[PATCH] D58632: [X86] Improve lowering of idemptotent RMW operations

[Sam McCall via Phabricator via llvm-commits]

sammccall added a comment.

We've seen crashes bisected to this patch with `fatal error: error in backend: Cannot emit physreg copy instruction`.

I've only seen it with SLH so far. Will try to reduce a testcase, but I think we'll likely need to revert this revision.


Repository:
  rL LLVM

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D58632/new/

https://reviews.llvm.org/D58632