X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/1a2b5d37e1d44b47cd51220945f4ba29c228a419..11652ab3dc44bf12d5fa9095d1495b5cd3102ff7:/src/reduce.c

diff --git a/src/reduce.c b/src/reduce.c
index c4a2bd1c..58bf43ea 100644
--- a/src/reduce.c
+++ b/src/reduce.c
@@ -34,65 +34,29 @@
 #include "reduce.h"
 #include "reader.h"
 #include "getargs.h"
+#include "bitset.h"
 
-typedef unsigned *BSet;
 typedef short *rule;
 
 
 /* Set of all nonterminals which are not useless.  */
-static BSet N;
+static bitset N;
 
 /* Set of all rules which have no useless nonterminals in their RHS.  */
-static BSet P;
+static bitset P;
 
 /* Set of all accessible symbols.  */
-static BSet V;
+static bitset V;
 
 /* Set of symbols used to define rule precedence (so they are
    `useless', but no warning should be issued).  */
-static BSet V1;
+static bitset V1;
 
 static int nuseful_productions;
 static int nuseless_productions;
 static int nuseful_nonterminals;
 int nuseless_nonterminals;
 
-static bool
-bits_equal (BSet L, BSet R, int n)
-{
-  int i;
-
-  for (i = n - 1; i >= 0; i--)
-    if (L[i] != R[i])
-      return FALSE;
-  return TRUE;
-}
-
-
-static int
-nbits (unsigned i)
-{
-  int count = 0;
-
-  while (i != 0)
-    {
-      i ^= (i & ((unsigned) (-(int) i)));
-      ++count;
-    }
-  return count;
-}
-
-
-static int
-bits_size (BSet S, int n)
-{
-  int i, count = 0;
-
-  for (i = n - 1; i >= 0; i--)
-    count += nbits (S[i]);
-  return count;
-}
-
 /*-------------------------------------------------------------------.
 | Another way to do this would be with a set for each production and |
 | then do subset tests against N0, but even for the C grammar the    |
@@ -100,7 +64,7 @@ bits_size (BSet S, int n)
 `-------------------------------------------------------------------*/
 
 static bool
-useful_production (int i, BSet N0)
+useful_production (int i, bitset N0)
 {
   rule r;
   short n;
@@ -108,10 +72,9 @@ useful_production (int i, BSet N0)
   /* A production is useful if all of the nonterminals in its appear
      in the set of useful nonterminals.  */
 
-  for (r = &ritem[rules[i].rhs]; *r >= 0; r++)
-    if (ISVAR (n = *r))
-      if (!BITISSET (N0, n - ntokens))
-	return FALSE;
+  for (r = rules[i].rhs; *r >= 0; r++)
+    if (ISVAR (n = *r) && !bitset_test (N0, n - ntokens))
+      return FALSE;
   return TRUE;
 }
 
@@ -123,13 +86,14 @@ useful_production (int i, BSet N0)
 static void
 useless_nonterminals (void)
 {
-  BSet Np, Ns;
+  bitset Np, Ns;
   int i;
 
   /* N is set as built.  Np is set being built this iteration. P is
      set of all productions which have a RHS all in N.  */
 
-  Np = XCALLOC (unsigned, WORDSIZE (nvars));
+  Np = bitset_create (nvars, BITSET_FIXED);
+
 
