--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libiberty/splay-tree.c	Fri Jul 17 14:47:48 2009 +0900
@@ -0,0 +1,526 @@
+/* A splay-tree datatype.  
+   Copyright (C) 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
+   Contributed by Mark Mitchell (mark@markmitchell.com).
+
+This file is part of GNU CC.
+   
+GNU CC is free software; you can redistribute it and/or modify it
+under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GNU CC is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU CC; see the file COPYING.  If not, write to
+the Free Software Foundation, 51 Franklin Street - Fifth Floor,
+Boston, MA 02110-1301, USA.  */
+
+/* For an easily readable description of splay-trees, see:
+
+     Lewis, Harry R. and Denenberg, Larry.  Data Structures and Their
+     Algorithms.  Harper-Collins, Inc.  1991.  */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#ifdef HAVE_STDLIB_H
+#include <stdlib.h>
+#endif
+
+#include <stdio.h>
+
+#include "libiberty.h"
+#include "splay-tree.h"
+
+static void splay_tree_delete_helper (splay_tree, splay_tree_node);
+static inline void rotate_left (splay_tree_node *,
+				splay_tree_node, splay_tree_node);
+static inline void rotate_right (splay_tree_node *,
+				splay_tree_node, splay_tree_node);
+static void splay_tree_splay (splay_tree, splay_tree_key);
+static int splay_tree_foreach_helper (splay_tree, splay_tree_node,
+                                      splay_tree_foreach_fn, void*);
+
+/* Deallocate NODE (a member of SP), and all its sub-trees.  */
+
+static void 
+splay_tree_delete_helper (splay_tree sp, splay_tree_node node)
+{
+  splay_tree_node pending = 0;
+  splay_tree_node active = 0;
+
+  if (!node)
+    return;
+
+#define KDEL(x)  if (sp->delete_key) (*sp->delete_key)(x);
+#define VDEL(x)  if (sp->delete_value) (*sp->delete_value)(x);
+
+  KDEL (node->key);
+  VDEL (node->value);
+
+  /* We use the "key" field to hold the "next" pointer.  */
+  node->key = (splay_tree_key)pending;
+  pending = (splay_tree_node)node;
+
+  /* Now, keep processing the pending list until there aren't any
+     more.  This is a little more complicated than just recursing, but
+     it doesn't toast the stack for large trees.  */
+
+  while (pending)
+    {
+      active = pending;
+      pending = 0;
+      while (active)
+	{
+	  splay_tree_node temp;
+
+	  /* active points to a node which has its key and value
+	     deallocated, we just need to process left and right.  */
+
+	  if (active->left)
+	    {
+	      KDEL (active->left->key);
+	      VDEL (active->left->value);
+	      active->left->key = (splay_tree_key)pending;
+	      pending = (splay_tree_node)(active->left);
+	    }
+	  if (active->right)
+	    {
+	      KDEL (active->right->key);
+	      VDEL (active->right->value);
+	      active->right->key = (splay_tree_key)pending;
+	      pending = (splay_tree_node)(active->right);
+	    }
+
+	  temp = active;
+	  active = (splay_tree_node)(temp->key);
+	  (*sp->deallocate) ((char*) temp, sp->allocate_data);
+	}
+    }
+#undef KDEL
+#undef VDEL
+}
+
+/* Rotate the edge joining the left child N with its parent P.  PP is the
+   grandparents' pointer to P.  */
+
+static inline void
+rotate_left (splay_tree_node *pp, splay_tree_node p, splay_tree_node n)
+{
+  splay_tree_node tmp;
+  tmp = n->right;
+  n->right = p;
+  p->left = tmp;
+  *pp = n;
+}
+
