[PATCH] D96780: [NPM][LTO] Update buildLTODefaultPipeline to be more in-line with the old pass manager

Tue Feb 16 08:45:17 PST 2021

fhahn added a comment.

Thanks for putting up the patch! I am a bit surprised that all those optimizations were not run during LTO and that this did not pop up before the switch.

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Comment at: llvm/lib/Passes/PassBuilder.cpp:1740
   // Nuke dead stores.
   MainFPM.addPass(DSEPass());
+  // FIXME: once we provide support for enabling MLSM, add it here.
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It looks like there are a few other passes missing here, like `LoopDeletion` and `MergedLoadStoreMotionPass`, and conditionally `LoopInterchange`/`ConstraintElimination`. Should they be added as well? 

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Comment at: llvm/lib/Passes/PassBuilder.cpp:1767

   MainFPM.addPass(InstCombinePass());
   MainFPM.addPass(SimplifyCFGPass(SimplifyCFGOptions().hoistCommonInsts(true)));
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Should we run `WarnMissedTransformationsPass` here, like in the legacy PM?

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D96780/new/

https://reviews.llvm.org/D96780