Re: [dpdk-dev] [PATCH] net/i40e: disable AVX512 with MinGW

[Bruce Richardson <bruce.richardson@intel.com>]

On Tue, Feb 02, 2021 at 05:06:39PM +0800, Leyi Rong wrote:
> Disable i40e AVX512 code path for Windows build regardless of CPU
> capability to avoid the MinGW build error:
> 	Error: invalid register for .seh_savexmm
> 
> Signed-off-by: Leyi Rong <leyi.rong@intel.com>
> ---
>  drivers/net/i40e/meson.build | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/net/i40e/meson.build b/drivers/net/i40e/meson.build
> index f5fc5a17e..26cd201ee 100644
> --- a/drivers/net/i40e/meson.build
> +++ b/drivers/net/i40e/meson.build
> @@ -56,6 +56,7 @@ if arch_subdir == 'x86'
>  
>  	if is_windows and cc.get_id() != 'clang'
>  		i40e_avx512_cc_support = false
> +		i40e_avx512_cpu_support = false
>  	endif
>  

This fix seems to imply that there is something else wrong in the logic in
the build file. If the compiler does not support avx512, the fact that the
CPU supports it should be completely irrelevant. Therefore, I think a more
correct fix (logically) should be to remove the "i40e_avx512_cpu_support"
from the next "if" condition, and only check the compiler support. We
don't do anything with the cpu support variable.

/Bruce