+/* Rotate the edge joining the right child N with its parent P.  PP is the
+   grandparents' pointer to P.  */
+
+static inline void
+rotate_right (splay_tree_node *pp, splay_tree_node p, splay_tree_node n)
+{
+  splay_tree_node tmp;
+  tmp = n->left;
+  n->left = p;
+  p->right = tmp;
+  *pp = n;
+}
+
+/* Bottom up splay of key.  */
+
+static void
+splay_tree_splay (splay_tree sp, splay_tree_key key)
+{
+  if (sp->root == 0)
+    return;
+
+  do {
+    int cmp1, cmp2;
+    splay_tree_node n, c;
+
+    n = sp->root;
+    cmp1 = (*sp->comp) (key, n->key);
+
+    /* Found.  */
+    if (cmp1 == 0)
+      return;
+
+    /* Left or right?  If no child, then we're done.  */
+    if (cmp1 < 0)
+      c = n->left;
+    else
+      c = n->right;
+    if (!c)
+      return;
+
+    /* Next one left or right?  If found or no child, we're done
+       after one rotation.  */
+    cmp2 = (*sp->comp) (key, c->key);
+    if (cmp2 == 0
+        || (cmp2 < 0 && !c->left)
+        || (cmp2 > 0 && !c->right))
+      {
+	if (cmp1 < 0)
+	  rotate_left (&sp->root, n, c);
+	else
+	  rotate_right (&sp->root, n, c);
+        return;
+      }
+
+    /* Now we have the four cases of double-rotation.  */
+    if (cmp1 < 0 && cmp2 < 0)
+      {
+	rotate_left (&n->left, c, c->left);
+	rotate_left (&sp->root, n, n->left);
+      }
+    else if (cmp1 > 0 && cmp2 > 0)
+      {
+	rotate_right (&n->right, c, c->right);
+	rotate_right (&sp->root, n, n->right);
+      }
+    else if (cmp1 < 0 && cmp2 > 0)
+      {
+	rotate_right (&n->left, c, c->right);
+	rotate_left (&sp->root, n, n->left);
+      }
+    else if (cmp1 > 0 && cmp2 < 0)
+      {
+	rotate_left (&n->right, c, c->left);
+	rotate_right (&sp->root, n, n->right);
+      }
+  } while (1);
+}
+
+/* Call FN, passing it the DATA, for every node below NODE, all of
+   which are from SP, following an in-order traversal.  If FN every
+   returns a non-zero value, the iteration ceases immediately, and the
+   value is returned.  Otherwise, this function returns 0.  */
+
+static int
+splay_tree_foreach_helper (splay_tree sp, splay_tree_node node,
+                           splay_tree_foreach_fn fn, void *data)
+{
+  int val;
+
+  if (!node)
+    return 0;
+
+  val = splay_tree_foreach_helper (sp, node->left, fn, data);
+  if (val)
+    return val;
+
+  val = (*fn)(node, data);
+  if (val)
+    return val;
+
+  return splay_tree_foreach_helper (sp, node->right, fn, data);
+}
+
+
+/* An allocator and deallocator based on xmalloc.  */
+static void *
+splay_tree_xmalloc_allocate (int size, void *data ATTRIBUTE_UNUSED)
+{
+  return (void *) xmalloc (size);
+}
+
+static void
+splay_tree_xmalloc_deallocate (void *object, void *data ATTRIBUTE_UNUSED)
+{
+  free (object);
+}
+
+
+/* Allocate a new splay tree, using COMPARE_FN to compare nodes,
+   DELETE_KEY_FN to deallocate keys, and DELETE_VALUE_FN to deallocate
+   values.  Use xmalloc to allocate the splay tree structure, and any
+   nodes added.  */
+
+splay_tree 
+splay_tree_new (splay_tree_compare_fn compare_fn,
+                splay_tree_delete_key_fn delete_key_fn,
+                splay_tree_delete_value_fn delete_value_fn)
+{
+  return (splay_tree_new_with_allocator
+          (compare_fn, delete_key_fn, delete_value_fn,
+           splay_tree_xmalloc_allocate, splay_tree_xmalloc_deallocate, 0));
+}
+
+
+/* Allocate a new splay tree, using COMPARE_FN to compare nodes,
