gistfile1.rb

require 'benchmark'
 
def fibonacci(n)
  def fib(current, nxt, n)
    return current if n == 0
 
    fib(nxt, current + nxt, n - 1)
  end
 
  fib(0, 1, n)
end
 
puts Benchmark.measure { fibonacci 5000 }
 
RubyVM::InstructionSequence.compile_option = {
  :tailcall_optimization => true,
  :trace_instruction => false }
 
eval <<end
  def fibonacci(n)
    def fib(current, nxt, n)
      return current if n == 0
 
      fib(nxt, current + nxt, n - 1)
    end
 
    fib(0, 1, n)
  end
end
 
puts Benchmark.measure { fibonacci 5000 }