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

[Måns Rullgård]

Vitor Sessak <vitor1001 at gmail.com> writes:

> 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
> Index: configure
> ===================================================================
> --- configure	(revision 21124)
> +++ configure	(working copy)
> @@ -950,6 +950,7 @@
>      dos_paths
>      ebp_available
>      ebx_available
> +    exp2f
>      fast_64bit
>      fast_cmov
>      fast_unaligned
> @@ -965,6 +966,7 @@
>      libdc1394_2
>      llrint
>      log2
> +    log2f
>      loongson
>      lrint
>      lrintf
> @@ -2370,8 +2372,10 @@
>  check_lib math.h sin -lm
>  check_lib va/va.h vaInitialize -lva
>  
> +check_func exp2f
>  check_func llrint
>  check_func log2
> +check_func log2f
>  check_func lrint
>  check_func lrintf
>  check_func round

OK

> Index: libavutil/internal.h
> ===================================================================
> --- libavutil/internal.h	(revision 21124)
> +++ libavutil/internal.h	(working copy)
> @@ -263,6 +263,13 @@
>      }\
>  }
>  
> +#if !HAVE_EXP2F
> +static av_always_inline av_const float exp2f(float x)
> +{
> +    return exp2(x);
> +}
> +#endif /* HAVE_EXP2F */
> +
>  #if !HAVE_LLRINT
>  static av_always_inline av_const long long llrint(double x)
>  {
> @@ -277,6 +284,13 @@
>  }
>  #endif /* HAVE_LOG2 */
>  
> +#if !HAVE_LOG2F
> +static av_always_inline av_const float log2f(float x)
> +{
> +    return log2(x);
> +}
> +#endif /* HAVE_LOG2F */
> +
>  #if !HAVE_LRINT
>  static av_always_inline av_const long int lrint(double x)
>  {

Approved by Michael, and looks good to me.

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