[PATCH] configure: win32 has 4 byte argument aligment, we have more

[Marcus Meissner]

On Sun, Apr 18, 2010 at 04:28:54PM -0600, Charles Davis wrote:
> On 4/18/10 4:17 PM, Marcus Meissner wrote:
> > Hi,
> > 
> > The Win32 ABI has its stack arguments aligned at 4 (2^2) bytes.
> > For MMX/SSE operations we however need to have the stack aligned
> > to 16 (2^4).
> > 
> > So specify this explicitly.
> > 
> > (This should probably be even part of attribute((stdcall)) perhaps
> >  in gcc. Not sure though.)
> From windef.h:
> 
> #   ifdef __APPLE__ /* Mac OS X uses a 16-byte aligned stack and not a
> 4-byte one */
> #    define __stdcall __attribute__((__stdcall__))
> __attribute__((__force_align_arg_pointer__))
> #   else
> #    define __stdcall __attribute__((__stdcall__))
> #   endif
> 
> Maybe then it's time we got rid of the #ifdef __APPLE__ block, then, and
> used the OS X definition everywhere? Or, we could use your switch, and
> that would obviate the need for __force_align_arg_pointer__ with gcc
> (but not clang, because it doesn't implement that switch yet).

Hmm. Sounds like an idea. I will test and send a patch.

Ciao, Marcus