[PATCH] build: allow disabling avx512 support via compiler flag

[Stokes, Ian]

> DPDK build checks for build support for various instruction sets by
> checking both the target machine and the compiler for support. However,
> any disabling of instruction sets via compiler flags was not taken into
> account in many cases. For AVX512 support, check for a user-specified
> "no-avx512f" flag in the c_args parameter before checking if the
> compiler can actually build AVX512 code.
> 
> As well as providing an option for the user, this can be used to test
> builds without AVX512 without having to use an older compiler.
> 
> Signed-off-by: Bruce Richardson <bruce.richardson at intel.com>
> ---
>  config/x86/meson.build | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/config/x86/meson.build b/config/x86/meson.build
> index 5455bb0210..47a5b0c04a 100644
> --- a/config/x86/meson.build
> +++ b/config/x86/meson.build
> @@ -17,7 +17,8 @@ endif
>  cc_avx512_flags = ['-mavx512f', '-mavx512vl', '-mavx512dq', '-mavx512bw']
>  cc_has_avx512 = false
>  target_has_avx512 = false
> -if binutils_ok and cc.has_multi_arguments(cc_avx512_flags)
> +if (binutils_ok and cc.has_multi_arguments(cc_avx512_flags)
> +        and '-mno-avx512f' not in get_option('c_args'))
>      # check if compiler is working with _mm512_extracti64x4_epi64
>      # Ref: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82887
>      code = '''#include <immintrin.h>
> --
> 2.43.0

Thanks Bruce,

tested ok for me, LGTM.

Acked-by: Ian Stokes <ian.stokes at intel.com>