[all-commits] [llvm/llvm-project] 99f8b7: [InstCombine] try to fold 'or' into 'mul' operand

RotateRight via All-commits all-commits at lists.llvm.org
Mon Nov 29 14:07:08 PST 2021

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 99f8b795cc03f9bcda7f9cbd9625c2976ae62bd5
  Author: Sanjay Patel <spatel at rotateright.com>
  Date:   2021-11-29 (Mon, 29 Nov 2021)

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

  Log Message:
  [InstCombine] try to fold 'or' into 'mul' operand

or (mul X, Y), X --> mul X, (add Y, 1) (when the multiply has no common bits with X)

We already have this fold if the pattern ends in 'add', but we can miss it if the
'add' becomes 'or' via another no-common-bits transform.

This is part of fixing:
...but it won't make a difference on that example yet.


Differential Revision: https://reviews.llvm.org/D114729

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