Re: [jamboost] Optimization

From: Vladimir Prus (ghost_at_[hidden])
Date: 2003-12-15 00:55:48

Hi Jürgen,

> > I would appreciate help with further optimizations.
>
> I don't know if I can free enough time to hack something. But I can help
> testing, as always ;-)

That's good help already.

> > First way to help is to run the current version on your project and
> > send me the profile. To get profile you can use "bjam -n -d+10 >
> > profile" Since I don't know how anonymous CVS works at the moment,
>
> I think anon cvs it up to up date now.

That's good to know!

> Second way to help is optimize something. Just look at your profile
>
> > (I usually import it into spreadsheet), sort by execution time, and
> > pick a rule which you'd like to optimize. I think best canditates are
> > "utils" rule, which are frequently called, but are not so complex in
> > intself. Then, optimize the rule ;-), e.g. by implementing it in "C".
>
> By which column shall I sort ?
> I've got "gross", "net" and "#entries". What do they mean exactly ?

#entries is the number of times a rule is called
gross is the total time spend in the rule and all rules called from it
net is the total time spend in the rule itself (excluding children).

As for which column to sort --- I use both net and cross, depending on current 
mood ;-) The net time is easier to interpret -- it estimeates the speedup you 
can get if you rewrite all the rule in C. The gross time may indicate larger 
blocks of inefficiency.

> And where can I find information about debug output except the source
> itself ?

Oops :-( Nowhere, I'm afraid.

- Volodya