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

[Vitor Sessak]

M?ns Rullg?rd wrote:
> Vitor Sessak <vitor1001 at gmail.com> writes:
> 
>> +#if !HAVE_LOG2F
>> +static av_always_inline av_const float log2f(float x)
>> +{
>> +    return log(x) * 1.44269504088896340736;
>> +}
>> +#endif /* HAVE_LOG2F */
> 
> Calling log2() should be better.  Most of the bad libs have a full set
> of double-precision functions.  It's the single-precision ones, which
> were added in C99 that are often missing.

Fine, even thought NetBSD lacks it (thats why we have a configure check 
for it, so no problem there).

>> +#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...

-Vitor
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