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

[Florian Hahn via llvm-commits]

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@@ -1307,6 +1313,9 @@ class VPInstruction : public VPRecipeWithIRFlags {
   bool isFPMathOp() const;
 #endif
 
+  /// Return the unroll part for this VPInstruction.
+  unsigned getUnrollPartOperand() const;
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fhahn wrote:

Ah I see. But almost all callers of `getUnrollPart` only need the `unsigned` value, so it seems more straightforward to retrieve the VPValue operand and extract the unsigned in one go? Changed back to `getUnrollPart()` for most cases, except `getLastUnrolledPartOperand` which returns a VPValue

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