[Ffmpeg-devel] [PATCH] minor H.264 asm optimization

Trent Piepho xyzzy
Thu Feb 22 21:42:19 CET 2007


On Thu, 22 Feb 2007, Reimar [iso-8859-1] D?ffinger wrote:
> Hello,
> On Thu, Feb 22, 2007 at 11:16:27AM -0000, M?ns Rullg?rd wrote:
> > Reimar D?ffinger said:
> > > attached patch reduces code size quite a lot for me, since my gcc (4.1.2)
> > > stupidly does loop unrolling.
> > > Not that this was tested only quickly, only on AMD64 and not properly
> > > benchmarked.
> >
> > Loop unrolling sometimes makes code faster, sometimes not.  You really should
> > benchmark this.
>
> No question, though benchmarking only on my PC is not sufficient anyway.
> Problem with benchmarking is, I am too stupid to get
> START_TIMER/STOP_TIMER to print anything, at least when used within that
> code (and yes, the code is executed).

To get output from the timer functions, use -msglevel global=7

Just running three times isn't sufficient to tell anything.  It gives you
almost no idea of the level of error.  It's pretty much the same as
flipping a coin or just picking the one you thought would be faster before
you benchmarked.




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