[FFmpeg-cvslog] r14475 - trunk/libavutil/internal.h

[Reimar Döffinger]

On Wed, Jul 30, 2008 at 02:55:17PM +0100, M?ns Rullg?rd wrote:
> 
> Diego Biurrun wrote:
> > On Wed, Jul 30, 2008 at 01:14:06PM +0100, M?ns Rullg?rd wrote:
> >>
> >> diego wrote:
> >> >
> >> > Log:
> >> > USE_FASTMEMCPY is now called CONFIG_FASTMEMCPY in MPlayer.
> >> >
> >> > --- trunk/libavutil/internal.h	(original)
> >> > +++ trunk/libavutil/internal.h	Wed Jul 30 14:02:22 2008
> >> > @@ -106,7 +106,7 @@
> >> >
> >> > -#ifdef USE_FASTMEMCPY
> >> > +#ifdef CONFIG_FASTMEMCPY
> >> >  #    include "libvo/fastmemcpy.h"
> >> >  #    define memcpy(a,b,c) fast_memcpy(a,b,c)
> >> >  #endif
> >>
> >> What is this fast_memcpy anyway?  If it is useful, it should be in
> >> FFmpeg.  If not, this hack should go away.
> >
> > This was discussed before without resolution.  I would surely like to
> > resolve this now.  What do you propose?
> 
> I see two options:
> 
> 1. Move fast_memcpy(), whatever it does, to libavutil.
> 2. Delete this hack.

fast_memcpy is GPL, so that might complicate things a bit.
It will complicate things even more, since it will speed up some things
and slow down other things (esp. memcpy with constant size which is
replaced by a compiler builtin otherwise).
I once started to make fast_memcpy uses explicit in MPlayer where they
helped performance and get rid of it where it does not, but it is still
incomplete.

Greetings,
Reimar D?ffinger