Using the stack from inline assembly

[Jeff Law]

On 12/13/2016 09:00 AM, Florian Weimer wrote:
> On 12/13/2016 04:56 PM, Jeff Law wrote:
>
>> It's probably wise to ensure the stack pointer keeps proper alignment
>> and such, but that's entirely within the asm itself.
>
> Right.  But I still need a way to express that the red zone is
> clobbered.  I just don't see *anything* that would allow me to express
> that.
>
>> No idea what's going on with Andrew's example, I haven't dug into it.
>
> Without optimization, GCC keeps a temporary in the red zone (%rbp is
> equal to %rsp), and the push/pop pair destroys that:
Good grief.  How lame (on GCC's part).   So with GCC using the red zone 
like this, then obviously you can't use push/pop like you want.

Jeff