[all-commits] [llvm/llvm-project] fe6893: Improve selection of conditional branch on amdgcn....

[Valery Pykhtin via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: fe6893b1d850795b386b0e5de6fdb3f6af31d87d
      https://github.com/llvm/llvm-project/commit/fe6893b1d850795b386b0e5de6fdb3f6af31d87d
  Author: Valery Pykhtin <valery.pykhtin at gmail.com>
  Date:   2023-11-06 (Mon, 06 Nov 2023)

  Changed paths:
    M llvm/lib/Target/AMDGPU/AMDGPUISelDAGToDAG.cpp
    M llvm/lib/Target/AMDGPU/SIISelLowering.cpp
    M llvm/lib/Target/AMDGPU/SIISelLowering.h
    M llvm/test/CodeGen/AMDGPU/GlobalISel/llvm.amdgcn.ballot.i32.ll
    M llvm/test/CodeGen/AMDGPU/GlobalISel/llvm.amdgcn.ballot.i64.ll
    M llvm/test/CodeGen/AMDGPU/llvm.amdgcn.ballot.i32.ll
    M llvm/test/CodeGen/AMDGPU/llvm.amdgcn.ballot.i64.ll

  Log Message:
  -----------
  Improve selection of conditional branch on amdgcn.ballot!=0 condition in SelectionDAG. (#68714)

Improve selection of the following pattern:

bool cnd = ...
if (amdgcn.ballot(cnd) != 0) {
  ...
}

which means "execute _then_ if any lane has satisfied the _cnd_
condition".