[FFmpeg-devel] [PATCH v2 1/3] avcodec/x86/vvc/vvc_alf: fix integer overflow

[Andreas Rheinhardt]

toqsxw at outlook.com:
> From: Wu Jianhua <toqsxw at outlook.com>
> 
> Some tests fails with certain seeds
> 
> tests/checkasm/checkasm 2325607578 --test=vvc_alf
> checkasm: using random seed 2325607578
> AVX2:
>     vvc_alf_filter_luma_120x20_12_avx2 (vvc_alf.c:104)
>     vvc_alf_filter_luma_120x24_12_avx2 (vvc_alf.c:104)
>     vvc_alf_filter_luma_120x28_12_avx2 (vvc_alf.c:104)
>     vvc_alf_filter_luma_120x32_12_avx2 (vvc_alf.c:104)
>     vvc_alf_filter_luma_120x36_12_avx2 (vvc_alf.c:104)
>     vvc_alf_filter_luma_120x40_12_avx2 (vvc_alf.c:104)
>     vvc_alf_filter_luma_120x44_12_avx2 (vvc_alf.c:104)
>     vvc_alf_filter_luma_120x48_12_avx2 (vvc_alf.c:104)
>     vvc_alf_filter_luma_120x52_12_avx2 (vvc_alf.c:104)
>     vvc_alf_filter_luma_120x56_12_avx2 (vvc_alf.c:104)
>     vvc_alf_filter_luma_120x60_12_avx2 (vvc_alf.c:104)
>     vvc_alf_filter_luma_120x64_12_avx2 (vvc_alf.c:104)
>     vvc_alf_filter_luma_120x68_12_avx2 (vvc_alf.c:104)
>     vvc_alf_filter_luma_120x72_12_avx2 (vvc_alf.c:104)
>     vvc_alf_filter_luma_120x76_12_avx2 (vvc_alf.c:104)
>     vvc_alf_filter_luma_120x80_12_avx2 (vvc_alf.c:104)
>     vvc_alf_filter_luma_120x84_12_avx2 (vvc_alf.c:104)
>     vvc_alf_filter_luma_120x88_12_avx2 (vvc_alf.c:104)
>     vvc_alf_filter_luma_120x92_12_avx2 (vvc_alf.c:104)
>     vvc_alf_filter_luma_120x96_12_avx2 (vvc_alf.c:104)
>     vvc_alf_filter_luma_120x100_12_avx2 (vvc_alf.c:104)
>     vvc_alf_filter_luma_120x104_12_avx2 (vvc_alf.c:104)
>     vvc_alf_filter_luma_120x108_12_avx2 (vvc_alf.c:104)
>     vvc_alf_filter_luma_120x112_12_avx2 (vvc_alf.c:104)
>     vvc_alf_filter_luma_120x116_12_avx2 (vvc_alf.c:104)
>     vvc_alf_filter_luma_120x120_12_avx2 (vvc_alf.c:104)
>     vvc_alf_filter_luma_120x124_12_avx2 (vvc_alf.c:104)
>     vvc_alf_filter_luma_120x128_12_avx2 (vvc_alf.c:104)
>   - vvc_alf.alf_filter   [FAILED]
>   - vvc_alf.alf_classify [OK]
> checkasm: 28 of 9216 tests have failed
> 
> Reported-by: James Almer <jamrial at gmail.com>
> Signed-off-by: Wu Jianhua <toqsxw at outlook.com>
> ---
>  libavcodec/x86/vvc/vvc_alf.asm | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/libavcodec/x86/vvc/vvc_alf.asm b/libavcodec/x86/vvc/vvc_alf.asm
> index 71e821c27b..f7b3e2a6cc 100644
> --- a/libavcodec/x86/vvc/vvc_alf.asm
> +++ b/libavcodec/x86/vvc/vvc_alf.asm
> @@ -356,7 +356,8 @@ SECTION .text
>  
>      FILTER_VB         xq
>  
> -    paddw             m0, m2
> +    ; sum += curr
> +    paddsw             m0, m2
>  
>      ; clip to pixel
>      CLIPW             m0, m14, m15

And can I get an answer to the question of whether the issue is present
when used by the actual decoder and not only the checkasm test?

- Andreas