jay/warshall.c

   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 #ifndef lint
  38 static char sccsid[] = "@(#)warshall.c  5.4 (Berkeley) 5/24/93";
  39 #endif /* not lint */
  40
  41 #include "defs.h"
  42
  43 transitive_closure(R, n)
  44 unsigned *R;
  45 int n;
  46 {
  47     register int rowsize;
  48     register unsigned i;
  49     register unsigned *rowj;
  50     register unsigned *rp;
  51     register unsigned *rend;
  52     register unsigned *ccol;
  53     register unsigned *relend;
  54     register unsigned *cword;
  55     register unsigned *rowi;
  56
  57     rowsize = WORDSIZE(n);
  58     relend = R + n*rowsize;
  59
  60     cword = R;
  61     i = 0;
  62     rowi = R;
  63     while (rowi < relend)
  64     {
  65         ccol = cword;
  66         rowj = R;
  67
  68         while (rowj < relend)
  69         {
  70             if (*ccol & (1 << i))
  71             {
  72                 rp = rowi;
  73                 rend = rowj + rowsize;
  74                 while (rowj < rend)
  75                     *rowj++ |= *rp++;
  76             }
  77             else
  78             {
  79                 rowj += rowsize;
  80             }
  81
  82             ccol += rowsize;
  83         }
  84
  85         if (++i >= BITS_PER_WORD)
  86         {
  87             i = 0;
  88             cword++;
  89         }
  90
  91         rowi += rowsize;
  92     }
  93 }
  94
  95 reflexive_transitive_closure(R, n)
  96 unsigned *R;
  97 int n;
  98 {
  99     register int rowsize;
 100     register unsigned i;
 101     register unsigned *rp;
 102     register unsigned *relend;
 103
 104     transitive_closure(R, n);
 105
 106     rowsize = WORDSIZE(n);
 107     relend = R + n*rowsize;
 108
 109     i = 0;
 110     rp = R;
 111     while (rp < relend)
 112     {
 113         *rp |= (1 << i);
 114         if (++i >= BITS_PER_WORD)
 115         {
 116             i = 0;
 117             rp++;
 118         }
 119
 120         rp += rowsize;
 121     }
 122 }