From: "Mauricio Fernández" <mfp@...>
Date: 2005-07-22T02:59:12+09:00
Subject: Re: C extension makes things slower

On Fri, Jul 22, 2005 at 02:05:56AM +0900, Phil Tomson wrote:
> In article <42DF4F1D.2060607@capitain.de>,
> Pit Capitain  <pit@capitain.de> wrote:
> >Phil Tomson schrieb:
> >> And the results:
> >> l% ruby point.rb
> >>   Total time for pure ruby point test: 8.600752
> >>   ACO_Ext initializing...
> >>   Total time for extension point test: 6.086567
> However, here's the result of another run:
> 
>   Total time for pure ruby point test: 8.051388
>   ACO_Ext initializing...
>   Total time for extension point test: 9.212984

You're doing things like

static VALUE aco_point_diff(VALUE self, VALUE other){
  double self_x = NUM2DBL(rb_iv_get(self, "@x"));
  double self_y = NUM2DBL(rb_iv_get(self, "@y"));
  double other_x= NUM2DBL(rb_iv_get(other, "@x"));
  double other_y= NUM2DBL(rb_iv_get(other, "@y"));
  double xdiffsq= pow( (self_x - other_x),2 );
  double ydiffsq= pow( (self_y - other_y),2 );
  return rb_float_new(sqrt( xdiffsq  +  ydiffsq ) );

}

when you probably want something resembling

typedef struct {
        double x;
        double y;
} ACO_Point_Struct;

static VALUE
aco_point_diff(VALUE self, VALUE other)
{
  ACO_Point_Struct *_self, *_other;
  double dx, dy;

  Data_Get_Struct(self, ACO_Point_Struct, _self);
  Data_Get_Struct(other, ACO_Point_Struct, _other);

  dx = _self->x - _other->x;
  dy = _self->y - _other->y;
  return rb_float_new(sqrt(dx * dx + dy * dy));
}

etc


-- 
Mauricio Fernandez