[FFmpeg-cvslog] r16488 - in trunk: configure libavutil/mem.c

[ramiro]

Michael Niedermayer wrote:
> On Thu, Jan 08, 2009 at 07:40:18PM -0200, ramiro wrote:
>> Michael Niedermayer wrote:
>>> On Thu, Jan 08, 2009 at 09:34:06PM +0100, Vitor Sessak wrote:
>>>> ramiro wrote:
>>>>> Author: ramiro
>>>>> Date: Thu Jan  8 00:36:34 2009
>>>>> New Revision: 16488
>>>>>
>>>>> Log:
>>>>> Use posix_memalign() if available.
>>>> By looking at FATE, it looks like this change broke H264 decoding on gcc 
>>>> 2.95.3. See for example 
>>>> http://fate.multimedia.cx/index.php?test_result=6753660 .
>>> as far as i understand it fate didnt build 3 revissions and this one
>>> does not look like the most likely cause, 16490 looks more likely
>> I couldn't get a hold of gcc 2.95 to test, but this patch should fix it.
> 
> i seriously doubt this patch will fix it. The problem IIRC was that
> gcc 2.95 had some problem with alignment somewhere. gcc 2.95 should not
> have any problem with sse as such.

I finally got gcc 2.95 working. This patch really changes nothing.

So, what could be done here?
- check gcc version in configure and have sse depend on it
or
- #if defined(HAVE_SSE) && (!defined(__GNUC__) || __GNUC__ > 2)
or
- disable HAVE_SSE in some internal header based on __GNUC__

I'm slightly more in favor of configure, because then we can keep 
HAVE_SSE as the only basis to disable building SSE code in the future. 
This patch only disabled selecting it at run-time. The functions are 
still being built.

Ramiro Polla