[PATCH] D122299: [InstCombine] Fix missing nsw flag when fold -(x-y) to y-x

[Roman Lebedev via Phabricator via llvm-commits]

lebedev.ri requested changes to this revision.
lebedev.ri added a comment.
This revision now requires changes to proceed.

Must we do this? I was really hoping we wouldn't.
Does this actually unblock some measurable improvement?

Consider: https://alive2.llvm.org/ce/z/XYfMSm
Both `sub`s have `NSW`, so i believe the code will now produce: https://alive2.llvm.org/ce/z/vUseE6


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D122299/new/

https://reviews.llvm.org/D122299