scyther/src/warshall.c
ccremers 0ce88af6ac - [[[ Broken commit ]]]
Committing partial new Warshall work because it is getting too big.
2006-02-26 15:00:58 +00:00

86 lines
1.3 KiB
C

// @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;
}
}