[Python-Dev] Reordering opcodes (PEP 203 Augmented Assignment)

[Vladimir Marangozov]

M.-A. Lemburg wrote:
> 
> If you need help, I can dig up those old tools and patches...

Yes, please do. I think I'll come up with a patch posted to SF for
your collective review.

[Eric Reymond, on opcode stats by MAL]
> >           LOAD_FAST(124) :   19323126 ================================
> >          SET_LINENO(127) :   15055591 ========================
> >          LOAD_CONST(100) :    9254683 ===============
> >           LOAD_NAME(101) :    8218954 =============
> > ...
>
> Some thoughts:
>
> 1. That looks as close to a Poisson distribution as makes no difference.
>    I wonder what that means?

Well, it's difficult to say what this means without looking at the tools
that were used to generate these stats.

>
> 2. Microtuning in the implementations of the top 3 opcodes looks indicated,
>    as they seem to constitute more than 50% of all calls.

Imagine what will happen if SET_LINENO disappears <wink> But this is
very tricky business which is more complicated than it looks like...

>
> 3. On the other hand, what do you get when you weight these by average
>    time per opcode?

I haven't run 100M opcodes, but you may want to have a look at some old
micro-profiling I did long time ago:

http://starship.python.net/~vlad/tprof/

The relevant file for the main loop is:

http://starship.python.net/~vlad/tprof/pybench-0.6/python-151-orig-thr/__t.eval_code2_ceval.c

I am not sure this makes any sense by now, though.

-- 
       Vladimir MARANGOZOV          | Vladimir.Marangozov@inrialpes.fr
http://sirac.inrialpes.fr/~marangoz | tel:(+33-4)76615277 fax:76615252