(CFLAGS-tst-align.c): Add -mpreferred-stack-boundary=4.

1 files changed, 804 insertions, 679 deletions

diff --git a/posix/regcomp.c b/posix/regcomp.c
index e99fd74924..5de5bf725a 100644
--- a/posix/regcomp.c
+++ b/posix/regcomp.c
@@ -1,5 +1,5 @@
 /* Extended regular expression matching and search library.
-   Copyright (C) 2002,2003,2004,2005,2006,2007 Free Software Foundation, Inc.
+   Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Isamu Hasegawa <isamu@yamato.ibm.com>.
 
@@ -19,11 +19,12 @@
    02111-1307 USA.  */
 
 static reg_errcode_t re_compile_internal (regex_t *preg, const char * pattern,
-					  size_t length, reg_syntax_t syntax);
+					  int length, reg_syntax_t syntax);
 static void re_compile_fastmap_iter (regex_t *bufp,
 				     const re_dfastate_t *init_state,
 				     char *fastmap);
-static reg_errcode_t init_dfa (re_dfa_t *dfa, size_t pat_len);
+static reg_errcode_t init_dfa (re_dfa_t *dfa, int pat_len);
+static void init_word_char (re_dfa_t *dfa);
 #ifdef RE_ENABLE_I18N
 static void free_charset (re_charset_t *cset);
 #endif /* RE_ENABLE_I18N */
@@ -32,31 +33,38 @@ static reg_errcode_t create_initial_state (re_dfa_t *dfa);
 #ifdef RE_ENABLE_I18N
 static void optimize_utf8 (re_dfa_t *dfa);
 #endif
-static reg_errcode_t analyze (regex_t *preg);
-static reg_errcode_t preorder (bin_tree_t *root,
-			       reg_errcode_t (fn (void *, bin_tree_t *)),
-			       void *extra);
-static reg_errcode_t postorder (bin_tree_t *root,
-				reg_errcode_t (fn (void *, bin_tree_t *)),
-				void *extra);
-static reg_errcode_t optimize_subexps (void *extra, bin_tree_t *node);
-static reg_errcode_t lower_subexps (void *extra, bin_tree_t *node);
-static bin_tree_t *lower_subexp (reg_errcode_t *err, regex_t *preg,
-				 bin_tree_t *node);
-static reg_errcode_t calc_first (void *extra, bin_tree_t *node);
-static reg_errcode_t calc_next (void *extra, bin_tree_t *node);
-static reg_errcode_t link_nfa_nodes (void *extra, bin_tree_t *node);
-static int duplicate_node (re_dfa_t *dfa, int org_idx, unsigned int constraint);
-static int search_duplicated_node (const re_dfa_t *dfa, int org_node,
+struct subexp_optimize
+{
+  re_dfa_t *dfa;
+  re_token_t *nodes;
+  int no_sub, re_nsub;
+};
+static bin_tree_t *optimize_subexps (struct subexp_optimize *so,
+                                     bin_tree_t *node, int sidx, int depth);
+static reg_errcode_t analyze (re_dfa_t *dfa);
+static reg_errcode_t analyze_tree (re_dfa_t *dfa, bin_tree_t *node);
+static void calc_first (re_dfa_t *dfa, bin_tree_t *node);
+static void calc_next (re_dfa_t *dfa, bin_tree_t *node);
+static void calc_epsdest (re_dfa_t *dfa, bin_tree_t *node);
+static reg_errcode_t duplicate_node_closure (re_dfa_t *dfa, int top_org_node,
+					     int top_clone_node, int root_node,
+					     unsigned int constraint);
+static reg_errcode_t duplicate_node (int *new_idx, re_dfa_t *dfa, int org_idx,
+				     unsigned int constraint);
+static int search_duplicated_node (re_dfa_t *dfa, int org_node,
 				   unsigned int constraint);
 static reg_errcode_t calc_eclosure (re_dfa_t *dfa);
 static reg_errcode_t calc_eclosure_iter (re_node_set *new_set, re_dfa_t *dfa,
 					 int node, int root);
-static reg_errcode_t calc_inveclosure (re_dfa_t *dfa);
+static void calc_inveclosure (re_dfa_t *dfa);
 static int fetch_number (re_string_t *input, re_token_t *token,
 			 reg_syntax_t syntax);
+static void fetch_token (re_token_t *result, re_string_t *input,
+			 reg_syntax_t syntax);
 static int peek_token (re_token_t *token, re_string_t *input,
-			reg_syntax_t syntax) internal_function;
+			reg_syntax_t syntax);
+static int peek_token_bracket (re_token_t *token, re_string_t *input,
+			       reg_syntax_t syntax);
 static bin_tree_t *parse (re_string_t *regexp, regex_t *preg,
 			  reg_syntax_t syntax, reg_errcode_t *err);
 static bin_tree_t *parse_reg_exp (re_string_t *regexp, regex_t *preg,
@@ -86,40 +94,58 @@ static reg_errcode_t parse_bracket_element (bracket_elem_t *elem,
 static reg_errcode_t parse_bracket_symbol (bracket_elem_t *elem,
 					  re_string_t *regexp,
 					  re_token_t *token);
+#ifndef _LIBC
+# ifdef RE_ENABLE_I18N
+static reg_errcode_t build_range_exp (re_bitset_ptr_t sbcset,
+				      re_charset_t *mbcset, int *range_alloc,
+				      bracket_elem_t *start_elem,
+				      bracket_elem_t *end_elem);
+static reg_errcode_t build_collating_symbol (re_bitset_ptr_t sbcset,
+					     re_charset_t *mbcset,
+					     int *coll_sym_alloc,
+					     const unsigned char *name);
+# else /* not RE_ENABLE_I18N */
+static reg_errcode_t build_range_exp (re_bitset_ptr_t sbcset,
+				      bracket_elem_t *start_elem,
+				      bracket_elem_t *end_elem);
+static reg_errcode_t build_collating_symbol (re_bitset_ptr_t sbcset,
+					     const unsigned char *name);
+# endif /* not RE_ENABLE_I18N */
+#endif /* not _LIBC */
 #ifdef RE_ENABLE_I18N
-static reg_errcode_t build_equiv_class (bitset_t sbcset,
+static reg_errcode_t build_equiv_class (re_bitset_ptr_t sbcset,
 					re_charset_t *mbcset,
 					int *equiv_class_alloc,
 					const unsigned char *name);
-static reg_errcode_t build_charclass (RE_TRANSLATE_TYPE trans,
-				      bitset_t sbcset,
+static reg_errcode_t build_charclass (unsigned RE_TRANSLATE_TYPE trans,
+				      re_bitset_ptr_t sbcset,
 				      re_charset_t *mbcset,
 				      int *char_class_alloc,
 				      const unsigned char *class_name,
 				      reg_syntax_t syntax);
 #else  /* not RE_ENABLE_I18N */
-static reg_errcode_t build_equiv_class (bitset_t sbcset,
+static reg_errcode_t build_equiv_class (re_bitset_ptr_t sbcset,
 					const unsigned char *name);
-static reg_errcode_t build_charclass (RE_TRANSLATE_TYPE trans,
-				      bitset_t sbcset,
+static reg_errcode_t build_charclass (unsigned RE_TRANSLATE_TYPE trans,
+				      re_bitset_ptr_t sbcset,
 				      const unsigned char *class_name,
 				      reg_syntax_t syntax);
 #endif /* not RE_ENABLE_I18N */
 static bin_tree_t *build_charclass_op (re_dfa_t *dfa,
-				       RE_TRANSLATE_TYPE trans,
+				       unsigned RE_TRANSLATE_TYPE trans,
 				       const unsigned char *class_name,
 				       const unsigned char *extra,
 				       int non_match, reg_errcode_t *err);
 static bin_tree_t *create_tree (re_dfa_t *dfa,
 				bin_tree_t *left, bin_tree_t *right,
-				re_token_type_t type);
-static bin_tree_t *create_token_tree (re_dfa_t *dfa,
-				      bin_tree_t *left, bin_tree_t *right,
-				      const re_token_t *token);
+				re_token_type_t type, int index);
+static bin_tree_t *re_dfa_add_tree_node (re_dfa_t *dfa,
+					 bin_tree_t *left, bin_tree_t *right,
+					 const re_token_t *token)
+  __attribute ((noinline));
 static bin_tree_t *duplicate_tree (const bin_tree_t *src, re_dfa_t *dfa);
-static void free_token (re_token_t *node);
-static reg_errcode_t free_tree (void *extra, bin_tree_t *node);
-static reg_errcode_t mark_opt_subexp (void *extra, bin_tree_t *node);
+static void mark_opt_subexp (const bin_tree_t *src, re_dfa_t *dfa);
+static void mark_opt_subexp_iter (const bin_tree_t *src, re_dfa_t *dfa, int idx);
 
 /* This table gives an error message for each of the error codes listed
    in regex.h.  Obviously the order here has to be same as there.
@@ -299,8 +325,10 @@ re_set_fastmap (char *fastmap, int icase, int ch)
    Compile fastmap for the initial_state INIT_STATE.  */
 
 static void
-re_compile_fastmap_iter (regex_t *bufp, const re_dfastate_t *init_state,
-			 char *fastmap)
+re_compile_fastmap_iter (bufp, init_state, fastmap)
+     regex_t *bufp;
+     const re_dfastate_t *init_state;
+     char *fastmap;
 {
   re_dfa_t *dfa = (re_dfa_t *) bufp->buffer;
   int node_cnt;
@@ -326,26 +354,21 @@ re_compile_fastmap_iter (regex_t *bufp, const re_dfastate_t *init_state,
 		     &&	dfa->nodes[node].type == CHARACTER
 		     && dfa->nodes[node].mb_partial)
 		*p++ = dfa->nodes[node].opr.c;
-	      memset (&state, '\0', sizeof (state));
+	      memset (&state, 0, sizeof (state));
 	      if (mbrtowc (&wc, (const char *) buf, p - buf,
 			   &state) == p - buf
-		  && (__wcrtomb ((char *) buf, towlower (wc), &state)
-		      != (size_t) -1))
+		  && __wcrtomb ((char *) buf, towlower (wc), &state) > 0)
 		re_set_fastmap (fastmap, 0, buf[0]);
 	    }
 #endif
 	}
       else if (type == SIMPLE_BRACKET)
 	{
-	  int i, ch;
-	  for (i = 0, ch = 0; i < BITSET_WORDS; ++i)
-	    {
-	      int j;
-	      bitset_word_t w = dfa->nodes[node].opr.sbcset[i];
-	      for (j = 0; j < BITSET_WORD_BITS; ++j, ++ch)
-		if (w & ((bitset_word_t) 1 << j))
-		  re_set_fastmap (fastmap, icase, ch);
-	    }
+	  int i, j, ch;
+	  for (i = 0, ch = 0; i < BITSET_UINTS; ++i)
+	    for (j = 0; j < UINT_BITS; ++j, ++ch)
+	      if (dfa->nodes[node].opr.sbcset[i] & (1 << j))
+		re_set_fastmap (fastmap, icase, ch);
 	}
 #ifdef RE_ENABLE_I18N
       else if (type == COMPLEX_BRACKET)
@@ -364,11 +387,13 @@ re_compile_fastmap_iter (regex_t *bufp, const re_dfastate_t *init_state,
 			  is a valid collation element, and don't catch
 			  'b' since 'b' is the only collation element
 			  which starts from 'b'.  */
+		  int j, ch;
 		  const int32_t *table = (const int32_t *)
 		    _NL_CURRENT (LC_COLLATE, _NL_COLLATE_TABLEMB);
-		  for (i = 0; i < SBC_MAX; ++i)
-		    if (table[i] < 0)
-		      re_set_fastmap (fastmap, icase, i);
+		  for (i = 0, ch = 0; i < BITSET_UINTS; ++i)
+		    for (j = 0; j < UINT_BITS; ++j, ++ch)
+		      if (table[ch] < 0)
+			re_set_fastmap (fastmap, icase, ch);
 		}
 # else
 	      if (dfa->mb_cur_max > 1)
@@ -382,13 +407,12 @@ re_compile_fastmap_iter (regex_t *bufp, const re_dfastate_t *init_state,
 	      char buf[256];
 	      mbstate_t state;
 	      memset (&state, '\0', sizeof (state));
-	      if (__wcrtomb (buf, cset->mbchars[i], &state) != (size_t) -1)
-		re_set_fastmap (fastmap, icase, *(unsigned char *) buf);
+	      __wcrtomb (buf, cset->mbchars[i], &state);
+	      re_set_fastmap (fastmap, icase, *(unsigned char *) buf);
 	      if ((bufp->syntax & RE_ICASE) && dfa->mb_cur_max > 1)
 		{
-		  if (__wcrtomb (buf, towlower (cset->mbchars[i]), &state)
-		      != (size_t) -1)
-		    re_set_fastmap (fastmap, 0, *(unsigned char *) buf);
+		  __wcrtomb (buf, towlower (cset->mbchars[i]), &state);
+		  re_set_fastmap (fastmap, 0, *(unsigned char *) buf);
 		}
 	    }
 	}
@@ -508,8 +532,8 @@ weak_alias (__regcomp, regcomp)
 size_t
 regerror (errcode, preg, errbuf, errbuf_size)
     int errcode;
-    const regex_t *__restrict preg;
-    char *__restrict errbuf;
+    const regex_t *preg;
+    char *errbuf;
     size_t errbuf_size;
 {
   const char *msg;
@@ -555,10 +579,14 @@ weak_alias (__regerror, regerror)
    UTF-8 is used.  Otherwise we would allocate memory just to initialize
    it the same all the time.  UTF-8 is the preferred encoding so this is
    a worthwhile optimization.  */
-static const bitset_t utf8_sb_map =
+static const bitset utf8_sb_map =
 {
   /* Set the first 128 bits.  */
-  [0 ... 0x80 / BITSET_WORD_BITS - 1] = BITSET_WORD_MAX
+# if UINT_MAX == 0xffffffff
+  0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff
+# else
+#  error "Add case for new unsigned int size"
+# endif
 };
 #endif
 
