On Sun, Oct 11, 2015 at 9:12 PM, Ganesh Ajjanagadde <gajja...@mit.edu> wrote: > On Sun, Oct 11, 2015 at 6:04 PM, Ronald S. Bultje <rsbul...@gmail.com> wrote: >> Hi, >> >> On Sun, Oct 11, 2015 at 5:52 PM, Andreas Cadhalpun < >> andreas.cadhal...@googlemail.com> wrote: >> >>> On 11.10.2015 23:44, Ronald S. Bultje wrote: >>> > It's a non-installed header and only used in one place (flacenc). >>> > Since ff_ctz is static inline, it's fine to use that instead. >>> > --- >>> > doc/APIchanges | 3 --- >>> > libavcodec/flacenc.c | 2 +- >>> > libavutil/intmath.c | 5 ----- >>> > libavutil/intmath.h | 14 ++++++-------- >>> > 4 files changed, 7 insertions(+), 17 deletions(-) >>> >>> Should be fine. >> >> >> Thanks, pushed. > > Since there is still time, and I did not think of this before, I would > like to replace ff_ctz with ff_ctz32. There are a couple of reasons: > 1. It is used with an int32 argument in flacenc. > 2. I can do a deBruijn optimization for this as well. With an int also > I could do it, but it would need some ifdefry depending on whether int > is 32 bit or 64 bits. > > Let me see if I understand API/ABI with respect to this proposed > change correctly now: > API is not broken, as this is not public. > ABI is broken, since the width of operands to ff_ctz has could change > from 64 to 32 bits.
That actually raises the question of whether int = 32 bits is assumed everywhere. For instance, if int = 64 bits, at least on the Intel compiler, ff_ctz is broken: AFAIK, _bit_scan_forward operates on 32 bit operands. > >> >> Ronald >> _______________________________________________ >> 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
