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Re: altivec triplets: comments?
On Wed, Nov 07, 2001 at 09:36:43PM -0500, Aldy Hernandez wrote:
> >>>>> "Geoff" == Geoff Keating <firstname.lastname@example.org> writes:
> > The other problems only happen if you have a call-saved altivec
> > register, or use them for argument passing. There's nothing that
> > prevents you from making all the altivec registers call-clobbered, and
> > prohibiting passing arguments in altivec registers, and then
> > everything should Just Work, although perhaps a little less efficiently.
> Vector registers are only used to hold arguments for -mabi=altivec,
> otherwise they go in the stack. Also, altivec registers are
> call-saved only for altivec abi. So theoretically it should just
Oh, I see that we actually already have 128-bit alignment for our
stack in SysV. I didn't know that.
Just to clarify my understanding - do the ABI changes include
anything that would disturb non-Altivec-aware assembly (such as the
stubs in glibc)? I suppose they could in the presence of
__attribute__((aligned)) and hard-coded structure offsets, but
hopefully we don't have that problem very often.
(Is -mabi=altivec orthogonal to -maltivec, or does it imply it?)
Daniel Jacobowitz Carnegie Mellon University
MontaVista Software Debian GNU/Linux Developer