[FFmpeg-devel] [PATCH 1/2] avcodec/x86: move simple_idct to external assembly

[Michael Niedermayer]

On Mon, May 29, 2017 at 09:40:49PM +0200, James Darnley wrote:
> On 2017-05-29 16:51, James Darnley wrote:
> > ---
> > Changes:
> >  - Changed type of d40000 constant to dwords because it gets used as dwords.
> >  - Changed or removed HAVE_MMX_INLINE preprocessor guards.
> >  - Added note about conversion from inline.
> >  - New file no longer has "2" suffix.
> >  - Whitespace (indentation and alignment).
> > 
> >  libavcodec/tests/x86/dct.c     |   2 +-
> >  libavcodec/x86/Makefile        |   4 +-
> >  libavcodec/x86/idctdsp_init.c  |   4 -
> >  libavcodec/x86/simple_idct.asm | 889 +++++++++++++++++++++++++++++++++++++++
> >  libavcodec/x86/simple_idct.c   | 929 -----------------------------------------
> >  5 files changed, 892 insertions(+), 936 deletions(-)
> >  create mode 100644 libavcodec/x86/simple_idct.asm
> >  delete mode 100644 libavcodec/x86/simple_idct.c
> 
> Ronald queried on IRC about the performance.  The libavcodec/tests/dct
> utility reports these numbers
> 
> Yorkfield:
>  - inline:   IDCT SIMPLE-MMX: 15715.9 kdct/s
>  - external: IDCT SIMPLE-MMX: 15699.9 kdct/s
> 
> Skylake-U:
>  - inline:   IDCT SIMPLE-MMX: 11193.3 kdct/s
>  - external: IDCT SIMPLE-MMX: 11189.7 kdct/s

Its better to benchmark by decoding some videos as the sparsness of
the coeffs affects speed

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

If you think the mosad wants you dead since a long time then you are either
wrong or dead since a long time.
-------------- 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/20170529/82086a07/attachment.sig>