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

[Florian Hahn via llvm-commits]

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@@ -102,9 +102,7 @@ bool vputils::isUniformAcrossVFsAndUFs(VPValue *V) {
     return all_of(R->operands(), isUniformAcrossVFsAndUFs);
   }
 
-  auto *CanonicalIV = R->getParent()->getPlan()->getCanonicalIV();
-  // Canonical IV chain is uniform.
-  if (V == CanonicalIV || V == CanonicalIV->getBackedgeValue())
+  if (isa<VPRegionValue>(V))
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fhahn wrote:

This should probably be handled below, as VPInstruction BinaryOp with all operands inform across VFs and UFs. Will do separately.

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