@@ -570,7 +598,16 @@ free_dfa_content (re_dfa_t *dfa)
 
   if (dfa->nodes)
     for (i = 0; i < dfa->nodes_len; ++i)
-      free_token (dfa->nodes + i);
+      {
+	re_token_t *node = dfa->nodes + i;
+#ifdef RE_ENABLE_I18N
+	if (node->type == COMPLEX_BRACKET && node->duplicated == 0)
+	  free_charset (node->opr.mbcset);
+	else
+#endif /* RE_ENABLE_I18N */
+	  if (node->type == SIMPLE_BRACKET && node->duplicated == 0)
+	    re_free (node->opr.sbcset);
+      }
   re_free (dfa->nexts);
   for (i = 0; i < dfa->nodes_len; ++i)
     {
@@ -707,8 +744,11 @@ libc_freeres_fn (free_mem)
    SYNTAX indicate regular expression's syntax.  */
 
 static reg_errcode_t
-re_compile_internal (regex_t *preg, const char * pattern, size_t length,
-		     reg_syntax_t syntax)
+re_compile_internal (preg, pattern, length, syntax)
+     regex_t *preg;
+     const char * pattern;
+     int length;
+     reg_syntax_t syntax;
 {
   reg_errcode_t err = REG_NOERROR;
   re_dfa_t *dfa;
@@ -748,13 +788,10 @@ re_compile_internal (regex_t *preg, const char * pattern, size_t length,
       return err;
     }
 #ifdef DEBUG
-  /* Note: length+1 will not overflow since it is checked in init_dfa.  */
   dfa->re_str = re_malloc (char, length + 1);
   strncpy (dfa->re_str, pattern, length + 1);
 #endif
 
-  __libc_lock_init (dfa->lock);
-
   err = re_string_construct (&regexp, pattern, length, preg->translate,
 			     syntax & RE_ICASE, dfa);
   if (BE (err != REG_NOERROR, 0))
@@ -774,17 +811,29 @@ re_compile_internal (regex_t *preg, const char * pattern, size_t length,
   if (BE (dfa->str_tree == NULL, 0))
     goto re_compile_internal_free_return;
 
-  /* Analyze the tree and create the nfa.  */
-  err = analyze (preg);
-  if (BE (err != REG_NOERROR, 0))
-    goto re_compile_internal_free_return;
-
 #ifdef RE_ENABLE_I18N
   /* If possible, do searching in single byte encoding to speed things up.  */
   if (dfa->is_utf8 && !(syntax & RE_ICASE) && preg->translate == NULL)
     optimize_utf8 (dfa);
 #endif
 
+  if (preg->re_nsub > 0)
+    {
+      struct subexp_optimize so;
+
+      so.dfa = dfa;
+      so.nodes = dfa->nodes;
+      so.no_sub = preg->no_sub;
+      so.re_nsub = preg->re_nsub;
+      dfa->str_tree = optimize_subexps (&so, dfa->str_tree, -1, 0);
+    }
+
+  /* Analyze the tree and collect information which is necessary to
+     create the dfa.  */
+  err = analyze (dfa);
+  if (BE (err != REG_NOERROR, 0))
+    goto re_compile_internal_free_return;
+
   /* Then create the initial state of the dfa.  */
   err = create_initial_state (dfa);
 
@@ -806,9 +855,11 @@ re_compile_internal (regex_t *preg, const char * pattern, size_t length,
    as the initial length of some arrays.  */
 
 static reg_errcode_t
-init_dfa (re_dfa_t *dfa, size_t pat_len)
+init_dfa (dfa, pat_len)
+     re_dfa_t *dfa;
+     int pat_len;
 {
-  unsigned int table_size;
+  int table_size;
 #ifndef _LIBC
   char *codeset_name;
 #endif
@@ -818,15 +869,13 @@ init_dfa (re_dfa_t *dfa, size_t pat_len)
   /* Force allocation of str_tree_storage the first time.  */
   dfa->str_tree_storage_idx = BIN_TREE_STORAGE_SIZE;
 
-  /* Avoid overflows.  */
-  if (pat_len == SIZE_MAX)
-    return REG_ESPACE;
-
   dfa->nodes_alloc = pat_len + 1;
   dfa->nodes = re_malloc (re_token_t, dfa->nodes_alloc);
 
+  dfa->states_alloc = pat_len + 1;
+
   /*  table_size = 2 ^ ceil(log pat_len) */
-  for (table_size = 1; ; table_size <<= 1)
+  for (table_size = 1; table_size > 0; table_size <<= 1)
     if (table_size > pat_len)
       break;
 
@@ -845,9 +894,9 @@ init_dfa (re_dfa_t *dfa, size_t pat_len)
   codeset_name = nl_langinfo (CODESET);
 # else
   codeset_name = getenv ("LC_ALL");
-  if (codeset_name == NULL || codeset_name[0] == '\0')
+  if (codeset_name == NULL || codeset[0] == '\0')
     codeset_name = getenv ("LC_CTYPE");
-  if (codeset_name == NULL || codeset_name[0] == '\0')
+  if (codeset_name == NULL || codeset[0] == '\0')
     codeset_name = getenv ("LANG");
   if (codeset_name == NULL)
     codeset_name = "";
@@ -873,19 +922,22 @@ init_dfa (re_dfa_t *dfa, size_t pat_len)
 	{
 	  int i, j, ch;
 
-	  dfa->sb_char = (re_bitset_ptr_t) calloc (sizeof (bitset_t), 1);
+	  dfa->sb_char = (re_bitset_ptr_t) calloc (sizeof (bitset), 1);
 	  if (BE (dfa->sb_char == NULL, 0))
 	    return REG_ESPACE;
 
-	  /* Set the bits corresponding to single byte chars.  */
-	  for (i = 0, ch = 0; i < BITSET_WORDS; ++i)
-	    for (j = 0; j < BITSET_WORD_BITS; ++j, ++ch)
+	  /* Clear all bits by, then set those corresponding to single
+	     byte chars.  */
+	  bitset_empty (dfa->sb_char);
+
+	  for (i = 0, ch = 0; i < BITSET_UINTS; ++i)
+	    for (j = 0; j < UINT_BITS; ++j, ++ch)
 	      {
-		wint_t wch = __btowc (ch);
+		wchar_t wch = __btowc (ch);
 		if (wch != WEOF)
-		  dfa->sb_char[i] |= (bitset_word_t) 1 << j;
+		  dfa->sb_char[i] |= 1 << j;
 # ifndef _LIBC
-		if (isascii (ch) && wch != ch)
+		if (isascii (ch) && wch != (wchar_t) ch)
 		  dfa->map_notascii = 1;
 # endif
 	      }
@@ -903,21 +955,22 @@ init_dfa (re_dfa_t *dfa, size_t pat_len)
    character used by some operators like "\<", "\>", etc.  */
 
 static void
-internal_function
-init_word_char (re_dfa_t *dfa)
+init_word_char (dfa)
+     re_dfa_t *dfa;
 {
   int i, j, ch;
   dfa->word_ops_used = 1;
-  for (i = 0, ch = 0; i < BITSET_WORDS; ++i)
-    for (j = 0; j < BITSET_WORD_BITS; ++j, ++ch)
+  for (i = 0, ch = 0; i < BITSET_UINTS; ++i)
+    for (j = 0; j < UINT_BITS; ++j, ++ch)
       if (isalnum (ch) || ch == '_')
-	dfa->word_char[i] |= (bitset_word_t) 1 << j;
+	dfa->word_char[i] |= 1 << j;
 }
 
 /* Free the work area which are only used while compiling.  */
 
 static void
-free_workarea_compile (regex_t *preg)
+free_workarea_compile (preg)
+     regex_t *preg;
 {
   re_dfa_t *dfa = (re_dfa_t *) preg->buffer;
   bin_tree_storage_t *storage, *next;
@@ -936,7 +989,8 @@ free_workarea_compile (regex_t *preg)
 /* Create initial states for all contexts.  */
 
 static reg_errcode_t
-create_initial_state (re_dfa_t *dfa)
+create_initial_state (dfa)
+     re_dfa_t *dfa;
 {
   int first, i;
   reg_errcode_t err;
@@ -944,7 +998,7 @@ create_initial_state (re_dfa_t *dfa)
 
   /* Initial states have the epsilon closure of the node which is
      the first node of the regular expression.  */
-  first = dfa->str_tree->first->node_idx;
+  first = dfa->str_tree->first;
   dfa->init_node = first;
   err = re_node_set_init_copy (&init_nodes, dfa->eclosures + first);
   if (BE (err != REG_NOERROR, 0))
@@ -1018,7 +1072,8 @@ create_initial_state (re_dfa_t *dfa)
    DFA nodes where needed.  */
 
 static void
-optimize_utf8 (re_dfa_t *dfa)
+optimize_utf8 (dfa)
+     re_dfa_t *dfa;
 {
   int node, i, mb_chars = 0, has_period = 0;
 
@@ -1049,20 +1104,18 @@ optimize_utf8 (re_dfa_t *dfa)
       case OP_ALT:
       case END_OF_RE:
       case OP_DUP_ASTERISK:
+      case OP_DUP_QUESTION:
       case OP_OPEN_SUBEXP:
       case OP_CLOSE_SUBEXP:
 	break;
-      case COMPLEX_BRACKET:
-	return;
       case SIMPLE_BRACKET:
-	/* Just double check.  The non-ASCII range starts at 0x80.  */
-	assert (0x80 % BITSET_WORD_BITS == 0);
-        for (i = 0x80 / BITSET_WORD_BITS; i < BITSET_WORDS; ++i)
+	/* Just double check.  */
+        for (i = 0x80 / UINT_BITS; i < BITSET_UINTS; ++i)
 	  if (dfa->nodes[node].opr.sbcset[i])
 	    return;
 	break;
       default:
-	abort ();
+	return;
       }
 
   if (mb_chars || has_period)
@@ -1082,13 +1135,90 @@ optimize_utf8 (re_dfa_t *dfa)
 }
 #endif
 
