[FFmpeg-devel] [PATCH] avutil/x86/intmath: remove inline asm implementations for clip functions

[Rémi Denis-Courmont]

Le 3 juin 2025 19:15:57 GMT+03:00, Niklas Haas <ffmpeg at haasn.xyz> a écrit :
>On Mon, 02 Jun 2025 15:41:33 -0300 James Almer <jamrial at gmail.com> wrote:
>> GCC/Clang is smart enough to emit minss/maxss the same way as these functions.
>> The only theoretical benefit was in x86_32, where x87 floats are used, but the
>> penalty of making the clipping opaque to the compiler's scheduler plus moving
>> values from mmx regs to xmm and back will offset any potential speedup.
>> x86_32 builds targetting anything made in the last two decades and a half
>> should use -msse -mfp=sse anyway.
>
>As mention in the another thread, x87 FPU usage causes non-bitexact results in
>swscale. Should we at this point consider setting -mfpu=sse by default for
>x86_32 builds?

As a general rule, I prefer to leave the choice of compiler flags to the distributor than to hard-code them in project specific build scripts.