   /* The set being computed is a set of nonterminals which can derive
      the empty string or strings consisting of all terminals. At each
@@ -149,26 +113,21 @@ useless_nonterminals (void)
 
   while (1)
     {
-      for (i = WORDSIZE (nvars) - 1; i >= 0; i--)
-	Np[i] = N[i];
-      for (i = 1; i <= nrules; i++)
-	{
-	  if (!BITISSET (P, i))
-	    {
-	      if (useful_production (i, N))
-		{
-		  SETBIT (Np, rules[i].lhs - ntokens);
-		  SETBIT (P, i);
-		}
-	    }
-	}
-      if (bits_equal (N, Np, WORDSIZE (nvars)))
+      bitset_copy (Np, N);
+      for (i = 1; i < nrules + 1; i++)
+	if (!bitset_test (P, i)
+	    && useful_production (i, N))
+	  {
+	    bitset_set (Np, rules[i].lhs - ntokens);
+	    bitset_set (P, i);
+	  }
+      if (bitset_equal_p (N, Np))
 	break;
       Ns = Np;
       Np = N;
       N = Ns;
     }
-  XFREE (N);
+  bitset_free (N);
   N = Np;
 }
 
@@ -176,7 +135,7 @@ useless_nonterminals (void)
 static void
 inaccessable_symbols (void)
 {
-  BSet Vp, Vs, Pp;
+  bitset Vp, Vs, Pp;
   int i;
   short t;
   rule r;
@@ -204,31 +163,30 @@ inaccessable_symbols (void)
      terminals are printed (if running in verbose mode) so that the
      user can know.  */
 
-  Vp = XCALLOC (unsigned, WORDSIZE (nsyms));
-  Pp = XCALLOC (unsigned, WORDSIZE (nrules + 1));
+  Vp = bitset_create (nsyms, BITSET_FIXED);
+  Pp = bitset_create (nrules + 1, BITSET_FIXED);
 
   /* If the start symbol isn't useful, then nothing will be useful. */
-  if (BITISSET (N, start_symbol - ntokens))
+  if (bitset_test (N, start_symbol - ntokens))
     {
-      SETBIT (V, start_symbol);
+      bitset_set (V, start_symbol);
 
       while (1)
 	{
-	  for (i = WORDSIZE (nsyms) - 1; i >= 0; i--)
-	    Vp[i] = V[i];
-	  for (i = 1; i <= nrules; i++)
+	  bitset_copy (Vp, V);
+	  for (i = 1; i < nrules + 1; i++)
 	    {
-	      if (!BITISSET (Pp, i)
-		  && BITISSET (P, i)
-		  && BITISSET (V, rules[i].lhs))
+	      if (!bitset_test (Pp, i)
+		  && bitset_test (P, i)
+		  && bitset_test (V, rules[i].lhs))
 		{
-		  for (r = &ritem[rules[i].rhs]; *r >= 0; r++)
-		    if (ISTOKEN (t = *r) || BITISSET (N, t - ntokens))
-		      SETBIT (Vp, t);
-		  SETBIT (Pp, i);
+		  for (r = rules[i].rhs; *r >= 0; r++)
+		    if (ISTOKEN (t = *r) || bitset_test (N, t - ntokens))
+		      bitset_set (Vp, t);
+		  bitset_set (Pp, i);
 		}
 	    }
-	  if (bits_equal (V, Vp, WORDSIZE (nsyms)))
+	  if (bitset_equal_p (V, Vp))
 	    break;
 	  Vs = Vp;
 	  Vp = V;
@@ -236,30 +194,30 @@ inaccessable_symbols (void)
 	}
     }
 
-  XFREE (V);
+  bitset_free (V);
   V = Vp;
 
   /* Tokens 0, 1, and 2 are internal to Bison.  Consider them useful. */
-  SETBIT (V, 0);		/* end-of-input token */
-  SETBIT (V, 1);		/* error token */
-  SETBIT (V, 2);		/* some undefined token */
+  bitset_set (V, 0);		/* end-of-input token */
+  bitset_set (V, 1);		/* error token */
+  bitset_set (V, 2);		/* some undefined token */
 
-  XFREE (P);
+  bitset_free (P);
   P = Pp;
 
-  nuseful_productions = bits_size (P, WORDSIZE (nrules + 1));
+  nuseful_productions = bitset_count (P);
   nuseless_productions = nrules - nuseful_productions;
 
   nuseful_nonterminals = 0;
   for (i = ntokens; i < nsyms; i++)
-    if (BITISSET (V, i))
+    if (bitset_test (V, i))
       nuseful_nonterminals++;
   nuseless_nonterminals = nvars - nuseful_nonterminals;
 
