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

[Maarten Lankhorst]

Hi Marcus,

2010/4/19 Marcus Meissner <meissner(a)suse.de>:
> 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.)
> Are you sure this is the case in win64 too? I'd assume that it would
> probably be 16 byte aligned there, since the first 4 arguments would
> be passed in registers and it could ensure stack alignment since they
> owned the abi from the start. If not it would definitely be 8.

Cheers,
Maarten

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

[Marcus Meissner]

On Mon, Apr 19, 2010 at 02:50:58PM +0200, Maarten Lankhorst wrote:
> Hi Marcus,
>
> 2010/4/19 Marcus Meissner <meissner(a)suse.de>:
> > 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.)
> > Are you sure this is the case in win64 too? I'd assume that it would
> > probably be 16 byte aligned there, since the first 4 arguments would
> > be passed in registers and it could ensure stack alignment since they
> > owned the abi from the start. If not it would definitely be 8.

No, not Win64. My bad.

My second patch would adjust only the __stdcall and __cdecl stuff 
on Win32, but ... see other mails.

Ciao, Marcus