[llvm] [VPlan] Unroll VPReplicateRecipe by VF. (PR #142433)

[Florian Hahn via llvm-commits]

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@@ -608,6 +608,32 @@ Value *VPInstruction::generate(VPTransformState &State) {
     return Builder.CreateVectorSplat(
         State.VF, State.get(getOperand(0), /*IsScalar*/ true), "broadcast");
   }
+  case VPInstruction::BuildStructVector: {
+    // For struct types, we need to build a new 'wide' struct type, where each
+    // element is widened, i.e. we crate a struct of vectors .
+    auto *StructTy =
+        cast<StructType>(State.TypeAnalysis.inferScalarType(getOperand(0)));
+    Value *Res = PoisonValue::get(toVectorizedTy(StructTy, State.VF));
+    for (const auto &[Idx, Op] : enumerate(operands())) {
+      for (unsigned I = 0; I != StructTy->getNumElements(); I++) {
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fhahn wrote:

Currently this matches the construction order as `packScalarIntoVectorizedValue`, would probably be good to only adjust once its last user has been removed.

Currently that's stil lin State.set, but will double-check if that code is actually used for struct types (only should be relevant for recipes in replicate regions)

https://github.com/llvm/llvm-project/pull/142433