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Re: altivec triplets: comments?
> Cc: Aldy Hernandez <firstname.lastname@example.org>, email@example.com
> From: Alexandre Oliva <firstname.lastname@example.org>
> Organization: GCC Team, Red Hat
> Date: 18 Nov 2001 09:56:35 -0200
> User-Agent: Gnus/5.0805 (Gnus v5.8.5) Emacs/20.7
> On Nov 7, 2001, Geoff Keating <email@example.com> wrote:
> > Daniel commented that
> >> For instance, there aren't triplets for every new MIPS
> >> processor supported by GCC
> > but actually, when we build a special version of Linux for some weird
> > MIPS ABI, a different triplet _is_ used. For instance,
> > mips-linux-gnu
> > mipsisa32-linux-gnu
> In this case, wouldn't it make sense for powerpc-linux-gnualtivec be
> spelled powerpcaltivec-linux-gnu? Otherwise, you wouldn't be able to
> do something like powerpc-linux-gnulibc2.2.
That means something different. The triplet we want isn't saying that
the processor has the altivec instructions, but that the libc has been
compiled for the altivec ABI.
> I don't like powerpcaltivec much, but I think it's better than
> gnualtivec, and, at least, there's more tradition to encode this kind
> of change in the machine type than in the kernel-OS type.
> powerpc-eabi* are more of an exception than a rule, IMO.
> > and in fact there are a bunch of triplets for particular MIPS
> > processors, although most of these don't change the ABI they just
> > change the ISA.
> Indeed. I don't recall any precedent to changing the triplet to
> accomodate an ABI change. Most often, trailing text has been added to
> indicate a change in object format, not ABI.
That's exactly what the '2.2' means in 'powerpc-linux-gnulibc2.2'; it
indicates an ABI change.
- Geoffrey Keating <firstname.lastname@example.org> <email@example.com>