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diff --git a/sys/contrib/opensolaris/uts/common/sys/avl_impl.h b/sys/contrib/opensolaris/uts/common/sys/avl_impl.h
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+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License, Version 1.0 only
+ * (the "License").  You may not use this file except in compliance
+ * with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+/*
+ * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
+ * Use is subject to license terms.
+ */
+
+#ifndef	_AVL_IMPL_H
+#define	_AVL_IMPL_H
+
+#pragma ident	"%Z%%M%	%I%	%E% SMI"
+
+/*
+ * This is a private header file.  Applications should not directly include
+ * this file.
+ */
+
+#include <sys/types.h>
+
+#ifdef	__cplusplus
+extern "C" {
+#endif
+
+
+/*
+ * generic AVL tree implementation for kernel use
+ *
+ * There are 5 pieces of information stored for each node in an AVL tree
+ *
+ * 	pointer to less than child
+ * 	pointer to greater than child
+ * 	a pointer to the parent of this node
+ *	an indication  [0/1]  of which child I am of my parent
+ * 	a "balance" (-1, 0, +1)  indicating which child tree is taller
+ *
+ * Since they only need 3 bits, the last two fields are packed into the
+ * bottom bits of the parent pointer on 64 bit machines to save on space.
+ */
+
+#ifndef _LP64
+
+struct avl_node {
+	struct avl_node *avl_child[2];	/* left/right children */
+	struct avl_node *avl_parent;	/* this node's parent */
+	unsigned short avl_child_index;	/* my index in parent's avl_child[] */
+	short avl_balance;		/* balance value: -1, 0, +1 */
+};
+
+#define	AVL_XPARENT(n)		((n)->avl_parent)
+#define	AVL_SETPARENT(n, p)	((n)->avl_parent = (p))
+
+#define	AVL_XCHILD(n)		((n)->avl_child_index)
+#define	AVL_SETCHILD(n, c)	((n)->avl_child_index = (unsigned short)(c))
+
+#define	AVL_XBALANCE(n)		((n)->avl_balance)
+#define	AVL_SETBALANCE(n, b)	((n)->avl_balance = (short)(b))
+
+#else /* _LP64 */
+
+/*
+ * for 64 bit machines, avl_pcb contains parent pointer, balance and child_index
+ * values packed in the following manner:
+ *
+ * |63                                  3|        2        |1          0 |
+ * |-------------------------------------|-----------------|-------------|
+ * |      avl_parent hi order bits       | avl_child_index | avl_balance |
+ * |                                     |                 |     + 1     |
+ * |-------------------------------------|-----------------|-------------|
+ *
+ */
+struct avl_node {
+	struct avl_node *avl_child[2];	/* left/right children nodes */
+	uintptr_t avl_pcb;		/* parent, child_index, balance */
+};
+
+/*
+ * macros to extract/set fields in avl_pcb
+ *
+ * pointer to the parent of the current node is the high order bits
+ */
+#define	AVL_XPARENT(n)		((struct avl_node *)((n)->avl_pcb & ~7))
+#define	AVL_SETPARENT(n, p)						\
+	((n)->avl_pcb = (((n)->avl_pcb & 7) | (uintptr_t)(p)))
+
+/*
+ * index of this node in its parent's avl_child[]: bit #2
+ */
+#define	AVL_XCHILD(n)		(((n)->avl_pcb >> 2) & 1)
+#define	AVL_SETCHILD(n, c)						\
+	((n)->avl_pcb = (uintptr_t)(((n)->avl_pcb & ~4) | ((c) << 2)))
+
+/*
+ * balance indication for a node, lowest 2 bits. A valid balance is
+ * -1, 0, or +1, and is encoded by adding 1 to the value to get the
+ * unsigned values of 0, 1, 2.
+ */
+#define	AVL_XBALANCE(n)		((int)(((n)->avl_pcb & 3) - 1))
+#define	AVL_SETBALANCE(n, b)						\
+	((n)->avl_pcb = (uintptr_t)((((n)->avl_pcb & ~3) | ((b) + 1))))
+
+#endif /* _LP64 */
+
+
+
+/*
+ * switch between a node and data pointer for a given tree
+ * the value of "o" is tree->avl_offset
+ */
+#define	AVL_NODE2DATA(n, o)	((void *)((uintptr_t)(n) - (o)))
+#define	AVL_DATA2NODE(d, o)	((struct avl_node *)((uintptr_t)(d) + (o)))
+
+
+
+/*
+ * macros used to create/access an avl_index_t
+ */
+#define	AVL_INDEX2NODE(x)	((avl_node_t *)((x) & ~1))
+#define	AVL_INDEX2CHILD(x)	((x) & 1)
+#define	AVL_MKINDEX(n, c)	((avl_index_t)(n) | (c))
+
+
+/*
+ * The tree structure. The fields avl_root, avl_compar, and avl_offset come
+ * first since they are needed for avl_find().  We want them to fit into
+ * a single 64 byte cache line to make avl_find() as fast as possible.
+ */
+struct avl_tree {
+	struct avl_node *avl_root;	/* root node in tree */
+	int (*avl_compar)(const void *, const void *);
+	size_t avl_offset;		/* offsetof(type, avl_link_t field) */
+	ulong_t avl_numnodes;		/* number of nodes in the tree */
+	size_t avl_size;		/* sizeof user type struct */
+};
+
+
+/*
+ * This will only by used via AVL_NEXT() or AVL_PREV()
+ */
+extern void *avl_walk(struct avl_tree *, void *, int);
+
+#ifdef	__cplusplus
+}
+#endif
+
+#endif	/* _AVL_IMPL_H */