+static bin_tree_t *
+optimize_subexps (so, node, sidx, depth)
+     struct subexp_optimize *so;
+     bin_tree_t *node;
+     int sidx, depth;
+{
+  int idx, new_depth, new_sidx;
+  bin_tree_t *ret;
+  if (node == NULL)
+    return NULL;
+
+  new_depth = 0;
+  new_sidx = sidx;
+  if ((depth & 1) && node->type == CONCAT
+      && node->right && node->right->type == 0
+      && so->nodes[idx = node->right->node_idx].type == OP_CLOSE_SUBEXP)
+    {
+      new_depth = depth + 1;
+      if (new_depth == 2
+          || (so->nodes[idx].opr.idx < 8 * sizeof (so->dfa->used_bkref_map)
+              && so->dfa->used_bkref_map & (1 << so->nodes[idx].opr.idx)))
+        new_sidx = so->nodes[idx].opr.idx;
+    }
+  node->left = optimize_subexps (so, node->left, new_sidx, new_depth);
+  new_depth = (depth & 1) == 0 && node->type == CONCAT
+              && node->left && node->left->type == 0
+              && so->nodes[node->left->node_idx].type == OP_OPEN_SUBEXP
+              ? depth + 1 : 0;
+  node->right = optimize_subexps (so, node->right, sidx, new_depth);
+                                     
+  if (node->type != CONCAT)
+    return node;
+  if ((depth & 1) == 0
+      && node->left
+      && node->left->type == 0
+      && so->nodes[idx = node->left->node_idx].type == OP_OPEN_SUBEXP)
+    ret = node->right;
+  else if ((depth & 1)
+           && node->right
+           && node->right->type == 0
+           && so->nodes[idx = node->right->node_idx].type == OP_CLOSE_SUBEXP)
+    ret = node->left;
+  else
+    return node;
+
+  if (so->nodes[idx].opr.idx < 8 * sizeof (so->dfa->used_bkref_map)
+      && so->dfa->used_bkref_map & (1 << so->nodes[idx].opr.idx))
+    return node;
+
+  if (!so->no_sub)
+    {
+      int i;
+
+      if (depth < 2)
+        return node;
+
+      if (so->dfa->subexp_map == NULL)
+        {
+          so->dfa->subexp_map = re_malloc (int, so->re_nsub);
+          if (so->dfa->subexp_map == NULL)
+            return node;
+
+          for (i = 0; i < so->re_nsub; i++)
+            so->dfa->subexp_map[i] = i;
+        }
+
+      i = so->nodes[idx].opr.idx;
+      assert (sidx < i);
+      so->dfa->subexp_map[i] = sidx;
+    }
+
+  so->nodes[idx].type = OP_DELETED_SUBEXP;
+  ret->parent = node->parent;
+  return ret;
+}
+
 /* Analyze the structure tree, and calculate "first", "next", "edest",
    "eclosure", and "inveclosure".  */
 
 static reg_errcode_t
-analyze (regex_t *preg)
+analyze (dfa)
+     re_dfa_t *dfa;
 {
-  re_dfa_t *dfa = (re_dfa_t *) preg->buffer;
+  int i;
   reg_errcode_t ret;
 
   /* Allocate arrays.  */
@@ -1096,310 +1226,225 @@ analyze (regex_t *preg)
   dfa->org_indices = re_malloc (int, dfa->nodes_alloc);
   dfa->edests = re_malloc (re_node_set, dfa->nodes_alloc);
   dfa->eclosures = re_malloc (re_node_set, dfa->nodes_alloc);
+  dfa->inveclosures = re_malloc (re_node_set, dfa->nodes_alloc);
   if (BE (dfa->nexts == NULL || dfa->org_indices == NULL || dfa->edests == NULL
-	  || dfa->eclosures == NULL, 0))
+	  || dfa->eclosures == NULL || dfa->inveclosures == NULL, 0))
     return REG_ESPACE;
-
-  dfa->subexp_map = re_malloc (int, preg->re_nsub);
-  if (dfa->subexp_map != NULL)
+  /* Initialize them.  */
+  for (i = 0; i < dfa->nodes_len; ++i)
     {
-      int i;
-      for (i = 0; i < preg->re_nsub; i++)
-	dfa->subexp_map[i] = i;
-      preorder (dfa->str_tree, optimize_subexps, dfa);
-      for (i = 0; i < preg->re_nsub; i++)
-	if (dfa->subexp_map[i] != i)
-	  break;
-      if (i == preg->re_nsub)
-	{
-	  free (dfa->subexp_map);
-	  dfa->subexp_map = NULL;
-	}
+      dfa->nexts[i] = -1;
+      re_node_set_init_empty (dfa->edests + i);
+      re_node_set_init_empty (dfa->eclosures + i);
+      re_node_set_init_empty (dfa->inveclosures + i);
     }
 
-  ret = postorder (dfa->str_tree, lower_subexps, preg);
-  if (BE (ret != REG_NOERROR, 0))
-    return ret;
-  ret = postorder (dfa->str_tree, calc_first, dfa);
-  if (BE (ret != REG_NOERROR, 0))
-    return ret;
-  preorder (dfa->str_tree, calc_next, dfa);
-  ret = preorder (dfa->str_tree, link_nfa_nodes, dfa);
-  if (BE (ret != REG_NOERROR, 0))
-    return ret;
-  ret = calc_eclosure (dfa);
-  if (BE (ret != REG_NOERROR, 0))
-    return ret;
-
-  /* We only need this during the prune_impossible_nodes pass in regexec.c;
-     skip it if p_i_n will not run, as calc_inveclosure can be quadratic.  */
-  if ((!preg->no_sub && preg->re_nsub > 0 && dfa->has_plural_match)
-      || dfa->nbackref)
+  ret = analyze_tree (dfa, dfa->str_tree);
+  if (BE (ret == REG_NOERROR, 1))
     {
-      dfa->inveclosures = re_malloc (re_node_set, dfa->nodes_len);
-      if (BE (dfa->inveclosures == NULL, 0))
-        return REG_ESPACE;
-      ret = calc_inveclosure (dfa);
+      ret = calc_eclosure (dfa);
+      if (ret == REG_NOERROR)
+	calc_inveclosure (dfa);
     }
-
   return ret;
 }
 
-/* Our parse trees are very unbalanced, so we cannot use a stack to
-   implement parse tree visits.  Instead, we use parent pointers and
-   some hairy code in these two functions.  */
-static reg_errcode_t
-postorder (bin_tree_t *root, reg_errcode_t (fn (void *, bin_tree_t *)),
-	   void *extra)
-{
-  bin_tree_t *node, *prev;
-
-  for (node = root; ; )
-    {
-      /* Descend down the tree, preferably to the left (or to the right
-	 if that's the only child).  */
-      while (node->left || node->right)
-	if (node->left)
-          node = node->left;
-        else
-          node = node->right;
-
-      do
-	{
-	  reg_errcode_t err = fn (extra, node);
-	  if (BE (err != REG_NOERROR, 0))
-	    return err;
-          if (node->parent == NULL)
-	    return REG_NOERROR;
-	  prev = node;
-	  node = node->parent;
-	}
-      /* Go up while we have a node that is reached from the right.  */
-      while (node->right == prev || node->right == NULL);
-      node = node->right;
-    }
-}
-
-static reg_errcode_t
-preorder (bin_tree_t *root, reg_errcode_t (fn (void *, bin_tree_t *)),
-	  void *extra)
-{
-  bin_tree_t *node;
-
-  for (node = root; ; )
-    {
-      reg_errcode_t err = fn (extra, node);
-      if (BE (err != REG_NOERROR, 0))
-	return err;
+/* Helper functions for analyze.
+   This function calculate "first", "next", and "edest" for the subtree
+   whose root is NODE.  */
 
-      /* Go to the left node, or up and to the right.  */
-      if (node->left)
-	node = node->left;
-      else
-	{
-	  bin_tree_t *prev = NULL;
-	  while (node->right == prev || node->right == NULL)
-	    {
-	      prev = node;
-	      node = node->parent;
-	      if (!node)
-	        return REG_NOERROR;
-	    }
-	  node = node->right;
-	}
-    }
-}
-
-/* Optimization pass: if a SUBEXP is entirely contained, strip it and tell
-   re_search_internal to map the inner one's opr.idx to this one's.  Adjust
-   backreferences as well.  Requires a preorder visit.  */
 static reg_errcode_t
-optimize_subexps (void *extra, bin_tree_t *node)
+analyze_tree (dfa, node)
+     re_dfa_t *dfa;
+     bin_tree_t *node;
 {
-  re_dfa_t *dfa = (re_dfa_t *) extra;
+  reg_errcode_t ret;
+  if (node->first == -1)
+    calc_first (dfa, node);
+  if (node->next == -1)
+    calc_next (dfa, node);
+  calc_epsdest (dfa, node);
 
-  if (node->token.type == OP_BACK_REF && dfa->subexp_map)
+  /* Calculate "first" etc. for the left child.  */
+  if (node->left != NULL)
     {
-      int idx = node->token.opr.idx;
-      node->token.opr.idx = dfa->subexp_map[idx];
-      dfa->used_bkref_map |= 1 << node->token.opr.idx;
+      ret = analyze_tree (dfa, node->left);
+      if (BE (ret != REG_NOERROR, 0))
+	return ret;
     }
-
-  else if (node->token.type == SUBEXP
-           && node->left && node->left->token.type == SUBEXP)
+  /* Calculate "first" etc. for the right child.  */
+  if (node->right != NULL)
     {
-      int other_idx = node->left->token.opr.idx;
-
-      node->left = node->left->left;
-      if (node->left)
-        node->left->parent = node;
-
-      dfa->subexp_map[other_idx] = dfa->subexp_map[node->token.opr.idx];
-      if (other_idx < BITSET_WORD_BITS)
-	  dfa->used_bkref_map &= ~((bitset_word_t) 1 << other_idx);
+      ret = analyze_tree (dfa, node->right);
+      if (BE (ret != REG_NOERROR, 0))
+	return ret;
     }
-
   return REG_NOERROR;
 }
 
-/* Lowering pass: Turn each SUBEXP node into the appropriate concatenation
-   of OP_OPEN_SUBEXP, the body of the SUBEXP (if any) and OP_CLOSE_SUBEXP.  */
-static reg_errcode_t
-lower_subexps (void *extra, bin_tree_t *node)
+/* Calculate "first" for the node NODE.  */
+static void
+calc_first (dfa, node)
+     re_dfa_t *dfa;
+     bin_tree_t *node;
 {
-  regex_t *preg = (regex_t *) extra;
-  reg_errcode_t err = REG_NOERROR;
+  int idx, type;
+  idx = node->node_idx;
+  type = (node->type == 0) ? dfa->nodes[idx].type : node->type;
 
-  if (node->left && node->left->token.type == SUBEXP)
-    {
-      node->left = lower_subexp (&err, preg, node->left);
-      if (node->left)
-	node->left->parent = node;
-    }
-  if (node->right && node->right->token.type == SUBEXP)
+  switch (type)
     {
-      node->right = lower_subexp (&err, preg, node->right);
-      if (node->right)
-	node->right->parent = node;
+#ifdef DEBUG
+    case OP_OPEN_BRACKET:
+    case OP_CLOSE_BRACKET:
+    case OP_OPEN_DUP_NUM:
+    case OP_CLOSE_DUP_NUM:
+    case OP_DUP_PLUS:
+    case OP_NON_MATCH_LIST:
+    case OP_OPEN_COLL_ELEM:
+    case OP_CLOSE_COLL_ELEM:
+    case OP_OPEN_EQUIV_CLASS:
+    case OP_CLOSE_EQUIV_CLASS:
+    case OP_OPEN_CHAR_CLASS:
+    case OP_CLOSE_CHAR_CLASS:
+      /* These must not appear here.  */
+      assert (0);
+#endif
+    case END_OF_RE:
+    case CHARACTER:
+    case OP_PERIOD:
+    case OP_DUP_ASTERISK:
+    case OP_DUP_QUESTION:
+#ifdef RE_ENABLE_I18N
+    case OP_UTF8_PERIOD:
+    case COMPLEX_BRACKET:
+#endif /* RE_ENABLE_I18N */
+    case SIMPLE_BRACKET:
+    case OP_BACK_REF:
+    case ANCHOR:
+    case OP_OPEN_SUBEXP:
+    case OP_CLOSE_SUBEXP:
+      node->first = idx;
+      break;
+    case OP_ALT:
+      node->first = idx;
+      break;
+      /* else fall through */
+    default:
+#ifdef DEBUG
+      assert (node->left != NULL);
+#endif
+      if (node->left->first == -1)
+	calc_first (dfa, node->left);
+      node->first = node->left->first;
+      break;
     }
-
-  return err;
 }
 
-static bin_tree_t *
-lower_subexp (reg_errcode_t *err, regex_t *preg, bin_tree_t *node)
-{
-  re_dfa_t *dfa = (re_dfa_t *) preg->buffer;
-  bin_tree_t *body = node->left;
-  bin_tree_t *op, *cls, *tree1, *tree;
-
-  if (preg->no_sub
-      /* We do not optimize empty subexpressions, because otherwise we may
-	 have bad CONCAT nodes with NULL children.  This is obviously not
-	 very common, so we do not lose much.  An example that triggers
-	 this case is the sed "script" /\(\)/x.  */
-      && node->left != NULL
-      && (node->token.opr.idx >= BITSET_WORD_BITS
-	  || !(dfa->used_bkref_map
-	       & ((bitset_word_t) 1 << node->token.opr.idx))))
-    return node->left;
-
-  /* Convert the SUBEXP node to the concatenation of an
-     OP_OPEN_SUBEXP, the contents, and an OP_CLOSE_SUBEXP.  */
-  op = create_tree (dfa, NULL, NULL, OP_OPEN_SUBEXP);
-  cls = create_tree (dfa, NULL, NULL, OP_CLOSE_SUBEXP);
-  tree1 = body ? create_tree (dfa, body, cls, CONCAT) : cls;
-  tree = create_tree (dfa, op, tree1, CONCAT);
-  if (BE (tree == NULL || tree1 == NULL || op == NULL || cls == NULL, 0))
-    {
-      *err = REG_ESPACE;
-      return NULL;
-    }
+/* Calculate "next" for the node NODE.  */
 
