1 /* $OpenBSD: warshall.c,v 1.8 2003/06/19 16:34:53 pvalchev Exp $ */
2 /* $NetBSD: warshall.c,v 1.4 1996/03/19 03:21:51 jtc Exp $ */
3
4 /*
5 * Copyright (c) 1989 The Regents of the University of California.
6 * All rights reserved.
7 *
8 * This code is derived from software contributed to Berkeley by
9 * Robert Paul Corbett.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. Neither the name of the University nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36 #ifndef lint
37 #if 0
38 static char sccsid[] = "@(#)warshall.c 5.4 (Berkeley) 5/24/93";
39 #else
40 static char rcsid[] = "$OpenBSD: warshall.c,v 1.8 2003/06/19 16:34:53 pvalchev Exp $";
41 #endif
42 #endif /* not lint */
43
44 #include "defs.h"
45
46 void transitive_closure(unsigned int *, int);
47
48 void
transitive_closure(unsigned int * R,int n)49 transitive_closure(unsigned int *R, int n)
50 {
51 int rowsize;
52 unsigned i;
53 unsigned *rowj;
54 unsigned *rp;
55 unsigned *rend;
56 unsigned *ccol;
57 unsigned *relend;
58 unsigned *cword;
59 unsigned *rowi;
60
61 rowsize = WORDSIZE(n);
62 relend = R + n*rowsize;
63
64 cword = R;
65 i = 0;
66 rowi = R;
67 while (rowi < relend)
68 {
69 ccol = cword;
70 rowj = R;
71
72 while (rowj < relend)
73 {
74 if (*ccol & (1 << i))
75 {
76 rp = rowi;
77 rend = rowj + rowsize;
78 while (rowj < rend)
79 *rowj++ |= *rp++;
80 }
81 else
82 {
83 rowj += rowsize;
84 }
85
86 ccol += rowsize;
87 }
88
89 if (++i >= BITS_PER_WORD)
90 {
91 i = 0;
92 cword++;
93 }
94
95 rowi += rowsize;
96 }
97 }
98
99 void
reflexive_transitive_closure(unsigned int * R,int n)100 reflexive_transitive_closure(unsigned int *R, int n)
101 {
102 int rowsize;
103 unsigned i;
104 unsigned *rp;
105 unsigned *relend;
106
107 transitive_closure(R, n);
108
109 rowsize = WORDSIZE(n);
110 relend = R + n*rowsize;
111
112 i = 0;
113 rp = R;
114 while (rp < relend)
115 {
116 *rp |= (1 << i);
117 if (++i >= BITS_PER_WORD)
118 {
119 i = 0;
120 rp++;
121 }
122
123 rp += rowsize;
124 }
125 }
126