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