[all-commits] [llvm/llvm-project] 865c1f: [InstCombine] Preserve NSW flags for neg instructi...

[Yingwei Zheng via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 865c1fda6f3e258b47a4f7992bb19ca2e9edcfa1
      https://github.com/llvm/llvm-project/commit/865c1fda6f3e258b47a4f7992bb19ca2e9edcfa1
  Author: Yingwei Zheng <dtcxzyw2333 at gmail.com>
  Date:   2023-11-17 (Fri, 17 Nov 2023)

  Changed paths:
    M llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
    M llvm/test/Transforms/InstCombine/div.ll
    M llvm/test/Transforms/InstCombine/sdiv-exact-by-negative-power-of-two.ll

  Log Message:
  -----------
  [InstCombine] Preserve NSW flags for neg instructions (#72548)

Alive2: https://alive2.llvm.org/ce/z/F9HG3M

This missed optimization is discovered with the help of
https://github.com/AliveToolkit/alive2/pull/962.