[PATCH] D138814: [InstCombine] Combine a/lshr of add -> uadd.with.overflow

[Pierre van Houtryve via Phabricator via llvm-commits]

Pierre-vh updated this revision to Diff 479537.
Pierre-vh marked 3 inline comments as done.
Pierre-vh added a comment.

- Add new tests (rebased)
- Fix the combine to check for the EXACT amount of leading zeroes to ensure the transform is correct. Otherwise, if there's too little/too many leading zeroes it could mean that the shift was checking something other than the OV bit, I think.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D138814/new/

https://reviews.llvm.org/D138814

Files:
  llvm/lib/Transforms/InstCombine/InstCombineInternal.h
  llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp
  llvm/test/Transforms/InstCombine/pr34349.ll
  llvm/test/Transforms/InstCombine/shift-add.ll

-------------- next part --------------
A non-text attachment was scrubbed...
Name: D138814.479537.patch
Type: text/x-patch
Size: 15267 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20221202/b6d6389f/attachment.bin>