[foreign-memaccess] RFR 8219852: Create a set of standard benchmarks

[Jorn Vernee]

Hi,

I'd make one change in both classes:

     static final int ELEM_SIZE = 1_000_000;
     static final int CARRIER_SIZE = (int)JAVA_INT.byteSize();
     static final int ALLOC_SIZE = ELEM_SIZE * CARRIER_SIZE;

So that we loop over 1 million ints as well. This maintains the scaling 
between 1 -> 1_000_000 and nanoseconds -> milliseconds.

You can also still replace the '4' with 'CARRIER_SIZE' in both classes 
when initializing the unsafe memory.

Otherwise looks good.

Cheers,
Jorn

On 10/01/2020 00:56, Maurizio Cimadamore wrote:
> And here's a new revision - I realized that I was not using the BB API 
> correctly and was not multiplying the index of the getInt by the 
> carrier size.
>
> http://cr.openjdk.java.net/~mcimadamore/panama/8219852_part2_v3/
>
> Maurizio
>
> On 09/01/2020 21:31, Maurizio Cimadamore wrote:
>> I have uploaded a new revision of the benchmark. I've now changed 
>> both LoopOverConstant and LoopOverNonConstant to use int instead of 
>> byte as a carrier, as the byte case is specialized in the BB API 
>> (bound check is intrinsified), so I think int is a more 
>> representative and complex case.
>>
>> I also added baseline cases for unsafe in the LoopOverNonConstant as 
>> well.
>>
>> http://cr.openjdk.java.net/~mcimadamore/panama/8219852_part2_v2/
>>
>> Maurizio
>>
>> On 09/01/2020 17:41, Maurizio Cimadamore wrote:
>>> Here's the benchmark which tests constant segments.
>>>
>>> http://cr.openjdk.java.net/~mcimadamore/panama/8219852_part2/
>>>
>>> I've also tweaked your benchmark to test both loop case and single 
>>> access case. To do that, I slightly changed the benchmark so that 
>>> the benchmark state keeps track of the address, rather than the 
>>> segment (to avoid calls to baseAddress() - which is not there in the 
>>> other benchmark).
>>>
>>> Maurizio
>>>
>>> On 09/01/2020 15:37, Maurizio Cimadamore wrote:
>>>> Looks good!
>>>>
>>>> Maurizio
>>>>
>>>> On 09/01/2020 15:21, Jorn Vernee wrote:
>>>>> On 09/01/2020 15:58, Maurizio Cimadamore wrote:
>>>>>> Looks good and works on my machine.
>>>>>>
>>>>>> I'd suggest a couple of changes:
>>>>>>
>>>>>> * benchmarks are java/foreign, shouldn't they be 
>>>>>> jdk.incubator.foreign, for consistency with module/package name?
>>>>> Good point. (I copied what I had from a while back before we 
>>>>> switched to the incubator module)
>>>>>>
>>>>>> * Hoisting seems general as a name - I think what you want to 
>>>>>> test here is hoisting when segment is non-final, non-static 
>>>>>> variable - I have a similar benchmark for true constant segments 
>>>>>> that I'd like to upload, so we need slightly more precise names :-)
>>>>>
>>>>> Could do LoopOverNonConstant?
>>>>>
>>>>> Updated webrev: 
>>>>> http://cr.openjdk.java.net/~jvernee/panama/webrevs/8219852/webrev.01/
>>>>>
>>>>> Jorn
>>>>>
>>>>>>
>>>>>> Cheers
>>>>>> Maurizio
>>>>>>
>>>>>> On 09/01/2020 14:32, Jorn Vernee wrote:
>>>>>>> make test TEST="micro:java.foreign" 
>>>>>>> MICRO="VM_OPTIONS=--add-modules jdk.incubator.foreign"