anchor.diff:      (let* ((ifps (/ 1.0 (/ milliseconds 1000.0)))
              (interactions-per-second (/ (* num-bodies num-bodies iterations)
                                          (/ milliseconds 1000)
  -                                       (1.0e9)))
  -           (gflops (* interactions-per-second *flops-per-interactions*)))
  +                                       1.0e9))
  +           (gflops (* interactions-per-second *flops-per-interaction*)))
         (values ifps interactions-per-second gflops))))
   
   (let ((fps-count 0)
  
positive.code:     (incf fps-count)
      (when (>= fps-count fps-limit)
        (multiple-value-bind (ifps interactions-per-second gflops)
                             (compute-perf-stats num-bodies (get-elapsed-time) fps-count 1)
          (glut:set-window-title
            (format nil template num-bodies ifps interactions-per-second gflops))
          (setf fps-count 0)
  
negative.code:           stop-event (cffi:foreign-alloc 'cu-event))
      (cu-event-create start-event cu-event-default)
      (cu-event-create stop-event cu-event-default))
    
    (defun destroy-timer-events ()
      (cu-event-destroy (cffi:mem-ref start-event 'cu-event))
      (cu-event-destroy (cffi:mem-ref stop-event 'cu-event))
  