[FFmpeg-devel] [PATCH] md5: optimize second round by using 4-operation form of G()

[Michael Niedermayer]

On Sun, May 19, 2013 at 12:11:51PM +0200, Giorgio Vazzana wrote:
> 2013/5/18 Giorgio Vazzana <mywing81 at gmail.com>:
> > Hello,
> >
> > here's another trick we could use to improve speed.
> > Nicolas, if you have time, could you run the benchmark again to see if
> > it's worth including this? Thanks.
> 
> Ok, here's some benchmark results (test based on Nicolas' code):
> 
> AMD Athlon(tm) II X3 450 Processor, x86_64
> 
> # without patch
> $ for i in $(seq 1 4); do ./avutil_md5_test2; done
> size: 1048576  runs: 1024  time:    5.821 +- 0.019
> size: 1048576  runs: 1024  time:    5.822 +- 0.019
> size: 1048576  runs: 1024  time:    5.841 +- 0.018
> size: 1048576  runs: 1024  time:    5.821 +- 0.018
> 
> # with patch
> $ for i in $(seq 1 4); do ./avutil_md5_test2; done
> size: 1048576  runs: 1024  time:    5.646 +- 0.019
> size: 1048576  runs: 1024  time:    5.646 +- 0.018
> size: 1048576  runs: 1024  time:    5.642 +- 0.019
> size: 1048576  runs: 1024  time:    5.641 +- 0.019

patch applied

thanks

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

During times of universal deceit, telling the truth becomes a
revolutionary act. -- George Orwell
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 198 bytes
Desc: Digital signature
URL: <http://ffmpeg.org/pipermail/ffmpeg-devel/attachments/20130520/ea10ba93/attachment.asc>