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Re: [PATCH] x86-64: Add sinf with FMA
On Fri, Dec 8, 2017 at 8:07 AM, Arjan van de Ven <arjan@linux.intel.com> wrote:
> On 12/8/2017 8:02 AM, Nick Alcock wrote:
>>
>> On 4 Dec 2017, H. J. Lu uttered the following:
>>
>>> On Skylake, bench-sinf reports performance improvement:
>>>
>>> Before After Improvement
>>> max 153.996 100.094 54%
>>> min 8.546 6.852 25%
>>> mean 18.1223 14.4616 25%
>>>
>>> Any comments?
>>
>>
>> Do we have any benchmark runs on older processors? They're not remotely
>> obsolete: Intel is still selling Broadwell server parts, and the vast
>> majority of SSE2-capable parts out there at present are not as new as
>> Skylake.
>
>
> (oh and Haswell & Broadwell also support FMA already)
On Haswell, without FMA:
"sinf": {
"": {
"duration": 3.4905e+10,
"iterations": 1.91281e+09,
"max": 450.098,
"min": 8.091,
"mean": 18.2481
}
}
With FMA:
"sinf": {
"": {
"duration": 3.49046e+10,
"iterations": 2.44188e+09,
"max": 173.855,
"min": 7.253,
"mean": 14.2942
}
}
FMA is faster on HSW. I expect Broadwell should also be faster with FMA.
--
H.J.