1 /* $OpenBSD: warshall.c,v 1.11 2014/03/13 01:18:22 tedu 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 #include "defs.h"
37
38 void transitive_closure(unsigned int *, int);
39
40 void
transitive_closure(unsigned int * R,int n)41 transitive_closure(unsigned int *R, int n)
42 {
43 int rowsize;
44 unsigned int i;
45 unsigned int *rowj, *rp, *rend, *ccol, *relend, *cword, *rowi;
46
47 rowsize = WORDSIZE(n);
48 relend = R + n * rowsize;
49
50 cword = R;
51 i = 0;
52 rowi = R;
53 while (rowi < relend) {
54 ccol = cword;
55 rowj = R;
56
57 while (rowj < relend) {
58 if (*ccol & (1 << i)) {
59 rp = rowi;
60 rend = rowj + rowsize;
61 while (rowj < rend)
62 *rowj++ |= *rp++;
63 } else {
64 rowj += rowsize;
65 }
66
67 ccol += rowsize;
68 }
69
70 if (++i >= BITS_PER_WORD) {
71 i = 0;
72 cword++;
73 }
74 rowi += rowsize;
75 }
76 }
77
78 void
reflexive_transitive_closure(unsigned int * R,int n)79 reflexive_transitive_closure(unsigned int *R, int n)
80 {
81 int rowsize;
82 unsigned int i;
83 unsigned int *rp, *relend;
84
85 transitive_closure(R, n);
86
87 rowsize = WORDSIZE(n);
88 relend = R + n * rowsize;
89
90 i = 0;
91 rp = R;
92 while (rp < relend) {
93 *rp |= (1 << i);
94 if (++i >= BITS_PER_WORD) {
95 i = 0;
96 rp++;
97 }
98 rp += rowsize;
99 }
100 }
101