[FFmpeg-devel] libavutil simd

Luca Barbato lu_zero
Mon Oct 1 14:31:13 CEST 2007

Michael Niedermayer wrote:
> and all who disagree with that please think a little, would you want libc
> to fork or install a sigill handlder when you call sqrt() printf() or any
> other simple function?
> and besides wanting or not do you think that if libc did that, it would work
> with no sideeffects?

What about having an av_check_cpu_features in which you check by ANY
means the features and sets accordingly the library functions/a flag
(pretty much as we generate tables and so on)?

> its dead simple a library cannot detect some things at runtime, detect it at
> compile time or leave it to the application
> you can provide some example code in the docs for applications if you like to
> or write libavtrash to contain such hacks with a big warning that
> detect_altivec() will install a sigill handler and or fork()

Fine, now, should we expose the function variants _{altivec,sse,foo} in
the api or just have the implementation switched somehow?



Luca Barbato

Gentoo/linux Gentoo/PPC

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