On 11/26/18 12:18 PM, Jakub Jelinek wrote:
> On Mon, Nov 26, 2018 at 12:03:53PM +0100, Martin Liška wrote:
>>> For Cascade Lake the model number is the same as Skylake Server,
>>> it can only be distinguished based on the stepping (5 vs 4)
>>
>> Very interesting, probably the first time a distinguish is based on stepping
>> number?
>
> Wouldn't it be better to distinguish it based on availability of VNNI, like
> we do for unknown family/model?
>
>>> Like gcc -mcpu=native needs to learn about this.
>>
>> I'm attaching patch that does that. Note that it's completely untested as I
>> don't have
>> access to any of the new machines (Skylake server).
Would be possible, the only ugly place would be in libgcc/config/i386/cpuinfo.c
where we
call:
get_intel_cpu (family, model, stepping, brand_id);
/* Find available features. */
get_available_features (ecx, edx, max_level, &avx512_vnni);
one would need a feature to distinguish CPU model. Do we really want that?
Martin
>
> Jakub
>
