[PATCH] D112840: [PassManager] `buildFunctionSimplificationPipeline()`: schedule another `LoopDeletion` pass run before last `LICM`

[Roman Lebedev via Phabricator via llvm-commits]

lebedev.ri added a comment.

In D112840#3097772 <https://reviews.llvm.org/D112840#3097772>, @aeubanks wrote:

> any numbers for actual performance gains? not sure that it's worth addressing some specifically bad code in a blog post for 0.5% compile time, but I'll run this patch on some internal benchmarks



> do you know after which pass the loop becomes deletable? presumably some pass between LPM2 and LPM3 causes the loop to be deletable since LPM2 contains a LoopDeletionPass

Answered inline.



================
Comment at: llvm/lib/Passes/PassBuilderPipelines.cpp:527
   // opportunities opened up by them.
   FPM.addPass(InstCombinePass());
   invokePeepholeEPCallbacks(FPM, Level);
----------------
> do you know after which pass the loop becomes deletable? presumably some pass between LPM2 and LPM3 causes the loop to be deletable since LPM2 contains a LoopDeletionPass

In that particular case after this one.


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https://reviews.llvm.org/D112840