From: Eric Hodel <drbrain@...7.net>
Date: 2005-05-04T07:45:47+09:00
Subject: Re: I rock.

On 03 May 2005, at 15:21, Ryan Davis wrote:

> On May 3, 2005, at 1:32 PM, Gyoung-Yoon Noh wrote:
>
>> Python has PyRex which enables writing CPython extensions
>> with python-like syntax. I guess Ruby2RubyC can do a foundation
>> role for future great works such as writing extensions with ruby
>> syntax, enhancing performance easily with type conversion,
>> or can be used as intermediate format for translating Ruby to C.
>
> Ruby2RubyC will probably not, for the first few months at least, 
> improve performance with any sort of type conversion at all. In fact, 
> I suspect that Eric's current version will start to get fairly severe 
> penalties until we move away from using rb_funcall for everything.

Yup, it only bypasses the fast parts of eval.c (AST walking), and none 
of the slow parts (rb_funcall) so you get almost zero speed benefit out 
of it currently.  (See the "time factorial(9999)" output further up the 
thread).

> If you want performance then you should either hand write (using 
> RubyInline!) or take a peek at zenoptimizer when it gets released in 
> my ZenHacks package (it uses a combination of ruby2c and rubyinline 
> with a custom lightweight profiler I wrote last week).

Yes.  When you find a slow part, you could use this as your template.  
You'll have working Ruby/C code to refactor into faster C code in no 
time at all.

I should be able to skip rb_funcall for places where I know the types, 
and directly call the C implementation of a method.  That will be more 
work though, because I'll have to fall back in case a TypeError is 
raised in addition to pulling the right bits from the VALUE.

Or something.

-- 
Eric Hodel - drbrain@segment7.net - http://segment7.net
FEC2 57F1 D465 EB15 5D6E  7C11 332A 551C 796C 9F04