[PATCH] D15240: X86: Don't emit SAHF/LAHF for 64-bit targets unless explicitly supported

[Michael Hordijk via llvm-commits]

hoffbrinkle added a subscriber: hoffbrinkle.
hoffbrinkle added a comment.

@jfb, this brings back the issue we solved with http://reviews.llvm.org/D6629.  We can't issue PUSHFQ/POPFQ as the POPFQ can corrupt EFLAGS by loading a stale value.


Repository:
  rL LLVM

http://reviews.llvm.org/D15240