1 ! Copyright (C) 2009 Doug Coleman.
2 ! See http://factorcode.org/license.txt for BSD license.
3 USING: accessors arrays fry kernel locals math math.bitwise
7 ! Multiply-with-carry RNG
9 TUPLE: cmwc Q a b c i r mod ;
11 TUPLE: cmwc-seed Q c ;
13 : <cmwc> ( length a b c -- cmwc )
18 swap [ 1 - >>i ] [ 0 <array> >>Q ] bi
20 dup Q>> length 1 - >>mod ;
24 [ length 1 - >>i ] bi ;
26 M:: cmwc random-32* ( cmwc -- n )
27 cmwc dup mod>> '[ 1 + _ bitand ] change-i
29 [ [ i>> ] [ Q>> ] bi nth * ]
32 t -32 shift cmwc (>>c)
34 t cmwc [ b>> bitand ] [ c>> + ] bi 64 bits t!
36 cmwc [ 1 + ] change-c drop
37 t cmwc b>> - 64 bits t!
40 cmwc [ r>> t - 32 bits dup ] [ i>> ] [ Q>> ] tri set-nth ;
42 : cmwc-4096 ( -- cmwc )
44 [ 18782 4294967295 362436 <cmwc> ]
45 [ '[ [ random-32 ] replicate ] with-system-random seed-random ] bi ;