[PATCH] Fix PR 47272 to restore Altivec vec_ld/vec_st

[Richard Guenther]

On Mon, 24 Jan 2011, Mark Mitchell wrote:

> On 1/24/2011 1:31 PM, Michael Meissner wrote:
> 
> > So after some debate within IBM, we've come to the conclusion that I should not
> > have changed the semantics of __builtin_vec_ld and __builtin_vec_st, and that
> > we should go back to using the Altivec form for these instructions
> 
> Can you explain why that's desirable?  I think that the first thing to
> do is to convince ourselves that's technically desirable; if we can't do
> that, then there's no need to think about whether to do it now or later.
> 
> My gut instinct is that having released 4.5, we should just live with
> the semantics we now have; we've broken compatibility with some Altivec
> code when compiled for Power 7, but breaking compatibility again seems
> like it will just confuse things worse.

I think we should revert to the pre-4.5 behavior and also fix 4.5.
Especially so if there are other compilers that follow the pre-4.5
behavior - are there?

Richard.

--
Richard Guenther <rguenther@suse.de>
Novell / SUSE Labs
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