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/* Parser accelerator module */
#include <stdio.h>
#include "PROTO.h"
#include "grammar.h"
#include "token.h"
#include "malloc.h"
static void
fixstate(g, d, s)
grammar *g;
dfa *d;
state *s;
{
arc *a;
int k;
int *accel;
int nl = g->g_ll.ll_nlabels;
s->s_accept = 0;
accel = NEW(int, nl);
for (k = 0; k < nl; k++)
accel[k] = -1;
a = s->s_arc;
for (k = s->s_narcs; --k >= 0; a++) {
int lbl = a->a_lbl;
label *l = &g->g_ll.ll_label[lbl];
int type = l->lb_type;
if (a->a_arrow >= (1 << 7)) {
printf("XXX too many states!\n");
continue;
}
if (ISNONTERMINAL(type)) {
dfa *d1 = finddfa(g, type);
int ibit;
if (type - NT_OFFSET >= (1 << 7)) {
printf("XXX too high nonterminal number!\n");
continue;
}
for (ibit = 0; ibit < g->g_ll.ll_nlabels; ibit++) {
if (testbit(d1->d_first, ibit)) {
if (accel[ibit] != -1)
printf("XXX ambiguity!\n");
accel[ibit] = a->a_arrow | (1 << 7) |
((type - NT_OFFSET) << 8);
}
}
}
else if (lbl == EMPTY)
s->s_accept = 1;
else if (lbl >= 0 && lbl < nl)
accel[lbl] = a->a_arrow;
}
while (nl > 0 && accel[nl-1] == -1)
nl--;
for (k = 0; k < nl && accel[k] == -1;)
k++;
if (k < nl) {
int i;
s->s_accel = NEW(int, nl-k);
if (s->s_accel == NULL) {
fprintf(stderr, "no mem to add parser accelerators\n");
exit(1);
}
s->s_lower = k;
s->s_upper = nl;
for (i = 0; k < nl; i++, k++)
s->s_accel[i] = accel[k];
}
DEL(accel);
}
static void
fixdfa(g, d)
grammar *g;
dfa *d;
{
state *s;
int j;
s = d->d_state;
for (j = 0; j < d->d_nstates; j++, s++)
fixstate(g, d, s);
}
void
addaccelerators(g)
grammar *g;
{
dfa *d;
int i;
#ifdef DEBUG
printf("Adding parser accellerators ...\n");
#endif
d = g->g_dfa;
for (i = g->g_ndfas; --i >= 0; d++)
fixdfa(g, d);
g->g_accel = 1;
#ifdef DEBUG
printf("Done.\n");
#endif
}
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