[PATCH] D139275: [SimplifyCFG] `FoldBranchToCommonDest()`: deal with mismatched IV's in PHI's in common successor block

Mon Jan 2 11:41:03 PST 2023

lebedev.ri added a comment.

In D139275#4022015 <https://reviews.llvm.org/D139275#4022015>, @apilipenko wrote:

> FYI, this change caused widespread performance regressions in our testing. We haven't investigated further since the change was reverted.

> I can re-run these tests and do some analysis on the next revision once you decide to reapply.

At this point this is waiting on @alexfh's reproducer mostly.
I'm not sure what sequence of events you have in mind,
but presumably it may be good to have an idea
about at least some of those regressions before this is relanded?

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D139275/new/

https://reviews.llvm.org/D139275