[FFmpeg-cvslog] r12188 - in trunk/libavcodec: armv4l/dsputil_iwmmxt.c dsputil.h i386/cputest.c i386/dsputil_mmx.c

Måns Rullgård mans
Sun Feb 24 20:55:10 CET 2008


Rich Felker <dalias at aerifal.cx> writes:

> On Sun, Feb 24, 2008 at 03:46:23PM +0100, reimar wrote:
>> Author: reimar
>> Date: Sun Feb 24 15:46:22 2008
>> New Revision: 12188
>> 
>> Log:
>> __asm __volatile -> asm volatile, improves code consistency and works
>> (as far as that is possible) with the Sun C compiler.
>
> Indeed, this is much saner. __asm is reserved for the implementation
> so using it is rather inadvisible.

There is nothing wrong with using a reserved identifier to invoke
implementation-specific functionality.  It is declaring things in the
reserved namespace that should never be done.

It is of course generally bad to rely on specific implementation
details, but when it comes to inline assembler, that is the only
option.

> asm is reserved for the application, so at worst, if the
> implementation doesn't support asm but does support __asm, then just
> use -Dasm=__asm and be happy. The other way around is not valid,
> though.

This is a good reason to use the _-less version.

-- 
M?ns Rullg?rd
mans at mansr.com




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