[all-commits] [llvm/llvm-project] cf4315: [AArch64] Ensure condition (SUBS) has no uses of v...

[David Green via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: cf43154bc37540f32d0a345b7d5aa99d21f73cee
      https://github.com/llvm/llvm-project/commit/cf43154bc37540f32d0a345b7d5aa99d21f73cee
  Author: David Green <david.green at arm.com>
  Date:   2022-10-04 (Tue, 04 Oct 2022)

  Changed paths:
    M llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
    M llvm/test/CodeGen/AArch64/and-mask-removal.ll

  Log Message:
  -----------
  [AArch64] Ensure condition (SUBS) has no uses of value in performCONDCombine

performCONDCombine removes and 0xff in patterns of
SUBS (and (add(..), 0xff), C)
under certain complex conditions. It doesn't come up often,
but in the lowering of usub.sat where the SUBS is both used as a
condition and as a value, the And is removed where it would only be
valid for the condition.

Fixes #58109.

Differential Revision: https://reviews.llvm.org/D135043