On Wed, Sep 2, 2015 at 5:17 PM, Michael Niedermayer <michae...@gmx.at> wrote: > From: Michael Niedermayer <mich...@niedermayer.cc> > > This function avoids the undefined corner cases which affects other absolute > value functions and macros
LGTM, except for the comment/commit message. This does not avoid all weird cases, see e.g https://stackoverflow.com/questions/202537/c-macro-question-x-vs-x but only the reasonable ones, roughly speaking where one does not do arithmetic expression inside the macro. Somewhere a note should ideally be made regarding this. Furthermore, the commit message ideally should say that this a macro, not a function to guard people against such abuse of it. > > Signed-off-by: Michael Niedermayer <mich...@niedermayer.cc> > --- > libavutil/common.h | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/libavutil/common.h b/libavutil/common.h > index 14343d9..89906be 100644 > --- a/libavutil/common.h > +++ b/libavutil/common.h > @@ -63,10 +63,14 @@ > * Absolute value, Note, INT_MIN / INT64_MIN result in undefined behavior as > they > * are not representable as absolute values of their type. This is the same > * as with *abs() > + * @see FFNABS() > */ > #define FFABS(a) ((a) >= 0 ? (a) : (-(a))) > #define FFSIGN(a) ((a) > 0 ? 1 : -1) > > +// Negative Absolute value, this works for all integers of all types > +#define FFNABS(a) ((a) <= 0 ? (a) : (-(a))) > + > #define FFMAX(a,b) ((a) > (b) ? (a) : (b)) > #define FFMAX3(a,b,c) FFMAX(FFMAX(a,b),c) > #define FFMIN(a,b) ((a) > (b) ? (b) : (a)) > -- > 1.7.9.5 > > _______________________________________________ > 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
