[FFmpeg-devel] [PATCH] configure+libm.h: add fmin/fmax/fminf/fmaxf emulation

[Hendrik Leppkes]

On Fri, Oct 30, 2015 at 11:35 PM, Michael Niedermayer <michaelni at gmx.at> wrote:
> From: Michael Niedermayer <michael at niedermayer.cc>
>
> This should fix the build failure of avf_showcqt.c
>
> An alternative solution would be to add a check for fmin/fmax to fate-source and
> then to replace them by FFMIN/FFMAX, i can do that if preferred?
>
> Untested due to lack of a affected platform
>
> Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
> ---
>  configure        |    8 ++++++++
>  libavutil/libm.h |   28 ++++++++++++++++++++++++++++
>  2 files changed, 36 insertions(+)
>
> diff --git a/configure b/configure
> index 95790f4..e6f5d2c 100755
> --- a/configure
> +++ b/configure
> @@ -1770,6 +1770,10 @@ MATH_FUNCS="
>      exp2
>      exp2f
>      expf
> +    fmax
> +    fmaxf
> +    fmin
> +    fminf
>      isinf
>      isnan
>      ldexpf
> @@ -5304,6 +5308,10 @@ check_lib math.h sin -lm && LIBM="-lm"
>  disabled crystalhd || check_lib libcrystalhd/libcrystalhd_if.h DtsCrystalHDVersion -lcrystalhd || disable crystalhd
>
>  atan2f_args=2
> +fmax_args=2
> +fmaxf_args=2
> +fmin_args=2
> +fminf_args=2
>  copysign_args=2
>  ldexpf_args=2
>  powf_args=2
> diff --git a/libavutil/libm.h b/libavutil/libm.h
> index 6c17b28..ba837a2 100644
> --- a/libavutil/libm.h
> +++ b/libavutil/libm.h
> @@ -43,6 +43,34 @@
>  #define atan2f(y, x) ((float)atan2(y, x))
>  #endif
>
> +#if !HAVE_FMAX
> +#undef fmax
> +static av_always_inline double fmax(double x, double y)
> +{
> +    if (x < y) return y;
> +    else       return x;
> +}
> +#endif
> +
> +#if !HAVE_FMIN
> +#undef fmin
> +static av_always_inline double fmin(double x, double y)
> +{
> +    if (x < y) return x;
> +    else       return y;
> +}
> +#endif

Wasn't there a concern that these emulations don't behave identical to
the C library versions in regards to NaN handling?
I faintly remember something in the previous discussion.

> +
> +#if !HAVE_FMAXF
> +#undef fmaxf
> +#define fmaxf(y, x) ((float)fmax(y, x))
> +#endif
> +
> +#if !HAVE_FMINF
> +#undef fminf
> +#define fminf(y, x) ((float)fmin(y, x))
> +#endif
> +
>  #if !HAVE_POWF
>  #undef powf
>  #define powf(x, y) ((float)pow(x, y))
> --
> 1.7.9.5
>
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel at ffmpeg.org
> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel