[FFmpeg-devel] [RFC] replace some static with asm_visibility or so

Uoti Urpala uoti.urpala
Sun Jan 27 18:21:40 CET 2008

On Sun, 2008-01-27 at 16:59 +0100, Michael Niedermayer wrote:
> seriously, IIRC ICC which this is about cant handle the gazillion asm
> arguments either, so irronically it could be that there is not a single
> case, not even obscure which would work any better afterwards

I tested the cleaned up version of cabac.h asm I posted earlier with ICC
and it did work (it had 4 array parameters in one asm block). I
successfully benchmarked decoding with MPlayer that had h264.c compiled
with ICC, asm enabled (rest of the code was still compiled with gcc). It
was faster than the gcc version at the time but by less than 10% IIRC.

> and compilation with gcc 2.95, 3.0, 3.1, ... would be totally broken.

Maybe but those are not too relevant (do you really know whether
something like 3.0 would work even now?). And asm changes would not
break anything "totally" in the sense that you could at least compile
without asm.

gcc 3.4 would be a somewhat interesting case to test.

> gcc 4.* and gcc svn might
> with some luck be able to compile the code as long as you dont try to use
> PIC on x86-32.

What current MANGLE does in that case is generate non-PIC code. If you
don't need it to be fully PIC you could just turn the PIC flag off for
the affected files.

> support and cause some minor speedloss with bad luck it wont work at all
> afterwards with any compiler

The cabac.h change I tested certainly did not make the code slower.

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