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Re: mplayer



On Tue, Jul 15, 2003 at 06:17:37PM -0500, Billy Biggs wrote:
> Andrew Suffield (asuffield@debian.org):
> 
> > On Tue, Jul 15, 2003 at 11:59:19PM +0100, Andrew Suffield wrote:
> > > > That should avoid any speed penalties.
> > > 
> > > The mplayer developers needed run-time CPU detection to be slower than
> > > compile-time, so they implemented it in a broken fashion.
> > 
> > Oh, that or they're completely inept. I guess I should apply Hanlon's
> > razor here. But we're talking ineptitude on the scale you'd expect
> > from somebody who just started programming.
> 
>   Maybe you'd like to educate us on how to select optimized routines at
> runtime without penalties.  I know that in my application I have
> gratuitous use of function pointers to deal with this.  What do you
> recommend I do to avoid that penalty?

Same thing you do with every similar performance issue. Push it
outwards from the inner loop until it's no longer a problem.

This is really basic stuff...

Throw me some simple code and I'll demonstrate the transformation, but
when it comes to something like mplayer, I just don't care enough to
fix their braindamage. It's easier to use xine, which is faster anyway
on an SMP box (and some modern non-SMP boxes).

-- 
  .''`.  ** Debian GNU/Linux ** | Andrew Suffield
 : :' :  http://www.debian.org/ | Dept. of Computing,
 `. `'                          | Imperial College,
   `-             -><-          | London, UK

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