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

[via llvm-commits]

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@@ -846,6 +850,7 @@ void VPlan::prepareToExecute(Value *TripCountV, Value *VectorTripCountV,
 /// Assumes a single pre-header basic-block was created for this. Introduce
 /// additional basic-blocks as needed, and fill them all.
 void VPlan::execute(VPTransformState *State) {
+  State->UF = 1;
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ayalz wrote:

A related thought: is InnerLoopUnroller still employed, when VF=1;UF>1, now that unrolling is implemented earlier in VPlan?

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