[all-commits] [llvm/llvm-project] 700791: [InstCombine] Add additional test for invert of ls...

[Nikita Popov via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 7007919cfde7c7515c0c2cc9b7d66616225d0b17
      https://github.com/llvm/llvm-project/commit/7007919cfde7c7515c0c2cc9b7d66616225d0b17
  Author: Nikita Popov <npopov at redhat.com>
  Date:   2023-12-01 (Fri, 01 Dec 2023)

  Changed paths:
    M llvm/test/Transforms/InstCombine/free-inversion.ll

  Log Message:
  -----------
  [InstCombine] Add additional test for invert of lshr (NFC)


  Commit: faebb1b2e6891687e4f608b74205985ec78ade40
      https://github.com/llvm/llvm-project/commit/faebb1b2e6891687e4f608b74205985ec78ade40
  Author: Nikita Popov <npopov at redhat.com>
  Date:   2023-12-01 (Fri, 01 Dec 2023)

  Changed paths:
    M llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
    M llvm/test/Transforms/InstCombine/free-inversion.ll

  Log Message:
  -----------
  Reapply [InstCombine] Support inverting lshr with non-negative operand

My initial patch contained a typo, resulting in the wrong value
being checked for non-negativeness.

-----

If the lshr operand is non-negative, we can treat it the same
way as an ashr. Ideally we would represent this as "lshr nneg",
but for now just perform the necessary ValueTracking query.

Proof: https://alive2.llvm.org/ce/z/Ahg4ri


Compare: https://github.com/llvm/llvm-project/compare/852f6be69679...faebb1b2e689