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2 points by fallintothis 5547 days ago | link | parent

Another benchmark ported from an SBCL version (http://shootout.alioth.debian.org/u32q/benchmark.php?test=pi...), pidigits:

  (= digits-per-line*     10
     default-stop-digits* 1000)

  (def make-digit-generator ()
    (with (zq 1 zr 0 zt 1 k 0 4k+2 2 2k+1 1)
      (with (extract [trunc:/ (+ (* zq _) zr) zt]
             comp    (fn (aq ar at bq br bt)
                       (= zq (* aq bq)
                          zr (+ (* aq br) (* ar bt))
                          zt (* at bt))))
        (fn ()
          (let y (extract 3)
            (until (is y (extract 4))
              (comp zq zr zt (++ k) (++ 4k+2 4) (++ 2k+1 2))
              (= y (extract 3)))
            (comp 10 (* -10 y) 1 zq zr zt)
            y)))))

  (def spigot ((o digits default-stop-digits*))
    (with (digits-printed 0
           next-digit     (make-digit-generator))
      (while (> digits 0)
        (if (>= digits digits-per-line*)
            (do (repeat digits-per-line* (pr (next-digit)))
                (++ digits-printed digits-per-line*))
            (do (repeat digits (pr (next-digit)))
                (sp (- digits-per-line* digits))
                (++ digits-printed digits)))
        (prn "\t:" digits-printed)
        (-- digits digits-per-line*))))

  (= benchmark time:spigot)
Then

  Use (quit) to quit, (tl) to return here after an interrupt.
  arc> (load "pidigits.arc")
  nil
  arc> (benchmark)
  3141592653      :10
  5897932384      :20
  6264338327      :30
  9502884197      :40
  1693993751      :50
  0582097494      :60
  4592307816      :70
  4062862089      :80
  9862803482      :90
  5342117067      :100
  9821480865      :110
  1328230664      :120
  7093844609      :130
  5505822317      :140
  2535940812      :150
  8481117450      :160
  2841027019      :170
  3852110555      :180
  9644622948      :190
  9549303819      :200
  6442881097      :210
  5665933446      :220
  1284756482      :230
  3378678316      :240
  5271201909      :250
  1456485669      :260
  2346034861      :270
  0454326648      :280
  2133936072      :290
  6024914127      :300
  3724587006      :310
  6063155881      :320
  7488152092      :330
  0962829254      :340
  0917153643      :350
  6789259036      :360
  0011330530      :370
  5488204665      :380
  2138414695      :390
  1941511609      :400
  4330572703      :410
  6575959195      :420
  3092186117      :430
  3819326117      :440
  9310511854      :450
  8074462379      :460
  9627495673      :470
  5188575272      :480
  4891227938      :490
  1830119491      :500
  2983367336      :510
  2440656643      :520
  0860213949      :530
  4639522473      :540
  7190702179      :550
  8609437027      :560
  7053921717      :570
  6293176752      :580
  3846748184      :590
  6766940513      :600
  2000568127      :610
  1452635608      :620
  2778577134      :630
  2757789609      :640
  1736371787      :650
  2146844090      :660
  1224953430      :670
  1465495853      :680
  7105079227      :690
  9689258923      :700
  5420199561      :710
  1212902196      :720
  0864034418      :730
  1598136297      :740
  7477130996      :750
  0518707211      :760
  3499999983      :770
  7297804995      :780
  1059731732      :790
  8160963185      :800
  9502445945      :810
  5346908302      :820
  6425223082      :830
  5334468503      :840
  5261931188      :850
  1710100031      :860
  3783875288      :870
  6587533208      :880
  3814206171      :890
  7766914730      :900
  3598253490      :910
  4287554687      :920
  3115956286      :930
  3882353787      :940
  5937519577      :950
  8185778053      :960
  2171226806      :970
  6130019278      :980
  7661119590      :990
  9216420198      :1000
  time: 94562 msec.
  nil
Versus the same run in GNU clisp with the Shootout's SBCL code:

  > (time (spigot 1000))

  [OUTPUT ELIDED]

  Real time: 1.022299 sec.
  Run time: 0.888055 sec.
  Space: 104310256 Bytes
  GC: 133, GC time: 0.420025 sec.
  NIL
Their outputs were the same, so the Arc program seems to be working (to say nothing of its optimality; I basically did a straight port). This benchmark's fun if only because you get to watch pi being calculated before your eyes. Nifty algorithm.


2 points by conanite 5540 days ago | link

This is an awesome reference, thanks. I'll be using a few of these. The pi calculation uncovered a rainbow weakness: rainbow relies on java "long" integers for 'int types; but these are 64-bit signed integers and the algorithm fails at the 5th digit. So I'll need to think of a way to incorporate arbitrary-precision maths before I can run this benchmark. One thing is certain: using java's BigXXX family of numeric types is going to hurt.

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