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

[via llvm-commits]

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@@ -3145,6 +3167,8 @@ class VPlan {
   /// Represents the loop-invariant VF * UF of the vector loop region.
   VPValue VFxUF;
 
+  VPValue VF;
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ayalz wrote:

Outside users as in preheader should be able to retrieve it from the loop region.
If code is emitted to generate VF it should be placed carefully, in the preheader...

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