-  op->token.opr.idx = cls->token.opr.idx = node->token.opr.idx;
-  op->token.opt_subexp = cls->token.opt_subexp = node->token.opt_subexp;
-  return tree;
-}
-
-/* Pass 1 in building the NFA: compute FIRST and create unlinked automaton
-   nodes.  Requires a postorder visit.  */
-static reg_errcode_t
-calc_first (void *extra, bin_tree_t *node)
+static void
+calc_next (dfa, node)
+     re_dfa_t *dfa;
+     bin_tree_t *node;
 {
-  re_dfa_t *dfa = (re_dfa_t *) extra;
-  if (node->token.type == CONCAT)
+  int idx, type;
+  bin_tree_t *parent = node->parent;
+  if (parent == NULL)
     {
-      node->first = node->left->first;
-      node->node_idx = node->left->node_idx;
+      node->next = -1;
+      idx = node->node_idx;
+      if (node->type == 0)
+	dfa->nexts[idx] = node->next;
+      return;
     }
-  else
-    {
-      node->first = node;
-      node->node_idx = re_dfa_add_node (dfa, node->token);
-      if (BE (node->node_idx == -1, 0))
-        return REG_ESPACE;
-    }
-  return REG_NOERROR;
-}
 
-/* Pass 2: compute NEXT on the tree.  Preorder visit.  */
-static reg_errcode_t
-calc_next (void *extra, bin_tree_t *node)
-{
-  switch (node->token.type)
+  idx = parent->node_idx;
+  type = (parent->type == 0) ? dfa->nodes[idx].type : parent->type;
+
+  switch (type)
     {
     case OP_DUP_ASTERISK:
-      node->left->next = node;
+      node->next = idx;
       break;
     case CONCAT:
-      node->left->next = node->right->first;
-      node->right->next = node->next;
-      break;
+      if (parent->left == node)
+	{
+	  if (parent->right->first == -1)
+	    calc_first (dfa, parent->right);
+	  node->next = parent->right->first;
+	  break;
+	}
+      /* else fall through */
     default:
-      if (node->left)
-	node->left->next = node->next;
-      if (node->right)
-        node->right->next = node->next;
+      if (parent->next == -1)
+	calc_next (dfa, parent);
+      node->next = parent->next;
       break;
     }
-  return REG_NOERROR;
+  idx = node->node_idx;
+  if (node->type == 0)
+    dfa->nexts[idx] = node->next;
 }
 
-/* Pass 3: link all DFA nodes to their NEXT node (any order will do).  */
-static reg_errcode_t
-link_nfa_nodes (void *extra, bin_tree_t *node)
-{
-  re_dfa_t *dfa = (re_dfa_t *) extra;
-  int idx = node->node_idx;
-  reg_errcode_t err = REG_NOERROR;
+/* Calculate "edest" for the node NODE.  */
 
-  switch (node->token.type)
+static void
+calc_epsdest (dfa, node)
+     re_dfa_t *dfa;
+     bin_tree_t *node;
+{
+  int idx;
+  idx = node->node_idx;
+  if (node->type == 0)
     {
-    case CONCAT:
-      break;
-
-    case END_OF_RE:
-      assert (node->next == NULL);
-      break;
-
-    case OP_DUP_ASTERISK:
-    case OP_ALT:
-      {
-	int left, right;
-	dfa->has_plural_match = 1;
-	if (node->left != NULL)
-	  left = node->left->first->node_idx;
-	else
-	  left = node->next->node_idx;
-	if (node->right != NULL)
-	  right = node->right->first->node_idx;
-	else
-	  right = node->next->node_idx;
-	assert (left > -1);
-	assert (right > -1);
-	err = re_node_set_init_2 (dfa->edests + idx, left, right);
-      }
-      break;
-
-    case ANCHOR:
-    case OP_OPEN_SUBEXP:
-    case OP_CLOSE_SUBEXP:
-      err = re_node_set_init_1 (dfa->edests + idx, node->next->node_idx);
-      break;
-
-    case OP_BACK_REF:
-      dfa->nexts[idx] = node->next->node_idx;
-      if (node->token.type == OP_BACK_REF)
-	re_node_set_init_1 (dfa->edests + idx, dfa->nexts[idx]);
-      break;
-
-    default:
-      assert (!IS_EPSILON_NODE (node->token.type));
-      dfa->nexts[idx] = node->next->node_idx;
-      break;
+      if (dfa->nodes[idx].type == OP_DUP_ASTERISK
+	  || dfa->nodes[idx].type == OP_DUP_QUESTION)
+	{
+	  if (node->left->first == -1)
+	    calc_first (dfa, node->left);
+	  if (node->next == -1)
+	    calc_next (dfa, node);
+	  re_node_set_init_2 (dfa->edests + idx, node->left->first,
+			      node->next);
+	}
+      else if (dfa->nodes[idx].type == OP_ALT)
+	{
+	  int left, right;
+	  if (node->left != NULL)
+	    {
+	      if (node->left->first == -1)
+		calc_first (dfa, node->left);
+	      left = node->left->first;
+	    }
+	  else
+	    {
+	      if (node->next == -1)
+		calc_next (dfa, node);
+	      left = node->next;
+	    }
+	  if (node->right != NULL)
+	    {
+	      if (node->right->first == -1)
+		calc_first (dfa, node->right);
+	      right = node->right->first;
+	    }
+	  else
+	    {
+	      if (node->next == -1)
+		calc_next (dfa, node);
+	      right = node->next;
+	    }
+	  re_node_set_init_2 (dfa->edests + idx, left, right);
+	}
+      else if (dfa->nodes[idx].type == ANCHOR
+	       || dfa->nodes[idx].type == OP_OPEN_SUBEXP
+	       || dfa->nodes[idx].type == OP_CLOSE_SUBEXP
+	       || dfa->nodes[idx].type == OP_BACK_REF)
+	re_node_set_init_1 (dfa->edests + idx, node->next);
+      else
+        assert (!IS_EPSILON_NODE (dfa->nodes[idx].type));
     }
-
-  return err;
 }
 
 /* Duplicate the epsilon closure of the node ROOT_NODE.
@@ -1407,10 +1452,13 @@ link_nfa_nodes (void *extra, bin_tree_t *node)
    to their own constraint.  */
 
 static reg_errcode_t
-internal_function
-duplicate_node_closure (re_dfa_t *dfa, int top_org_node, int top_clone_node,
-			int root_node, unsigned int init_constraint)
+duplicate_node_closure (dfa, top_org_node, top_clone_node, root_node,
+			init_constraint)
+     re_dfa_t *dfa;
+     int top_org_node, top_clone_node, root_node;
+     unsigned int init_constraint;
 {
+  reg_errcode_t err;
   int org_node, clone_node, ret;
   unsigned int constraint = init_constraint;
   for (org_node = top_org_node, clone_node = top_clone_node;;)
@@ -1424,9 +1472,9 @@ duplicate_node_closure (re_dfa_t *dfa, int top_org_node, int top_clone_node,
 	     edests of the back reference.  */
 	  org_dest = dfa->nexts[org_node];
 	  re_node_set_empty (dfa->edests + clone_node);
-	  clone_dest = duplicate_node (dfa, org_dest, constraint);
-	  if (BE (clone_dest == -1, 0))
-	    return REG_ESPACE;
+	  err = duplicate_node (&clone_dest, dfa, org_dest, constraint);
+	  if (BE (err != REG_NOERROR, 0))
+	    return err;
 	  dfa->nexts[clone_node] = dfa->nexts[org_node];
 	  ret = re_node_set_insert (dfa->edests + clone_node, clone_dest);
 	  if (BE (ret < 0, 0))
@@ -1462,9 +1510,9 @@ duplicate_node_closure (re_dfa_t *dfa, int top_org_node, int top_clone_node,
 		}
 	      constraint |= dfa->nodes[org_node].opr.ctx_type;
 	    }
-	  clone_dest = duplicate_node (dfa, org_dest, constraint);
-	  if (BE (clone_dest == -1, 0))
-	    return REG_ESPACE;
+	  err = duplicate_node (&clone_dest, dfa, org_dest, constraint);
+	  if (BE (err != REG_NOERROR, 0))
+	    return err;
 	  ret = re_node_set_insert (dfa->edests + clone_node, clone_dest);
 	  if (BE (ret < 0, 0))
 	    return REG_ESPACE;
@@ -1472,7 +1520,7 @@ duplicate_node_closure (re_dfa_t *dfa, int top_org_node, int top_clone_node,
       else /* dfa->edests[org_node].nelem == 2 */
 	{
 	  /* In case of the node can epsilon-transit, and it has two
-	     destinations. In the bin_tree_t and DFA, that's '|' and '*'.   */
+	     destinations. E.g. '|', '*', '+', '?'.   */
 	  org_dest = dfa->edests[org_node].elems[0];
 	  re_node_set_empty (dfa->edests + clone_node);
 	  /* Search for a duplicated node which satisfies the constraint.  */
@@ -1480,10 +1528,9 @@ duplicate_node_closure (re_dfa_t *dfa, int top_org_node, int top_clone_node,
 	  if (clone_dest == -1)
 	    {
 	      /* There are no such a duplicated node, create a new one.  */
-	      reg_errcode_t err;
-	      clone_dest = duplicate_node (dfa, org_dest, constraint);
-	      if (BE (clone_dest == -1, 0))
-		return REG_ESPACE;
+	      err = duplicate_node (&clone_dest, dfa, org_dest, constraint);
+	      if (BE (err != REG_NOERROR, 0))
+		return err;
 	      ret = re_node_set_insert (dfa->edests + clone_node, clone_dest);
 	      if (BE (ret < 0, 0))
 		return REG_ESPACE;
@@ -1502,9 +1549,9 @@ duplicate_node_closure (re_dfa_t *dfa, int top_org_node, int top_clone_node,
 	    }
 
 	  org_dest = dfa->edests[org_node].elems[1];
-	  clone_dest = duplicate_node (dfa, org_dest, constraint);
-	  if (BE (clone_dest == -1, 0))
-	    return REG_ESPACE;
+	  err = duplicate_node (&clone_dest, dfa, org_dest, constraint);
+	  if (BE (err != REG_NOERROR, 0))
+	    return err;
 	  ret = re_node_set_insert (dfa->edests + clone_node, clone_dest);
 	  if (BE (ret < 0, 0))
 	    return REG_ESPACE;
@@ -1519,8 +1566,10 @@ duplicate_node_closure (re_dfa_t *dfa, int top_org_node, int top_clone_node,
    satisfies the constraint CONSTRAINT.  */
 
 static int
-search_duplicated_node (const re_dfa_t *dfa, int org_node,
-			unsigned int constraint)
+search_duplicated_node (dfa, org_node, constraint)
+     re_dfa_t *dfa;
+     int org_node;
+     unsigned int constraint;
 {
   int idx;
   for (idx = dfa->nodes_len - 1; dfa->nodes[idx].duplicated && idx > 0; --idx)
@@ -1533,51 +1582,54 @@ search_duplicated_node (const re_dfa_t *dfa, int org_node,
 }
 
 /* Duplicate the node whose index is ORG_IDX and set the constraint CONSTRAINT.
-   Return the index of the new node, or -1 if insufficient storage is
-   available.  */
+   The new index will be stored in NEW_IDX and return REG_NOERROR if succeeded,
+   otherwise return the error code.  */
 
-static int
-duplicate_node (re_dfa_t *dfa, int org_idx, unsigned int constraint)
+static reg_errcode_t
+duplicate_node (new_idx, dfa, org_idx, constraint)
+     re_dfa_t *dfa;
+     int *new_idx, org_idx;
+     unsigned int constraint;
 {
-  int dup_idx = re_dfa_add_node (dfa, dfa->nodes[org_idx]);
-  if (BE (dup_idx != -1, 1))
-    {
-      dfa->nodes[dup_idx].constraint = constraint;
-      if (dfa->nodes[org_idx].type == ANCHOR)
-	dfa->nodes[dup_idx].constraint |= dfa->nodes[org_idx].opr.ctx_type;
-      dfa->nodes[dup_idx].duplicated = 1;
-
-      /* Store the index of the original node.  */
-      dfa->org_indices[dup_idx] = org_idx;
-    }
-  return dup_idx;
+  int dup_idx = re_dfa_add_node (dfa, dfa->nodes[org_idx], 1);
+  if (BE (dup_idx == -1, 0))
+    return REG_ESPACE;
+  dfa->nodes[dup_idx].constraint = constraint;
+  if (dfa->nodes[org_idx].type == ANCHOR)
+    dfa->nodes[dup_idx].constraint |= dfa->nodes[org_idx].opr.ctx_type;
+  dfa->nodes[dup_idx].duplicated = 1;
+  re_node_set_init_empty (dfa->edests + dup_idx);
+  re_node_set_init_empty (dfa->eclosures + dup_idx);
+  re_node_set_init_empty (dfa->inveclosures + dup_idx);
+
+  /* Store the index of the original node.  */
+  dfa->org_indices[dup_idx] = org_idx;
+  *new_idx = dup_idx;
+  return REG_NOERROR;
 }
 
