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

[James Almer]

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.

LGTM otherwise.

> -static inline 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;
> -}
> +int av_size_mult(size_t a, size_t b, size_t *r);
>   
>   /**
>    * Set the maximum size that may be allocated in one block.
>