[llvm] [LoopVectorize] Vectorize select-cmp reduction pattern for increasing integer induction variable (PR #67812)

[Mel Chen via llvm-commits]

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@@ -900,6 +993,11 @@ bool RecurrenceDescriptor::isReductionPHI(PHINode *Phi, Loop *TheLoop,
                       << *Phi << "\n");
     return true;
   }
+  if (AddReductionVar(Phi, RecurKind::IFindLastIV, TheLoop, FMF, RedDes, DB, AC,
----------------
Mel-Chen wrote:

Good question. We don't need to call `AddReductionVar` again for FFindLastIV.
This is because at the end of function `isFindLastIVPattern`, IFindLastIV can be transformed into FFindLastIV if the predicate is an fcmp instruction.

https://github.com/llvm/llvm-project/pull/67812