--- /dev/null	2017-01-22 10:16:57.869617664 -0800
+++ new/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.virtual/src/org/graalvm/compiler/virtual/phases/ea/VirtualUtil.java	2017-02-15 17:09:39.789563289 -0800
@@ -0,0 +1,165 @@
+/*
+ * 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 org.graalvm.compiler.virtual.phases.ea;
+
+import static org.graalvm.compiler.core.common.GraalOptions.TraceEscapeAnalysis;
+
+import java.util.List;
+import java.util.Map;
+
+import org.graalvm.compiler.debug.Debug;
+import org.graalvm.compiler.debug.GraalError;
+import org.graalvm.compiler.debug.TTY;
+import org.graalvm.compiler.graph.Node;
+import org.graalvm.compiler.graph.NodeFlood;
+import org.graalvm.compiler.nodes.AbstractEndNode;
+import org.graalvm.compiler.nodes.FixedNode;
+import org.graalvm.compiler.nodes.StructuredGraph;
+
+import jdk.vm.ci.meta.ResolvedJavaMethod;
+
+public final class VirtualUtil {
+
+    private VirtualUtil() {
+        GraalError.shouldNotReachHere();
+    }
+
+    public static boolean assertNonReachable(StructuredGraph graph, List<Node> obsoleteNodes) {
+        // helper code that determines the paths that keep obsolete nodes alive:
+
+        NodeFlood flood = graph.createNodeFlood();
+        Map<Node, Node> path = Node.newIdentityMap();
+        flood.add(graph.start());
+        for (Node current : flood) {
+            if (current instanceof AbstractEndNode) {
+                AbstractEndNode end = (AbstractEndNode) current;
+                flood.add(end.merge());
+                if (!path.containsKey(end.merge())) {
+                    path.put(end.merge(), end);
+                }
+            } else {
+                for (Node successor : current.successors()) {
+                    flood.add(successor);
+                    if (!path.containsKey(successor)) {
+                        path.put(successor, current);
+                    }
+                }
+            }
+        }
+
+        for (Node node : obsoleteNodes) {
+            if (node instanceof FixedNode && !node.isDeleted()) {
+                assert !flood.isMarked(node) : node;
+            }
+        }
+
+        for (Node node : graph.getNodes()) {
+            if (flood.isMarked(node)) {
+                for (Node input : node.inputs()) {
+                    flood.add(input);
+                    if (!path.containsKey(input)) {
+                        path.put(input, node);
+                    }
+                }
+            }
+        }
+        for (Node current : flood) {
+            for (Node input : current.inputs()) {
+                flood.add(input);
+                if (!path.containsKey(input)) {
+                    path.put(input, current);
+                }
+            }
+        }
+        boolean success = true;
+        for (Node node : obsoleteNodes) {
+            if (!node.isDeleted() && flood.isMarked(node)) {
+                TTY.println("offending node path:");
+                Node current = node;
+                TTY.print(current.toString());
+                while (true) {
+                    current = path.get(current);
+                    if (current != null) {
+                        TTY.print(" -> " + current.toString());
+                        if (current instanceof FixedNode && !obsoleteNodes.contains(current)) {
+                            break;
+                        }
+                    }
+                }
+                success = false;
+            }
+        }
+        if (!success) {
+            TTY.println();
+            Debug.dump(Debug.BASIC_LOG_LEVEL, graph, "assertNonReachable");
+        }
+        return success;
+    }
+
+    public static void trace(String format) {
+        if (Debug.isEnabled() && TraceEscapeAnalysis.getValue() && Debug.isLogEnabled()) {
+            Debug.logv(format);
+        }
+    }
+
+    public static void trace(String format, Object obj) {
+        if (Debug.isEnabled() && TraceEscapeAnalysis.getValue() && Debug.isLogEnabled()) {
+            Debug.logv(format, obj);
+        }
+    }
+
+    public static void trace(String format, Object obj, Object obj2) {
+        if (Debug.isEnabled() && TraceEscapeAnalysis.getValue() && Debug.isLogEnabled()) {
+            Debug.logv(format, obj, obj2);
+        }
+    }
+
+    public static void trace(String format, Object obj, Object obj2, Object obj3) {
+        if (Debug.isEnabled() && TraceEscapeAnalysis.getValue() && Debug.isLogEnabled()) {
+            Debug.logv(format, obj, obj2, obj3);
+        }
+    }
+
+    public static void trace(String format, Object obj, Object obj2, Object obj3, Object obj4) {
+        if (Debug.isEnabled() && TraceEscapeAnalysis.getValue() && Debug.isLogEnabled()) {
+            Debug.logv(format, obj, obj2, obj3, obj4);
+        }
+    }
+
+    public static boolean matches(StructuredGraph graph, String filter) {
+        if (filter != null) {
+            return matchesHelper(graph, filter);
+        }
+        return true;
+    }
+
+    private static boolean matchesHelper(StructuredGraph graph, String filter) {
+        if (filter.startsWith("~")) {
+            ResolvedJavaMethod method = graph.method();
+            return method == null || !method.format("%H.%n").contains(filter.substring(1));
+        } else {
+            ResolvedJavaMethod method = graph.method();
+            return method != null && method.format("%H.%n").contains(filter);
+        }
+    }
+}