Comment by igouy | Hacker News Reader

Comment by igouy | Hacker News Reader

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READER BEWARE!

>>our versions got rejected because they perform slower on CPython (while being faster on PyPy)<<

Maciej Fijalkowski knows that I asked him to contribute a PyPy version of n-body because the written-for-CPython version failed with PyPy.

Maciej Fijalkowski knows that his own PyPy version of n-body "performed slower on CPython (while being faster on PyPy)" -- AND WAS NOT REJECTED.

http://mail.python.org/pipermail/pypy-dev/2011-April/007177....

Justify your accusation or take it back!

>> you can use gmp library for C, CPython, but not PyPy via ctypes <<

Joe La Fata's pi-digits code worked first time on x86 and x64, on PyPy and CPython and Python3; and used ctypes to get to GMP -- AND WAS NOT REJECTED

http://anonscm.debian.org/viewvc/shootout/shootout/bench/pid...

Justify your accusation or take it back!

>> C can use a bad random (that's fast, but also gives a really bad distribution), while PyPy not because Python comes with a random in stdlib <<

The fasta task uses random numbers, and every fasta program (including C and Python) implements the same random function.

http://shootout.alioth.debian.org/u32/program.php?test=fasta...

http://shootout.alioth.debian.org/u32/program.php?test=fasta...

Justify your accusation or take it back!

----

Tell Maciej Fijalkowski to justify his accusations!

Look Igor -- I don't care how things are now since PyPy got kicked out anyway, so I seriously don't care any more.

gmpy uses C extension, it's not using ctypes. We disagreed over a ctypes version at some point.

random - indeed it got fixed (and it's too late to edit a parent if you wonder)

>> we were not allowed to use array.array module, despite being in standard library. <<

2 April 2011, Joe LaFata contributed a faster for PyPy spectral-norm program. His program worked first time on x86 and x64, on PyPy and CPython and Python 3. His program was measured and published within 24 hours.

    from array     import array

http://shootout.alioth.debian.org/u32/program.php?test=spect...

Justify your accusation or take it back!

>> gmpy uses C extension, it's not using ctypes. <<

    import ctypes
    from ctypes.util import find_library

 	_libgmp = ctypes.CDLL(find_library("gmp"))

 	class mpz_t_struct(ctypes.Structure):
 	_fields_ = [("mp_alloc", ctypes.c_int),
 	("mp_size", ctypes.c_int),
 	("mp_d", ctypes.c_void_p)]

>> random - indeed it got fixed <<

Nonsense! The fasta task has ALWAYS required ALL the programs to implement the same random function.

(Use a different random function and the program output will fail the diff.)

>> so I seriously don't care any more <<

You don't seem to care that your accusations are demonstrably false.

seriously, I don't think this is the correct medium - however you did refuse our solution using ctypes and you did refuse our solution using array at some point. Maybe you changed your mind later. This is one example:

http://mail.python.org/pipermail/pypy-dev/2011-April/007169....

You also kicked PyPy out around the same time the array benchmark was introduced (within days).

>> I don't think this is the correct medium <<

You chose to make false accusations here.

>> however you did refuse our solution using ctypes and you did refuse our solution using array at some point <<

You don't seem to know what program was supposedly refused for using array - so why do you continue to make that accusation?

Presumably by "our solution using ctypes" you mean Alex Gaynor's revcomp program - I'll say something about that where you linked to his blog post.

>> You also kicked PyPy out around the same time the array benchmark was introduced (within days). <<

No more than coincidence -- Joe LaFata contributed excellent PyPy pi-digits, spectral-norm, mandelbrot programs in one week; and they were all accepted.

This is a full writeup: http://alexgaynor.net/2011/apr/03/my-experience-computer-lan...

You're correct, I got my facts wrong. We were allowed to use ctypes for gmpy, but not for something else. We weren't allowed to submit a ctypes-using and array-using benchmark that didn't work on CPython due to a CPython bug.

the end result of us trying to be slightly better was that we ended up being kicked and a few other people ended up being kicked as well, though they weren't really guilty.

Overall the experience was that the results are not "fair" and are guarded by arbitrary rules that are not really written anywhere. One of those rules is that an arbitrary (typically most popular, but not necesarilly so) implementation is only allowed. This makes it much less trustworthy that it can actually be.

>> a full writeup <<

No.

The blog post tell's us that Alex Gaynor confirmed "with some CPython core developers" that his program didn't work because of a bug in CPython.

But the blog post doesn't tell us that Alex Gaynor never said there was any problem with a CPython bug.

Alex Gaynor's blog post tell's us that "It's also not possible to send any messages once your ticket has been marked as closed, meaning to dispute a decision you basically need to pray the maintainer reopens it for some reason."

But that's completely untrue! You can send messages when the ticket is marked closed! And you can open topics in the public forum! And you can click on a username and send email in 2 clicks.

There just wouldn't be any story to blog about, if Alex Gaynor admitted that he could easily have told me -- the bug is in CPython not in my program, so show my program -- but chose to say nothing.

>> arbitrary rules that are not really written anywhere ... an arbitrary ... implementation is only allowed <<

Have you even read the home page?

"There exist multiple implementations for some programming languages - different C++ compilers, different Java VMs - but those other language implementations are not shown here."

Cool that you're linking to this mail, this shows yet another problem that I forgot about - that pypy extensions are uncool, while GCC extensions are cool (and say a custom malloc library for GCbench - after all the benchmark does not do anything, an empty malloc would do just fine).

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