[FFmpeg-devel] [PATCH] lavu/libm: add copysign hack

[Ganesh Ajjanagadde]

On Fri, Dec 18, 2015 at 12:41 PM, Ronald S. Bultje <rsbultje at gmail.com> wrote:
> Hi,
>
> On Fri, Dec 18, 2015 at 2:18 PM, Ganesh Ajjanagadde <gajjanagadde at gmail.com>
> wrote:
>>
>> For systems with broken libms.
>> Tested with NAN, -NAN, INFINITY, -INFINITY, +/-x for regular double x and
>> combinations of these.
>>
>> Signed-off-by: Ganesh Ajjanagadde <gajjanagadde at gmail.com>
>> ---
>>  configure        | 2 +-
>>  libavutil/libm.h | 9 +++++++++
>>  2 files changed, 10 insertions(+), 1 deletion(-)
>>
>> diff --git a/configure b/configure
>> index 123d1df..7917386 100755
>> --- a/configure
>> +++ b/configure
>> @@ -2852,7 +2852,7 @@ cropdetect_filter_deps="gpl"
>>  delogo_filter_deps="gpl"
>>  deshake_filter_select="pixelutils"
>>  drawtext_filter_deps="libfreetype"
>> -dynaudnorm_filter_deps="copysign erf"
>> +dynaudnorm_filter_deps="erf"
>>  ebur128_filter_deps="gpl"
>>  eq_filter_deps="gpl"
>>  fftfilt_filter_deps="avcodec"
>> diff --git a/libavutil/libm.h b/libavutil/libm.h
>> index 6d8bd68..637de19 100644
>> --- a/libavutil/libm.h
>> +++ b/libavutil/libm.h
>> @@ -62,6 +62,15 @@ static av_always_inline float cbrtf(float x)
>>  }
>>  #endif
>>
>> +#if !HAVE_COPYSIGN
>> +static av_always_inline double copysign(double x, double y)
>> +{
>> +    uint64_t vx = av_double2int(x);
>> +    uint64_t vy = av_double2int(y);
>> +    return av_int2double((vx & 0x7fffffffffffffff) | (vy &
>> 0x8000000000000000));
>> +}
>> +#endif
>
>
> Don't these need type suffixes (e.g. UINT64_C(val)) on some systems?

I believe not, see
http://en.cppreference.com/w/cpp/language/integer_literal and a long
discussion at libav-devel
https://lists.libav.org/pipermail/libav-devel/2015-October/072866.html
and related messages.

>
> Ronald