[all-commits] [llvm/llvm-project] 2c5d1b: [DAGCombiner] Reassociate the operands from (OR (O...

[Konstantina Mitropoulou via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 2c5d1b5ab7034be70eb3c6249b9a2fd512ffb658
      https://github.com/llvm/llvm-project/commit/2c5d1b5ab7034be70eb3c6249b9a2fd512ffb658
  Author: Konstantina Mitropoulou <Konstantina.Mitropoulou at amd.com>
  Date:   2023-08-08 (Tue, 08 Aug 2023)

  Changed paths:
    M llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
    M llvm/test/CodeGen/AMDGPU/combine_andor_with_cmps.ll
    M llvm/test/CodeGen/AMDGPU/wave32.ll
    M llvm/test/CodeGen/Hexagon/isel/logical.ll
    M llvm/test/CodeGen/X86/v8i1-masks.ll

  Log Message:
  -----------
  [DAGCombiner] Reassociate the operands from (OR (OR(CMP1, CMP2)), CMP3) to (OR (OR(CMP1, CMP3)), CMP2)

This happens when CMP1 and CMP3 have the same predicate (or CMP2 and CMP3 have
the same predicate).

This helps optimizations such as the fololowing one:
CMP(A,C)||CMP(B,C) => CMP(MIN/MAX(A,B), C)
CMP(A,C)&&CMP(B,C) => CMP(MIN/MAX(A,B), C)

Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D156215