[FFmpeg-devel] [FFmpeg-cvslog] r11100 - in trunk/libavcodec/i386: cavsdsp_mmx.c dsputil_mmx.c dsputil_mmx.h h264dsp_mmx.c mpegvideo_mmx.c vc1dsp_mmx.c

[Uoti Urpala]

On Fri, 2007-11-30 at 21:11 +0100, Michael Niedermayer wrote:
> On Fri, Nov 30, 2007 at 07:04:42PM +0200, Uoti Urpala wrote:
> > Any linker stuff like (3) or (4) cannot give the full available
> speedup;
> 
> yes, but adding -Bsymbolic to ld is easy, getting the vissibility correct
> migh not be, i dunno, iam happy with a clean patch which fixes the vissibility
> of symbols to the minimum overrideable and vissible as well
> still i think (3) is simpler ...

Getting visibility correct is very straightforward and obvious if you do
it per symbol, but requires a code change for each symbol whose
visibility you want to change. Basically you'd have 'static' for things
visible only in the same translation unit, and 'FF_PRIVATE' (or some
better macro name) for things visible only in the same library. Pragmas
allow getting the result with much fewer code changes but result in less
obvious code.

-Bsymbolic is "simpler" of course but it does not achieve the same
things.