Re: [dpdk-dev] [PATCH v2 3/3] eal/windows: librte_net build on Windows

[Fady Bader <fady@mellanox.com>]

> -----Original Message-----
> From: Bruce Richardson <bruce.richardson@intel.com>
> Sent: Wednesday, July 22, 2020 1:31 PM
> To: Fady Bader <fady@mellanox.com>
> Cc: Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>; Narcisa Ana Maria Vasile
> <navasile@linux.microsoft.com>; dev@dpdk.org; Thomas Monjalon
> <thomas@monjalon.net>; Tasnim Bashar <tbashar@mellanox.com>; Tal
> Shnaiderman <talshn@mellanox.com>; Yohad Tor <yohadt@mellanox.com>;
> harini.ramakrishnan@microsoft.com; ocardona@microsoft.com;
> ranjit.menon@intel.com; olivier.matz@6wind.com
> Subject: Re: [dpdk-dev] [PATCH v2 3/3] eal/windows: librte_net build on
> Windows
> 
> On Wed, Jul 22, 2020 at 10:20:48AM +0000, Fady Bader wrote:
> >
> >
> > > -----Original Message-----
> > > From: Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>
> > > Sent: Monday, July 20, 2020 7:27 PM
> > > To: Fady Bader <fady@mellanox.com>
> > > Cc: Narcisa Ana Maria Vasile <navasile@linux.microsoft.com>;
> > > dev@dpdk.org; Thomas Monjalon <thomas@monjalon.net>; Tasnim Bashar
> > > <tbashar@mellanox.com>; Tal Shnaiderman <talshn@mellanox.com>; Yohad
> > > Tor <yohadt@mellanox.com>; harini.ramakrishnan@microsoft.com;
> > > ocardona@microsoft.com; anand.rawat@intel.com;
> > > ranjit.menon@intel.com; olivier.matz@6wind.com
> > > Subject: Re: [dpdk-dev] [PATCH v2 3/3] eal/windows: librte_net build
> > > on Windows
> > >
> > > On Mon, 20 Jul 2020 12:54:08 +0000, Fady Bader wrote:
> > > [snip]
> > > > > Getting the same error with a setup similar to Dmitry's. My setup:
> > > > > SDK 10.0.18362,
> > > >
> > > > I'm sending v4 patch that should resolve this.
> > > >
> > > > > clang 9.0.0. What version of clang are you using on your system?
> > > > > You can try installing LLVM 9.0.0 from
> > > > > https://eur03.safelinks.protection.outlook.com/?url=https%3A%2F%
> > > > > 2Fre
> > > > > leases.ll
> > > > >
> > >
> vm.org%2Fdownload.html&amp;data=02%7C01%7Cfady%40mellanox.com%7C0b
> > > > >
> > >
> 29fed755494b55361d08d82a9ff2b4%7Ca652971c7d2e4d9ba6a4d149256f461b%7C
> > > > > 0
> > > > >
> > >
> %7C0%7C637306213753996879&amp;sdata=5lPQtvt8EO7q8OAYN60J8rIdYdNJHjsS
> > > > > Pp%2B6P9PL3N0%3D&amp;reserved=0
> > > >
> > > > Thanks for the link, even with clang and SDK version same as yours
> > > > and Dmitry's I'm still passing compilation and not getting the error
> described.
> > > > That's because the _m_prefetchw function that is defined in
> > > > Clang's prfchwintrin.h is an intrinsic function corresponding to
> > > > the instruction PREFETCHW that is part of the instruction set
> > > > extension 3DNOW, my processor doesn't support this instruction set
> > > > extension, so my
> > > compiler isn't reaching the part where it defines _m_prefetchw.
> > > > I think your processor does support the 3DNOW instruction set
> > > > extension and that why you are reaching this part and I'm not.
> > >
> > > You can try building DPDK for a machine with RDSEED like so:
> > >
> > > 	meson -Dmachine=broadwell -Dexamples=helloworld build
> >
> > Even with this option I still don't get the error. With this option
> > RDSEED is enabled but the reason I'm not getting the error is that
> > 3DNOW is not supported by my machine and its disabled.
> > Do you know of such way that I can enable instruction set extenuations
> > for the project compilation?
> >
> The prefetchw should be available for broadwell and later machine types, even
> without 3dnow - which AFAIK is unsupported by all modern x86 processors. I am
> using a machine of type "skylake-avx512" (using the compiler name for it!), and
> proc/cpuinfo shows "3dnowprefetch" in the supported CPU flags.
> 
> Regards,
> /Bruce

Thanks now its clear.