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#ifndef lint
static char rcsid[] = "$Id: closure.c,v 1.1 1995/10/18 08:47:05 deraadt Exp $";
#endif /* not lint */
#include "defs.h"
short *itemset;
short *itemsetend;
unsigned *ruleset;
static unsigned *first_derives;
static unsigned *EFF;
set_EFF()
{
register unsigned *row;
register int symbol;
register short *sp;
register int rowsize;
register int i;
register int rule;
rowsize = WORDSIZE(nvars);
EFF = NEW2(nvars * rowsize, unsigned);
row = EFF;
for (i = start_symbol; i < nsyms; i++)
{
sp = derives[i];
for (rule = *sp; rule > 0; rule = *++sp)
{
symbol = ritem[rrhs[rule]];
if (ISVAR(symbol))
{
symbol -= start_symbol;
SETBIT(row, symbol);
}
}
row += rowsize;
}
reflexive_transitive_closure(EFF, nvars);
#ifdef DEBUG
print_EFF();
#endif
}
set_first_derives()
{
register unsigned *rrow;
register unsigned *vrow;
register int j;
register unsigned k;
register unsigned cword;
register short *rp;
int rule;
int i;
int rulesetsize;
int varsetsize;
rulesetsize = WORDSIZE(nrules);
varsetsize = WORDSIZE(nvars);
first_derives = NEW2(nvars * rulesetsize, unsigned) - ntokens * rulesetsize;
set_EFF();
rrow = first_derives + ntokens * rulesetsize;
for (i = start_symbol; i < nsyms; i++)
{
vrow = EFF + ((i - ntokens) * varsetsize);
k = BITS_PER_WORD;
for (j = start_symbol; j < nsyms; k++, j++)
{
if (k >= BITS_PER_WORD)
{
cword = *vrow++;
k = 0;
}
if (cword & (1 << k))
{
rp = derives[j];
while ((rule = *rp++) >= 0)
{
SETBIT(rrow, rule);
}
}
}
vrow += varsetsize;
rrow += rulesetsize;
}
#ifdef DEBUG
print_first_derives();
#endif
FREE(EFF);
}
closure(nucleus, n)
short *nucleus;
int n;
{
register int ruleno;
register unsigned word;
register unsigned i;
register short *csp;
register unsigned *dsp;
register unsigned *rsp;
register int rulesetsize;
short *csend;
unsigned *rsend;
int symbol;
int itemno;
rulesetsize = WORDSIZE(nrules);
rsp = ruleset;
rsend = ruleset + rulesetsize;
for (rsp = ruleset; rsp < rsend; rsp++)
*rsp = 0;
csend = nucleus + n;
for (csp = nucleus; csp < csend; ++csp)
{
symbol = ritem[*csp];
if (ISVAR(symbol))
{
dsp = first_derives + symbol * rulesetsize;
rsp = ruleset;
while (rsp < rsend)
*rsp++ |= *dsp++;
}
}
ruleno = 0;
itemsetend = itemset;
csp = nucleus;
for (rsp = ruleset; rsp < rsend; ++rsp)
{
word = *rsp;
if (word)
{
for (i = 0; i < BITS_PER_WORD; ++i)
{
if (word & (1 << i))
{
itemno = rrhs[ruleno+i];
while (csp < csend && *csp < itemno)
*itemsetend++ = *csp++;
*itemsetend++ = itemno;
while (csp < csend && *csp == itemno)
++csp;
}
}
}
ruleno += BITS_PER_WORD;
}
while (csp < csend)
*itemsetend++ = *csp++;
#ifdef DEBUG
print_closure(n);
#endif
}
finalize_closure()
{
FREE(itemset);
FREE(ruleset);
FREE(first_derives + ntokens * WORDSIZE(nrules));
}
#ifdef DEBUG
print_closure(n)
int n;
{
register short *isp;
printf("\n\nn = %d\n\n", n);
for (isp = itemset; isp < itemsetend; isp++)
printf(" %d\n", *isp);
}
print_EFF()
{
register int i, j;
register unsigned *rowp;
register unsigned word;
register unsigned k;
printf("\n\nEpsilon Free Firsts\n");
for (i = start_symbol; i < nsyms; i++)
{
printf("\n%s", symbol_name[i]);
rowp = EFF + ((i - start_symbol) * WORDSIZE(nvars));
word = *rowp++;
k = BITS_PER_WORD;
for (j = 0; j < nvars; k++, j++)
{
if (k >= BITS_PER_WORD)
{
word = *rowp++;
k = 0;
}
if (word & (1 << k))
printf(" %s", symbol_name[start_symbol + j]);
}
}
}
print_first_derives()
{
register int i;
register int j;
register unsigned *rp;
register unsigned cword;
register unsigned k;
printf("\n\n\nFirst Derives\n");
for (i = start_symbol; i < nsyms; i++)
{
printf("\n%s derives\n", symbol_name[i]);
rp = first_derives + i * WORDSIZE(nrules);
k = BITS_PER_WORD;
for (j = 0; j <= nrules; k++, j++)
{
if (k >= BITS_PER_WORD)
{
cword = *rp++;
k = 0;
}
if (cword & (1 << k))
printf(" %d\n", j);
}
}
fflush(stdout);
}
#endif
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