[plt-scheme] Number crunching -> Matthias, Eli

Have you considered benchmarking STALIN?




On Jul 2, 2009, at 11:47 PM, Philippos Apolinarius wrote:

> I think that number crunching is so important that it should  
> receive ad hoc optimization, if a more general approach fails. To  
> bring the discussion to a concrete example, I attached a small  
> benchmark to this article.  PLT, Bigloo and Gambit take about the  
> same time to run the program below. However, Bigloo and Gambit  
> become ten times faster with a very simple optimization.
>
>  (define-syntax $
>      (syntax-rules ()
>        ( ($ m c i j) (vector-ref m (+fx (*fx c i) j)))
>      )
>   )
>
>   (define-syntax $!
>      (syntax-rules ()
>        ( ($! m c i j v) (vector-set! m (+fx (*fx c i) j) v))
>      )
>    )
>
> BTW, use the option -Obench to compile Bigloo. When one uses the  
> *fx, +fx, *fl, +fl and /fl in few other places, Bigloo speed is  
> multiplied by 20 (the time is divided by 20). It would be great if  
> PLT had similar directives to control optimization.
>
> If I missed something, and there is a way to make PLT approach the  
> speed of Bigloo and Gambit in the example below, please let me  
> know.  However, I read an article in this list, where you people  
> suggest exactly this, to add unsafe arithmetic operators to improve  
> performance.
>
>
>
> (module matplt scheme
>    (require (lib "4.ss" "srfi"))
>
>   (define iii 0)
>
>  (define-syntax $mk
>     (syntax-rules ()
>        ( ($mk c v) (make-vector c v)) ))
>
>  (define-syntax $
>      (syntax-rules ()
>        ( ($ m c i j) (vector-ref m (+ (* c i) j)))
>      )
>   )
>
>   (define-syntax $!
>      (syntax-rules ()
>        ( ($! m c i j v) (vector-set! m (+ (* c i) j) v))
>      )
>    )
>
>
>
>
> (define (prt m r c)
>    (do ( (i 0 (+  i 1)) ) ( (>=  i r) )
>       (newline)
>       (do ((j 0 (+  j 1)) )  ( (>=  j c) )
>          (printf " %4.3f " ($ m c i j) ) )))
>
> (define (make-system r)
>   (let* ( (c (+  r 1))
>           (m ($mk (*  r c) 0.0 ))
>           (xx 0.0)
>           (s 0.0) )
>
>     (do ( (i 0 (+  i 1))  ) ( (>=  i r) m)
>        (set! s 0.0)
>        (do ((j 0 (+  j 1) ) ) ( (>=  j r) ($! m c i j  s) )
>           (set! xx (exact->inexact (random 3873)))
>           (set! s (+ s xx))
>           ($! m c i j xx )) )  ))
>
> (define (swapit m c k l)
>   (let ((t 0.0))
>    (set! iii (+  iii 1))
>    (do ( (j 0 (+  j 1)) ) ( (>=  j c) )
>       (set! t ($ m c k j ) )
>       ($! m c k j  ($ m c l j) )
>       ($! m c l j t) )  )  )
>
> (define (find-max m c k i)
>     (do ( (l (+  k 1) (+  l 1)) )
>         ( (>=  l (-  c 1)) (when (not (= i k))  (swapit m  c k i )))
>       (when (> (abs ($ m c l k)) (abs ($ m c i k)) )
>             (set! i l) )  ))
>
> (define (solvit m r)
>    (let ( (c (+  r 1))
>            (rat 0.0)
>            (mkk 0.0))
>
>       (do ( (k 0 (+  k 1)) ) ( (>=  k (-  r 1)))
>         (find-max m c k k)
>         (set! mkk ($ m c  k k) )
>
>         (do ( ( i (+  k 1)(+  i 1)) ) ( (>=  i r))
>            (set! rat (/  ($ m c i k) mkk  ))
>              (do ( (j  k  (+  j 1))) ( (>=  j c) )
>                  ($! m c i j (- ($ m c i j)
>                                    (* rat ($ m c k j ) ) ) )
>              )
>           )
>        )
>
>      (do ( (i (-  r 1) (-  i 1) ) ) ((<  i 0) m)
>         (do ( (j (+  i 1) (+  j 1))
>               (tx 0.0 (- tx (* ($ m c i j)
>                                ($ m c j r    )) )) )
>             ( (>=  j r)
>               ($! m c i r
>                  (/ (+ ($ m c  i r ) tx)
>                        ($ m c i i)) ) ) ))
>    )
> )
>
> (define (elms argv)
>   (cond ( (<  (length argv) 2) 2000)
>         ( (string->number (cadr argv)) (string->number (cadr argv)) )
>         (else 2000)))
>
> (define (main argv)
>    (let* ( (r (elms argv)) (c (+  r 1)) (m (solvit (make-system r)  
> r) ) )
>       (do ( (i 0 (+  i 1))) ( (>=  i (min r 10)) )
>           (display  (list($ m c i r)) )  )
>    (newline)
>    (newline) (display iii)) )
>
>    (time (main '(xx "500")))
>
> )
>
>
>
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