#include "derives.h"
#include "warshall.h"
+/* NITEMSET is the size of the array ITEMSET. */
short *itemset;
-short *itemsetend;
+int nitemset;
+
static unsigned *ruleset;
/* internal data. See comments before set_fderives and set_firsts. */
static unsigned *fderives;
static unsigned *firsts;
-#define FDERIVES(Symbol) (fderives + (Symbol) * rulesetsize)
-#define FIRSTS(Symbol) (firsts + (Symbol) * varsetsize)
+/* Retrieve the FDERIVES/FIRSTS sets of the nonterminals numbered Var. */
+#define FDERIVES(Var) (fderives + ((Var) - ntokens) * rulesetsize)
+#define FIRSTS(Var) (firsts + ((Var) - ntokens) * varsetsize)
/* number of words required to hold a bit for each rule */
static int rulesetsize;
`-----------------*/
static void
-print_closure (int n)
+print_closure (const char *title, short *array, size_t size)
{
- short *isp;
-
- fprintf (stderr, "n = %d\n", n);
- for (isp = itemset; isp < itemsetend; isp++)
- fprintf (stderr, " %d\n", *isp);
- fprintf (stderr, "\n\n");
+ size_t i;
+ fprintf (stderr, "Closure: %s\n", title);
+ for (i = 0; i < size; ++i)
+ {
+ short *rp;
+ fprintf (stderr, " %2d: .", array[i]);
+ for (rp = &ritem[array[i]]; *rp >= 0; ++rp)
+ fprintf (stderr, " %s", tags[*rp]);
+ fprintf (stderr, " (rule %d)\n", -*rp - 1);
+ }
+ fputs ("\n\n", stderr);
}
static void
print_firsts (void)
{
- int i;
- int j;
- unsigned *rowp;
+ int i, j;
fprintf (stderr, "FIRSTS\n");
-
for (i = ntokens; i < nsyms; i++)
{
fprintf (stderr, "\t%s firsts\n", tags[i]);
-
- rowp = FIRSTS (i - ntokens);
-
for (j = 0; j < nvars; j++)
- if (BITISSET (rowp, j))
+ if (BITISSET (FIRSTS (i), j))
fprintf (stderr, "\t\t%d (%s)\n", j + ntokens, tags[j + ntokens]);
}
fprintf (stderr, "\n\n");
{
int i;
int j;
- unsigned *rp;
fprintf (stderr, "FDERIVES\n");
for (i = ntokens; i < nsyms; i++)
{
fprintf (stderr, "\t%s derives\n", tags[i]);
- rp = FDERIVES (i);
-
for (j = 0; j <= nrules; j++)
- if (BITISSET (rp, j))
- fprintf (stderr, "\t\t%d (%s)\n", j, tags[j]);
+ if (BITISSET (FDERIVES (i), j))
+ {
+ short *rhsp;
+ fprintf (stderr, "\t\t%d:", j - 1);
+ for (rhsp = &ritem[rule_table[j].rhs]; *rhsp >= 0; ++rhsp)
+ fprintf (stderr, " %s", tags[*rhsp]);
+ fputc ('\n', stderr);
+ }
}
fprintf (stderr, "\n\n");
}
static void
set_firsts (void)
{
- unsigned *row;
- int symbol;
- short *sp;
- int rowsize;
-
- int i;
+ int i, j;
- varsetsize = rowsize = WORDSIZE (nvars);
+ varsetsize = WORDSIZE (nvars);
- firsts = XCALLOC (unsigned, nvars * rowsize);
+ firsts = XCALLOC (unsigned, nvars * varsetsize);
- row = firsts;
for (i = ntokens; i < nsyms; i++)
- {
- sp = derives[i];
- while (*sp >= 0)
- {
- symbol = ritem[rule_table[*sp++].rhs];
- if (ISVAR (symbol))
- {
- symbol -= ntokens;
- SETBIT (row, symbol);
- }
- }
-
- row += rowsize;
- }
+ for (j = 0; derives[i][j] >= 0; ++j)
+ {
+ int symbol = ritem[rule_table[derives[i][j]].rhs];
+ if (ISVAR (symbol))
+ SETBIT (FIRSTS (i), symbol - ntokens);
+ }
RTC (firsts, nvars);
static void
set_fderives (void)
{
- unsigned *rrow;
