[llvm] [VPlan] Make canonical IV part of the region (PR #156262)

[Florian Hahn via llvm-commits]

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@@ -79,7 +79,7 @@ class UnrollState {
   void unrollBlock(VPBlockBase *VPB);
 
   VPValue *getValueForPart(VPValue *V, unsigned Part) {
-    if (Part == 0 || V->isLiveIn())
+    if (Part == 0 || V->isLiveIn() || isa<VPRegionValue>(V))
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fhahn wrote:

this is now a joint `isa<>`

https://github.com/llvm/llvm-project/pull/156262