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/* $Id: warshall.c,v 1.7 2010/06/06 22:48:51 tom Exp $ */
#include "defs.h"
static void
transitive_closure(unsigned *R, int n)
{
int rowsize;
unsigned i;
unsigned *rowj;
unsigned *rp;
unsigned *rend;
unsigned *ccol;
unsigned *relend;
unsigned *cword;
unsigned *rowi;
rowsize = WORDSIZE(n);
relend = R + n * rowsize;
cword = R;
i = 0;
rowi = R;
while (rowi < relend)
{
ccol = cword;
rowj = R;
while (rowj < relend)
{
if (*ccol & (unsigned)(1 << i))
{
rp = rowi;
rend = rowj + rowsize;
while (rowj < rend)
*rowj++ |= *rp++;
}
else
{
rowj += rowsize;
}
ccol += rowsize;
}
if (++i >= BITS_PER_WORD)
{
i = 0;
cword++;
}
rowi += rowsize;
}
}
void
reflexive_transitive_closure(unsigned *R, int n)
{
int rowsize;
unsigned i;
unsigned *rp;
unsigned *relend;
transitive_closure(R, n);
rowsize = WORDSIZE(n);
relend = R + n * rowsize;
i = 0;
rp = R;
while (rp < relend)
{
*rp |= (unsigned)(1 << i);
if (++i >= BITS_PER_WORD)
{
i = 0;
rp++;
}
rp += rowsize;
}
}
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