[pypy-dev] offtopic, ontopic, ...

[Stefan Behnel]

Maciej Fijalkowski, 13.02.2012 21:41:
> On Mon, Feb 13, 2012 at 9:37 PM, Stefan Behnel wrote:
>> What are
>> you using for comparison? speed.pypy.org? Have you noticed that amongst all
>> those benchmarks there that PyPy was specifically tuned for, there is not a
>> single benchmark that was selected specifically for Cython? There are
>> always lies, damn lies and then there are benchmarks, don't forget that.
> 
> Well, those benchmarks were not really selected for pypy. There is a
> very limited set of available interesting python benchmarks and we
> made the selection rather on "what is slow" rather than "what is
> fast", if any sort of pypy-related things were considered, barring the
> obvious "does it run on PyPy".

Mind my wording. The thing is that the PyPy devs used these benchmarks to
tune PyPy, i.e. they became the exact set of software that PyPy is
particularly fast for. That makes them less interesting benchmarks for
others and reduces their value for comparison, unless a similar amount of
continuous effort (years, I presume) is spent in other projects to tune
their tools for the exact same set (or even just a subset) of this software.

I'm not trying to suggest that the choice of benchmarks is bad in any way
or that they are not representing real-world requirements, not at all. But
PyPy has a special advantage in running exactly this benchmark suite.

To make this clear (and I don't think this is just my personal point of
view), it is not the intention of the Cython project to run the specific,
unmodified (or even partly or fully statically typed) software in this
benchmark suite anywhere near as fast as PyPy, simply because we are
focussing on other ways of tuning and rewriting code than would be required
for running these benchmarks the way they are. It's not only because we
can't, it's because it would be a useless waste of programmer resources to
even try. It's the kind of software that PyPy was (and is being) designed
and tuned to run, and it saves us a lot of effort to just let it do that.


> I agree that cython offers a much better experience than ctypes.

Phew, I'm happy you say that. :)


> PS. Sorry for the tone of my original email, it was a bit unprofessional.

Same here. Happens to all of us.

Thanks, Martijn, for hooking in just-in-time (which finally gets us back on
topic for this list).

Stefan