scyther/src/warshall.c
2013-10-05 23:56:12 +01:00

105 lines
2.1 KiB
C

/*
* Scyther : An automatic verifier for security protocols.
* Copyright (C) 2007-2013 Cas Cremers
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
// @file warshall.c
/* Based on public-domain code from Berkeley Yacc */
#include "warshall.h"
void
transitive_closure (unsigned int *R, int n)
{
register int rowsize;
register unsigned mask;
register unsigned *rowj;
register unsigned *rp;
register unsigned *rend;
register unsigned *ccol;
register unsigned *relend;
register unsigned *cword;
register unsigned *rowi;
rowsize = WORDSIZE (n);
relend = R + n * rowsize;
cword = R;
mask = 1;
rowi = R;
while (rowi < relend)
{
ccol = cword;
rowj = R;
while (rowj < relend)
{
if (*ccol & mask)
{
rp = rowi;
rend = rowj + rowsize;
while (rowj < rend)
*rowj++ |= *rp++;
}
else
{
rowj += rowsize;
}
ccol += rowsize;
}
mask <<= 1;
if (mask == 0)
{
mask = 1;
cword++;
}
rowi += rowsize;
}
}
void
reflexive_transitive_closure (unsigned int *R, int n)
{
register int rowsize;
register unsigned mask;
register unsigned *rp;
register unsigned *relend;
transitive_closure (R, n);
rowsize = WORDSIZE (n);
relend = R + n * rowsize;
mask = 1;
rp = R;
while (rp < relend)
{
*rp |= mask;
mask <<= 1;
if (mask == 0)
{
mask = 1;
rp++;
}
rp += rowsize;
}
}