1 ! Copyright (C) 2007, 2008 Slava Pestov, Doug Coleman.
2 ! See http://factorcode.org/license.txt for BSD license.
3 USING: arrays assocs combinators combinators.smart fry kernel
4 macros math math.bits sequences sequences.private words ;
8 : clear-bit ( x n -- y ) 2^ bitnot bitand ; inline
9 : set-bit ( x n -- y ) 2^ bitor ; inline
10 : bit-clear? ( x n -- ? ) 2^ bitand 0 = ; inline
11 : unmask ( x n -- ? ) bitnot bitand ; inline
12 : unmask? ( x n -- ? ) unmask 0 > ; inline
13 : mask ( x n -- ? ) bitand ; inline
14 : mask? ( x n -- ? ) mask 0 > ; inline
15 : wrap ( m n -- m' ) 1 - bitand ; inline
16 : bits ( m n -- m' ) 2^ wrap ; inline
17 : mask-bit ( m n -- m' ) 2^ mask ; inline
18 : on-bits ( n -- m ) 2^ 1 - ; inline
19 : toggle-bit ( m n -- m' ) 2^ bitxor ; inline
21 : shift-mod ( n s w -- n )
22 [ shift ] dip 2^ wrap ; inline
24 : bitroll ( x s w -- y )
26 [ shift-mod ] [ [ - ] keep shift-mod ] 3bi bitor ; inline
28 : bitroll-32 ( n s -- n' ) 32 bitroll ; inline
30 : bitroll-64 ( n s -- n' ) 64 bitroll ; inline
33 : w+ ( int int -- int ) + 32 bits ; inline
34 : w- ( int int -- int ) - 32 bits ; inline
35 : w* ( int int -- int ) * 32 bits ; inline
38 : W+ ( int int -- int ) + 64 bits ; inline
39 : W- ( int int -- int ) - 64 bits ; inline
40 : W* ( int int -- int ) * 64 bits ; inline
43 MACRO: flags ( values -- )
44 [ 0 ] [ [ ?execute bitor ] curry compose ] reduce ;
46 : symbols>flags ( symbols assoc -- flag-bits )
53 GENERIC: (bitfield-quot) ( spec -- quot )
55 M: integer (bitfield-quot) ( spec -- quot )
56 [ swapd shift bitor ] curry ;
58 M: pair (bitfield-quot) ( spec -- quot )
59 first2 over word? [ [ swapd execute ] dip ] [ ] ?
60 [ shift bitor ] append 2curry ;
64 MACRO: bitfield ( bitspec -- )
65 [ 0 ] [ (bitfield-quot) compose ] reduce ;
76 8 <bits> 0 [ [ 1 + ] when ] reduce
77 ] B{ } map-as '[ HEX: ff bitand _ nth-unsafe ]
78 (( byte -- table )) define-declared
80 \ byte-bit-count make-inline
84 GENERIC: (bit-count) ( x -- n )
90 [ -8 shift byte-bit-count ]
91 [ -16 shift byte-bit-count ]
92 [ -24 shift byte-bit-count ]
98 [ byte-bit-count ] [ -8 shift (bit-count) ] bi +
103 : bit-count ( x -- n )
104 dup 0 < [ bitnot ] when (bit-count) ; inline
106 : >signed ( x n -- y )
107 2dup neg 1 + shift 1 = [ 2^ - ] [ drop ] if ;
109 : >odd ( n -- int ) 0 set-bit ; foldable
111 : >even ( n -- int ) 0 clear-bit ; foldable
113 : next-even ( m -- n ) >even 2 + ; foldable
115 : next-odd ( m -- n ) dup even? [ 1 + ] [ 2 + ] if ; foldable