Re: [RFC PATCH 3/4] x86/asm: Make alternative macro interfaces more clear and consistent
From: Josh Poimboeuf
Date: Thu Aug 31 2017 - 13:31:39 EST
On Thu, Aug 31, 2017 at 12:25:42PM -0500, Josh Poimboeuf wrote:
> 2) Put "sp" in the clobbers list instead of as an i/o constraint. This
> mostly works for GCC, and doesn't break clang. However, it causes
> GCC to insert a "lea -0x10(%rbp),%rsp" in the epilogue of every
> affected function.
And maybe this extra instruction is negligible for performance and not a
big deal? I might look at this one after the holiday too.
--
Josh