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

[via llvm-commits]

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@@ -608,6 +608,35 @@ 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.
+    auto *StructTy =
+        cast<StructType>(State.TypeAnalysis.inferScalarType(getOperand(0)));
+    auto NumOfElements = ElementCount::getFixed(getNumOperands());
+    Value *Res = PoisonValue::get(toVectorizedTy(StructTy, NumOfElements));
+    assert(NumOfElements.getKnownMinValue() == StructTy->getNumElements() &&
+           "number of operands must match number of elements in StructTy");
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ayalz wrote:

By "number of elements in StructTy", does StructTy->getNumElements() refer to the number of fields in StructTy or the number of elements in each of these fields. Tests seem to have two fields and VF=2.

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