RE: [PATCH] [X86_64]: Enable support for next generation AMD Zen3 CPU

[Kumar, Venkataramanan via Gcc-patches]

[AMD Public Use]

Hi Honza,

> -----Original Message-----
> From: Jan Hubicka <hubi...@ucw.cz>
> Sent: Friday, December 4, 2020 5:25 PM
> To: Kumar, Venkataramanan <venkataramanan.ku...@amd.com>
> Cc: gcc-patches@gcc.gnu.org; Uros Bizjak <ubiz...@gmail.com>
> Subject: Re: [PATCH] [X86_64]: Enable support for next generation AMD
> Zen3 CPU
> 
> [CAUTION: External Email]
> 
> > [AMD Official Use Only - Internal Distribution Only]
> >
> > Hi Maintainers,
> >
> > PFA, the patch that enables support for the next generation AMD Zen3
> CPU via -march=znver3.
> > This is a very basic enablement patch. As of now the cost, tuning and
> scheduler changes are kept same as znver2.
> > Further changes to the cost and tunings will be done later.
> 
> Hello,
> the changes to x86-tune.def and x86-tune-sched.c seems fine to me.
> There is one patch on
> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgcc.
> gnu.org%2Fpipermail%2Fgcc-patches%2F2020-
> May%2F545415.html&amp;data=04%7C01%7CVenkataramanan.Kumar%40a
> md.com%7Ce25a15789ca8494e5f4d08d8984b7615%7C3dd8961fe4884e608e1
> 1a82d994e183d%7C0%7C0%7C637426797168805753%7CUnknown%7CTWFpb
> GZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI
> 6Mn0%3D%7C1000&amp;sdata=1hax0HYCbxs1LGQEFULlvLh%2BTRo3xJzuj70
> kIRtFnDk%3D&amp;reserved=0
> I did not see significant difference on specs, but do we want to change the
> default?

You mean the tune " X86_TUNE_SSE_PACKED_SINGLE_INSN_OPTIMAL" has no impact on 
SPEC and  other benchmarks ?
I have not done performance experiments with this tune on Zen machines.   

Let me check on this and get back to you. 

> 
> Honza
> >
> > Ok for trunk ?
> >
> > Regards,
> > Venkat.
> 

Regards,
Venkat.