OpenEuphoria

Re: Speed of global function

• Posted by Robert Craig <rds at RapidEuphoria.com> Aug 16, 2003
• 390 views

jxliv7 at hotmail.com wrote:
> Rob, this doesn't make sense.
> 
> execution time range in seconds with various iterations and elements
> t =  3.02	   30.65      17.03	copy of RDS code
> s =  3.96	   39.44      22.3      Ricardo's code
> r =  2.3	   22.9       12.65 	RDS code
> 							
> Ricardo, the guy who wrote the original Test2 claimed that it
> was sometimes faster than your global routine.
> 
> i am thoroughly confused. can you help me see what's going on...?

So you seem to be saying that the official reverse() in misc.e
is the fastest, but you are concerned that a similar routine
that you coded using different variables is quite a bit slower.
You also found Ricardo Forno's reverse to be slower than
the official one.

I just tried your code on my Pentium-4 machine,
and it showed Forno's routine to be the fastest (by 20%
over the official), your rewritten reverse() to be 2nd fastest and
the official one to be third fastest, although
yours and the official one were very close.

On my Pentium-2 under Linux I got essentially the same
results, but the gap between fastest and slowest was narrow.

A few years ago, on this list, we considered several
different ways of doing reverse(), and I remember
that the top contenders were pretty close, and
sometimes the relative order varied
from one machine to the next. I can't really explain it,
but when you have small loops the modern Pentiums do some
really sophisticated and unpredictable stuff to
speed things up.

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