[all-commits] [llvm/llvm-project] 08f038: InstCombine: Fold and/or of fcmp into class

[Matt Arsenault via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 08f0388711e49de2af54746d2d764d128dace5ce
      https://github.com/llvm/llvm-project/commit/08f0388711e49de2af54746d2d764d128dace5ce
  Author: Matt Arsenault <Matthew.Arsenault at amd.com>
  Date:   2023-02-23 (Thu, 23 Feb 2023)

  Changed paths:
    M llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
    M llvm/test/Transforms/InstCombine/and-fcmp.ll
    M llvm/test/Transforms/InstCombine/create-class-from-logic-fcmp.ll

  Log Message:
  -----------
  InstCombine: Fold and/or of fcmp into class

This is motivated by patterns like !isfinite || zero. The AMDGPU math
libraries have a lot of patterns like this, and I'm trying to fix the
code to be more portable and less dependent on directly calling class
intrinsics.

I believe this is the first place where new is.fpclass calls are
introduced. There are more class-like compares that could be
recognized; this is a set I currently care about plus a few extras.

Keep the == 0 cases disabled for now. It depends on the denormal
mode. If we just check IEEE mode now, it will break my use case
without another patch I'm working on.