[PATCH] D106041: [WIP][SimpleLoopUnswitch] Re-fix introduction of UB when hoisted condition may be undef or poison

[Roman Lebedev via Phabricator via llvm-commits]

lebedev.ri added a comment.

I'd need to see the test to guess where we need to add it.
Generally, simpleloopunswitch is only run once,
scheduled in `PassBuilder::buildFunctionSimplificationPipeline()` (line 761),

  LPM1.addPass(
      SimpleLoopUnswitchPass(/* NonTrivial */ Level == OptimizationLevel::O3 &&
                             EnableO3NonTrivialUnswitching));

While the very next simplifycfg (line 796) runs before the first instcombine run (line 797),
there's further simplifycfg run (line 858) that runs after instcombine.
So i'm not sure what's going on, and i won't be able to help without a test...


Repository:
  rG LLVM Github Monorepo

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https://reviews.llvm.org/D106041