[FFmpeg-devel] [PATCH v1] configure: fix mmi check

[Jiaxun Yang]

在 2021/7/23 上午9:39, Jin Bo 写道:
> pxor is loongson media extension instruction, it's not
> supported yet on upstream gcc complier. Disable mmi to
> avoid build error if the compiler does not support it.

Hi Bo,

Well I have to repeat that your statement is *NOT* true.

Upstream GCC *DO* support Loongson MMI.

Disabling Loongson MMI just because different instruction naming is 
unacceptable from my aspect, note that beside usage in your company we 
have other distros like Debian and AOSC, they have strict upstream policy .

My suggestion is to use instruction macro to workaround the problem.

Thanks.

- Jiaxun

> ---
>   configure | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/configure b/configure
> index bb6b096414..ec536dea40 100755
> --- a/configure
> +++ b/configure
> @@ -5963,7 +5963,7 @@ elif enabled mips; then
>       enabled loongson3 && check_inline_asm loongson3 '"gsldxc1 $f0, 0($2, $3)"' '-mloongson-ext' && append MMIFLAGS '-mloongson-ext'
>   
>       # MMI can be detected at runtime too
> -    enabled mmi && check_inline_asm mmi '"punpcklhw $f0, $f0, $f0"' '-mloongson-mmi' && append MMIFLAGS '-mloongson-mmi'
> +    enabled mmi && check_inline_asm mmi '"pxor $f0, $f0, $f0"' '-mloongson-mmi' && append MMIFLAGS '-mloongson-mmi'
>   
>       if enabled bigendian && enabled msa; then
>           disable msa