[PATCH] D47408: [PM/LoopUnswitch] When using the new SimpleLoopUnswitch pass, schedule loop-cleanup passes at the beginning of the loop pass pipeline, and re-enqueue loops after even trivial unswitching.

[Fedor Sergeev via Phabricator via llvm-commits]

fedor.sergeev added inline comments.


================
Comment at: llvm/lib/Passes/PassBuilder.cpp:396-397
   // `SimplifyCFGPass` and `InstCombinePass` are used. We have
   // `LoopSimplifyCFGPass` which isn't yet powerful enough, and the closest to
   // the other we have is `LoopInstSimplify`.
   LoopPassManager LPM1(DebugLogging), LPM2(DebugLogging);
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chandlerc wrote:
> fedor.sergeev wrote:
> > Time to update the comment? :)
> No? I think this is still true. We still break it into two pipelines. I don't think LoopSimplifyCFG has had enough of SimplifyCFG ported to it to make it effective to re-merge the loop pipelines (yet).
It kind of leaves an impression of "either SimplifyCFG or LoopSimplifyCFG", while with this change it is both.

Perhaps:
"These can and should be *removed* (not replaced) as soon as their equivalents are ready as a full replacement"


Repository:
  rL LLVM

https://reviews.llvm.org/D47408