--- a/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/GuardedValueNode.java	Mon Jul 15 13:36:59 2013 +0200
+++ b/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/GuardedValueNode.java	Mon Jul 15 16:39:11 2013 +0200
@@ -34,7 +34,7 @@
  * 
  * A GuardedValueNode will only go away if its guard is null or {@link StructuredGraph#start()}.
  */
-public class GuardedValueNode extends FloatingGuardedNode implements LIRLowerable, Virtualizable, Node.IterableNodeType, GuardingNode, Canonicalizable {
+public class GuardedValueNode extends FloatingGuardedNode implements LIRLowerable, Virtualizable, Node.IterableNodeType, GuardingNode, Canonicalizable, ValueProxy {
 
     @Input private ValueNode object;
 
@@ -81,4 +81,9 @@
         }
         return this;
     }
+
+    @Override
+    public ValueNode getOriginalValue() {
+        return object;
+    }
 }

--- a/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/GuardingPiNode.java	Mon Jul 15 13:36:59 2013 +0200
+++ b/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/GuardingPiNode.java	Mon Jul 15 16:39:11 2013 +0200
@@ -34,7 +34,7 @@
  * A node that changes the stamp of its input based on some condition being true.
  */
 @NodeInfo(nameTemplate = "GuardingPi(!={p#negated}) {p#reason/s}")
-public class GuardingPiNode extends FixedWithNextNode implements Lowerable, GuardingNode, Canonicalizable {
+public class GuardingPiNode extends FixedWithNextNode implements Lowerable, GuardingNode, Canonicalizable, ValueProxy {
 
     @Input private ValueNode object;
     @Input private LogicNode condition;
@@ -109,4 +109,9 @@
     public ValueNode asNode() {
         return this;
     }
+
+    @Override
+    public ValueNode getOriginalValue() {
+        return object;
+    }
 }

--- a/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/PiNode.java	Mon Jul 15 13:36:59 2013 +0200
+++ b/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/PiNode.java	Mon Jul 15 16:39:11 2013 +0200
@@ -36,7 +36,7 @@
  * is as narrow or narrower than the PiNode's type. The PiNode, and therefore also the scheduling
  * restriction enforced by the anchor, will go away.
  */
-public class PiNode extends FloatingGuardedNode implements LIRLowerable, Virtualizable, Node.IterableNodeType, GuardingNode, Canonicalizable {
+public class PiNode extends FloatingGuardedNode implements LIRLowerable, Virtualizable, Node.IterableNodeType, GuardingNode, Canonicalizable, ValueProxy {
 
     @Input private ValueNode object;
 
@@ -82,4 +82,9 @@
         }
         return this;
     }
+
+    @Override
+    public ValueNode getOriginalValue() {
+        return object;
+    }
 }

--- a/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/ProxyNode.java	Mon Jul 15 13:36:59 2013 +0200
+++ b/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/ProxyNode.java	Mon Jul 15 16:39:11 2013 +0200
@@ -35,7 +35,7 @@
  * loop.
  */
 @NodeInfo(nameTemplate = "{p#type/s}Proxy")
-public class ProxyNode extends FloatingNode implements Node.IterableNodeType, ValueNumberable, Canonicalizable, Virtualizable, LIRLowerable {
+public class ProxyNode extends FloatingNode implements Node.IterableNodeType, ValueNumberable, Canonicalizable, Virtualizable, LIRLowerable, ValueProxy {
 
     @Input(notDataflow = true) private AbstractBeginNode proxyPoint;
     @Input private ValueNode value;
@@ -116,4 +116,8 @@
         return graph.unique(new ProxyNode(value, exit, PhiType.Memory, location));
     }
 
+    @Override
+    public ValueNode getOriginalValue() {
+        return value;
+    }
 }

--- a/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/TypeProfileProxyNode.java	Mon Jul 15 13:36:59 2013 +0200
+++ b/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/TypeProfileProxyNode.java	Mon Jul 15 16:39:11 2013 +0200
@@ -32,7 +32,7 @@
 /**
  * A node that attaches a type profile to a proxied input node.
  */
-public final class TypeProfileProxyNode extends FloatingNode implements Canonicalizable, Node.IterableNodeType {
+public final class TypeProfileProxyNode extends FloatingNode implements Canonicalizable, Node.IterableNodeType, ValueProxy {
 