+   DELETE_KEY_FN to deallocate keys, and DELETE_VALUE_FN to deallocate
+   values.  */
+
+splay_tree 
+splay_tree_new_with_allocator (splay_tree_compare_fn compare_fn,
+                               splay_tree_delete_key_fn delete_key_fn,
+                               splay_tree_delete_value_fn delete_value_fn,
+                               splay_tree_allocate_fn allocate_fn,
+                               splay_tree_deallocate_fn deallocate_fn,
+                               void *allocate_data)
+{
+  splay_tree sp = (splay_tree) (*allocate_fn) (sizeof (struct splay_tree_s),
+                                               allocate_data);
+  sp->root = 0;
+  sp->comp = compare_fn;
+  sp->delete_key = delete_key_fn;
+  sp->delete_value = delete_value_fn;
+  sp->allocate = allocate_fn;
+  sp->deallocate = deallocate_fn;
+  sp->allocate_data = allocate_data;
+
+  return sp;
+}
+
+/* Deallocate SP.  */
+
+void 
+splay_tree_delete (splay_tree sp)
+{
+  splay_tree_delete_helper (sp, sp->root);
+  (*sp->deallocate) ((char*) sp, sp->allocate_data);
+}
+
+/* Insert a new node (associating KEY with DATA) into SP.  If a
+   previous node with the indicated KEY exists, its data is replaced
+   with the new value.  Returns the new node.  */
+
+splay_tree_node
+splay_tree_insert (splay_tree sp, splay_tree_key key, splay_tree_value value)
+{
+  int comparison = 0;
+
+  splay_tree_splay (sp, key);
+
+  if (sp->root)
+    comparison = (*sp->comp)(sp->root->key, key);
+
+  if (sp->root && comparison == 0)
+    {
+      /* If the root of the tree already has the indicated KEY, just
+	 replace the value with VALUE.  */
+      if (sp->delete_value)
+	(*sp->delete_value)(sp->root->value);
+      sp->root->value = value;
+    } 
+  else 
+    {
+      /* Create a new node, and insert it at the root.  */
+      splay_tree_node node;
+      
+      node = ((splay_tree_node)
+              (*sp->allocate) (sizeof (struct splay_tree_node_s),
+                               sp->allocate_data));
+      node->key = key;
+      node->value = value;
+      
+      if (!sp->root)
+	node->left = node->right = 0;
+      else if (comparison < 0)
+	{
+	  node->left = sp->root;
+	  node->right = node->left->right;
+	  node->left->right = 0;
+	}
+      else
+	{
+	  node->right = sp->root;
+	  node->left = node->right->left;
+	  node->right->left = 0;
+	}
+
+      sp->root = node;
+    }
+
+  return sp->root;
+}
+
+/* Remove KEY from SP.  It is not an error if it did not exist.  */
+
+void
+splay_tree_remove (splay_tree sp, splay_tree_key key)
+{
+  splay_tree_splay (sp, key);
+
+  if (sp->root && (*sp->comp) (sp->root->key, key) == 0)
+    {
+      splay_tree_node left, right;
+
+      left = sp->root->left;
+      right = sp->root->right;
+
+      /* Delete the root node itself.  */
+      if (sp->delete_value)
+	(*sp->delete_value) (sp->root->value);
+      (*sp->deallocate) (sp->root, sp->allocate_data);
+
+      /* One of the children is now the root.  Doesn't matter much
+	 which, so long as we preserve the properties of the tree.  */
+      if (left)
+	{
+	  sp->root = left;
+
+	  /* If there was a right child as well, hang it off the 
+	     right-most leaf of the left child.  */
+	  if (right)
+	    {
+	      while (left->right)
+		left = left->right;
+	      left->right = right;
+	    }
+	}
+      else
+	sp->root = right;
+    }
+}
+
