[llvm] [VPlan] Implement interleaving as VPlan-to-VPlan transform. (PR #95842)

[via llvm-commits]

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@@ -495,19 +495,18 @@ Value *VPInstruction::generatePerPart(VPTransformState &State, unsigned Part) {
 
     RecurKind RK = RdxDesc.getRecurrenceKind();
 
-    VPValue *LoopExitingDef = getOperand(1);
     Type *PhiTy = OrigPhi->getType();
-    VectorParts RdxParts(State.UF);
-    for (unsigned Part = 0; Part < State.UF; ++Part)
-      RdxParts[Part] = State.get(LoopExitingDef, Part, PhiR->isInLoop());
+    VectorParts RdxParts(NumParts);
+    for (unsigned Part = 0; Part != NumParts; ++Part)
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ayalz wrote:

```suggestion
    for (unsigned Part = 0; Part < NumParts; ++Part)
```
consistent w/ below?

https://github.com/llvm/llvm-project/pull/95842