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

Måns Rullgård mans
Tue Jan 12 13:58:31 CET 2010

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.

M?ns Rullg?rd
mans at mansr.com

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