[PATCH] D81728: [InstCombine] Add target-specific inst combining

[Sebastian Neubauer via Phabricator via llvm-commits]

Flakebi added a comment.

Summarizing the comments, the important points are

1. Everyone agrees on moving target specific stuff out of Transforms/InstCombine into target specific folders
2. Keep //running// the instruction combining in the InstCombine pass, so the fixed-point iteration works

The majority of target specific code is intrinsic combining, there is only one more amdgpu specific part in InstCombineSimplifyDemanded.cpp:SimplifyDemandedVectorElts. Unless someone has an idea on how to implement this in a more generic way, I’ll keep it like in the current diff, only combining intrinsics in `TargetTransformInfo::instCombineIntrinsic`.

> Actually implementing this would require us to export the InstCombiner class, which is part of InstCombineInternal.h. I don't think we would want to do this in its current form. This would require a larger refactoring to separate out the implementation and API portions of InstCombine.

Good point, I’ll try to add that here in the next week.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D81728/new/

https://reviews.llvm.org/D81728