+/* Lookup KEY in SP, returning VALUE if present, and NULL 
+   otherwise.  */
+
+splay_tree_node
+splay_tree_lookup (splay_tree sp, splay_tree_key key)
+{
+  splay_tree_splay (sp, key);
+
+  if (sp->root && (*sp->comp)(sp->root->key, key) == 0)
+    return sp->root;
+  else
+    return 0;
+}
+
+/* Return the node in SP with the greatest key.  */
+
+splay_tree_node
+splay_tree_max (splay_tree sp)
+{
+  splay_tree_node n = sp->root;
+
+  if (!n)
+    return NULL;
+
+  while (n->right)
+    n = n->right;
+
+  return n;
+}
+
+/* Return the node in SP with the smallest key.  */
+
+splay_tree_node
+splay_tree_min (splay_tree sp)
+{
+  splay_tree_node n = sp->root;
+
+  if (!n)
+    return NULL;
+
+  while (n->left)
+    n = n->left;
+
+  return n;
+}
+
+/* Return the immediate predecessor KEY, or NULL if there is no
+   predecessor.  KEY need not be present in the tree.  */
+
+splay_tree_node
+splay_tree_predecessor (splay_tree sp, splay_tree_key key)
+{
+  int comparison;
+  splay_tree_node node;
+
+  /* If the tree is empty, there is certainly no predecessor.  */
+  if (!sp->root)
+    return NULL;
+
+  /* Splay the tree around KEY.  That will leave either the KEY
+     itself, its predecessor, or its successor at the root.  */
+  splay_tree_splay (sp, key);
+  comparison = (*sp->comp)(sp->root->key, key);
+
+  /* If the predecessor is at the root, just return it.  */
+  if (comparison < 0)
+    return sp->root;
+
+  /* Otherwise, find the rightmost element of the left subtree.  */
+  node = sp->root->left;
+  if (node)
+    while (node->right)
+      node = node->right;
+
+  return node;
+}
+
+/* Return the immediate successor KEY, or NULL if there is no
+   successor.  KEY need not be present in the tree.  */
+
+splay_tree_node
+splay_tree_successor (splay_tree sp, splay_tree_key key)
+{
+  int comparison;
+  splay_tree_node node;
+
+  /* If the tree is empty, there is certainly no successor.  */
+  if (!sp->root)
+    return NULL;
+
+  /* Splay the tree around KEY.  That will leave either the KEY
+     itself, its predecessor, or its successor at the root.  */
+  splay_tree_splay (sp, key);
+  comparison = (*sp->comp)(sp->root->key, key);
+
+  /* If the successor is at the root, just return it.  */
+  if (comparison > 0)
+    return sp->root;
+
+  /* Otherwise, find the leftmost element of the right subtree.  */
+  node = sp->root->right;
+  if (node)
+    while (node->left)
+      node = node->left;
+
+  return node;
+}
+
+/* Call FN, passing it the DATA, for every node in SP, following an
+   in-order traversal.  If FN every returns a non-zero value, the
+   iteration ceases immediately, and the value is returned.
+   Otherwise, this function returns 0.  */
+
+int
+splay_tree_foreach (splay_tree sp, splay_tree_foreach_fn fn, void *data)
+{
+  return splay_tree_foreach_helper (sp, sp->root, fn, data);
+}
+
+/* Splay-tree comparison function, treating the keys as ints.  */
+
+int
+splay_tree_compare_ints (splay_tree_key k1, splay_tree_key k2)
+{
+  if ((int) k1 < (int) k2)
+    return -1;
+  else if ((int) k1 > (int) k2)
+    return 1;
+  else 
+    return 0;
+}
+
+/* Splay-tree comparison function, treating the keys as pointers.  */
+
+int
+splay_tree_compare_pointers (splay_tree_key k1, splay_tree_key k2)
+{
+  if ((char*) k1 < (char*) k2)
+    return -1;
+  else if ((char*) k1 > (char*) k2)
+    return 1;
+  else 
+    return 0;
+}