warshall.c revision 1.2 
1/*	$NetBSD: warshall.c,v 1.4 1996/03/19 03:21:51 jtc Exp $	*/
2
3/*
4 * Copyright (c) 1989 The Regents of the University of California.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Robert Paul Corbett.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 *    must display the following acknowledgement:
20 *	This product includes software developed by the University of
21 *	California, Berkeley and its contributors.
22 * 4. Neither the name of the University nor the names of its contributors
23 *    may be used to endorse or promote products derived from this software
24 *    without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * SUCH DAMAGE.
37 */
38
39#ifndef lint
40#if 0
41static char sccsid[] = "@(#)warshall.c	5.4 (Berkeley) 5/24/93";
42#else
43static char rcsid[] = "$NetBSD: warshall.c,v 1.4 1996/03/19 03:21:51 jtc Exp $";
44#endif
45#endif /* not lint */
46
47#include "defs.h"
48
49transitive_closure(R, n)
50unsigned *R;
51int n;
52{
53    register int rowsize;
54    register unsigned i;
55    register unsigned *rowj;
56    register unsigned *rp;
57    register unsigned *rend;
58    register unsigned *ccol;
59    register unsigned *relend;
60    register unsigned *cword;
61    register unsigned *rowi;
62
63    rowsize = WORDSIZE(n);
64    relend = R + n*rowsize;
65
66    cword = R;
67    i = 0;
68    rowi = R;
69    while (rowi < relend)
70    {
71	ccol = cword;
72	rowj = R;
73
74	while (rowj < relend)
75	{
76	    if (*ccol & (1 << i))
77	    {
78		rp = rowi;
79		rend = rowj + rowsize;
80		while (rowj < rend)
81		    *rowj++ |= *rp++;
82	    }
83	    else
84	    {
85		rowj += rowsize;
86	    }
87
88	    ccol += rowsize;
89	}
90
91	if (++i >= BITS_PER_WORD)
92	{
93	    i = 0;
94	    cword++;
95	}
96
97	rowi += rowsize;
98    }
99}
100
101reflexive_transitive_closure(R, n)
102unsigned *R;
103int n;
104{
105    register int rowsize;
106    register unsigned i;
107    register unsigned *rp;
108    register unsigned *relend;
109
110    transitive_closure(R, n);
111
112    rowsize = WORDSIZE(n);
113    relend = R + n*rowsize;
114
115    i = 0;
116    rp = R;
117    while (rp < relend)
118    {
119	*rp |= (1 << i);
120	if (++i >= BITS_PER_WORD)
121	{
122	    i = 0;
123	    rp++;
124	}
125
126	rp += rowsize;
127    }
128}
129