[PATCH] D74446: AMDGPU/GlobalISel: Custom lower 32-bit G_UDIV/G_UREM

[Matt Arsenault via Phabricator via llvm-commits]

arsenm created this revision.
arsenm added reviewers: nhaehnle, kerbowa, foad, rampitec.
Herald added subscribers: Petar.Avramovic, hiraditya, t-tye, tpr, dstuttard, rovka, yaxunl, wdng, jvesely, kzhuravl.
Herald added a project: LLVM.

AMDGPUCodeGenPrepare expands this most of the time, but not always. We
will always at least need a fallback option here. This is the 3rd
implementation of the same expansion in the backend. Eventually I
would like to eliminate the IR expansion (and the DAG version
obviously).

      

Currently the new legalizer path produces a better result, since the
IR expansion results in extra operations which need to be combined
out. Notably, the IR expansion results in multiplies by 0.


https://reviews.llvm.org/D74446

Files:
  llvm/lib/Target/AMDGPU/AMDGPUGISel.td
  llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.cpp
  llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.h
  llvm/lib/Target/AMDGPU/AMDGPURegisterBankInfo.cpp
  llvm/lib/Target/AMDGPU/SIInstructions.td
  llvm/test/CodeGen/AMDGPU/GlobalISel/legalize-sdiv.mir
  llvm/test/CodeGen/AMDGPU/GlobalISel/legalize-srem.mir
  llvm/test/CodeGen/AMDGPU/GlobalISel/legalize-udiv.mir
  llvm/test/CodeGen/AMDGPU/GlobalISel/legalize-urem.mir
  llvm/test/CodeGen/AMDGPU/GlobalISel/udiv.i32.ll
  llvm/test/CodeGen/AMDGPU/GlobalISel/urem.i32.ll

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