freebsd-skq/contrib/byacc/warshall.c
bapt 913116490c Import byacc from invisible island, it brings us lots of compatibilities with
bison, keeping full compatibility with our previous yacc implementation.

Also bring the ability to create reentrant parser

This fix bin/140309 [1]

PR:		bin/140309 [1]
Submitted by:	Philippe Pepiot <ksh@philpep.org> [1]
Approved by:	des (mentor)
MFC after:	1 month
2012-05-21 13:31:26 +00:00

83 lines
1.1 KiB
C

/* $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;
}
}