--- a/graal/com.oracle.graal.graph/src/com/oracle/graal/graph/Graph.java	Tue Nov 05 19:44:09 2013 +0100
+++ b/graal/com.oracle.graal.graph/src/com/oracle/graal/graph/Graph.java	Tue Nov 05 19:54:32 2013 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2011, 2011, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2011, 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
@@ -394,15 +394,55 @@
         }
     }
 
-    public boolean isNew(int mark, Node node) {
-        return node.id >= mark;
+    public boolean isNew(Mark mark, Node node) {
+        return node.id >= mark.getValue();
     }
 
     /**
-     * Gets a mark that can be used with {@link #getNewNodes(int)}.
+     * A snapshot of the {@linkplain Graph#getNodeCount() live node count} in a graph.
      */
-    public int getMark() {
-        return nodeIdCount();
+    public static class Mark {
+        private final int value;
+
+        Mark(Graph graph) {
+            this.value = graph.nodeIdCount();
+        }
+
+        @Override
+        public boolean equals(Object obj) {
+            if (obj instanceof Mark) {
+                Mark other = (Mark) obj;
+                return other.getValue() == getValue();
+            }
+            return false;
+        }
+
+        @Override
+        public int hashCode() {
+            return value;
+        }
+
+        /**
+         * Determines if this mark is positioned at the first live node in the graph.
+         */
+        public boolean isStart() {
+            return value == 0;
+        }
+
+        /**
+         * Gets the {@linkplain Graph#getNodeCount() live node count} of the associated graph when
+         * this object was created.
+         */
+        int getValue() {
+            return value;
+        }
+    }
+
+    /**
+     * Gets a mark that can be used with {@link #getNewNodes}.
+     */
+    public Mark getMark() {
+        return new Mark(this);
     }
 
     private class NodeIterator implements Iterator<Node> {
@@ -459,8 +499,8 @@
      * Returns an {@link Iterable} providing all nodes added since the last {@link Graph#getMark()
      * mark}.
      */
-    public NodeIterable<Node> getNewNodes(int mark) {
-        final int index = mark;
+    public NodeIterable<Node> getNewNodes(Mark mark) {
+        final int index = mark.getValue();
         return new AbstractNodeIterable<Node>() {
 
             @Override