[Cython] compiler performance issue for extended utility code

[Stefan Behnel]

Vitja Makarov, 07.10.2011 18:01:
>> 2011/10/7 Stefan Behnel:
>>> Vitja Makarov, 06.10.2011 23:12:
>>>>
>>>> Here is small comparison on compiling urllib.py with cython:
>>>>
>>>> ((e8527c5...)) vitja at mchome:~/work/cython-vitek-git/zzz$ time python
>>>> ../cython.py urllib.py
>>>>
>>>> real    0m1.699s
>>>> user    0m1.650s
>>>> sys     0m0.040s
>>>> (master) vitja at mchome:~/work/cython-vitek-git/zzz$ time python
>>>> ../cython.py urllib.py
>>>>
>>>> real    0m2.830s
>>>> user    0m2.790s
>>>> sys     0m0.030s
>>>>
>>>>
>>>> It's about 1.5 times slower.
>>>
>>> That's a pretty serious regression for
>>> plain Python code then. Again, this needs proper profiling.
>
> I've added return statement on top of CythonScope.test_cythonscope,
> now I have these timings:
>
> (master) vitja at mchome:~/work/cython-vitek-git/zzz$ time python
> ../cython.py urllib.py
>
> real	0m1.764s
> user	0m1.700s
> sys	0m0.060s

Ok, then it's only a bug. "create_testscope" is on by default in Main.py, 
Context.__init__(). I don't know what it does exactly, but my guess is that 
the option should a) be off by default and b) should rather be passed in by 
the test runner as part of the compile options rather than being a 
parameter of the Context class. AFAICT, it's currently only used in 
TreeFragment.py, where it is being switched off explicitly for parsing code 
snippets.

Stefan