On 3/25/2016 4:55 PM, Ganesh Ajjanagadde wrote: > If anyone cares here, I do not know why we can't use inline asm or > intrinsics
With Inline asm and intrinsics you're 100% dependent on the compiler doing the right thing. The latter more so than the former. So a function compiled with gcc 4.9 might be faster or slower than the same function compiled with gcc 5.3, or msvc 2102, 2013, 2015, or icc, or clang, or even ancient gcc toolchains that somehow keep being used. Hand written asm guarantees the functions will perform exactly the same and as optimally as the developer can write it regardless of compiler, with the latter only handling things until the relevant function calls. Inline asm and intrinsics are only acceptable for simple functionality (single instructions or such) that actually make sense being inlined, like intmath and intreadwrite functions in libavutil. _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
