--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/graal/com.oracle.truffle.sl/src/com/oracle/truffle/sl/nodes/FrameSlotNode.java	Fri Jan 18 13:29:14 2013 +0100
@@ -0,0 +1,44 @@
+/*
+ * Copyright (c) 2012, 2012, 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.truffle.sl.nodes;
+
+import com.oracle.truffle.api.frame.*;
+
+public abstract class FrameSlotNode extends TypedNode implements FrameSlotTypeListener {
+
+    protected final FrameSlot slot;
+
+    public FrameSlotNode(FrameSlot slot) {
+        this.slot = slot;
+        slot.registerOneShotTypeListener(this);
+    }
+
+    @Override
+    public void typeChanged(FrameSlot changedSlot, Class< ? > oldType) {
+        if (getParent() != null) {
+            replace(specialize(changedSlot.getType()));
+        }
+    }
+
+    protected abstract FrameSlotNode specialize(Class< ? > clazz);
+}