   /* A token that was used in %prec should not be warned about.  */
-  for (i = 1; i < nrules; i++)
+  for (i = 1; i < nrules + 1; i++)
     if (rules[i].precsym != 0)
-      SETBIT (V1, rules[i].precsym);
+      bitset_set (V1, rules[i].precsym);
 }
 
 static void
@@ -283,8 +241,8 @@ reduce_grammar_tables (void)
 
 	np = 0;
 	ni = 0;
-	for (pn = 1; pn <= nrules; pn++)
-	  if (BITISSET (P, pn))
+	for (pn = 1; pn < nrules + 1; pn++)
+	  if (bitset_test (P, pn))
 	    {
 	      np++;
 	      if (pn != np)
@@ -294,10 +252,10 @@ reduce_grammar_tables (void)
 		  rules[np].prec  = rules[pn].prec;
 		  rules[np].assoc = rules[pn].assoc;
 		  rules[np].rhs   = rules[pn].rhs;
-		  if (rules[np].rhs != ni)
+		  if (rules[np].rhs - ritem != ni)
 		    {
-		      pi = rules[np].rhs;
-		      rules[np].rhs = ni;
+		      pi = rules[np].rhs - ritem;
+		      rules[np].rhs = ritem + ni;
 		      while (ritem[pi] >= 0)
 			ritem[ni++] = ritem[pi++];
 		      ritem[ni++] = -np;
@@ -323,8 +281,8 @@ reduce_grammar_tables (void)
   if (nuseless_productions > 0)
     {
       int pn;
-      for (pn = 1; pn <= nrules; pn++)
-	rules[pn].useful = BITISSET (P, pn);
+      for (pn = 1; pn < nrules + 1; pn++)
+	rules[pn].useful = bitset_test (P, pn);
     }
 }
 
@@ -337,7 +295,6 @@ static void
 nonterminals_reduce (void)
 {
   int i, n;
-  rule r;
 
   /* Map the nonterminals to their new index: useful first, useless
      afterwards.  Kept for later report.  */
@@ -345,10 +302,10 @@ nonterminals_reduce (void)
   short *nontermmap = XCALLOC (short, nvars) - ntokens;
   n = ntokens;
   for (i = ntokens; i < nsyms; i++)
-    if (BITISSET (V, i))
+    if (bitset_test (V, i))
       nontermmap[i] = n++;
   for (i = ntokens; i < nsyms; i++)
-    if (!BITISSET (V, i))
+    if (!bitset_test (V, i))
       nontermmap[i] = n++;
 
 
@@ -365,7 +322,7 @@ nonterminals_reduce (void)
 
