Re: [Patch] [x86_64]: Add bdver4 for multi versioning and fix AMD cpu model detection.

[Uros Bizjak <ubizjak@gmail.com>]

On Tue, Oct 13, 2015 at 5:16 PM, Kumar, Venkataramanan
<Venkataramanan.Kumar@amd.com> wrote:
> Hi Uros,
>
> I realized both GCC 4.9 and GCC 5 branches includes processor subtype AMDFAM15H_BDVER4.
> So I need to back port not only model selection fix but also the detection of model for bdver4.
>
> Is that fine?

OK, but to avoid ABI mismatches, please double check that enum values
passed between library and compiled code are always the same in all
gcc releases.

Uros.

> Regards,
> Venkat.
>
>> -----Original Message-----
>> From: Kumar, Venkataramanan
>> Sent: Friday, October 09, 2015 3:31 PM
>> To: 'Uros Bizjak'
>> Cc: gcc-patches@gcc.gnu.org
>> Subject: RE: [Patch] [x86_64]: Add bdver4 for multi versioning and fix AMD
>> cpu model detection.
>>
>> Thank you Uros,
>>
>> I will  test and commit model selection change in all release branches as well.
>>
>> Regards,
>> Venkat.
>>
>> > -----Original Message-----
>> > From: Uros Bizjak [mailto:ubizjak@gmail.com]
>> > Sent: Friday, October 09, 2015 3:25 PM
>> > To: Kumar, Venkataramanan
>> > Cc: gcc-patches@gcc.gnu.org
>> > Subject: Re: [Patch] [x86_64]: Add bdver4 for multi versioning and fix
>> > AMD cpu model detection.
>> >
>> > On Fri, Oct 9, 2015 at 11:50 AM, Kumar, Venkataramanan
>> > <Venkataramanan.Kumar@amd.com> wrote:
>> > > Hi Uros,
>> > >
>> > > Please find below patch that adds bdver4 target for multi versioning.
>> > > Also I while computing model, the extended_model is incorrectly left
>> > shifted  by 4. I have removed it now.
>> > >
>> > > Is below patch Ok for trunk ?
>> > > GCC bootstrap and regressions passed.
>> >
>> > OK for trunk and release branches, where applicable. IMO, model
>> > selection fix should be applied to all release branches.
>> >
>> > Thanks,
>> > Uros.
>> >
>> > > diff --git a/libgcc/ChangeLog b/libgcc/ChangeLog index
>> > > bb3a722..8676747 100644
>> > > --- a/libgcc/ChangeLog
>> > > +++ b/libgcc/ChangeLog
>> > > @@ -1,3 +1,8 @@
>> > > +2015-10-09  Venkataramanan Kumar
>> > <venkataramanan.kumar@amd.com>
>> > > +
>> > > +       * config/i386/cpuinfo.c (get_amd_cpu): Detect bdver4.
>> > > +       (__cpu_indicator_init): Fix model selection for AMD CPUs.
>> > > +
>> > >  2015-10-05  Kirill Yukhin  <kirill.yukhin@intel.com>
>> > >
>> > >         * config/i386/cpuinfo.c (get_intel_cpu): Detect "skylake-avx512".
>> > > diff --git a/libgcc/config/i386/cpuinfo.c
>> > > b/libgcc/config/i386/cpuinfo.c index 0cbbc85..1313ca3 100644
>> > > --- a/libgcc/config/i386/cpuinfo.c
>> > > +++ b/libgcc/config/i386/cpuinfo.c
>> > > @@ -169,6 +169,9 @@ get_amd_cpu (unsigned int family, unsigned int
>> > model)
>> > >        /* Bulldozer version 3 "Steamroller"  */
>> > >        if (model >= 0x30 && model <= 0x4f)
>> > >         __cpu_model.__cpu_subtype = AMDFAM15H_BDVER3;
>> > > +      /* Bulldozer version 4 "Excavator"   */
>> > > +      if (model >= 0x60 && model <= 0x7f)
>> > > +       __cpu_model.__cpu_subtype = AMDFAM15H_BDVER4;
>> > >        break;
>> > >      /* AMD Family 16h "btver2" */
>> > >      case 0x16:
>> > > @@ -455,7 +458,7 @@ __cpu_indicator_init (void)
>> > >        if (family == 0x0f)
>> > >         {
>> > >           family += extended_family;
>> > > -         model += (extended_model << 4);
>> > > +         model += extended_model;
>> > >         }
>> > >
>> > >        /* Get CPU type.  */
>> > >
>> > > Regards,
>> > > Venkat.
>> > >
>> > >
>> > >
>> > >
>> > >
>> > >