-static reg_errcode_t
-calc_inveclosure (re_dfa_t *dfa)
+static void
+calc_inveclosure (dfa)
+     re_dfa_t *dfa;
 {
-  int src, idx, ret;
-  for (idx = 0; idx < dfa->nodes_len; ++idx)
-    re_node_set_init_empty (dfa->inveclosures + idx);
-
+  int src, idx, dest;
   for (src = 0; src < dfa->nodes_len; ++src)
     {
-      int *elems = dfa->eclosures[src].elems;
+      if (dfa->nodes[src].type == OP_DELETED_SUBEXP)
+        continue;
       for (idx = 0; idx < dfa->eclosures[src].nelem; ++idx)
 	{
-	  ret = re_node_set_insert_last (dfa->inveclosures + elems[idx], src);
-	  if (BE (ret == -1, 0))
-	    return REG_ESPACE;
+	  dest = dfa->eclosures[src].elems[idx];
+	  re_node_set_insert_last (dfa->inveclosures + dest, src);
 	}
     }
-
-  return REG_NOERROR;
 }
 
 /* Calculate "eclosure" for all the node in DFA.  */
 
 static reg_errcode_t
-calc_eclosure (re_dfa_t *dfa)
+calc_eclosure (dfa)
+     re_dfa_t *dfa;
 {
   int node_idx, incomplete;
 #ifdef DEBUG
@@ -1600,6 +1652,8 @@ calc_eclosure (re_dfa_t *dfa)
 #ifdef DEBUG
       assert (dfa->eclosures[node_idx].nelem != -1);
 #endif
+      if (dfa->nodes[node_idx].type == OP_DELETED_SUBEXP)
+        continue;
 
       /* If we have already calculated, skip it.  */
       if (dfa->eclosures[node_idx].nelem != 0)
@@ -1621,7 +1675,10 @@ calc_eclosure (re_dfa_t *dfa)
 /* Calculate epsilon closure of NODE.  */
 
 static reg_errcode_t
-calc_eclosure_iter (re_node_set *new_set, re_dfa_t *dfa, int node, int root)
+calc_eclosure_iter (new_set, dfa, node, root)
+     re_node_set *new_set;
+     re_dfa_t *dfa;
+     int node, root;
 {
   reg_errcode_t err;
   unsigned int constraint;
@@ -1644,6 +1701,8 @@ calc_eclosure_iter (re_node_set *new_set, re_dfa_t *dfa, int node, int root)
       && dfa->edests[node].nelem
       && !dfa->nodes[dfa->edests[node].elems[0]].duplicated)
     {
+      int org_node, cur_node;
+      org_node = cur_node = node;
       err = duplicate_node_closure (dfa, node, node, node, constraint);
       if (BE (err != REG_NOERROR, 0))
 	return err;
@@ -1699,8 +1758,10 @@ calc_eclosure_iter (re_node_set *new_set, re_dfa_t *dfa, int node, int root)
    We must not use this function inside bracket expressions.  */
 
 static void
-internal_function
-fetch_token (re_token_t *result, re_string_t *input, reg_syntax_t syntax)
+fetch_token (result, input, syntax)
+     re_token_t *result;
+     re_string_t *input;
+     reg_syntax_t syntax;
 {
   re_string_skip_bytes (input, peek_token (result, input, syntax));
 }
@@ -1709,8 +1770,10 @@ fetch_token (re_token_t *result, re_string_t *input, reg_syntax_t syntax)
    We must not use this function inside bracket expressions.  */
 
 static int
-internal_function
-peek_token (re_token_t *token, re_string_t *input, reg_syntax_t syntax)
+peek_token (token, input, syntax)
+     re_token_t *token;
+     re_string_t *input;
+     reg_syntax_t syntax;
 {
   unsigned char c;
 
@@ -1796,7 +1859,7 @@ peek_token (re_token_t *token, re_string_t *input, reg_syntax_t syntax)
 	  if (!(syntax & RE_NO_GNU_OPS))
 	    {
 	      token->type = ANCHOR;
-	      token->opr.ctx_type = NOT_WORD_DELIM;
+	      token->opr.ctx_type = INSIDE_WORD;
 	    }
 	  break;
 	case 'w':
@@ -1948,8 +2011,10 @@ peek_token (re_token_t *token, re_string_t *input, reg_syntax_t syntax)
    We must not use this function out of bracket expressions.  */
 
 static int
-internal_function
-peek_token_bracket (re_token_t *token, re_string_t *input, reg_syntax_t syntax)
+peek_token_bracket (token, input, syntax)
+     re_token_t *token;
+     re_string_t *input;
+     reg_syntax_t syntax;
 {
   unsigned char c;
   if (re_string_eoi (input))
@@ -2045,8 +2110,11 @@ peek_token_bracket (re_token_t *token, re_string_t *input, reg_syntax_t syntax)
    EOR means end of regular expression.  */
 
 static bin_tree_t *
-parse (re_string_t *regexp, regex_t *preg, reg_syntax_t syntax,
-       reg_errcode_t *err)
+parse (regexp, preg, syntax, err)
+     re_string_t *regexp;
+     regex_t *preg;
+     reg_syntax_t syntax;
+     reg_errcode_t *err;
 {
   re_dfa_t *dfa = (re_dfa_t *) preg->buffer;
   bin_tree_t *tree, *eor, *root;
@@ -2056,9 +2124,9 @@ parse (re_string_t *regexp, regex_t *preg, reg_syntax_t syntax,
   tree = parse_reg_exp (regexp, preg, &current_token, syntax, 0, err);
   if (BE (*err != REG_NOERROR && tree == NULL, 0))
     return NULL;
-  eor = create_tree (dfa, NULL, NULL, END_OF_RE);
+  eor = re_dfa_add_tree_node (dfa, NULL, NULL, &current_token);
   if (tree != NULL)
-    root = create_tree (dfa, tree, eor, CONCAT);
+    root = create_tree (dfa, tree, eor, CONCAT, 0);
   else
     root = eor;
   if (BE (eor == NULL || root == NULL, 0))
@@ -2079,8 +2147,13 @@ parse (re_string_t *regexp, regex_t *preg, reg_syntax_t syntax,
    ALT means alternative, which represents the operator `|'.  */
 
 static bin_tree_t *
-parse_reg_exp (re_string_t *regexp, regex_t *preg, re_token_t *token,
-	       reg_syntax_t syntax, int nest, reg_errcode_t *err)
+parse_reg_exp (regexp, preg, token, syntax, nest, err)
+     re_string_t *regexp;
+     regex_t *preg;
+     re_token_t *token;
+     reg_syntax_t syntax;
+     int nest;
+     reg_errcode_t *err;
 {
   re_dfa_t *dfa = (re_dfa_t *) preg->buffer;
   bin_tree_t *tree, *branch = NULL;
@@ -2090,6 +2163,7 @@ parse_reg_exp (re_string_t *regexp, regex_t *preg, re_token_t *token,
 
   while (token->type == OP_ALT)
     {
+      re_token_t alt_token = *token;
       fetch_token (token, regexp, syntax | RE_CARET_ANCHORS_HERE);
       if (token->type != OP_ALT && token->type != END_OF_RE
 	  && (nest == 0 || token->type != OP_CLOSE_SUBEXP))
@@ -2100,12 +2174,13 @@ parse_reg_exp (re_string_t *regexp, regex_t *preg, re_token_t *token,
 	}
       else
 	branch = NULL;
-      tree = create_tree (dfa, tree, branch, OP_ALT);
+      tree = re_dfa_add_tree_node (dfa, tree, branch, &alt_token);
       if (BE (tree == NULL, 0))
 	{
 	  *err = REG_ESPACE;
 	  return NULL;
 	}
+      dfa->has_plural_match = 1;
     }
   return tree;
 }
@@ -2120,8 +2195,13 @@ parse_reg_exp (re_string_t *regexp, regex_t *preg, re_token_t *token,
    CAT means concatenation.  */
 
 static bin_tree_t *
-parse_branch (re_string_t *regexp, regex_t *preg, re_token_t *token,
-	      reg_syntax_t syntax, int nest, reg_errcode_t *err)
+parse_branch (regexp, preg, token, syntax, nest, err)
+     re_string_t *regexp;
+     regex_t *preg;
+     re_token_t *token;
+     reg_syntax_t syntax;
+     int nest;
+     reg_errcode_t *err;
 {
   bin_tree_t *tree, *exp;
   re_dfa_t *dfa = (re_dfa_t *) preg->buffer;
@@ -2139,7 +2219,7 @@ parse_branch (re_string_t *regexp, regex_t *preg, re_token_t *token,
 	}
       if (tree != NULL && exp != NULL)
 	{
-	  tree = create_tree (dfa, tree, exp, CONCAT);
+	  tree = create_tree (dfa, tree, exp, CONCAT, 0);
 	  if (tree == NULL)
 	    {
 	      *err = REG_ESPACE;
@@ -2160,15 +2240,20 @@ parse_branch (re_string_t *regexp, regex_t *preg, re_token_t *token,
 */
 
 static bin_tree_t *
-parse_expression (re_string_t *regexp, regex_t *preg, re_token_t *token,
-		  reg_syntax_t syntax, int nest, reg_errcode_t *err)
+parse_expression (regexp, preg, token, syntax, nest, err)
+     re_string_t *regexp;
+     regex_t *preg;
+     re_token_t *token;
+     reg_syntax_t syntax;
+     int nest;
+     reg_errcode_t *err;
 {
   re_dfa_t *dfa = (re_dfa_t *) preg->buffer;
   bin_tree_t *tree;
   switch (token->type)
     {
     case CHARACTER:
-      tree = create_token_tree (dfa, NULL, NULL, token);
+      tree = re_dfa_add_tree_node (dfa, NULL, NULL, token);
       if (BE (tree == NULL, 0))
 	{
 	  *err = REG_ESPACE;
@@ -2182,8 +2267,8 @@ parse_expression (re_string_t *regexp, regex_t *preg, re_token_t *token,
 	    {
 	      bin_tree_t *mbc_remain;
 	      fetch_token (token, regexp, syntax);
-	      mbc_remain = create_token_tree (dfa, NULL, NULL, token);
-	      tree = create_tree (dfa, tree, mbc_remain, CONCAT);
+	      mbc_remain = re_dfa_add_tree_node (dfa, NULL, NULL, token);
+	      tree = create_tree (dfa, tree, mbc_remain, CONCAT, 0);
 	      if (BE (mbc_remain == NULL || tree == NULL, 0))
 		{
 		  *err = REG_ESPACE;
@@ -2210,7 +2295,7 @@ parse_expression (re_string_t *regexp, regex_t *preg, re_token_t *token,
 	  return NULL;
 	}
       dfa->used_bkref_map |= 1 << token->opr.idx;
-      tree = create_token_tree (dfa, NULL, NULL, token);
+      tree = re_dfa_add_tree_node (dfa, NULL, NULL, token);
       if (BE (tree == NULL, 0))
 	{
 	  *err = REG_ESPACE;
@@ -2255,7 +2340,7 @@ parse_expression (re_string_t *regexp, regex_t *preg, re_token_t *token,
       token->type = CHARACTER;
       /* mb_partial and word_char bits should be initialized already
 	 by peek_token.  */
-      tree = create_token_tree (dfa, NULL, NULL, token);
+      tree = re_dfa_add_tree_node (dfa, NULL, NULL, token);
       if (BE (tree == NULL, 0))
 	{
 	  *err = REG_ESPACE;
@@ -2264,27 +2349,18 @@ parse_expression (re_string_t *regexp, regex_t *preg, re_token_t *token,
       break;
     case ANCHOR:
       if ((token->opr.ctx_type
-	   & (WORD_DELIM | NOT_WORD_DELIM | WORD_FIRST | WORD_LAST))
+	   & (WORD_DELIM | INSIDE_WORD | WORD_FIRST | WORD_LAST))
 	  && dfa->word_ops_used == 0)
 	init_word_char (dfa);
-      if (token->opr.ctx_type == WORD_DELIM
-          || token->opr.ctx_type == NOT_WORD_DELIM)
+      if (token->opr.ctx_type == WORD_DELIM)
 	{
 	  bin_tree_t *tree_first, *tree_last;
-	  if (token->opr.ctx_type == WORD_DELIM)
-	    {
-	      token->opr.ctx_type = WORD_FIRST;
-	      tree_first = create_token_tree (dfa, NULL, NULL, token);
-	      token->opr.ctx_type = WORD_LAST;
-            }
-          else
-            {
-	      token->opr.ctx_type = INSIDE_WORD;
-	      tree_first = create_token_tree (dfa, NULL, NULL, token);
-	      token->opr.ctx_type = INSIDE_NOTWORD;
-            }
-	  tree_last = create_token_tree (dfa, NULL, NULL, token);
-	  tree = create_tree (dfa, tree_first, tree_last, OP_ALT);
+	  token->opr.ctx_type = WORD_FIRST;
+	  tree_first = re_dfa_add_tree_node (dfa, NULL, NULL, token);
+	  token->opr.ctx_type = WORD_LAST;
+	  tree_last = re_dfa_add_tree_node (dfa, NULL, NULL, token);
+	  token->type = OP_ALT;
+	  tree = re_dfa_add_tree_node (dfa, tree_first, tree_last, token);
 	  if (BE (tree_first == NULL || tree_last == NULL || tree == NULL, 0))
 	    {
 	      *err = REG_ESPACE;
@@ -2293,7 +2369,7 @@ parse_expression (re_string_t *regexp, regex_t *preg, re_token_t *token,
 	}
       else
 	{
-	  tree = create_token_tree (dfa, NULL, NULL, token);
+	  tree = re_dfa_add_tree_node (dfa, NULL, NULL, token);
 	  if (BE (tree == NULL, 0))
 	    {
 	      *err = REG_ESPACE;
@@ -2307,7 +2383,7 @@ parse_expression (re_string_t *regexp, regex_t *preg, re_token_t *token,
       fetch_token (token, regexp, syntax);
       return tree;
     case OP_PERIOD:
-      tree = create_token_tree (dfa, NULL, NULL, token);
+      tree = re_dfa_add_tree_node (dfa, NULL, NULL, token);
       if (BE (tree == NULL, 0))
 	{
 	  *err = REG_ESPACE;
@@ -2363,6 +2439,7 @@ parse_expression (re_string_t *regexp, regex_t *preg, re_token_t *token,
 	  *err = REG_BADRPT;
 	  return NULL;
 	}
+      dfa->has_plural_match = 1;
     }
 
