Re: adding n32, n64 and o32-on-64-bit-kernel support to the mips port

[Alexandre Oliva <aoliva at redhat dot com>]

On Jan 17, 2003, Guido Guenther <agx@sigxcpu.org> wrote:

> a1, a2  don't need to be marked as clobbered when unused since the
> kernel restores them.

Even though the kernel currently preserves them, the information I got
from Ralf Baechle is that it could very well stop doing so.  There are
no guarantees about it, so we'd better not depend on that.  The 
registers that may be clobbered by a syscall are the same that may be
clobbered by a regular function call, except that the kernel won't
clobber floating-point registers, by design.

-- 
Alexandre Oliva   Enjoy Guarana', see http://www.ic.unicamp.br/~oliva/
Red Hat GCC Developer                 aoliva@{redhat.com, gcc.gnu.org}
CS PhD student at IC-Unicamp        oliva@{lsd.ic.unicamp.br, gnu.org}
Free Software Evangelist                Professional serial bug killer