Simply taking the Zbb REV8 instruction into use in a simple loop gives
some significant savings:
bswap_buf_c: 1081.0
bswap_buf_rvb_b: 771.0
But we can also use the 64-bit REV8 as a pseudo-SIMD instruction with
just one additional shift, and one fewer load, effectively doubling the
bandwidth. Consequently, this patch is useful even if the compile-time
target has Zbb enabled for C code:
bswap_buf_c: 1081.0
bswap_buf_rvb_b: 341.0 (this patch)
On the other hand, this approach fails miserably for bswap16_buf as the
ratio of shifts and stores becomes unfavorable compared to naïve C:
bswap16_buf_c: 1542.0
bswap16_buf_rvb_b: 1803.7
Unrolling to process 128 bits (4 samples) at a time actually worsens
performance ever so slightly:
bswap_buf_c: 1081.0
bswap_buf_rvb_b: 408.5
Passing an explicit filename to this command is only necessary if the
documentation in the @file block refers to a file different from the
one the block resides in.
Originally committed as revision 22921 to svn://svn.ffmpeg.org/ffmpeg/trunk
Otherwise doxygen complains about ambiguous filenames when files exist
under the same name in different subdirectories.
Originally committed as revision 16912 to svn://svn.ffmpeg.org/ffmpeg/trunk
Consistently apply this rule: the guard name is obtained from the
filename by stripping the leading "lib", converting '/' and '.' to
'_' and uppercasing the resulting name. Guard names in the root
directory have to be prefixed by "FFMPEG_".
Originally committed as revision 15120 to svn://svn.ffmpeg.org/ffmpeg/trunk
move it from sdp.c into utils.c. Also add new header internal.h specifically
for lavf-specific internal API. See discussion in "Realmedia patch" thread
on mailinglist.
Originally committed as revision 15002 to svn://svn.ffmpeg.org/ffmpeg/trunk
Log:
Add missing header #includes.
Policy violation (change not approved by maintainer)
and while discussions where ongoing and no consensus has been reached.
Originally committed as revision 14500 to svn://svn.ffmpeg.org/ffmpeg/trunk
Rémi Denis-Courmont
Timothy Gu
Diego Biurrun
Christophe Gisquet
Mans Rullgard
Stefano Sabatini
Ronald S. Bultje
Michael Niedermayer
Luca Abeni
Fabrice Bellard