[FFmpeg-devel] [PATCH] lavu/mem: un-inline av_size_mult()

Anton Khirnov anton at khirnov.net
Thu Jun 10 18:01:36 EEST 2021


Quoting James Almer (2021-05-31 13:56:20)
> On 5/31/2021 6:26 AM, Anton Khirnov wrote:
> > There seems to be no compelling reason for it to be inline.
> > ---
> >   libavutil/mem.c | 18 ++++++++++++++++++
> >   libavutil/mem.h | 19 +------------------
> >   2 files changed, 19 insertions(+), 18 deletions(-)
> > 
> > diff --git a/libavutil/mem.c b/libavutil/mem.c
> > index a52d33d4a6..063635fb22 100644
> > --- a/libavutil/mem.c
> > +++ b/libavutil/mem.c
> > @@ -547,3 +547,21 @@ void av_fast_mallocz(void *ptr, unsigned int *size, size_t min_size)
> >   {
> >       fast_malloc(ptr, size, min_size, 1);
> >   }
> > +
> > +int av_size_mult(size_t a, size_t b, size_t *r)
> > +{
> > +    size_t t;
> > +
> > +#if (!defined(__INTEL_COMPILER) && AV_GCC_VERSION_AT_LEAST(5,1)) || AV_HAS_BUILTIN(__builtin_mul_overflow)
> > +    if (__builtin_mul_overflow(a, b, &t))
> > +        return AVERROR(EINVAL);
> > +#else
> > +    t = a * b;
> > +    /* Hack inspired from glibc: don't try the division if nelem and elsize
> > +     * are both less than sqrt(SIZE_MAX). */
> > +    if ((a | b) >= ((size_t)1 << (sizeof(size_t) * 4)) && a && t / a != b)
> > +        return AVERROR(EINVAL);
> > +#endif
> > +    *r = t;
> > +    return 0;
> > +}
> > diff --git a/libavutil/mem.h b/libavutil/mem.h
> > index c876111afb..e9d343eaf0 100644
> > --- a/libavutil/mem.h
> > +++ b/libavutil/mem.h
> > @@ -31,7 +31,6 @@
> >   #include <stdint.h>
> >   
> >   #include "attributes.h"
> > -#include "error.h"
> >   #include "avutil.h"
> >   #include "version.h"
> >   
> > @@ -672,23 +671,7 @@ void *av_dynarray2_add(void **tab_ptr, int *nb_ptr, size_t elem_size,
> >    * @param[out] r   Pointer to the result of the operation
> >    * @return 0 on success, AVERROR(EINVAL) on overflow
> >    */
> 
> You should also move the doxy.

Why?

-- 
Anton Khirnov


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