUnitStride, CurrentPart, Builder);
+  Value *Ptr = State.get(getOperand(0), VPLane(0));
+  const DataLayout &DL = Builder.GetInsertBlock()->getDataLayout();
+  Type *IndexTy = DL.getIndexType(Ptr->getType());
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artagnon wrote:

Not sure what you mean? The type inferrence will infer a pointer type for VPVector(End)Recipe, since it just has the pointer operand -- do you mean replacing `Ptr->getType()` with `VPTypeAnalysis(getParent()->getPlan()).inferScalarType(this)`, which would get the live-in IR value's type? Seems worse than using State.get to get the correct Value?

https://github.com/llvm/llvm-project/pull/169396