   return tree;
@@ -2376,14 +2453,26 @@ parse_expression (re_string_t *regexp, regex_t *preg, re_token_t *token,
 */
 
 static bin_tree_t *
-parse_sub_exp (re_string_t *regexp, regex_t *preg, re_token_t *token,
-	       reg_syntax_t syntax, int nest, reg_errcode_t *err)
+parse_sub_exp (regexp, preg, token, syntax, nest, err)
+     re_string_t *regexp;
+     regex_t *preg;
+     re_token_t *token;
+     reg_syntax_t syntax;
+     int nest;
+     reg_errcode_t *err;
 {
   re_dfa_t *dfa = (re_dfa_t *) preg->buffer;
-  bin_tree_t *tree;
+  bin_tree_t *tree, *left_par, *right_par;
   size_t cur_nsub;
   cur_nsub = preg->re_nsub++;
 
+  left_par = re_dfa_add_tree_node (dfa, NULL, NULL, token);
+  if (BE (left_par == NULL, 0))
+    {
+      *err = REG_ESPACE;
+      return NULL;
+    }
+  dfa->nodes[left_par->node_idx].opr.idx = cur_nsub;
   fetch_token (token, regexp, syntax | RE_CARET_ANCHORS_HERE);
 
   /* The subexpression may be a null string.  */
@@ -2392,31 +2481,41 @@ parse_sub_exp (re_string_t *regexp, regex_t *preg, re_token_t *token,
   else
     {
       tree = parse_reg_exp (regexp, preg, token, syntax, nest, err);
-      if (BE (*err == REG_NOERROR && token->type != OP_CLOSE_SUBEXP, 0))
-        *err = REG_EPAREN;
-      if (BE (*err != REG_NOERROR, 0))
+      if (BE (*err != REG_NOERROR && tree == NULL, 0))
 	return NULL;
     }
-
-  if (cur_nsub <= '9' - '1')
-    dfa->completed_bkref_map |= 1 << cur_nsub;
-
-  tree = create_tree (dfa, tree, NULL, SUBEXP);
-  if (BE (tree == NULL, 0))
+  if (BE (token->type != OP_CLOSE_SUBEXP, 0))
+    {
+      *err = REG_EPAREN;
+      return NULL;
+    }
+  right_par = re_dfa_add_tree_node (dfa, NULL, NULL, token);
+  dfa->completed_bkref_map |= 1 << cur_nsub;
+  tree = ((tree == NULL) ? right_par
+	  : create_tree (dfa, tree, right_par, CONCAT, 0));
+  tree = create_tree (dfa, left_par, tree, CONCAT, 0);
+  if (BE (right_par == NULL || tree == NULL, 0))
     {
       *err = REG_ESPACE;
       return NULL;
     }
-  tree->token.opr.idx = cur_nsub;
+  dfa->nodes[right_par->node_idx].opr.idx = cur_nsub;
+
   return tree;
 }
 
 /* This function parse repetition operators like "*", "+", "{1,3}" etc.  */
 
 static bin_tree_t *
-parse_dup_op (bin_tree_t *elem, re_string_t *regexp, re_dfa_t *dfa,
-	      re_token_t *token, reg_syntax_t syntax, reg_errcode_t *err)
+parse_dup_op (elem, regexp, dfa, token, syntax, err)
+     bin_tree_t *elem;
+     re_string_t *regexp;
+     re_dfa_t *dfa;
+     re_token_t *token;
+     reg_syntax_t syntax;
+     reg_errcode_t *err;
 {
+  re_token_t dup_token;
   bin_tree_t *tree = NULL, *old_tree = NULL;
   int i, start, end, start_idx = re_string_cur_idx (regexp);
   re_token_t start_token = *token;
@@ -2479,13 +2578,9 @@ parse_dup_op (bin_tree_t *elem, re_string_t *regexp, re_dfa_t *dfa,
 
   fetch_token (token, regexp, syntax);
 
-  if (BE (elem == NULL, 0))
+  /* Treat "<re>{0}*" etc. as "<re>{0}".  */
+  if (BE (elem == NULL || (start == 0 && end == 0), 0))
     return NULL;
-  if (BE (start == 0 && end == 0, 0))
-    {
-      postorder (elem, free_tree, NULL);
-      return NULL;
-    }
 
   /* Extract "<re>{n,m}" to "<re><re>...<re><re>{0,<m-n>}".  */
   if (BE (start > 0, 0))
@@ -2494,7 +2589,7 @@ parse_dup_op (bin_tree_t *elem, re_string_t *regexp, re_dfa_t *dfa,
       for (i = 2; i <= start; ++i)
 	{
 	  elem = duplicate_tree (elem, dfa);
-	  tree = create_tree (dfa, tree, elem, CONCAT);
+	  tree = create_tree (dfa, tree, elem, CONCAT, 0);
 	  if (BE (elem == NULL || tree == NULL, 0))
 	    goto parse_dup_op_espace;
 	}
@@ -2509,10 +2604,9 @@ parse_dup_op (bin_tree_t *elem, re_string_t *regexp, re_dfa_t *dfa,
   else
     old_tree = NULL;
 
-  if (elem->token.type == SUBEXP)
-    postorder (elem, mark_opt_subexp, (void *) (long) elem->token.opr.idx);
-
-  tree = create_tree (dfa, elem, NULL, (end == -1 ? OP_DUP_ASTERISK : OP_ALT));
+  mark_opt_subexp (elem, dfa);
+  dup_token.type = (end == -1 ? OP_DUP_ASTERISK : OP_DUP_QUESTION);
+  tree = re_dfa_add_tree_node (dfa, elem, NULL, &dup_token);
   if (BE (tree == NULL, 0))
     goto parse_dup_op_espace;
 
@@ -2522,17 +2616,17 @@ parse_dup_op (bin_tree_t *elem, re_string_t *regexp, re_dfa_t *dfa,
   for (i = start + 2; i <= end; ++i)
     {
       elem = duplicate_tree (elem, dfa);
-      tree = create_tree (dfa, tree, elem, CONCAT);
+      tree = create_tree (dfa, tree, elem, CONCAT, 0);
       if (BE (elem == NULL || tree == NULL, 0))
         goto parse_dup_op_espace;
 
-      tree = create_tree (dfa, tree, NULL, OP_ALT);
+      tree = re_dfa_add_tree_node (dfa, tree, NULL, &dup_token);
       if (BE (tree == NULL, 0))
         goto parse_dup_op_espace;
     }
 
   if (old_tree)
-    tree = create_tree (dfa, old_tree, tree, CONCAT);
+    tree = create_tree (dfa, old_tree, tree, CONCAT, 0);
 
   return tree;
 
@@ -2554,14 +2648,15 @@ parse_dup_op (bin_tree_t *elem, re_string_t *regexp, re_dfa_t *dfa,
      update it.  */
 
 static reg_errcode_t
-internal_function
 # ifdef RE_ENABLE_I18N
-build_range_exp (bitset_t sbcset, re_charset_t *mbcset, int *range_alloc,
-		 bracket_elem_t *start_elem, bracket_elem_t *end_elem)
+build_range_exp (sbcset, mbcset, range_alloc, start_elem, end_elem)
+     re_charset_t *mbcset;
+     int *range_alloc;
 # else /* not RE_ENABLE_I18N */
-build_range_exp (bitset_t sbcset, bracket_elem_t *start_elem,
-		 bracket_elem_t *end_elem)
+build_range_exp (sbcset, start_elem, end_elem)
 # endif /* not RE_ENABLE_I18N */
+     re_bitset_ptr_t sbcset;
+     bracket_elem_t *start_elem, *end_elem;
 {
   unsigned int start_ch, end_ch;
   /* Equivalence Classes and Character Classes can't be a range start/end.  */
@@ -2580,9 +2675,7 @@ build_range_exp (bitset_t sbcset, bracket_elem_t *start_elem,
 
 # ifdef RE_ENABLE_I18N
   {
-    wchar_t wc;
-    wint_t start_wc;
-    wint_t end_wc;
+    wchar_t wc, start_wc, end_wc;
     wchar_t cmp_buf[6] = {L'\0', L'\0', L'\0', L'\0', L'\0', L'\0'};
 
     start_ch = ((start_elem->type == SB_CHAR) ? start_elem->opr.ch
@@ -2675,13 +2768,15 @@ build_range_exp (bitset_t sbcset, bracket_elem_t *start_elem,
    pointer argument since we may update it.  */
 
 static reg_errcode_t
-internal_function
 # ifdef RE_ENABLE_I18N
-build_collating_symbol (bitset_t sbcset, re_charset_t *mbcset,
-			int *coll_sym_alloc, const unsigned char *name)
+build_collating_symbol (sbcset, mbcset, coll_sym_alloc, name)
+     re_charset_t *mbcset;
+     int *coll_sym_alloc;
 # else /* not RE_ENABLE_I18N */
-build_collating_symbol (bitset_t sbcset, const unsigned char *name)
+build_collating_symbol (sbcset, name)
 # endif /* not RE_ENABLE_I18N */
+     re_bitset_ptr_t sbcset;
+     const unsigned char *name;
 {
   size_t name_len = strlen ((const char *) name);
   if (BE (name_len != 1, 0))
@@ -2698,8 +2793,12 @@ build_collating_symbol (bitset_t sbcset, const unsigned char *name)
    "[[.a-a.]]" etc.  */
 
