[all-commits] [llvm/llvm-project] 712d35: GlobalISel: Fold some idempotent operations

[Matt Arsenault via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 712d35b417dd1beb373c51a9076db18811433d59
      https://github.com/llvm/llvm-project/commit/712d35b417dd1beb373c51a9076db18811433d59
  Author: Matt Arsenault <Matthew.Arsenault at amd.com>
  Date:   2022-11-16 (Wed, 16 Nov 2022)

  Changed paths:
    M llvm/include/llvm/Target/GlobalISel/Combine.td
    A llvm/test/CodeGen/AMDGPU/GlobalISel/postlegalizer-combiner-fcanonicalize.mir
    A llvm/test/CodeGen/AMDGPU/GlobalISel/postlegalizer-combiner-freeze.mir

  Log Message:
  -----------
  GlobalISel: Fold some idempotent operations

This makes the existing fabs_fabs fold redundant, which
I thought was using more tablegen matching, but apparently not.
I'm not sure how to make match work with multiple opcodes. There
are a few more this could handle, but these are the ones that
legalization are more likely to introduce.