[FFmpeg-devel] [PATCH] avutil: Move av_rint64_clip_* to internal.h

[Ganesh Ajjanagadde]

On Sat, Nov 14, 2015 at 9:49 PM, Michael Niedermayer
<michael at niedermayer.cc> wrote:
> On Sat, Nov 14, 2015 at 11:01:55PM -0300, James Almer wrote:
>> On 11/14/2015 10:48 PM, Michael Niedermayer wrote:
>> > From: Michael Niedermayer <michael at niedermayer.cc>
>> >
>> > This should avoid build failures on VS2012
>> > Feel free to changes this to a different solution
>> >
>> > Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
>> > ---
>> >  libavutil/common.h   |   39 ---------------------------------------
>> >  libavutil/internal.h |   40 ++++++++++++++++++++++++++++++++++++++++
>> >  2 files changed, 40 insertions(+), 39 deletions(-)
>> >
>> > diff --git a/libavutil/common.h b/libavutil/common.h
>> > index 813fb37..6f0f582 100644
>> > --- a/libavutil/common.h
>> > +++ b/libavutil/common.h
>> > @@ -298,42 +298,6 @@ static av_always_inline av_const double av_clipd_c(double a, double amin, double
>> >      else               return a;
>> >  }
>> >
>> > -/**
>> > - * Clip and convert a double value into the long long amin-amax range.
>> > - * This function is needed because conversion of floating point to integers when
>> > - * it does not fit in the integer's representation does not necessarily saturate
>> > - * correctly (usually converted to a cvttsd2si on x86) which saturates numbers
>> > - * > INT64_MAX to INT64_MIN. The standard marks such conversions as undefined
>> > - * behavior, allowing this sort of mathematically bogus conversions. This provides
>> > - * a safe alternative that is slower obviously but assures safety and better
>> > - * mathematical behavior.
>> > - * @param a value to clip
>> > - * @param amin minimum value of the clip range
>> > - * @param amax maximum value of the clip range
>> > - * @return clipped value
>> > - */
>> > -static av_always_inline av_const int64_t av_rint64_clip_c(double a, int64_t amin, int64_t amax)
>> > -{
>> > -    int64_t res;
>> > -#if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
>> > -    if (amin > amax) abort();
>> > -#endif
>> > -    // INT64_MAX+1,INT64_MIN are exactly representable as IEEE doubles
>> > -    // do range checks first
>> > -    if (a >=  9223372036854775808.0)
>> > -        return amax;
>> > -    if (a <= -9223372036854775808.0)
>> > -       return amin;
>> > -
>> > -    // safe to call llrint and clip accordingly
>> > -    res = llrint(a);
>> > -    if (res > amax)
>> > -        return amax;
>> > -    if (res < amin)
>> > -        return amin;
>> > -    return res;
>> > -}
>> > -
>> >  /** Compute ceil(log2(x)).
>> >   * @param x value used to compute ceil(log2(x))
>> >   * @return computed ceiling of log2(x)
>> > @@ -547,9 +511,6 @@ static av_always_inline av_const int av_popcount64_c(uint64_t x)
>> >  #ifndef av_clipd
>> >  #   define av_clipd         av_clipd_c
>> >  #endif
>> > -#ifndef av_rint64_clip
>> > -#   define av_rint64_clip   av_rint64_clip_c
>> > -#endif
>> >  #ifndef av_popcount
>> >  #   define av_popcount      av_popcount_c
>> >  #endif
>> > diff --git a/libavutil/internal.h b/libavutil/internal.h
>> > index 5c2cd99..cb0c8cd 100644
>> > --- a/libavutil/internal.h
>> > +++ b/libavutil/internal.h
>> > @@ -257,6 +257,46 @@ void avpriv_request_sample(void *avc,
>> >  #endif
>> >
>> >  /**
>> > + * Clip and convert a double value into the long long amin-amax range.
>> > + * This function is needed because conversion of floating point to integers when
>> > + * it does not fit in the integer's representation does not necessarily saturate
>> > + * correctly (usually converted to a cvttsd2si on x86) which saturates numbers
>> > + * > INT64_MAX to INT64_MIN. The standard marks such conversions as undefined
>> > + * behavior, allowing this sort of mathematically bogus conversions. This provides
>> > + * a safe alternative that is slower obviously but assures safety and better
>> > + * mathematical behavior.
>> > + * @param a value to clip
>> > + * @param amin minimum value of the clip range
>> > + * @param amax maximum value of the clip range
>> > + * @return clipped value
>> > + */
>> > +static av_always_inline av_const int64_t av_rint64_clip_c(double a, int64_t amin, int64_t amax)
>>
>> IMO rename it to avpriv_rint64_clip() or even ff_rint64_clip() since it's inlined
>> and not public/exported.
>>
>> > +{
>> > +    int64_t res;
>> > +#if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
>> > +    if (amin > amax) abort();
>> > +#endif
>> > +    // INT64_MAX+1,INT64_MIN are exactly representable as IEEE doubles
>> > +    // do range checks first
>> > +    if (a >=  9223372036854775808.0)
>> > +        return amax;
>> > +    if (a <= -9223372036854775808.0)
>> > +       return amin;
>> > +
>> > +    // safe to call llrint and clip accordingly
>> > +    res = llrint(a);
>> > +    if (res > amax)
>> > +        return amax;
>> > +    if (res < amin)
>> > +        return amin;
>> > +    return res;
>> > +}
>> > +
>> > +#ifndef av_rint64_clip
>> > +#   define av_rint64_clip   av_rint64_clip_c
>> > +#endif
>>
>> No need for this chunk.
>>
>> > +
>> > +/**
>> >   * A wrapper for open() setting O_CLOEXEC.
>> >   */
>> >  av_warn_unused_result
>> >
>>
>>
>> In any case should be ok.
>
> changes made, applied
>
> thanks

Thanks for showing and applying the solution, now have a better sense for it.

>
> [...]
> --
> Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
>
> When the tyrant has disposed of foreign enemies by conquest or treaty, and
> there is nothing more to fear from them, then he is always stirring up
> some war or other, in order that the people may require a leader. -- Plato
>
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