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

[Michael Niedermayer]

Hi

On Tuesday 15 July 2003 10:51, Michael Niedermayer wrote:
> Hi
>
> On Tuesday 15 July 2003 04:29, Felix Buenemann wrote:
> > 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 =))
>
> hmm, probably they would have dissqualified us rather ...
>
> > (michael's code: Cycles: 7423830  1121.179)
> >
> > Btw. what algorithm are you implementing or did you invent it yourself?
>
> as arpi already said, the cheater method :)
ok, heres a serious try ...
PS: set DIM=528

[...]
-- 
Michael
level[i]= get_vlc(); i+=get_vlc();		(violates patent EP0266049)
median(mv[y-1][x], mv[y][x-1], mv[y+1][x+1]);	(violates patent #5,905,535)
buf[i]= qp - buf[i-1];				(violates patent #?)
for more examples, see http://mplayerhq.hu/~michael/patent.html
stop it, see http://petition.eurolinux.org & http://petition.ffii.org/eubsa/en
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