[Python-Dev] Python 3 optimizations...

[stefan brunthaler]

> wpython has reached 1.1 final version. If you are interested, you can find
> it here: http://code.google.com/p/wpython2/ and you can download the new
> slides that cover the improvements over 1.0 alpha.
>
Thanks for the hint, I will definitely check your new slides.


> Did you used wpython wordcode format, or a new one?
>
No, actually I was well into working on my stuff when you announced
wpython last year. My latest instruction format uses a native machine
word (64bit) that contains two 32bit halves with the opcode in the
lower half and the operand in the upper half. While the opcode
certainly does not exceed 10bits or so, I need more than a byte to
support more operations (my latest interpreter has 395 instructions).
Our instruction decoding is almost identical, though.


> Yes, you're right. wpython approach is to encode as much information as it
> can to save space, decoding time, "specialize" some opcodes, etc..
>
Yes, I see that wpython eliminates common instruction sequences. From
my understanding, it corresponds to using static superinstructions in
combination with a changed instruction format. Aside of the
optimizations in the operation implementation wpython allows to
eliminate some instruction dispatches, which are notoriously
inefficient. I think it is a very nice approach and some form of
inline caching with quickening might well boost performance even more.

Cheers,
--stefan