[llvm] [VPlan] Update scalar induction resume values in VPlan. (PR #110577)

[via llvm-commits]

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@@ -7808,6 +7813,27 @@ EpilogueVectorizerMainLoop::createEpilogueVectorizedLoopSkeleton(
   // the second pass for the scalar loop. The induction resume values for the
   // inductions in the epilogue loop are created before executing the plan for
   // the epilogue loop.
+  VPBasicBlock *ScalarPHVPBB = Plan.getScalarPreheader();
+  VPBuilder ScalarPHBuilder(ScalarPHVPBB, ScalarPHVPBB->begin());
+  for (VPRecipeBase &R :
+       Plan.getVectorLoopRegion()->getEntryBasicBlock()->phis()) {
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ayalz wrote:

Iterating over the IRI's of scalar header instead of the integer/fp induction header phi recipes of vector header, relieves the need for such a mapping - to find PhiR which wraps IndPhi (by searching thru the recipes of scalar header for each IndPhi), as in plural createInductionResumeValues()?

https://github.com/llvm/llvm-project/pull/110577