[Python-Dev] Pie-thon benchmarks (original) (raw)

Tim Peters tim.one at comcast.net
Mon Dec 15 15:21:16 EST 2003

[Tim]

"Not that hard" depends on your background. The idea is to bury Dan under esoteric algorithms from a huge number of obscure specialties .

[Dan Sugalski]

Heh. You're expecting me to do far too much work. I plan on tackling bytecode optimization only if it turns out that a straightforward transform from python bytecode to parrot bytecode is isn't sufficiently faster than CPython. Funky algorithms expressed entirely in python bytecode won't make much of a difference...

There is a serious point buried in this. This is how Python spells small-int multiplication in the bytecode:

BINARY_MULTIPLY

And this is how it spells unbounded-int Karatsuba multiplication in the bytecode:

BINARY_MULTIPLY

Same thing, and floating multiply, complex multiply, catenating N copies of a string, and arbitrary user-defined Python code overloading infix "*" for a class are spelled BINARY_MULTIPLY in the bytecode too. There's simply nothing in the bytecode to distinguish these cases.

It wouldn't be hard for Guido to construct a vanilla-looking Python program that tickles some of the extreme-win special cases in the type-dependent implementations of the operators. That wouldn't be fair, so I'll hit him if he does , but in some smaller senses it can't be avoided. For example, all idiomatic Python programs use dicts (hashes), and the dict implementation dynamically keeps track of whether any non-string key has been added (Python dicts can be indexed by lots of things, not just strings). So long as it hasn't, special methods specialized to string keys are used; but as soon as, e.g., a float key is added, a Python dict switches to using slower, more-general methods. None of that is reflected in the bytecode, of course. There's a lot of stuff like that.

pystone tickles little of that nature, because pystone is such an atypical Python program. So, regardless of what the official benchmark turns out to be, I'll probably be more interested in your pystone result .

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