   /* Replace all symbol numbers in valid data structures.  */
 
-  for (i = 1; i <= nrules; i++)
+  for (i = 1; i < nrules + 1; i++)
     {
       rules[i].lhs = nontermmap[rules[i].lhs];
       if (ISVAR (rules[i].precsym))
@@ -406,7 +363,7 @@ reduce_output (FILE *out)
     bool b = FALSE;
     int i;
     for (i = 0; i < ntokens; i++)
-      if (!BITISSET (V, i) && !BITISSET (V1, i))
+      if (!bitset_test (V, i) && !bitset_test (V1, i))
 	{
 	  if (!b)
 	    fprintf (out, "%s\n\n", _("Terminals which are not used:"));
@@ -421,13 +378,13 @@ reduce_output (FILE *out)
     {
       int i;
       fprintf (out, "%s\n\n", _("Useless rules:"));
-      for (i = 1; i <= nrules; i++)
+      for (i = 1; i < nrules + 1; i++)
 	if (!rules[i].useful)
 	  {
 	    rule r;
 	    fprintf (out, "#%-4d  ", i - 1);
 	    fprintf (out, "%s:", symbols[rules[i].lhs]->tag);
-	    for (r = &ritem[rules[i].rhs]; *r >= 0; r++)
+	    for (r = rules[i].rhs; *r >= 0; r++)
 	      fprintf (out, " %s", symbols[*r]->tag);
 	    fputs (";\n", out);
 	  }
@@ -454,28 +411,28 @@ dump_grammar (FILE *out)
   fprintf (out, "\n\n");
   fprintf (out, "Rules\n-----\n\n");
   fprintf (out, "Num (Prec, Assoc, Useful, Ritem Range) Lhs -> Rhs (Ritem range) [Num]\n");
-  for (i = 1; i <= nrules; i++)
+  for (i = 1; i < nrules + 1; i++)
     {
       int rhs_count = 0;
       /* Find the last RHS index in ritems. */
-      for (r = &ritem[rules[i].rhs]; *r >= 0; ++r)
+      for (r = rules[i].rhs; *r >= 0; ++r)
 	++rhs_count;
       fprintf (out, "%3d (%2d, %2d, %2d, %2d-%2d)   %2d ->",
 	       i - 1,
 	       rules[i].prec, rules[i].assoc, rules[i].useful,
-	       rules[i].rhs, rules[i].rhs + rhs_count - 1,
+	       rules[i].rhs - ritem, rules[i].rhs - ritem + rhs_count - 1,
 	       rules[i].lhs);
       /* Dumped the RHS. */
-      for (r = &ritem[rules[i].rhs]; *r >= 0; r++)
+      for (r = rules[i].rhs; *r >= 0; r++)
 	fprintf (out, "%3d", *r);
       fprintf (out, "  [%d]\n", -(*r) - 1);
     }
   fprintf (out, "\n\n");
   fprintf (out, "Rules interpreted\n-----------------\n\n");
-  for (i = 1; i <= nrules; i++)
+  for (i = 1; i < nrules + 1; i++)
     {
       fprintf (out, "%-5d  %s :", i, symbols[rules[i].lhs]->tag);
-      for (r = &ritem[rules[i].rhs]; *r >= 0; r++)
+      for (r = rules[i].rhs; *r >= 0; r++)
 	fprintf (out, " %s", symbols[*r]->tag);
       fputc ('\n', out);
     }
@@ -524,22 +481,21 @@ reduce_grammar (void)
 
   /* Allocate the global sets used to compute the reduced grammar */
 
-  N = XCALLOC (unsigned, WORDSIZE (nvars));
-  P = XCALLOC (unsigned, WORDSIZE (nrules + 1));
-  V = XCALLOC (unsigned, WORDSIZE (nsyms));
-  V1 = XCALLOC (unsigned, WORDSIZE (nsyms));
+  N = bitset_create (nvars, BITSET_FIXED);
+  P =  bitset_create (nrules + 1, BITSET_FIXED);
+  V = bitset_create (nsyms, BITSET_FIXED);
+  V1 = bitset_create (nsyms, BITSET_FIXED);
 
   useless_nonterminals ();
   inaccessable_symbols ();
 
   reduced = (bool) (nuseless_nonterminals + nuseless_productions > 0);
-
   if (!reduced)
     return;
 
   reduce_print ();
 
-  if (!BITISSET (N, start_symbol - ntokens))
+  if (!bitset_test (N, start_symbol - ntokens))
     fatal (_("Start symbol %s does not derive any sentence"),
 	   symbols[start_symbol]->tag);
 
@@ -565,8 +521,8 @@ reduce_grammar (void)
 void
 reduce_free (void)
 {
-  XFREE (N);
-  XFREE (V);
-  XFREE (V1);
-  XFREE (P);
+  bitset_free (N);
+  bitset_free (V);
+  bitset_free (V1);
+  bitset_free (P);
 }