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0 pointsint_19h6y ago0 comments

I had a binary parser written in Python that took around 30 seconds on typical input on CPython. PyPy took that down to about 10 seconds. Rewriting it in C# took it down to 200 ms.

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twa9276y ago

If this was using a loop processing a single byte in an iteration I would expect a greater speedup on PyPy. I've seen 100x speedup in such cases.

int_19hOP6y ago

Not single byte, but individual fields (float32/int32/string etc). Yes, I expected a much more significant speed-up as well. It's probably because a lot of that code was driven by reflection-type techniques.

Curiously, IronPython did better than anything (but still slow). Haven't tried Jython.

Compiling the whole thing with Cython was less effective than PyPy.

twa9276y ago

Yes, reflection voids many JIT paths in PyPy, AFAIK. Maybe it was worth rewriting the Python code to get rid of the reflection?

j / k navigate · click thread line to collapse

0 pointsint_19h6y ago0 comments

I had a binary parser written in Python that took around 30 seconds on typical input on CPython. PyPy took that down to about 10 seconds. Rewriting it in C# took it down to 200 ms.

0 comments

twa9276y ago

If this was using a loop processing a single byte in an iteration I would expect a greater speedup on PyPy. I've seen 100x speedup in such cases.

int_19hOP6y ago

Curiously, IronPython did better than anything (but still slow). Haven't tried Jython.

Compiling the whole thing with Cython was less effective than PyPy.

twa9276y ago

Yes, reflection voids many JIT paths in PyPy, AFAIK. Maybe it was worth rewriting the Python code to get rid of the reflection?

j / k navigate · click thread line to collapse