Re: GCC/powerpc AltiVec expectations.

[Kumar Gala <kumar dot gala at motorola dot com>]

I am not sure if this is true on Mac OS X, but the Mac OS classic ABI 
allocates registers in numeric order if I remember correctly.  Therefor 
its much easier to use VRSAVE to know from (0 to N) are used and (N+1 to 
31) are not.  In a SVR4 ABI the allocation is not as straight forwarded 
and thus the OS has to look at each bit position of VRSAVE to determine 
what to save and restore.

- kumar

On Tuesday, July 2, 2002, at 12:46 PM, Alex Rosenberg wrote:


> on 7/2/02 10:32 AM, Aldy Hernandez at aldyh@redhat.com wrote:
>
> > On Tue, Jul 02, 2002 at 09:52:46AM -0700, Alex Rosenberg wrote:
> > > on 7/2/02 7:43 AM, Aldy Hernandez at aldyh@redhat.com wrote:
> > >
> > > > vrsave generation is on by default in gcc, though since the minority
> > > > OS need it, it should be switched to off.
> > > "Minority?"
> > linux doesn't need it.
> >
> > i believe macos x doesn't need it.
> Mac OS X requires it.
>
>
> on 7/2/02 10:36 AM, Matt Thomas at matt@3am-software.com wrote:
> > NetBSD won't need it either.  I assume OpenBSD/FreeBSD will just reuse
> > the NetBSD code so they probably won't either.
> I thought Matthew Green once mentioned VRSAVE support for NetBSD to me, 
> but
> I can't find a reference to that from the port-powerpc@netbsd.org list.
>
> +------------------------------------------------------------+
> | Alexander M. Rosenberg           <mailto:alexr@_spies.com> |
> | Nobody cares what I say. Remove the underscore to mail me. |