On 03/09/14 3:38 AM, Pascal Massimino wrote: > Hi, > > > On Tue, Sep 2, 2014 at 10:26 PM, Reimar Döffinger <reimar.doeffin...@gmx.de> > wrote: > >> On 03.09.2014, at 00:49, Pascal Massimino <pascal.massim...@gmail.com> >> wrote: >>> On Tue, Sep 2, 2014 at 9:39 AM, Michael Niedermayer <michae...@gmx.at> >>> wrote: >>> >>> >>> [ahem: ffmpeg doesn't feel like using intrinsics, by chance?] >> >> I tried that about 5 months back, once more. >> It still results in code that is slower than the plain C version, even >> when using SIMD, on trivial NEON audio format conversion (same thing in asm >> was about 8x faster). >> So you can get the same effect with less effort by disabling just >> disabling asm code. >> > > strange. I exclusively used intrinsics for libwebp (x86, but also > neon/aarch64) and was pretty > pleased with the result (say <2% perf loss, but 10x easier maintenance and > friendliness to non-guru contributors). > Agreed, coding style is weird, with all these 'const __m128i var = ...', > but... > My 2c. > > /skal
Adding to Michael's reasons, there's also the fact you need to compile the files with instruction set specific flags, which would be a PITA to handle from the build system. GCC 4.8 and above added some features to work around this, but we support other compilers as well as older GCC versions. _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
