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

[Ramiro Polla]

  wrote:
> ramiro <ramiro at lisha.ufsc.br> writes:
> 
>> Michael Niedermayer wrote:
>>> On Fri, Jan 09, 2009 at 03:35:52AM -0200, ramiro wrote:
>> [...]
>>>> 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.
>>> fine though you need approval from the configure maintainers for this
>> Patch attached.
>>
>> Ramiro Polla
>> Index: configure
>> ===================================================================
>> --- configure	(revision 16512)
>> +++ configure	(working copy)
>> @@ -1744,6 +1744,14 @@
>>      enabled ssse3 && check_asm ssse3 '"pabsw %xmm0, %xmm0"'
>>      enabled mmx2  && check_asm mmx2  '"movss %xmm0, %xmm0"'
>>  
>> +    if enabled sse; then
>> +        check_cpp <<EOF || die "This gcc version cannot compile SSE code properly, upgrade or use --disable-sse"
>> +#if defined(__GNUC__) && __GNUC__ < 2
>> +#error
>> +#endif
>> +EOF
>> +    fi
>> +
> 
> Rejected.  What is the purpose of that?  It's not even true.

The purpose is that a plain ./configure with gcc 2.95 should work or at 
least warn the user that he'll encounter problems with SSE code. It used 
to be silently disabled in cpuid.c, now it'll be explicit.

If the wording is wrong we can work on making it better.

Ramiro Polla