     @Input private ValueNode object;
     private final JavaTypeProfile profile;
@@ -130,4 +130,9 @@
         }
         assert graph.getNodes(TypeProfileProxyNode.class).count() == 0;
     }
+
+    @Override
+    public ValueNode getOriginalValue() {
+        return object;
+    }
 }

--- a/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/java/CheckCastNode.java	Mon Jul 15 13:36:59 2013 +0200
+++ b/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/java/CheckCastNode.java	Mon Jul 15 16:39:11 2013 +0200
@@ -37,7 +37,7 @@
 /**
  * Implements a type check against a compile-time known type.
  */
-public final class CheckCastNode extends FixedWithNextNode implements Canonicalizable, Lowerable, Node.IterableNodeType, Virtualizable {
+public final class CheckCastNode extends FixedWithNextNode implements Canonicalizable, Lowerable, Node.IterableNodeType, Virtualizable, ValueProxy {
 
     @Input private ValueNode object;
     private final ResolvedJavaType type;
@@ -193,4 +193,9 @@
             }
         }
     }
+
+    @Override
+    public ValueNode getOriginalValue() {
+        return object;
+    }
 }

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/spi/ValueProxy.java	Mon Jul 15 16:39:11 2013 +0200
@@ -0,0 +1,31 @@
+/*
+ * Copyright (c) 2013, 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.oracle.graal.nodes.spi;
+
+import com.oracle.graal.nodes.*;
+
+public interface ValueProxy {
+
+    ValueNode getOriginalValue();
+
+}

--- a/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/util/GraphUtil.java	Mon Jul 15 13:36:59 2013 +0200
+++ b/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/util/GraphUtil.java	Mon Jul 15 16:39:11 2013 +0200
@@ -30,6 +30,7 @@
 import com.oracle.graal.nodes.*;
 import com.oracle.graal.nodes.calc.*;
 import com.oracle.graal.nodes.java.*;
+import com.oracle.graal.nodes.spi.*;
 
 public class GraphUtil {
 
@@ -257,14 +258,6 @@
         return null;
     }
 
-    public static ValueNode unProxify(ValueNode proxy) {
-        ValueNode v = proxy;
-        while (v instanceof ProxyNode) {
-            v = ((ProxyNode) v).value();
-        }
-        return v;
-    }
-
     /**
      * Returns a string representation of the given collection of objects.
      * 
@@ -285,16 +278,31 @@
     }
 
     /**
+     * Gets the original value by iterating through all {@link ValueProxy ValueProxies}.
+     * 
+     * @param value The start value.
+     * @return The first non-proxy value encountered.
+     */
+    public static ValueNode unproxify(ValueNode value) {
+        ValueNode result = value;
+        while (result instanceof ValueProxy) {
+            result = ((ValueProxy) result).getOriginalValue();
+        }
+        return result;
+    }
+
+    /**
      * Tries to find an original value of the given node by traversing through proxies and
-     * unambiguous phis.
+     * unambiguous phis. Note that this method will perform an exhaustive search through phis. It is
+     * intended to be used during graph building, when phi nodes aren't yet canonicalized.
      * 
      * @param proxy The node whose original value should be determined.
      */
     public static ValueNode originalValue(ValueNode proxy) {
         ValueNode v = proxy;
         do {
-            if (v instanceof ProxyNode) {
-                v = ((ProxyNode) v).value();
+            if (v instanceof ValueProxy) {
+                v = ((ValueProxy) v).getOriginalValue();
             } else if (v instanceof PhiNode) {
                 v = ((PhiNode) v).singleValue();
             } else {
@@ -308,8 +316,8 @@
             NodeWorkList worklist = proxy.graph().createNodeWorkList();
             worklist.add(proxy);
             for (Node node : worklist) {
-                if (node instanceof ProxyNode) {
-                    worklist.add(((ProxyNode) node).value());
+                if (node instanceof ValueProxy) {
+                    worklist.add(((ValueProxy) node).getOriginalValue());
                 } else if (node instanceof PhiNode) {
                     worklist.addAll(((PhiNode) node).values());
                 } else {