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 * 4. Neither the name of the University nor the names of its contributors
17 *    may be used to endorse or promote products derived from this software
18 *    without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33#if 0
34#ifndef lint
35static char sccsid[] = "@(#)warshall.c	5.4 (Berkeley) 5/24/93";
36#endif
37#endif
38
39#include <sys/cdefs.h>
40__FBSDID("$FreeBSD$");
41
42#include "defs.h"
43
44static void transitive_closure(unsigned *, int);
45
46static void
47transitive_closure(unsigned *R, int n)
48{
49    int rowsize;
50    unsigned i;
51    unsigned *rowj;
52    unsigned *rp;
53    unsigned *rend;
54    unsigned *ccol;
55    unsigned *relend;
56    unsigned *cword;
57    unsigned *rowi;
58
59    rowsize = WORDSIZE(n);
60    relend = R + n*rowsize;
61
62    cword = R;
63    i = 0;
64    rowi = R;
65    while (rowi < relend)
66    {
67	ccol = cword;
68	rowj = R;
69
70	while (rowj < relend)
71	{
72	    if (*ccol & (1 << i))
73	    {
74		rp = rowi;
75		rend = rowj + rowsize;
76		while (rowj < rend)
77		    *rowj++ |= *rp++;
78	    }
79	    else
80	    {
81		rowj += rowsize;
82	    }
83
84	    ccol += rowsize;
85	}
86
87	if (++i >= BITS_PER_WORD)
88	{
89	    i = 0;
90	    cword++;
91	}
92
93	rowi += rowsize;
94    }
95}
96
97void
98reflexive_transitive_closure(unsigned *R, int n)
99{
100    int rowsize;
101    unsigned i;
102    unsigned *rp;
103    unsigned *relend;
104
105    transitive_closure(R, n);
106
107    rowsize = WORDSIZE(n);
108    relend = R + n*rowsize;
109
110    i = 0;
111    rp = R;
112    while (rp < relend)
113    {
114	*rp |= (1 << i);
115	if (++i >= BITS_PER_WORD)
116	{
117	    i = 0;
118	    rp++;
119	}
120
121	rp += rowsize;
122    }
123}
124