SBCL on my 2012 Mac mini: rjmacmini:~$ sbcl This is SBCL 1.4.2, an implementation of ANSI Common Lisp. More information about SBCL is available at

SBCL on my 2012 Mac mini: rjmacmini:~$ sbcl This is SBCL 1.4.2, an implementation of ANSI Common Lisp. More information about SBCL is available at <http://www.sbcl.org/>. SBCL is free software, provided as is, with absolutely no warranty. It is mostly in the public domain; some portions are provided under BSD-style licenses. See the CREDITS and COPYING files in the distribution for more information. * (defun fib (n) (declare (fixnum n) (optimize (speed 3) (debug 0) (safety 0))) (if (<= n 1) 1 (the fixnum (+ (fib (- n 1)) (fib (- n 2)))))) FIB * (time (fib 46)) Evaluation took: 14.957 seconds of real time 14.947616 seconds of total run time (14.934818 user, 0.012798 system) 99.94% CPU 38,799,794,836 processor cycles 0 bytes consed 2971215073 * (SAVE-LISP-AND-DIE "/tmp/fiblisp" :toplevel (lambda (&rest args) (print (fib 46))) :executable t) ; in: SAVE-LISP-AND-DIE "/tmp/fiblisp" ; (LAMBDA (&REST ARGS) (PRINT (FIB 46))) ; ; caught STYLE-WARNING: ; The variable ARGS is defined but never used. ; ; compilation unit finished ; caught 1 STYLE-WARNING condition [undoing binding stack and other enclosing state... done] [defragmenting immobile space... 643+15263+734+344+25029+16756 objects... done] [saving current Lisp image into /tmp/fiblisp: writing 0 bytes from the read-only space at 0x20000000 writing 848 bytes from the static space at 0x20100000 writing 1863680 bytes from the immobile space at 0x20300000 writing 11472480 bytes from the immobile space at 0x21b00000 writing 26542080 bytes from the dynamic space at 0x1000000000 done] rjmacmini:~$ time /tmp/fiblisp 2971215073 real 0m14.785s user 0m14.755s sys 0m0.020s rjmacmini:~$