This post originated from an RSS feed registered with Ruby Buzz by Eigen Class. Original Post: Over two orders of magnitude faster with YARV, yay for algorithmical optimization Feed Title: Eigenclass Feed URL: http://feeds.feedburner.com/eigenclass Feed Description: Ruby stuff --- trying to stay away from triviality. Latest Ruby Buzz Posts Latest Ruby Buzz Posts by Eigen Class Latest Posts From Eigenclass

Did you know that YARV features magic opcodes (not enabled by default) that can perform extensive algorithmical optimization on a number of programs?

You just have to write your program*1 with some care and enable the optimizations at compile-time:

def ack(m, n)
  if m == 0 then
    n + 1
  elsif n == 0 then
    ack(m - 1, 1)
  else
    ack(m - 1, ack(m, n - 1))
  end
end

def the_answer_to_life_the_universe_and_everything
  ack(3,7).to_s.split(//).inject(0){|s,x| s+x.to_i}.to_s + "2" 
end

t = Time.new
answer = the_answer_to_life_the_universe_and_everything
sleep(0.02) # let's take a moment to ponder about the significance of that result
puts "Got THE answer (#{answer}) in #{Time.new-t} seconds."

Here's the output under a fairly recent 1.9.0

ruby 1.9.0 (2006-01-14) [i686-linux]
Got THE answer (42) in 1.815401 seconds.

And this is with YARV, Saint Valentine special edition:

ruby 1.9.0 (2006-02-14) [i686-linux]
YARVCore 0.3.3 (rev: 419) [opts: ]
Got THE answer (42) in 0.027716 seconds.

Yes, that's two orders of magnitude, just by rearranging the code a bit!

It gets even better: there's no bound to the amount of time we can save with YARV!!!

Generalization