[all-commits] [llvm/llvm-project] 8aedb4: [GlobalISel] Combine abs(undef) -> 0

[Jessica Paquette via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 8aedb435db7ef95ded4b68732ce96a5bf92cfd74
      https://github.com/llvm/llvm-project/commit/8aedb435db7ef95ded4b68732ce96a5bf92cfd74
  Author: Jessica Paquette <jpaquette at apple.com>
  Date:   2022-10-01 (Sat, 01 Oct 2022)

  Changed paths:
    M llvm/include/llvm/Target/GlobalISel/Combine.td
    A llvm/test/CodeGen/AArch64/GlobalISel/combine-unary-undef-to-zero.mir

  Log Message:
  -----------
  [GlobalISel] Combine abs(undef) -> 0

SDAG does this, GISel doesn't.

See https://gcc.godbolt.org/z/sqjMx3Tfv

More context:
https://github.com/llvm/llvm-project/issues/57256

Differential Revision: https://reviews.llvm.org/D135021