[FFmpeg-devel] [PATCH] avcodec/huffman: replace qsort with AV_QSORT

[Michael Niedermayer]

On Sat, Oct 24, 2015 at 09:05:21AM -0400, Ganesh Ajjanagadde wrote:
> On Thu, Oct 22, 2015 at 10:25 PM, Ganesh Ajjanagadde
> <gajjanagadde at gmail.com> wrote:
> >
> > On Thu, Oct 22, 2015 at 9:28 PM, Timothy Gu <timothygu99 at gmail.com> wrote:
> > > On Thu, Oct 22, 2015 at 5:01 PM Ganesh Ajjanagadde <gajjanagadde at gmail.com>
> > > wrote:
> > >>
> > >> Sample benchmark (x86-64, Haswell, GNU/Linux), fraps-v2 from FATE:
> > >> new:
> > >> 280110 decicycles in qsort,       1 runs,      0 skips
> > >> 268260 decicycles in qsort,       2 runs,      0 skips
> > >>
> > >> old:
> > >> 1469910 decicycles in qsort,       1 runs,      0 skips
> > >>  952950 decicycles in qsort,       2 runs,      0 skips
> > >
> > >
> > > Usually it takes more than 2 runs to make sure something is faster than the
> > > other (try -stream_loop 10000 on the input).
> >
> > In this case the gain should be obvious due to inlining. Nevertheless,
> > here are new numbers. I chose vp6 for two reasons:
> > 1. Above was for fraps-v2, giving vp6 for more "completeness".
> > 2. stream_loop throws errors: Error while decoding stream #0:0:
> > Invalid data found when processing input for fraps-v2.
> >
> > Here they are:
> > vp6 (old):
> >   78930 decicycles in qsort,       1 runs,      0 skips
> >   45330 decicycles in qsort,       2 runs,      0 skips
> >   27825 decicycles in qsort,       4 runs,      0 skips
> >   17471 decicycles in qsort,       8 runs,      0 skips
> >   12296 decicycles in qsort,      16 runs,      0 skips
> >    9554 decicycles in qsort,      32 runs,      0 skips
> >    8404 decicycles in qsort,      64 runs,      0 skips
> >    7405 decicycles in qsort,     128 runs,      0 skips
> >    6740 decicycles in qsort,     256 runs,      0 skips
> >    7540 decicycles in qsort,     512 runs,      0 skips
> >    9498 decicycles in qsort,    1024 runs,      0 skips
> >    9938 decicycles in qsort,    2048 runs,      0 skips
> >    8043 decicycles in qsort,    4095 runs,      1 skips
> >
> > vp6 (new):
> >   15880 decicycles in qsort,       1 runs,      0 skips
> >   10730 decicycles in qsort,       2 runs,      0 skips
> >   10155 decicycles in qsort,       4 runs,      0 skips
> >    7805 decicycles in qsort,       8 runs,      0 skips
> >    6883 decicycles in qsort,      16 runs,      0 skips
> >    6305 decicycles in qsort,      32 runs,      0 skips
> >    5854 decicycles in qsort,      64 runs,      0 skips
> >    5152 decicycles in qsort,     128 runs,      0 skips
> >    4452 decicycles in qsort,     256 runs,      0 skips
> >    4161 decicycles in qsort,     511 runs,      1 skips
> >    4081 decicycles in qsort,    1023 runs,      1 skips
> >    4072 decicycles in qsort,    2047 runs,      1 skips
> >    4004 decicycles in qsort,    4095 runs,      1 skips
> 
> ping

LGTM

thanks

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

While the State exists there can be no freedom; when there is freedom there
will be no State. -- Vladimir Lenin
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 181 bytes
Desc: Digital signature
URL: <http://ffmpeg.org/pipermail/ffmpeg-devel/attachments/20151025/8d822a73/attachment.sig>