fibs benchmark performed by our Japanese friends: http://cx4a.blogspot.com/2011/09/clojure-13.html
(defn fib ^long [^long n]
(if (<= n 1)
1
(+ (fib (dec n)) (fib (- n 2)))))(defun fib (n)
(declare (optimize (speed 3) (safety 0))
(fixnum n))
(if (<= n 1)
1
(the fixnum (+ (fib (1- n)) (fib (- n 2))))))