* src/closure.c (closure): Use nrules instead of playing tricks

[bison.git] / src / closure.c

diff --git a/src/closure.c b/src/closure.c
index ad3a5be7af70a3870d6cbed9905646518285cd22..12bb5817f36f340af9696e23dd06891c106a31d6 100644 (file)
--- a/src/closure.c
+++ b/src/closure.c
@@ -26,9 +26,9 @@
 #include "derives.h"
 #include "warshall.h"
 
-/* ITEMSETSIZE is the size of the array ITEMSET.  */
+/* NITEMSET is the size of the array ITEMSET.  */
 short *itemset;
-int itemsetsize;
+int nitemset;
 
 static unsigned *ruleset;
 
@@ -36,8 +36,9 @@ static unsigned *ruleset;
 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;
@@ -51,33 +52,33 @@ static int varsetsize;
 `-----------------*/
 
 static void
-print_closure (int n)
+print_closure (const char *title, short *array, size_t size)
 {
-  int i;
-  fprintf (stderr, "n = %d\n", n);
-  for (i = 0; i < itemsetsize; ++i)
-    fprintf (stderr, "   %d\n", itemset[i]);
-  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);
+    }
+  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");
@@ -89,17 +90,14 @@ print_fderives (void)
 {
   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))
+       if (BITISSET (FDERIVES (i), j))
          {
            short *rhsp;
            fprintf (stderr, "\t\t%d:", j);
@@ -124,33 +122,19 @@ print_fderives (void)
 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);
 
@@ -171,46 +155,17 @@ set_firsts (void)
 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 ();
@@ -235,22 +190,17 @@ new_closure (int n)
 void
 closure (short *core, int n)
 {
-  int ruleno;
   /* Index over CORE. */
   int c;
 
   /* Index over RULESET. */
   int r;
 
-  int itemno;
+  /* A bit index over RULESET. */
+  int ruleno;
 
   if (trace_flag)
-    {
-      fprintf (stderr, "Entering closure (items = {");
-      for (c = 0; c < n; ++c)
-       fprintf (stderr, " %d ", core[c]);
-      fprintf (stderr, "})\n");
-    }
+    print_closure ("input", core, n);
 
   if (n == 0)
     {
@@ -268,41 +218,31 @@ closure (short *core, int n)
            ruleset[r] |= FDERIVES (ritem[core[c]])[r];
     }
 
-  ruleno = 0;
-  itemsetsize = 0;
+  nitemset = 0;
   c = 0;
-  for (r = 0; r < rulesetsize; ++r)
-    {
-      int b;
-
-      for (b = 0; b < BITS_PER_WORD; b++)
-       {
-         if (ruleset[r] & (1 << b))
-           {
-             itemno = rule_table[ruleno].rhs;
-             while (c < n && core[c] < itemno)
-               {
-                 itemset[itemsetsize] = core[c];
-                 itemsetsize++;
-                 c++;
-               }
-             itemset[itemsetsize] = itemno;
-             itemsetsize++;
-           }
-
-         ruleno++;
-       }
-    }
+  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)
     {
-      itemset[itemsetsize] = core[c];
-      itemsetsize++;
+      itemset[nitemset] = core[c];
+      nitemset++;
       c++;
     }
 
   if (trace_flag)
-    print_closure (n);
+    print_closure ("output", itemset, nitemset);
 }
 
 
@@ -311,5 +251,5 @@ free_closure (void)
 {
   XFREE (itemset);
   XFREE (ruleset);
-  XFREE (fderives + ntokens * rulesetsize);
+  XFREE (fderives);
 }