[all-commits] [llvm/llvm-project] 9acc40: [InstCombine] Recognize more rotation patterns (#7...

[Yingwei Zheng via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 9acc4042300a92856527169b28c43cebf179d6d5
      https://github.com/llvm/llvm-project/commit/9acc4042300a92856527169b28c43cebf179d6d5
  Author: Yingwei Zheng <dtcxzyw2333 at gmail.com>
  Date:   2024-01-18 (Thu, 18 Jan 2024)

  Changed paths:
    M llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
    M llvm/test/Transforms/InstCombine/funnel.ll

  Log Message:
  -----------
  [InstCombine] Recognize more rotation patterns (#78107)

InstCombine already handles the pattern `(shl ShVal, (X & (Width - 1)))
| (lshr ShVal, ((-X) & (Width - 1)))`. Under certain circumstances, `X &
(Width - 1)` will be simplified to `X`. Therefore, this patch adds
support for the pattern `(shl ShVal, X) | (lshr ShVal, ((-X) & (Width -
1)))`.

Alive2: https://alive2.llvm.org/ce/z/P7JQ2V