[all-commits] [llvm/llvm-project] 55c6d9: [InstCombine] Preserve nuw/nsw/exact flags when tr...

[Craig Topper via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 55c6d9103444aaf70bf680c3768c14e8649bf580
      https://github.com/llvm/llvm-project/commit/55c6d9103444aaf70bf680c3768c14e8649bf580
  Author: Craig Topper <craig.topper at sifive.com>
  Date:   2024-01-26 (Fri, 26 Jan 2024)

  Changed paths:
    M llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp
    M llvm/test/Transforms/InstCombine/shift-add.ll

  Log Message:
  -----------
  [InstCombine] Preserve nuw/nsw/exact flags when transforming (C shift (A add nuw C1)) --> ((C shift C1) shift A). (#79490)

If we weren't shifting out any non-zero bits or changing the sign before the transform, we
shouldn't be after.

Alive2: https://alive2.llvm.org/ce/z/mB-rWz