--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/graal/com.oracle.max.base/src/com/sun/max/collect/HashEntryChainedHashMapping.java	Sat Dec 17 19:59:18 2011 +0100
@@ -0,0 +1,93 @@
+/*
+ * Copyright (c) 2007, 2011, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code 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
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package com.sun.max.collect;
+
+/**
+ * A chained hash table whose {@linkplain HashEntry entries} record the hash of the key. This can provide better
+ * performance improvement when the cost of computing the key's hash code is high.
+ */
+public class HashEntryChainedHashMapping<K, V> extends ChainedHashMapping<K, V> {
+
+    public static class HashEntry<K, V> extends DefaultEntry<K, V> {
+
+        final int hashOfKey;
+
+        public HashEntry(int hashOfKey, K key, V value, Entry<K, V> next) {
+            super(key, value, next);
+            this.hashOfKey = hashOfKey;
+        }
+    }
+
+    /**
+     * Creates a chained hash table whose entries record the hash of the key.
+     *
+     * @param equivalence
+     *            the semantics of key comparison and hashing. If {@code null}, then {@link HashEquality} is used.
+     * @param initialCapacity
+     *            the initial capacity of the table
+     */
+    public HashEntryChainedHashMapping(HashEquivalence<K> equivalence, int initialCapacity) {
+        super(equivalence, initialCapacity);
+    }
+
+    /**
+     * Creates a chained hash table with {@linkplain HashEquality equality} key semantics whose entries record the hash
+     * of the key.
+     *
+     * @param initialCapacity
+     *            the initial capacity of the table
+     */
+    public HashEntryChainedHashMapping(int initialCapacity) {
+        super(initialCapacity);
+    }
+
+    /**
+     * Creates a chained hash table with an initial capacity of {@value ChainedHashMapping#DEFAULT_INITIAL_CAPACITY}
+     * whose entries record the hash of the key.
+     *
+     * @param equivalence
+     *            the semantics of key comparison and hashing. If {@code null}, then {@link HashEquality} is used.
+     */
+    public HashEntryChainedHashMapping(HashEquivalence<K> equivalence) {
+        super(equivalence);
+    }
+
+    /**
+     * Creates a chained hash table with {@linkplain HashEquality equality} key semantics and an initial capacity of
+     * {@value ChainedHashMapping#DEFAULT_INITIAL_CAPACITY} whose entries record the hash of the key.
+     */
+    public HashEntryChainedHashMapping() {
+        super();
+    }
+
+    @Override
+    protected Entry<K, V> createEntry(int hashOfKey, K key, V value, Entry<K, V> next) {
+        return new HashEntryChainedHashMapping.HashEntry<K, V>(hashOfKey, key, value, next);
+    }
+
+    @Override
+    protected boolean matches(Entry<K, V> entry, K key, int hashForKey) {
+        final K entryKey = entry.key();
+        return entryKey == key || (hashForKey == ((HashEntryChainedHashMapping.HashEntry) entry).hashOfKey && key.equals(entryKey));
+    }
+}