[PATCH] D29729: [InstCombine] don't lose nsw/nuw from add by converting to xor

[Sanjay Patel via Phabricator via llvm-commits]

spatel updated this revision to Diff 88197.
spatel added a comment.

Patch updated:
As suggested by Sanjoy, use 'or' rather than 'xor' when we have {nuw,nsw}. This allows the cmp tests to succeed.
There's a regression in the first add test because we don't recognize the larger pattern, but I've marked that with FIXME since this is still an overall improvement IMO.


https://reviews.llvm.org/D29729

Files:
  lib/Transforms/InstCombine/InstCombineAddSub.cpp
  test/Transforms/InstCombine/add.ll
  test/Transforms/InstCombine/icmp-add.ll

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