[FFmpeg-devel] gcc: Remove auto-vectorization limitation.

[Rémi Denis-Courmont]

Le 3 juin 2025 19:14:16 GMT+03:00, Niklas Haas <ffmpeg at haasn.xyz> a écrit :
>We have an open bug in swscale on 32-bit platforms where the use of x87 causes
>non-bitexact results in 32-bit platforms, resolved by setting -mfpu=sse at
>build time.
>
>Maybe we should think about setting this flag globally?

Enabling SSE is a separate discussion IMO. I suppose we could enable it on x86-32, but it should already be enabled on x86-64.

The problem with min/max has to do with NaN handling. If one of the two operands is NaN, FFMIN/FFMAX return the right hand side, whereas fminf/fmaxf return the number.

As long as we don't care about NaNs, we should allow whichever behaviour is most efficient on the architecture and that differs between x86, WASM, and the IEEE-style ones.