 static bin_tree_t *
-parse_bracket_exp (re_string_t *regexp, re_dfa_t *dfa, re_token_t *token,
-		   reg_syntax_t syntax, reg_errcode_t *err)
+parse_bracket_exp (regexp, dfa, token, syntax, err)
+     re_string_t *regexp;
+     re_dfa_t *dfa;
+     re_token_t *token;
+     reg_syntax_t syntax;
+     reg_errcode_t *err;
 {
 #ifdef _LIBC
   const unsigned char *collseqmb;
@@ -2721,28 +2820,23 @@ parse_bracket_exp (re_string_t *regexp, re_dfa_t *dfa, re_token_t *token,
     {
       int32_t hash = elem_hash ((const char *) name, name_len);
       int32_t elem = hash % table_size;
-      if (symb_table[2 * elem] != 0)
-	{
-	  int32_t second = hash % (table_size - 2) + 1;
-
-	  do
+      int32_t second = hash % (table_size - 2);
+      while (symb_table[2 * elem] != 0)
+	{
+	  /* First compare the hashing value.  */
+	  if (symb_table[2 * elem] == hash
+	      /* Compare the length of the name.  */
+	      && name_len == extra[symb_table[2 * elem + 1]]
+	      /* Compare the name.  */
+	      && memcmp (name, &extra[symb_table[2 * elem + 1] + 1],
+			 name_len) == 0)
 	    {
-	      /* First compare the hashing value.  */
-	      if (symb_table[2 * elem] == hash
-		  /* Compare the length of the name.  */
-		  && name_len == extra[symb_table[2 * elem + 1]]
-		  /* Compare the name.  */
-		  && memcmp (name, &extra[symb_table[2 * elem + 1] + 1],
-			     name_len) == 0)
-		{
-		  /* Yep, this is the entry.  */
-		  break;
-		}
-
-	      /* Next entry.  */
-	      elem += second;
+	      /* Yep, this is the entry.  */
+	      break;
 	    }
-	  while (symb_table[2 * elem] != 0);
+
+	  /* Next entry.  */
+	  elem += second;
 	}
       return elem;
     }
@@ -2824,7 +2918,7 @@ parse_bracket_exp (re_string_t *regexp, re_dfa_t *dfa, re_token_t *token,
   build_range_exp (sbcset, mbcset, range_alloc, start_elem, end_elem)
 	 re_charset_t *mbcset;
 	 int *range_alloc;
-	 bitset_t sbcset;
+	 re_bitset_ptr_t sbcset;
 	 bracket_elem_t *start_elem, *end_elem;
     {
       unsigned int ch;
@@ -2907,7 +3001,7 @@ parse_bracket_exp (re_string_t *regexp, re_dfa_t *dfa, re_token_t *token,
   build_collating_symbol (sbcset, mbcset, coll_sym_alloc, name)
 	 re_charset_t *mbcset;
 	 int *coll_sym_alloc;
-	 bitset_t sbcset;
+	 re_bitset_ptr_t sbcset;
 	 const unsigned char *name;
     {
       int32_t elem, idx;
@@ -2984,7 +3078,7 @@ parse_bracket_exp (re_string_t *regexp, re_dfa_t *dfa, re_token_t *token,
       /*
       if (MB_CUR_MAX > 1)
       */
-      collseqwc = _NL_CURRENT (LC_COLLATE, _NL_COLLATE_COLLSEQWC);
+	collseqwc = _NL_CURRENT (LC_COLLATE, _NL_COLLATE_COLLSEQWC);
       table_size = _NL_CURRENT_WORD (LC_COLLATE, _NL_COLLATE_SYMB_HASH_SIZEMB);
       symb_table = (const int32_t *) _NL_CURRENT (LC_COLLATE,
 						  _NL_COLLATE_SYMB_TABLEMB);
@@ -2992,7 +3086,7 @@ parse_bracket_exp (re_string_t *regexp, re_dfa_t *dfa, re_token_t *token,
 						   _NL_COLLATE_SYMB_EXTRAMB);
     }
 #endif
-  sbcset = (re_bitset_ptr_t) calloc (sizeof (bitset_t), 1);
+  sbcset = (re_bitset_ptr_t) calloc (sizeof (unsigned int), BITSET_UINTS);
 #ifdef RE_ENABLE_I18N
   mbcset = (re_charset_t *) calloc (sizeof (re_charset_t), 1);
 #endif /* RE_ENABLE_I18N */
@@ -3019,7 +3113,7 @@ parse_bracket_exp (re_string_t *regexp, re_dfa_t *dfa, re_token_t *token,
 #endif /* not RE_ENABLE_I18N */
       non_match = 1;
       if (syntax & RE_HAT_LISTS_NOT_NEWLINE)
-	bitset_set (sbcset, '\n');
+	bitset_set (sbcset, '\0');
       re_string_skip_bytes (regexp, token_len); /* Skip a token.  */
       token_len = peek_token_bracket (token, regexp, syntax);
       if (BE (token->type == END_OF_RE, 0))
@@ -3188,59 +3282,57 @@ parse_bracket_exp (re_string_t *regexp, re_dfa_t *dfa, re_token_t *token,
   /* Ensure only single byte characters are set.  */
   if (dfa->mb_cur_max > 1)
     bitset_mask (sbcset, dfa->sb_char);
+#endif /* RE_ENABLE_I18N */
+
+  /* Build a tree for simple bracket.  */
+  br_token.type = SIMPLE_BRACKET;
+  br_token.opr.sbcset = sbcset;
+  work_tree = re_dfa_add_tree_node (dfa, NULL, NULL, &br_token);
+  if (BE (work_tree == NULL, 0))
+    goto parse_bracket_exp_espace;
 
+#ifdef RE_ENABLE_I18N
   if (mbcset->nmbchars || mbcset->ncoll_syms || mbcset->nequiv_classes
       || mbcset->nranges || (dfa->mb_cur_max > 1 && (mbcset->nchar_classes
 						     || mbcset->non_match)))
     {
+      re_token_t alt_token;
       bin_tree_t *mbc_tree;
       int sbc_idx;
       /* Build a tree for complex bracket.  */
       dfa->has_mb_node = 1;
-      br_token.type = COMPLEX_BRACKET;
-      br_token.opr.mbcset = mbcset;
-      mbc_tree = create_token_tree (dfa, NULL, NULL, &br_token);
-      if (BE (mbc_tree == NULL, 0))
-	goto parse_bracket_exp_espace;
-      for (sbc_idx = 0; sbc_idx < BITSET_WORDS; ++sbc_idx)
+      for (sbc_idx = 0; sbc_idx < BITSET_UINTS; ++sbc_idx)
 	if (sbcset[sbc_idx])
 	  break;
       /* If there are no bits set in sbcset, there is no point
 	 of having both SIMPLE_BRACKET and COMPLEX_BRACKET.  */
-      if (sbc_idx < BITSET_WORDS)
-	{
-          /* Build a tree for simple bracket.  */
-          br_token.type = SIMPLE_BRACKET;
-          br_token.opr.sbcset = sbcset;
-          work_tree = create_token_tree (dfa, NULL, NULL, &br_token);
-          if (BE (work_tree == NULL, 0))
-            goto parse_bracket_exp_espace;
-
-          /* Then join them by ALT node.  */
-          work_tree = create_tree (dfa, work_tree, mbc_tree, OP_ALT);
-          if (BE (work_tree == NULL, 0))
-            goto parse_bracket_exp_espace;
-	}
-      else
+      if (sbc_idx == BITSET_UINTS)
 	{
 	  re_free (sbcset);
-	  work_tree = mbc_tree;
+	  dfa->nodes[work_tree->node_idx].type = COMPLEX_BRACKET;
+	  dfa->nodes[work_tree->node_idx].opr.mbcset = mbcset;
+	  return work_tree;
 	}
+      br_token.type = COMPLEX_BRACKET;
+      br_token.opr.mbcset = mbcset;
+      mbc_tree = re_dfa_add_tree_node (dfa, NULL, NULL, &br_token);
+      if (BE (mbc_tree == NULL, 0))
+	goto parse_bracket_exp_espace;
+      /* Then join them by ALT node.  */
+      alt_token.type = OP_ALT;
+      dfa->has_plural_match = 1;
+      work_tree = re_dfa_add_tree_node (dfa, work_tree, mbc_tree, &alt_token);
+      if (BE (mbc_tree != NULL, 1))
+	return work_tree;
     }
   else
-#endif /* not RE_ENABLE_I18N */
     {
-#ifdef RE_ENABLE_I18N
       free_charset (mbcset);
-#endif
-      /* Build a tree for simple bracket.  */
-      br_token.type = SIMPLE_BRACKET;
-      br_token.opr.sbcset = sbcset;
-      work_tree = create_token_tree (dfa, NULL, NULL, &br_token);
-      if (BE (work_tree == NULL, 0))
-        goto parse_bracket_exp_espace;
+      return work_tree;
     }
+#else /* not RE_ENABLE_I18N */
   return work_tree;
+#endif /* not RE_ENABLE_I18N */
 
  parse_bracket_exp_espace:
   *err = REG_ESPACE;
@@ -3255,9 +3347,15 @@ parse_bracket_exp (re_string_t *regexp, re_dfa_t *dfa, re_token_t *token,
 /* Parse an element in the bracket expression.  */
 
 static reg_errcode_t
-parse_bracket_element (bracket_elem_t *elem, re_string_t *regexp,
-		       re_token_t *token, int token_len, re_dfa_t *dfa,
-		       reg_syntax_t syntax, int accept_hyphen)
+parse_bracket_element (elem, regexp, token, token_len, dfa, syntax,
+		       accept_hyphen)
+     bracket_elem_t *elem;
+     re_string_t *regexp;
+     re_token_t *token;
+     int token_len;
+     re_dfa_t *dfa;
+     reg_syntax_t syntax;
+     int accept_hyphen;
 {
 #ifdef RE_ENABLE_I18N
   int cur_char_size;
@@ -3295,8 +3393,10 @@ parse_bracket_element (bracket_elem_t *elem, re_string_t *regexp,
    [=<equivalent_class>=].  */
 
 static reg_errcode_t
-parse_bracket_symbol (bracket_elem_t *elem, re_string_t *regexp,
-		      re_token_t *token)
+parse_bracket_symbol (elem, regexp, token)
+     bracket_elem_t *elem;
+     re_string_t *regexp;
+     re_token_t *token;
 {
   unsigned char ch, delim = token->opr.c;
   int i = 0;
@@ -3343,13 +3443,16 @@ parse_bracket_symbol (bracket_elem_t *elem, re_string_t *regexp,
 
 static reg_errcode_t
 #ifdef RE_ENABLE_I18N
-build_equiv_class (bitset_t sbcset, re_charset_t *mbcset,
-		   int *equiv_class_alloc, const unsigned char *name)
+build_equiv_class (sbcset, mbcset, equiv_class_alloc, name)
+     re_charset_t *mbcset;
+     int *equiv_class_alloc;
 #else /* not RE_ENABLE_I18N */
-build_equiv_class (bitset_t sbcset, const unsigned char *name)
+build_equiv_class (sbcset, name)
 #endif /* not RE_ENABLE_I18N */
+     re_bitset_ptr_t sbcset;
+     const unsigned char *name;
 {
-#ifdef _LIBC
+#if defined _LIBC
   uint32_t nrules = _NL_CURRENT_WORD (LC_COLLATE, _NL_COLLATE_NRULES);
   if (nrules != 0)
     {
@@ -3435,13 +3538,16 @@ build_equiv_class (bitset_t sbcset, const unsigned char *name)
 
 static reg_errcode_t
 #ifdef RE_ENABLE_I18N
-build_charclass (RE_TRANSLATE_TYPE trans, bitset_t sbcset,
-		 re_charset_t *mbcset, int *char_class_alloc,
-		 const unsigned char *class_name, reg_syntax_t syntax)
+build_charclass (trans, sbcset, mbcset, char_class_alloc, class_name, syntax)
+     re_charset_t *mbcset;
+     int *char_class_alloc;
 #else /* not RE_ENABLE_I18N */
-build_charclass (RE_TRANSLATE_TYPE trans, bitset_t sbcset,
-		 const unsigned char *class_name, reg_syntax_t syntax)
+build_charclass (trans, sbcset, class_name, syntax)
 #endif /* not RE_ENABLE_I18N */
+     unsigned RE_TRANSLATE_TYPE trans;
+     re_bitset_ptr_t sbcset;
+     const unsigned char *class_name;
+     reg_syntax_t syntax;
 {
   int i;
   const char *name = (const char *) class_name;
@@ -3471,45 +3577,39 @@ build_charclass (RE_TRANSLATE_TYPE trans, bitset_t sbcset,
 #endif /* RE_ENABLE_I18N */
 
