PPC CFLAGS [Was: Re: rpms/openarena/devel openarena.spec, 1.1, 1.2]

[David Woodhouse]

On Fri, 2007-01-12 at 14:08 +0100, Axel Thimm wrote:
> What is the difference? If a unit has been compiled with altivec and
> the resulting binary calls something in this unit on a non-altivec
> system your binary will still boom, or not?
> 
> E.g. if we need to support non-altivec system then altivec must be
> strictly banned unless - as you wrote - the software is smart enough
> to do it at runtime (which is seldom).

Not _so_ seldom, in Altivec-capable code. Programs like xine and mplayer
get it right. There are parts which are compiled with -maltivec but
they're conditionally called.

> Are there relevant numbers of G3 systems out there that we want to
> support (excluding the unreleased G3+altivec chip)?

I don't know about G3 but there are relevant numbers of Altivec-less
systems out there, since that includes POWER -- and in particular a
bunch of our build machines.

Do not build packages which use Altivec unconditionally -- always make
it check at runtime, just as we do for MMX/SSE/etc. 

-- 
dwmw2