Re: [PATCH 09/10] Support Intel AMX-FP16

[Jan Beulich <jbeulich@suse.com>]

On 19.10.2022 16:01, Jiang, Haochen wrote:
>> -----Original Message-----
>> From: Cui, Lili <lili.cui@intel.com>
>> Sent: Wednesday, October 19, 2022 6:34 PM
>>
>>>>>> -    "CpuAMX_TILE|CpuAMX_INT8|CpuAMX_BF16" },
>>>>>> +    "CpuAMX_TILE|CpuAMX_INT8|CpuAMX_BF16|CpuAMX_FP16" },
>>>>>>    { "CPU_ANY_MSRLIST_FLAGS",
>>>>>>      "CpuMSRLIST" },
>>>>>> +  { "CPU_ANY_AMX_FP16_FLAGS",
>>>>>> +    "CpuAMX_FP16" },
>>>>>>  };
>>>>>
>>>>> Same here then.
>>>> Done.
>>>
>>> I guess my comment here was a little misleading (I'm sorry for that),
>>> in that in addition I was expecting you to consider the comment
>>> regarding the need for the *_ANY_* constants that I did give for several of the
>> patches in this series.
>>> I think the question applies here as well: Are there dependent
>>> features known to appear? If not, there's no need for the extra constant.
>>>
>> Get you, there are no known dependencies now, and I will pay attention on it in
>> future ISAs.
> 
> But I suppose for AMX-FP16, the possibility of potential dependency is bigger than
> some like CMPCCXADD, MSRLIST. Since FP16 type is not that rare.

If you go look you'll find that we don't have ANY_* for a fair part (if
not a majority) of the features). Plus AMX-FP16 as a feature name suggests
more generality than there really is - the feature is about a specific
multiplication insn, not (like e.g. AVX512-FP16) about the introduction of
a set of insns on a basic data type (whether the set of insns could of
course widen down the road, and where the further ISAs would depend on the
more basic operations on that data type).

Jan