October 14th, 2008

Ioke runs iterative fibonacci


Today Ioke actually runs both recursive and iterative fibonacci. That might not seem as much, but the work to get that has put in place much of the framework needed for the rest of the implementation.

It’s a nice milestone, since Ioke is now Turing complete (having both conditionals and iteration). Most of the neat features I’m planning aren’t actually implemented yet, though.

In the time honored tradition of language performance measuring, I decided to compare iterative fibonacci performance to Ruby.

Keep in mind that I haven’t done any optimizations whatsoever, and I do loads of really expensive stuff all over Ioke. Specifically, there is no such thing as locals – what looks like locals here are actually regular attributes of a Context object. All lookup of names are using hash tables at the moment. It’s also fully interpreted code. Nothing is being compiled at this point. I’m running all the examples on SoyLatte (Java 1.6) on a MBP. I used the JVM -server flag when running Ioke and JRuby.

The Ruby code looks like this:

require 'benchmark'

def fib_iter_ruby(n)
   i = 0
   j = 1
   cur = 1
   while cur <= n
     k = i
     i = j
     j = k + j
     cur = cur + 1
   end
   i
end

puts Benchmark.measure { fib_iter_ruby(300000) }
puts Benchmark.measure { fib_iter_ruby(300000) }

And the Ioke code looks like this. I don’t have any benchmarking libraries yet, so I measured it using time:

fib = method(n,
  i = 0
  j = 1
  cur = 1
  while(cur <= n,
    k = i
    i = j
    j = k + j
    cur++)
  i)

System ifMain(fib(300000))

And what are the results? Not surprisingly, JRuby does well on this benchmark, and would probably do even better if I ran more iterations. The JRuby (this is current trunk, btw) time for calculating fib(300000) was 7.5s. MRI (ruby 1.8.6 (2008-03-03 patchlevel 114) [i686-darwin8.10.1]) ended up at exactly 14s. So where is Ioke in all this? I’m happy to say Ioke ended up taking 9.2s. I was really pleasantly surprised by that. But I have a feeling that recursive fib might not end up with those proportions. But the indication is that I haven’t done anything amazingly expensive yet, at least. That’s a good sign, although I have no problem sacrificing performance for expressability.

5 Comments | By Ola Bini | In: ioke | tags: , , . | #