--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/graal/Runtime/src/com/sun/hotspot/c1x/HotSpotConstantPool.java	Fri Apr 22 15:08:53 2011 +0200
@@ -0,0 +1,145 @@
+/*
+ * Copyright (c) 2010 Sun Microsystems, Inc.  All rights reserved.
+ *
+ * Sun Microsystems, Inc. has intellectual property rights relating to technology embodied in the product
+ * that is described in this document. In particular, and without limitation, these intellectual property
+ * rights may include one or more of the U.S. patents listed at http://www.sun.com/patents and one or
+ * more additional patents or pending patent applications in the U.S. and in other countries.
+ *
+ * U.S. Government Rights - Commercial software. Government users are subject to the Sun
+ * Microsystems, Inc. standard license agreement and applicable provisions of the FAR and its
+ * supplements.
+ *
+ * Use is subject to license terms. Sun, Sun Microsystems, the Sun logo, Java and Solaris are trademarks or
+ * registered trademarks of Sun Microsystems, Inc. in the U.S. and other countries. All SPARC trademarks
+ * are used under license and are trademarks or registered trademarks of SPARC International, Inc. in the
+ * U.S. and other countries.
+ *
+ * UNIX is a registered trademark in the U.S. and other countries, exclusively licensed through X/Open
+ * Company, Ltd.
+ */
+package com.sun.hotspot.c1x;
+
+import java.io.*;
+import java.util.*;
+
+import com.sun.cri.ri.*;
+
+/**
+ * Implementation of RiConstantPool for HotSpot.
+ *
+ * @author Thomas Wuerthinger, Lukas Stadler
+ */
+public class HotSpotConstantPool extends CompilerObject implements RiConstantPool {
+
+    private final long vmId;
+
+    private final FastLRUIntCache<RiMethod> methodCache = new FastLRUIntCache<RiMethod>();
+    private final FastLRUIntCache<RiField> fieldCache = new FastLRUIntCache<RiField>();
+    private final FastLRUIntCache<RiType> typeCache = new FastLRUIntCache<RiType>();
+
+    public static class FastLRUIntCache<T> implements Serializable {
+
+        private static final int InitialCapacity = 4;
+        private int lastKey;
+        private T lastObject;
+
+        private int[] keys;
+        private Object[] objects;
+        private int count;
+
+        @SuppressWarnings("unchecked")
+        private T access(int index) {
+            return (T) objects[index];
+        }
+
+        public T get(int key) {
+            if (key == lastKey) {
+                return lastObject;
+            } else if (count > 1) {
+                for (int i = 0; i < count; ++i) {
+                    if (keys[i] == key) {
+                        lastObject = access(i);
+                        lastKey = key;
+                        return lastObject;
+                    }
+                }
+            }
+            return null;
+        }
+
+        public void add(int key, T object) {
+            count++;
+            if (count == 1) {
+                lastKey = key;
+                lastObject = object;
+            } else {
+                ensureSize();
+                keys[count - 1] = key;
+                objects[count - 1] = object;
+                if (count == 2) {
+                    keys[0] = lastKey;
+                    objects[0] = lastObject;
+                }
+                lastKey = key;
+                lastObject = object;
+            }
+        }
+
+        private void ensureSize() {
+            if (keys == null) {
+                keys = new int[InitialCapacity];
+                objects = new Object[InitialCapacity];
+            } else if (count > keys.length) {
+                keys = Arrays.copyOf(keys, keys.length * 2);
+                objects = Arrays.copyOf(objects, objects.length * 2);
+            }
+        }
+    }
+
+    public HotSpotConstantPool(Compiler compiler, long vmId) {
+        super(compiler);
+        this.vmId = vmId;
+    }
+
+    @Override
+    public Object lookupConstant(int cpi) {
+        Object constant = compiler.getVMEntries().RiConstantPool_lookupConstant(vmId, cpi);
+        return constant;
+    }
+
+    @Override
+    public RiSignature lookupSignature(int cpi) {
+        return compiler.getVMEntries().RiConstantPool_lookupSignature(vmId, cpi);
+    }
+
+    @Override
+    public RiMethod lookupMethod(int cpi, int byteCode) {
+        RiMethod result = methodCache.get(cpi);
+        if (result == null) {
+            result = compiler.getVMEntries().RiConstantPool_lookupMethod(vmId, cpi, (byte) byteCode);
+            methodCache.add(cpi, result);
+        }
+        return result;
+    }
+
+    @Override
+    public RiType lookupType(int cpi, int opcode) {
+        RiType result = typeCache.get(cpi);
+        if (result == null) {
+            result = compiler.getVMEntries().RiConstantPool_lookupType(vmId, cpi);
+            typeCache.add(cpi, result);
+        }
+        return result;
+    }
+
+    @Override
+    public RiField lookupField(int cpi, int opcode) {
+        RiField result = fieldCache.get(cpi);
+        if (result == null) {
+            result = compiler.getVMEntries().RiConstantPool_lookupField(vmId, cpi, (byte) opcode);
+            fieldCache.add(cpi, result);
+        }
+        return result;
+    }
+}