 #define BUILD_CHARCLASS_LOOP(ctype_func)	\
-  do {						\
-    if (BE (trans != NULL, 0))			\
-      {						\
-	for (i = 0; i < SBC_MAX; ++i)		\
-  	  if (ctype_func (i))			\
-	    bitset_set (sbcset, trans[i]);	\
-      }						\
-    else					\
+    for (i = 0; i < SBC_MAX; ++i)		\
       {						\
-	for (i = 0; i < SBC_MAX; ++i)		\
-  	  if (ctype_func (i))			\
-	    bitset_set (sbcset, i);		\
-      }						\
-  } while (0)
+	if (ctype_func (i))			\
+	  {					\
+	    int ch = trans ? trans[i] : i;	\
+	    bitset_set (sbcset, ch);		\
+	  }					\
+      }
 
   if (strcmp (name, "alnum") == 0)
-    BUILD_CHARCLASS_LOOP (isalnum);
+    BUILD_CHARCLASS_LOOP (isalnum)
   else if (strcmp (name, "cntrl") == 0)
-    BUILD_CHARCLASS_LOOP (iscntrl);
+    BUILD_CHARCLASS_LOOP (iscntrl)
   else if (strcmp (name, "lower") == 0)
-    BUILD_CHARCLASS_LOOP (islower);
+    BUILD_CHARCLASS_LOOP (islower)
   else if (strcmp (name, "space") == 0)
-    BUILD_CHARCLASS_LOOP (isspace);
+    BUILD_CHARCLASS_LOOP (isspace)
   else if (strcmp (name, "alpha") == 0)
-    BUILD_CHARCLASS_LOOP (isalpha);
+    BUILD_CHARCLASS_LOOP (isalpha)
   else if (strcmp (name, "digit") == 0)
-    BUILD_CHARCLASS_LOOP (isdigit);
+    BUILD_CHARCLASS_LOOP (isdigit)
   else if (strcmp (name, "print") == 0)
-    BUILD_CHARCLASS_LOOP (isprint);
+    BUILD_CHARCLASS_LOOP (isprint)
   else if (strcmp (name, "upper") == 0)
-    BUILD_CHARCLASS_LOOP (isupper);
+    BUILD_CHARCLASS_LOOP (isupper)
   else if (strcmp (name, "blank") == 0)
-    BUILD_CHARCLASS_LOOP (isblank);
+    BUILD_CHARCLASS_LOOP (isblank)
   else if (strcmp (name, "graph") == 0)
-    BUILD_CHARCLASS_LOOP (isgraph);
+    BUILD_CHARCLASS_LOOP (isgraph)
   else if (strcmp (name, "punct") == 0)
-    BUILD_CHARCLASS_LOOP (ispunct);
+    BUILD_CHARCLASS_LOOP (ispunct)
   else if (strcmp (name, "xdigit") == 0)
-    BUILD_CHARCLASS_LOOP (isxdigit);
+    BUILD_CHARCLASS_LOOP (isxdigit)
   else
     return REG_ECTYPE;
 
@@ -3517,10 +3617,13 @@ build_charclass (RE_TRANSLATE_TYPE trans, bitset_t sbcset,
 }
 
 static bin_tree_t *
-build_charclass_op (re_dfa_t *dfa, RE_TRANSLATE_TYPE trans,
-		    const unsigned char *class_name,
-		    const unsigned char *extra, int non_match,
-		    reg_errcode_t *err)
+build_charclass_op (dfa, trans, class_name, extra, non_match, err)
+     re_dfa_t *dfa;
+     unsigned RE_TRANSLATE_TYPE trans;
+     const unsigned char *class_name;
+     const unsigned char *extra;
+     int non_match;
+     reg_errcode_t *err;
 {
   re_bitset_ptr_t sbcset;
 #ifdef RE_ENABLE_I18N
@@ -3531,7 +3634,7 @@ build_charclass_op (re_dfa_t *dfa, RE_TRANSLATE_TYPE trans,
   re_token_t br_token;
   bin_tree_t *tree;
 
-  sbcset = (re_bitset_ptr_t) calloc (sizeof (bitset_t), 1);
+  sbcset = (re_bitset_ptr_t) calloc (sizeof (unsigned int), BITSET_UINTS);
 #ifdef RE_ENABLE_I18N
   mbcset = (re_charset_t *) calloc (sizeof (re_charset_t), 1);
 #endif /* RE_ENABLE_I18N */
@@ -3549,6 +3652,10 @@ build_charclass_op (re_dfa_t *dfa, RE_TRANSLATE_TYPE trans,
   if (non_match)
     {
 #ifdef RE_ENABLE_I18N
+      /*
+      if (syntax & RE_HAT_LISTS_NOT_NEWLINE)
+	bitset_set(cset->sbcset, '\0');
+      */
       mbcset->non_match = 1;
 #endif /* not RE_ENABLE_I18N */
     }
@@ -3586,23 +3693,26 @@ build_charclass_op (re_dfa_t *dfa, RE_TRANSLATE_TYPE trans,
   /* Build a tree for simple bracket.  */
   br_token.type = SIMPLE_BRACKET;
   br_token.opr.sbcset = sbcset;
-  tree = create_token_tree (dfa, NULL, NULL, &br_token);
+  tree = re_dfa_add_tree_node (dfa, NULL, NULL, &br_token);
   if (BE (tree == NULL, 0))
     goto build_word_op_espace;
 
 #ifdef RE_ENABLE_I18N
   if (dfa->mb_cur_max > 1)
     {
+      re_token_t alt_token;
       bin_tree_t *mbc_tree;
       /* Build a tree for complex bracket.  */
       br_token.type = COMPLEX_BRACKET;
       br_token.opr.mbcset = mbcset;
       dfa->has_mb_node = 1;
-      mbc_tree = create_token_tree (dfa, NULL, NULL, &br_token);
+      mbc_tree = re_dfa_add_tree_node (dfa, NULL, NULL, &br_token);
       if (BE (mbc_tree == NULL, 0))
 	goto build_word_op_espace;
       /* Then join them by ALT node.  */
-      tree = create_tree (dfa, tree, mbc_tree, OP_ALT);
+      alt_token.type = OP_ALT;
+      dfa->has_plural_match = 1;
+      tree = re_dfa_add_tree_node (dfa, tree, mbc_tree, &alt_token);
       if (BE (mbc_tree != NULL, 1))
 	return tree;
     }
@@ -3630,7 +3740,10 @@ build_charclass_op (re_dfa_t *dfa, RE_TRANSLATE_TYPE trans,
    Return -2, If an error is occured.  */
 
 static int
-fetch_number (re_string_t *input, re_token_t *token, reg_syntax_t syntax)
+fetch_number (input, token, syntax)
+     re_string_t *input;
+     re_token_t *token;
+     reg_syntax_t syntax;
 {
   int num = -1;
   unsigned char c;
@@ -3670,17 +3783,12 @@ free_charset (re_charset_t *cset)
 /* Create a tree node.  */
 
 static bin_tree_t *
-create_tree (re_dfa_t *dfa, bin_tree_t *left, bin_tree_t *right,
-	     re_token_type_t type)
-{
-  re_token_t t;
-  t.type = type;
-  return create_token_tree (dfa, left, right, &t);
-}
-
-static bin_tree_t *
-create_token_tree (re_dfa_t *dfa, bin_tree_t *left, bin_tree_t *right,
-		   const re_token_t *token)
+create_tree (dfa, left, right, type, index)
+     re_dfa_t *dfa;
+     bin_tree_t *left;
+     bin_tree_t *right;
+     re_token_type_t type;
+     int index;
 {
   bin_tree_t *tree;
   if (BE (dfa->str_tree_storage_idx == BIN_TREE_STORAGE_SIZE, 0))
@@ -3698,12 +3806,11 @@ create_token_tree (re_dfa_t *dfa, bin_tree_t *left, bin_tree_t *right,
   tree->parent = NULL;
   tree->left = left;
   tree->right = right;
-  tree->token = *token;
-  tree->token.duplicated = 0;
-  tree->token.opt_subexp = 0;
-  tree->first = NULL;
-  tree->next = NULL;
-  tree->node_idx = -1;
+  tree->type = type;
+  tree->node_idx = index;
+  tree->first = -1;
+  tree->next = -1;
+  re_node_set_init_empty (&tree->eclosure);
 
   if (left != NULL)
     left->parent = tree;
@@ -3712,85 +3819,103 @@ create_token_tree (re_dfa_t *dfa, bin_tree_t *left, bin_tree_t *right,
   return tree;
 }
 
-/* Mark the tree SRC as an optional subexpression.
-   To be called from preorder or postorder.  */
+/* Create both a DFA node and a tree for it.  */
 
-static reg_errcode_t
-mark_opt_subexp (void *extra, bin_tree_t *node)
+static bin_tree_t *
+re_dfa_add_tree_node (dfa, left, right, token)
+     re_dfa_t *dfa;
+     bin_tree_t *left;
+     bin_tree_t *right;
+     const re_token_t *token;
 {
-  int idx = (int) (long) extra;
-  if (node->token.type == SUBEXP && node->token.opr.idx == idx)
-    node->token.opt_subexp = 1;
+  int new_idx = re_dfa_add_node (dfa, *token, 0);
 
-  return REG_NOERROR;
+  if (new_idx == -1)
+    return NULL;
+
+  return create_tree (dfa, left, right, 0, new_idx);
 }
 
-/* Free the allocated memory inside NODE. */
+/* Mark the tree SRC as an optional subexpression.  */
 
 static void
-free_token (re_token_t *node)
+mark_opt_subexp (src, dfa)
+     const bin_tree_t *src;
+     re_dfa_t *dfa;
 {
-#ifdef RE_ENABLE_I18N
-  if (node->type == COMPLEX_BRACKET && node->duplicated == 0)
-    free_charset (node->opr.mbcset);
-  else
-#endif /* RE_ENABLE_I18N */
-    if (node->type == SIMPLE_BRACKET && node->duplicated == 0)
-      re_free (node->opr.sbcset);
+  /* Pass an OPT_SUBEXP_IDX which is != 1 if the duplicated tree is
+     a subexpression.  */
+  if (src->type == CONCAT
+      && src->left->type == NON_TYPE
+      && dfa->nodes[src->left->node_idx].type == OP_OPEN_SUBEXP)
+    mark_opt_subexp_iter (src, dfa, dfa->nodes[src->left->node_idx].opr.idx);
 }
 
-/* Worker function for tree walking.  Free the allocated memory inside NODE
-   and its children. */
 
-static reg_errcode_t
-free_tree (void *extra, bin_tree_t *node)
+/* Recursive tree walker for mark_opt_subexp.  */
+
+static void
+mark_opt_subexp_iter (src, dfa, idx)
+     const bin_tree_t *src;
+     re_dfa_t *dfa;
+     int idx;
 {
-  free_token (&node->token);
-  return REG_NOERROR;
+  int node_idx;
+
+  if (src->type == NON_TYPE)
+    {
+      node_idx = src->node_idx;
+      if ((dfa->nodes[node_idx].type == OP_OPEN_SUBEXP
+	   || dfa->nodes[node_idx].type == OP_CLOSE_SUBEXP)
+	  && dfa->nodes[node_idx].opr.idx == idx)
+	dfa->nodes[node_idx].opt_subexp = 1;
+     }
+
+  if (src->left != NULL)
+    mark_opt_subexp_iter (src->left, dfa, idx);
+
+  if (src->right != NULL)
+    mark_opt_subexp_iter (src->right, dfa, idx);
 }
 
 
-/* Duplicate the node SRC, and return new node.  This is a preorder
-   visit similar to the one implemented by the generic visitor, but
-   we need more infrastructure to maintain two parallel trees --- so,
-   it's easier to duplicate.  */
+/* Duplicate the node SRC, and return new node.  */
 
 static bin_tree_t *
-duplicate_tree (const bin_tree_t *root, re_dfa_t *dfa)
+duplicate_tree (src, dfa)
+     const bin_tree_t *src;
+     re_dfa_t *dfa;
 {
-  const bin_tree_t *node;
-  bin_tree_t *dup_root;
-  bin_tree_t **p_new = &dup_root, *dup_node = root->parent;
+  bin_tree_t *left = NULL, *right = NULL, *new_tree;
+  int new_node_idx;
+  /* Since node indies must be according to Post-order of the tree,
+     we must duplicate the left at first.  */
+  if (src->left != NULL)
+    {
+      left = duplicate_tree (src->left, dfa);
+      if (left == NULL)
+	return NULL;
+    }
 
-  for (node = root; ; )
+  /* Secondaly, duplicate the right.  */
+  if (src->right != NULL)
     {
-      /* Create a new tree and link it back to the current parent.  */
-      *p_new = create_token_tree (dfa, NULL, NULL, &node->token);
-      if (*p_new == NULL)
+      right = duplicate_tree (src->right, dfa);
+      if (right == NULL)
 	return NULL;
-      (*p_new)->parent = dup_node;
-      (*p_new)->token.duplicated = 1;
-      dup_node = *p_new;
+    }
 
-      /* Go to the left node, or up and to the right.  */
-      if (node->left)
-	{
-	  node = node->left;
-	  p_new = &dup_node->left;
-	}
-      else
-	{
-	  const bin_tree_t *prev = NULL;
-	  while (node->right == prev || node->right == NULL)
-	    {
-	      prev = node;
-	      node = node->parent;
-	      dup_node = dup_node->parent;
-	      if (!node)
-	        return dup_root;
-	    }
-	  node = node->right;
-	  p_new = &dup_node->right;
-	}
+  /* At last, duplicate itself.  */
+  if (src->type == NON_TYPE)
+    {
+      new_node_idx = re_dfa_add_node (dfa, dfa->nodes[src->node_idx], 0);
+      dfa->nodes[new_node_idx].duplicated = 1;
+      if (BE (new_node_idx == -1, 0))
+	return NULL;
     }
+  else
+    new_node_idx = src->type;
+
+  new_tree = create_tree (dfa, left, right, src->type, new_node_idx);
+  return new_tree;
 }