[PATCH] D128080: [SDAG] convert sub from (Pow2-1) constant into xor

[Amaury SECHET via Phabricator via llvm-commits]

deadalnix added a comment.

It doesn't looks like it is helping D127115 <https://reviews.llvm.org/D127115>, but it looks useful on its own.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D128080/new/

https://reviews.llvm.org/D128080