- unsigned *vrow;
- int j;
- unsigned cword;
- short *rp;
- int b;
+ int i, j, k;
- int ruleno;
- int i;
-
- fderives = XCALLOC (unsigned, nvars * rulesetsize) - ntokens * rulesetsize;
+ fderives = XCALLOC (unsigned, nvars * rulesetsize);
set_firsts ();
- rrow = FDERIVES (ntokens);
-
- for (i = ntokens; i < nsyms; i++)
- {
- vrow = FIRSTS (i - ntokens);
- cword = *vrow++;
- b = 0;
- for (j = ntokens; j < nsyms; j++)
- {
- if (cword & (1 << b))
- {
- rp = derives[j];
- while ((ruleno = *rp++) > 0)
- SETBIT (rrow, ruleno);
- }
-
- b++;
- if (b >= BITS_PER_WORD && j + 1 < nsyms)
- {
- cword = *vrow++;
- b = 0;
- }
- }
-
- rrow += rulesetsize;
- }
+ for (i = ntokens; i < nsyms; ++i)
+ for (j = ntokens; j < nsyms; ++j)
+ if (BITISSET (FIRSTS (i), j - ntokens))
+ for (k = 0; derives[j][k] > 0; ++k)
+ SETBIT (FDERIVES (i), derives[j][k]);
if (trace_flag)
print_fderives ();
void
closure (short *core, int n)
{
- int ruleno;
- short *csp;
+ /* Index over CORE. */
+ int c;
- int itemno;
- int i;
+ /* Index over RULESET. */
+ int r;
+
+ /* A bit index over RULESET. */
+ int ruleno;
if (trace_flag)
- {
- fprintf (stderr, "Entering closure (items = {");
- for (i = 0; i < n; ++i)
- fprintf (stderr, " %d ", core[i]);
- fprintf (stderr, "}, nitems = %d)\n", n);
- }
+ print_closure ("input", core, n);
if (n == 0)
{
- for (i = 0; i < rulesetsize; ++i)
- ruleset[i] = FDERIVES (start_symbol)[i];
+ for (r = 0; r < rulesetsize; ++r)
+ ruleset[r] = FDERIVES (start_symbol)[r];
}
else
{
- for (i = 0; i < rulesetsize; ++i)
- ruleset[i] = 0;
-
- for (i = 0; i < n; ++i)
- {
- int symbol = ritem[core[i]];
- if (ISVAR (symbol))
- {
- int j;
- for (j = 0; j < rulesetsize; ++j)
- ruleset[j] |= FDERIVES (symbol)[j];
- }
- }
+ for (r = 0; r < rulesetsize; ++r)
+ ruleset[r] = 0;
+
+ for (c = 0; c < n; ++c)
+ if (ISVAR (ritem[core[c]]))
+ for (r = 0; r < rulesetsize; ++r)
+ ruleset[r] |= FDERIVES (ritem[core[c]])[r];
}
- ruleno = 0;
- itemsetend = itemset;
- csp = core;
- for (i= 0; i < rulesetsize; ++i)
+ nitemset = 0;
+ c = 0;
+ for (ruleno = 0; ruleno < nrules + 1; ++ruleno)
+ if (BITISSET (ruleset, ruleno))
+ {
+ int itemno = rule_table[ruleno].rhs;
+ while (c < n && core[c] < itemno)
+ {
+ itemset[nitemset] = core[c];
+ nitemset++;
+ c++;
+ }
+ itemset[nitemset] = itemno;
+ nitemset++;
+ }
+
+ while (c < n)
{
- int word = ruleset[i];
- if (word == 0)
- {
- ruleno += BITS_PER_WORD;
- }
- else
- {
- int b;
-
- for (b = 0; b < BITS_PER_WORD; b++)
- {
- if (word & (1 << b))
- {
- itemno = rule_table[ruleno].rhs;
- while (csp < (core + n ) && *csp < itemno)
- *itemsetend++ = *csp++;
- *itemsetend++ = itemno;
- }
-
- ruleno++;
- }
- }
+ itemset[nitemset] = core[c];
+ nitemset++;
+ c++;
}
- while (csp < (core + n))
- *itemsetend++ = *csp++;
-
if (trace_flag)
- print_closure (n);
+ print_closure ("output", itemset, nitemset);
}
{
XFREE (itemset);
XFREE (ruleset);
- XFREE (fderives + ntokens * rulesetsize);
+ XFREE (fderives);
}
projects / bison.git / blobdiff