[MPlayer-dev-eng] [OT] C-code Optimiation Contest

Felix Buenemann atmosfear at users.sourceforge.net
Tue Jul 15 04:29:49 CEST 2003


On Tuesday 15 July 2003 03:35, Michael Niedermayer wrote:
> Hi
>
> On Tuesday 15 July 2003 02:12, Arpi wrote:
> > Hi,
> >
> > > if you like to have some fun, try optimizing the attached simple matrix
> > > multiply and post your results.
> > >
> > > The Rules:
> > > 1. you may only modify multiply_d.[ch] (NUM should stay 512 though)
> > > 2. you may change compiler and optims in Makefile
> > > 3. precision must stay the same
> > > 4. to compare, you should compile the orginal code:
> > >     make && copy matrix matrix.org && (./matrix.org >res.org)
> > > 5. then later you can compare results via:
> > >    make && (./matrix >res.txt) && diff -q res.org res.txt
> > >
> > > Have fun!
> > >
> > > Btw. current results by me is 738% of original speed, arpis results are
> > > even better, as he included my tips in his alredy optimized code =))))
> >
> > ok here is my (ok, our:)) contribution:
> >
> > to get best results (19.628 faster than original) set DIM to 516 in the
> > .h
>
> hmm, only ~20x faster ...
> i get ~1000x faster (see attached) :)))
>
> [...]
now you know why we needed you @ LinuxTag, we would have won all coding 
contests! (That means at least 4 Notebooks =))

(michael's code: Cycles: 7423830  1121.179)

Btw. what algorithm are you implementing or did you invent it yourself?
-- 
Best Regards,
        Atmos
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