[PATCH] D143417: [InstCombine] Add fold for `(rem (mul/shl X, Y), (mul/shl X, Z))` -> `(mul X, (rem Y, Z))`

[Noah Goldstein via Phabricator via llvm-commits]

goldstein.w.n created this revision.
Herald added a subscriber: hiraditya.
Herald added a project: All.
goldstein.w.n requested review of this revision.
Herald added a project: LLVM.
Herald added a subscriber: llvm-commits.

Forked from D142901 <https://reviews.llvm.org/D142901> to handle the `mul`/`shl` when `Y` and `Z` are
non-constant.

`(srem (mul/shl X, Y), (mul/shl X, Z))`

  [If `Y`/`Z` are one use]
      -> `(mul/shl nuw nsw X, (srem Y, Z))`
          - https://alive2.llvm.org/ce/z/ccTFj2
          - https://alive2.llvm.org/ce/z/i_UQ5A
      -> `(mul/shl nsw X, (srem Y, Z))`
          - https://alive2.llvm.org/ce/z/mQKc63
          - https://alive2.llvm.org/ce/z/uERkKH

`(urem (mul/shl X, Y), (mul/shl X, Z))`

  [If `Y`/`Z` are one use]
      -> `(mul/shl nuw nsw X, (srem Y, Z))`
          - https://alive2.llvm.org/ce/z/mNnQqJ
          - https://alive2.llvm.org/ce/z/Bj_DR-
          - https://alive2.llvm.org/ce/z/X6ZEtQ
      -> `(mul/shl nuw X, (srem Y, Z))`
          - https://alive2.llvm.org/ce/z/SJYtUV


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D143417

Files:
  llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
  llvm/test/Transforms/InstCombine/urem-mul.ll

-------------- next part --------------
A non-text attachment was scrubbed...
Name: D143417.495189.patch
Type: text/x-patch
Size: 9182 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20230206/956a644e/attachment.bin>