OpenEuphoria

Re: Speed: sprintf vs. & operator

• Posted by Robert Craig <rds at RapidEuphoria.com> Jan 07, 2003
• 496 views

Rolf Schroeder writes:
> > t = time()
> > for i = 1 to 10000000 do
> >      fullName = fn & " " & mn & " " & ln
> > end for
> > ? time() - t
> > 
>
> Rob, could you spend a short explanation for this enhancement?

I've optimized expressions that contain multiple concatenations, e.g.

     x = a & b & c & d & ...

In 2.3 (interpreter or translator) it does a straightforward 
left to right evaluation, something like:
    temp1 = a & b          -- allocate space for temp1, copy a, copy b
    temp2 = temp1 & c  -- allocate space for temp2, copy temp1, copy c
    temp3 = temp2 & d  -- etc.
    etc.

This is the way that operators and operands are normally
evaluated (in just about any language).

In 2.4, to speed things up, the interpreter and translator do:
    
   x = a & b & c & d & ...

In *one* step, allocating space for the *final* result x,
then copying the data for a, b, c, d, ... *once* each.
So instead of allocating space multiple times,
it's done once. And instead of copying some of the input data
multiple times (in effect), each input is copied *once* to the
final destination.

> Do you have to offer more such impressive improvements for 2.4?

There are some other optimizations in 2.4,
such as most slices being 30% faster etc.
It should all be released in a couple of weeks.

Regards,
   Rob Craig
   Rapid Deployment Software
   http://www.RapidEuphoria.com