(defun sb-sprof-example-fun (x y)
  (declare #+(or) (type fixnum x)
           (type (unsigned-byte 16) y))
  (dotimes (i y)
    ;; exercise: see what happens when you replace
    ;; the quotient with (1+ most-positive-fixnum)
    (setf x (mod (+ x x) most-positive-fixnum)))
  (sleep 0.01)
  (values x (mod x y)))

(defun sb-sprof-example (&optional (mode :cpu))
  (declare (type (member :time :cpu :alloc) mode))
  (sb-sprof:with-profiling
      (:mode mode :report :flat 
       :loop t :max-samples 1000)
    (dotimes (i 200)
      (sb-sprof-example-fun 3 #xffff))))