[FFmpeg-devel] [PATCH] fix compilation in cygwin

[Vitor Sessak]

M?ns Rullg?rd wrote:
> Vitor Sessak <vitor1001 at gmail.com> writes:
> 
>> M?ns Rullg?rd wrote:
>>> Vitor Sessak <vitor1001 at gmail.com> writes:
>>>
>>>> M?ns Rullg?rd wrote:
>>>>> Vitor Sessak <vitor1001 at gmail.com> writes:
>>>>>
>>>>>> M?ns Rullg?rd wrote:
>>>>>>> Michael Kostylev <michael.kostylev at gmail.com> writes:
>>>>>>>
>>>>>>>> On Sun Jan 10 21:55:50 2010
>>>>>>>> Vitor Sessak wrote:
>>>>>>>>
>>>>>>>>>>> +#if !HAVE_EXP2F
>>>>>>>>>>> +static av_always_inline av_const float exp2f(float x)
>>>>>>>>>>> +{
>>>>>>>>>>> +    return exp(x) * 0.693147180559945;
>>>>>>>>>>> +}
>>>>>>>>>>> +#endif /* HAVE_EXP2F */
>>>>>>>>>> Same again.  exp2() should be preferred.
>>>>>>>>> Let's hope that at least exp2() is supported...
>>>>>>>> exp2() is missing in NetBSD and DragonFly.
>>>>>>> We have a replacement for it, so it's OK.
>>>>>> We have a replacement for log2(), but not for exp2().
>>>>>>
>>>>>> I'm slightly favorable of adding a replacement for exp2() (as
>>>>>> attached) as we do for log2(), since we can get some speed gain in
>>>>>> platforms where exp2() is supported and we'll eventually need exp2()
>>>>>> sooner or later.
>>>>>>
>>>>>> [...]
>>>>> Well, this caused things to break in new and interesting ways:
>>>>> libavutil/internal.h:275: error: static declaration of 'exp2f'
>>>>> follows non-static declaration
>>>>> libavutil/internal.h:296: error: static declaration of 'log2f' follows non-static declaration
>>>>> uClibc apparently has declarations for those functions, but no actual
>>>>> implementations.  This is truly the week of idiots.
>>>> BTW, wouldn't compilation fail if log2f() is a macro?
>>> No.  The functions are required to be available as actual functions,
>>> even if a macro is also defined.
>> What about if we define them as macros? Should work on any case.
>>
>> -Vitor
>> Index: libavutil/internal.h
>> ===================================================================
>> --- libavutil/internal.h	(revision 21155)
>> +++ libavutil/internal.h	(working copy)
>> @@ -264,17 +264,13 @@
>>  }
>>  
>>  #if !HAVE_EXP2
>> -static av_always_inline av_const double exp2(double x)
>> -{
>> -    return exp(x * 0.693147180559945);
>> -}
>> +#undef exp2
>> +#define exp2(x) exp((x) * 0.693147180559945)
>>  #endif /* HAVE_EXP2 */
>>  
>>  #if !HAVE_EXP2F
>> -static av_always_inline av_const float exp2f(float x)
>> -{
>> -    return exp2(x);
>> -}
>> +#undef exp2f
>> +#define exp2f(x) exp2(x)
>>  #endif /* HAVE_EXP2F */
>>  
>>  #if !HAVE_LLRINT
>> @@ -285,17 +281,13 @@
>>  #endif /* HAVE_LLRINT */
>>  
>>  #if !HAVE_LOG2
>> -static av_always_inline av_const double log2(double x)
>> -{
>> -    return log(x) * 1.44269504088896340736;
>> -}
>> +#undef log2
>> +#define log2(x) (log(x) * 1.44269504088896340736)
>>  #endif /* HAVE_LOG2 */
>>  
>>  #if !HAVE_LOG2F
>> -static av_always_inline av_const float log2f(float x)
>> -{
>> -    return log2(x);
>> -}
>> +#undef log2f
>> +#define log2f(x) log2(x)
>>  #endif /* HAVE_LOG2F */
>>  
>>  #if !HAVE_LRINT
> 
> Patch OK, I'm tired of having this broken.

Committed, let's hope FATE goes green.

-Vitor