source: vendor/FreeBSD-yacc/current/warshall.c@ 3181

Last change on this file since 3181 was 2464, checked in by bird, 20 years ago

FreeBSD CVS 2005-07-07

File size: 3.3 KB
Line 
1/*
2 * Copyright (c) 1989 The Regents of the University of California.
3 * All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Robert Paul Corbett.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 * must display the following acknowledgement:
18 * This product includes software developed by the University of
19 * California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 */
36
37#if 0
38#ifndef lint
39static char sccsid[] = "@(#)warshall.c 5.4 (Berkeley) 5/24/93";
40#endif
41#endif
42
43#include <sys/cdefs.h>
44__FBSDID("$FreeBSD: src/usr.bin/yacc/warshall.c,v 1.12 2002/04/09 11:39:05 ru Exp $");
45
46#include "defs.h"
47
48static void transitive_closure(unsigned *, int);
49
50static void
51transitive_closure(R, n)
52unsigned *R;
53int n;
54{
55 int rowsize;
56 unsigned i;
57 unsigned *rowj;
58 unsigned *rp;
59 unsigned *rend;
60 unsigned *ccol;
61 unsigned *relend;
62 unsigned *cword;
63 unsigned *rowi;
64
65 rowsize = WORDSIZE(n);
66 relend = R + n*rowsize;
67
68 cword = R;
69 i = 0;
70 rowi = R;
71 while (rowi < relend)
72 {
73 ccol = cword;
74 rowj = R;
75
76 while (rowj < relend)
77 {
78 if (*ccol & (1 << i))
79 {
80 rp = rowi;
81 rend = rowj + rowsize;
82 while (rowj < rend)
83 *rowj++ |= *rp++;
84 }
85 else
86 {
87 rowj += rowsize;
88 }
89
90 ccol += rowsize;
91 }
92
93 if (++i >= BITS_PER_WORD)
94 {
95 i = 0;
96 cword++;
97 }
98
99 rowi += rowsize;
100 }
101}
102
103void
104reflexive_transitive_closure(R, n)
105unsigned *R;
106int n;
107{
108 int rowsize;
109 unsigned i;
110 unsigned *rp;
111 unsigned *relend;
112
113 transitive_closure(R, n);
114
115 rowsize = WORDSIZE(n);
116 relend = R + n*rowsize;
117
118 i = 0;
119 rp = R;
120 while (rp < relend)
121 {
122 *rp |= (1 << i);
123 if (++i >= BITS_PER_WORD)
124 {
125 i = 0;
126 rp++;
127 }
128
129 rp += rowsize;
130 }
131}
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