Slower than Python

[Don]

On Monday, 4 March 2013 at 03:58:20 UTC, deadalnix wrote:
> On Monday, 4 March 2013 at 03:20:57 UTC, jerro wrote:
>>> Maybe it is time to look at the python implementation and see 
>>> why it is faster.
>>
>> It isn't faster:
>>
>> $ time python3 test.py
>>
>> real    0m14.217s
>> user    0m14.209s
>> sys     0m0.004s
>> $ gdmd -O -inline -release -noboundscheck test
>> $ time ./test
>>
>> real    0m5.323s
>> user    0m5.312s
>> sys     0m0.008s
>>
>> D code here uses the same string as the python code, not the 
>> one in cvk012c's D code.
>
> Using noboundcheck isn't fair as you give up on safety, so you 
> are not equivalent to python either.

But that does suggest that the main problem is that DMD has very 
little optimization aimed at reducing the number of bounds checks 
required.