[racket] translate from Racket to Common Lisp

2668 msecs when I declare `cycle-length' as `(Integer -> Integer)' and
change `(even? n)' to `else', or 2809 msecs if I add `[else 0]' instead
of changing `(even? n)'.

At Sun, 4 Nov 2012 18:30:21 -0600, Robby Findler wrote:
> And just to complete the list, how does the TR version fare?
> 
> Robby
> 
> On Sun, Nov 4, 2012 at 6:26 PM, Matthew Flatt <mflatt at cs.utah.edu> wrote:
> > Thanks!
> >
> > Sometimes, a x3 difference means that we're missing a straightforward
> > opportunity in performance, and that was the case here. The Racket
> > program spent most of its time in generic `/' by pessimistically
> > expecting a non-integer result.
> >
> > I've adjusted the JIT to optimistically compute and check a fixnum
> > result for a division of fixnums, and then the example runs about four
> > times as fast on my machine:
> >
> >  Old Racket:                12589 msec
> >  New Racket:                 3850 msec
> >  Racket with `quotient':     3851 msec  [old or new is the same]
> >  SBCL:                       5553 msec
> >  SBCL, unsafe fixnum:        2692 msec
> >  New Racket, in module:      2823 msec
> >  Racket, unsafe fixnum:      2405 msec  [uses `fxquotient']
> >
> > At Sun, 4 Nov 2012 15:54:51 +0000 (UTC), daniel rupistraliz wrote:
> >>
> >>
> >>  racket:
> >> Welcome to Racket v5.2.1.
> >> > (define (cycle-length n)
> >>     (cond
> >>       [(= n 1)
> >>        1]
> >>       [(odd? n)
> >>        (add1 (cycle-length (add1 (* 3 n))))]
> >>       [(even? n)
> >>        (add1 (cycle-length (/ n 2)))]))
> >>
> >> (time (for ([i (in-range 1 1000000)])
> >>           (cycle-length i)))
> >> >
> >> cpu time: 15016 real time: 15018 gc time: 0
> >>
> >> sbcl:
> >>
> >> (defun cycle-length(n)
> >>  (cond ((= n 1) 1)
> >>        ((oddp n) (1+ (cycle-length (1+ (* 3 n)))))
> >>        ((evenp n) (1+ (cycle-length (/ n 2))))))
> >>
> >>
> >> * (time (loop for i from 1 to 1000000 do (cycle-length i)))
> >>
> >> Evaluation took:
> >>   6.192 seconds of real time
> >>   6.192387 seconds of total run time (6.192387 user, 0.000000 system)
> >>   100.00% CPU
> >>   14,496,643,427 processor cycles
> >>   0 bytes consed
> >>
> >>
> >> With optimizations:
> >>
> >> (defun cycle-length(n)
> >>   (declare (fixnum n)
> >>          (ftype (function (fixnum) fixnum) cycle-length)
> >>          (optimize (speed 3) (safety 0) (compilation-speed 0)))
> >>   (cond ((= n 1) 1)
> >>       ((oddp n) (the fixnum (1+ (cycle-length
> >>                                  (the fixnum (1+ (the fixnum (* 3 n))))))))
> >>       ((evenp n) (cycle-length (the fixnum (/ n 2))))))
> >>
> >> CL-USER> (time (loop for i from 1 to (expt 10 6) do (cycle-length i)))
> >> Evaluation took:
> >>   3.515 seconds of real time
> >>   3.524220 seconds of total run time (3.524220 user, 0.000000 system)
> >>   100.26% CPU
> >>   8,228,949,701 processor cycles
> >>   33,008 bytes consed
> >>
> >> So racket = 15 seconds
> >>     sbcl  =  6 seconds
> >> sbcl optimized = 3.5 seconds.
> >>
> >>
> >> ____________________
> >>   Racket Users list:
> >>   http://lists.racket-lang.org/users
> > ____________________
> >   Racket Users list:
> >   http://lists.racket-lang.org/users