math.log() benchmark of first 1 billion int using std.parallelism

[John Colvin via Digitalmars-d-learn]

On Monday, 22 December 2014 at 18:27:48 UTC, Iov Gherman wrote:
> On Monday, 22 December 2014 at 17:50:20 UTC, John Colvin wrote:
>> On Monday, 22 December 2014 at 17:28:12 UTC, Iov Gherman wrote:
>>> So, I did some more testing with the one processing in 
>>> paralel:
>>>
>>> --- dmd:
>>> 4 secs, 977 ms
>>>
>>> --- dmd with flags: -O -release -inline -noboundscheck:
>>> 4 secs, 635 ms
>>>
>>> --- ldc:
>>> 6 secs, 271 ms
>>>
>>> --- gdc:
>>> 10 secs, 439 ms
>>>
>>> I also pushed the new bash scripts to the git repository.
>>
>> Flag suggestions:
>>
>> ldc2 -O3 -release -mcpu=native -singleobj
>>
>> gdc -O3 -frelease -march=native
>
> Tried it, here are the results:
>
> --- ldc:
> 6 secs, 271 ms
>
> --- ldc -O3 -release -mcpu=native -singleobj:
> 5 secs, 686 ms
>
> --- gdc:
> 10 secs, 439 ms
>
> --- gdc -O3 -frelease -march=native:
> 9 secs, 180 ms

That's very different to my results.

I see no important difference between ldc and dmd when using 
std.math, but when using core.stdc.math ldc halves its time where 
dmd only manages to get to ~80%