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

Måns Rullgård mans
Mon Jan 11 19:54:36 CET 2010


Michael Kostylev <michael.kostylev at gmail.com> writes:

> On Sun Jan 10 21:55:50 2010
> Vitor Sessak wrote:
>
>>>>+#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).
>
> Just for completeness:
>
>              log2 log2f exp2 exp2f
> FreeBSD      -    -     +    + 
> NetBSD       +    +     -    -
> DragonFly    +    +     -    -

Ah, so log and exp are mutually exclusive in bsd-land.  Who'd have
imagined _that_...

-- 
M?ns Rullg?rd
mans at mansr.com



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