[all-commits] [llvm/llvm-project] 61820f: CodeGen: Optimize lowering of is.fpclass fcZero|fc...

[Matt Arsenault via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 61820f8b5dac779d136a342d22f5e66f99c7b648
      https://github.com/llvm/llvm-project/commit/61820f8b5dac779d136a342d22f5e66f99c7b648
  Author: Matt Arsenault <Matthew.Arsenault at amd.com>
  Date:   2023-07-06 (Thu, 06 Jul 2023)

  Changed paths:
    M llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
    M llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
    M llvm/test/CodeGen/AMDGPU/llvm.is.fpclass.f16.ll
    M llvm/test/CodeGen/X86/is_fpclass.ll

  Log Message:
  -----------
  CodeGen: Optimize lowering of is.fpclass fcZero|fcSubnormal

Combine the two checks into a check if the exponent bits are 0. The
inverted case isn't reachable until a future change, and GlobalISel
currently doesn't attempt the inversion optimization.

https://reviews.llvm.org/D143182