--- a/graal/com.oracle.graal.graph/src/com/oracle/graal/graph/Node.java	Mon Apr 07 11:32:08 2014 +0200
+++ b/graal/com.oracle.graal.graph/src/com/oracle/graal/graph/Node.java	Mon Apr 07 11:32:09 2014 +0200
@@ -478,6 +478,10 @@
         }
     }
 
+    protected void updateUsagesInterface(NodeInterface oldInput, NodeInterface newInput) {
+        updateUsages(oldInput == null ? null : oldInput.asNode(), newInput == null ? null : newInput.asNode());
+    }
+
     /**
      * Updates the predecessor of the given nodes after a successor slot is changed from
      * oldSuccessor to newSuccessor: removes this node from oldSuccessor's predecessors and adds

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/graal/com.oracle.graal.graph/src/com/oracle/graal/graph/NodeInterface.java	Mon Apr 07 11:32:09 2014 +0200
@@ -0,0 +1,27 @@
+/*
+ * Copyright (c) 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.oracle.graal.graph;
+
+public interface NodeInterface {
+    Node asNode();
+}

--- a/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/FloatingGuardedNode.java	Mon Apr 07 11:32:08 2014 +0200
+++ b/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/FloatingGuardedNode.java	Mon Apr 07 11:32:09 2014 +0200
@@ -47,7 +47,7 @@
 
     @Override
     public void setGuard(GuardingNode guard) {
-        updateUsages(this.guard == null ? null : this.guard.asNode(), guard == null ? null : guard.asNode());
+        updateUsagesInterface(this.guard, guard);
         this.guard = guard;
     }
 }

--- a/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/InvokeNode.java	Mon Apr 07 11:32:08 2014 +0200
+++ b/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/InvokeNode.java	Mon Apr 07 11:32:09 2014 +0200
@@ -198,7 +198,7 @@
 
     @Override
     public void setGuard(GuardingNode guard) {
-        updateUsages(this.guard == null ? null : this.guard.asNode(), guard == null ? null : guard.asNode());
+        updateUsagesInterface(this.guard, guard);
         this.guard = guard;
     }
 }

--- a/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/InvokeWithExceptionNode.java	Mon Apr 07 11:32:08 2014 +0200
+++ b/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/InvokeWithExceptionNode.java	Mon Apr 07 11:32:09 2014 +0200
@@ -236,7 +236,7 @@
 
     @Override
     public void setGuard(GuardingNode guard) {
-        updateUsages(this.guard == null ? null : this.guard.asNode(), guard == null ? null : guard.asNode());
+        updateUsagesInterface(this.guard, guard);
         this.guard = guard;
     }
 

--- a/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/LoopBeginNode.java	Mon Apr 07 11:32:08 2014 +0200
+++ b/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/LoopBeginNode.java	Mon Apr 07 11:32:09 2014 +0200
@@ -198,7 +198,7 @@
     }
 
     public void setOverflowGuard(GuardingNode overflowGuard) {
-        updateUsages(this.overflowGuard == null ? null : this.overflowGuard.asNode(), overflowGuard == null ? null : overflowGuard.asNode());
+        updateUsagesInterface(this.overflowGuard, overflowGuard);
         this.overflowGuard = overflowGuard;
     }
 }

--- a/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/extended/FixedAccessNode.java	Mon Apr 07 11:32:08 2014 +0200
+++ b/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/extended/FixedAccessNode.java	Mon Apr 07 11:32:09 2014 +0200
@@ -93,7 +93,7 @@
 
     @Override
     public void setGuard(GuardingNode guard) {
-        updateUsages(this.guard == null ? null : this.guard.asNode(), guard == null ? null : guard.asNode());
+        updateUsagesInterface(this.guard, guard);
         this.guard = guard;
     }
 

--- a/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/extended/GuardingNode.java	Mon Apr 07 11:32:08 2014 +0200
+++ b/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/extended/GuardingNode.java	Mon Apr 07 11:32:09 2014 +0200
@@ -22,9 +22,10 @@
  */
 package com.oracle.graal.nodes.extended;
 
+import com.oracle.graal.graph.*;
 import com.oracle.graal.nodes.*;
 
-public interface GuardingNode {
+public interface GuardingNode extends NodeInterface {
 
     ValueNode asNode();
 }