On Wed, Nov 18, 2015 at 2:58 PM, Michael Niedermayer <michae...@gmx.at> wrote: > On Tue, Nov 17, 2015 at 04:54:10PM -0500, Ganesh Ajjanagadde wrote: >> isnan and isinf are actually macros as per the standard. In particular, >> the existing implementation has incorrect signature. Furthermore, this >> results in undefined behavior for e.g double values outside float range >> as per the standard. >> >> This patch corrects the undefined behavior for all usage within FFmpeg. >> >> Note that long double is not handled as it is not used in FFmpeg. >> Furthermore, even if at some point long double gets used, it is likely >> not needed to modify the macro in practice for usage in FFmpeg. See >> below for analysis. >> >> Getting long double to work strictly per the spec is significantly harder >> since a long double may be an IEEE 128 bit quad (very rare), 80 bit >> extended precision value (on GCC/Clang), or simply double (on recent >> Microsoft). >> On the other hand, any potential future usage of long double is likely >> for precision (when a platform offers extra precision) and not for range, >> since >> the range anyway varies and is not as portable as IEEE 754 single/double >> precision. In such cases, the implicit cast to a double is well defined >> and isinf and isnan should work as intended. >> >> Reviewed-by: Michael Niedermayer <mich...@niedermayer.cc> >> Signed-off-by: Ganesh Ajjanagadde <gajjanaga...@gmail.com> >> --- >> libavutil/libm.h | 34 ++++++++++++++++++++++++++++++++-- >> 1 file changed, 32 insertions(+), 2 deletions(-) > > probably ok > maybe wait a day or 2 before pushing so people can test it on more > obscure platforms > > thx
ok, will wait for 2 days for the hypot hack as well. Thanks. > > [...] > -- > Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB > > I do not agree with what you have to say, but I'll defend to the death your > right to say it. -- Voltaire > > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > http://ffmpeg.org/mailman/listinfo/ffmpeg-devel > _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
