Re: gcc 3.4 as default.
On Wednesday 07 July 2004 23:58, Claudio Martins wrote:
> On Wednesday 07 July 2004 23:22, Kurt Roeckx wrote:
> > Hi,
> >
> > I've been asked again if we want to use gcc 3.4 as default on
> > amd64 or stick with 3.3.
> >
> > The 3.3 version has some problems that are fixed in the 3.4
> > version. It should also generate faster code for us.
>
> Might this be the cause for certain applications like xine to take much
> more CPU on pure64 when playing mpeg streams (from a DVD, for example)?
>
> On this same machine (Athlon64 3400+), running debian i386, xine doesn't
> ususally show more than 1 or 2% CPU use on top. On pure64 it goes up to 30
> or 40%, despite the fact that it is using the same settings (XV hardware
> scalling) as debian i386.
I very much doubt it's the compiler.
You usually need to have crippled hardware too see that sort of CPU usage.
CDRom drives in PIO mode or not using XV hardware overlays are the usual
suspects.
It could be that i386 has hand-optimized mmx/sse assembly routines whereas
amd64 uses the generic C implementation. It still seems a big increase
though.
Paul
Reply to: