[PATCH] D71826: [Coroutines] Remove corresponding phi values when apply simplifyTerminatorLeadingToRet

[JunMa via Phabricator via llvm-commits]

junparser created this revision.
junparser added reviewers: modocache, GorNishanov, lewissbaker.
Herald added subscribers: llvm-commits, jfb, dexonsmith, hiraditya, EricWF, mehdi_amini.
Herald added a project: LLVM.

In addMustTailToCoroResumes, we set musttail on those resume instructions that are followed by a ret instruction. This is done by simplifyTerminatorLeadingToRet which replace a sequence of branches leading to a ret with a clone of the ret.

However it forgets to remove corresponding PHI values that come from basic block of replaced branch, and may cause jumpthreading pass hangs (https://bugs.llvm.org/show_bug.cgi?id=43720)

This patch fix this issue

Test Plan:
cppcoro library with O3 <https://reviews.llvm.org/owners/package/3/>+flto
check-llvm


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D71826

Files:
  llvm/lib/Transforms/Coroutines/CoroSplit.cpp
  llvm/test/Transforms/Coroutines/coro-split-musttail1.ll

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