Re: [PATCH v4 1/1] mbuf: enable to be compiled with MSVC

[Andre Muezerie <andremue@linux.microsoft.com>]

On Wed, Apr 09, 2025 at 01:39:36PM +0200, David Marchand wrote:
> On Tue, Apr 8, 2025 at 11:24 PM Andre Muezerie
> <andremue@linux.microsoft.com> wrote:
> > diff --git a/lib/net/meson.build b/lib/net/meson.build
> > index 7a6c419f40..c528fcc9a2 100644
> > --- a/lib/net/meson.build
> > +++ b/lib/net/meson.build
> > @@ -43,7 +43,12 @@ use_function_versioning = true
> >
> >  if dpdk_conf.has('RTE_ARCH_X86_64')
> >      sources += files('net_crc_sse.c')
> > -    cflags += ['-mpclmul', '-maes']
> > +    cflags_options = ['-mpclmul', '-maes']
> > +    foreach option:cflags_options
> > +        if cc.has_argument(option)
> > +            cflags += option
> > +        endif
> > +    endforeach
> 
> What guarantee do we have that MSVC builds with those instructions?
> 

The granularity msvc offers for extended instruction sets is different.
I had sent a patch that allows DPDK code to benefit from those settings,
but it likely needs to be updated after recent changes were merged. I'll
revisit that in the next few days.

For reference, here is what the original patch series looked like:
https://patches.dpdk.org/project/dpdk/list/?series=34803

> >      # only build AVX-512 support if we also have PCLMULQDQ support
> >      if cc.has_argument('-mvpclmulqdq')
> >          sources_avx512 += files('net_crc_avx512.c')
> 
> 
> -- 
> David Marchand