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

[Michael Kostylev]

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    +    +     -    -
DJGPP        +    [1]   +    -

[1] provided as a macro which is buried under crappy ifdeferry.

Michael