[FFmpeg-devel] [PATCH] lavu/cpu: disable MMX warning on non x86 platforms

[James Almer]

On 6/28/2017 10:21 AM, Clément Bœsch wrote:
> We have AV_CPU_FLAG_ARMV8 == AV_CPU_FLAG_SSE3 which causes a trigger of
> this MMX warning on AArch64.
> ---
>  libavutil/cpu.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/libavutil/cpu.c b/libavutil/cpu.c
> index 16e0c9278f..a22da0fa8c 100644
> --- a/libavutil/cpu.c
> +++ b/libavutil/cpu.c
> @@ -61,7 +61,8 @@ static int get_cpu_flags(void)
>  }
>  
>  void av_force_cpu_flags(int arg){
> -    if (   (arg & ( AV_CPU_FLAG_3DNOW    |
> +    if (ARCH_X86 &&
> +           (arg & ( AV_CPU_FLAG_3DNOW    |
>                      AV_CPU_FLAG_3DNOWEXT |
>                      AV_CPU_FLAG_MMXEXT   |
>                      AV_CPU_FLAG_SSE      |
> 

LGTM of course. Goes to show how the CLI or anything where log messages
are clearly visible are barely used on non-x86 targets.

This should be backported as well. It's not simply a warning as it
blindly sets the first bit of the cpuflags variable (MMX on x86, altivec
on PPC, armv6 on arm, etc).