;; this file:
;;   https://dataswamp.org/~incal/cl/bench/timing.cl
;;
;; code from:
;;   https://cl-cookbook.sourceforge.net/dates_and_times.html
;;   https://drmeister.wordpress.com/2015/07/30/timing-data-comparing-cclasp-to-c-sbcl-and-python/

(defmacro timing (&body forms)
    (let ((real1 (gensym))
          (real2 (gensym))
          (run1  (gensym))
          (run2  (gensym))
          (res   (gensym)))
    `(let*((,real1 (get-internal-real-time))
           (,run1  (get-internal-run-time))
           (,res   (progn ,@forms))
           (,run2  (get-internal-run-time))
           (,real2 (get-internal-real-time)))
       (format *debug-io* ";; ~f s real time~%"
         (/ (- ,real2 ,real1) internal-time-units-per-second))
       (format t ";; ~f s run time~%"
         (/ (- ,run2 ,run1) internal-time-units-per-second))
       ,res)))