--- /dev/null	2016-05-31 09:42:47.975716356 -0700
+++ new/src/jdk.vm.compiler/share/classes/org.graalvm.compiler.phases.common/src/org/graalvm/compiler/phases/common/DeadCodeEliminationPhase.java	2016-12-09 00:56:12.578088785 -0800
@@ -0,0 +1,132 @@
+/*
+ * 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 org.graalvm.compiler.phases.common;
+
+import org.graalvm.compiler.debug.Debug;
+import org.graalvm.compiler.debug.DebugCounter;
+import org.graalvm.compiler.graph.Node;
+import org.graalvm.compiler.graph.NodeFlood;
+import org.graalvm.compiler.nodes.AbstractEndNode;
+import org.graalvm.compiler.nodes.StructuredGraph;
+import org.graalvm.compiler.options.Option;
+import org.graalvm.compiler.options.OptionType;
+import org.graalvm.compiler.options.OptionValue;
+import org.graalvm.compiler.phases.Phase;
+
+public class DeadCodeEliminationPhase extends Phase {
+
+    public static class Options {
+
+        // @formatter:off
+        @Option(help = "Disable optional dead code eliminations", type = OptionType.Debug)
+        public static final OptionValue<Boolean> ReduceDCE = new OptionValue<>(true);
+        // @formatter:on
+    }
+
+    private static final DebugCounter counterNodesRemoved = Debug.counter("NodesRemoved");
+
+    public enum Optionality {
+        Optional,
+        Required;
+    }
+
+    /**
+     * Creates a dead code elimination phase that will be run irrespective of
+     * {@link Options#ReduceDCE}.
+     */
+    public DeadCodeEliminationPhase() {
+        this(Optionality.Required);
+    }
+
+    /**
+     * Creates a dead code elimination phase that will be run only if it is
+     * {@linkplain Optionality#Required non-optional} or {@link Options#ReduceDCE} is false.
+     */
+    public DeadCodeEliminationPhase(Optionality optionality) {
+        this.optional = optionality == Optionality.Optional;
+    }
+
+    private final boolean optional;
+
+    @Override
+    public void run(StructuredGraph graph) {
+        if (optional && Options.ReduceDCE.getValue()) {
+            return;
+        }
+
+        NodeFlood flood = graph.createNodeFlood();
+        int totalNodeCount = graph.getNodeCount();
+        flood.add(graph.start());
+        iterateSuccessorsAndInputs(flood);
+        int totalMarkedCount = flood.getTotalMarkedCount();
+        if (totalNodeCount == totalMarkedCount) {
+            // All nodes are live => nothing more to do.
+            return;
+        } else {
+            // Some nodes are not marked alive and therefore dead => proceed.
+            assert totalNodeCount > totalMarkedCount;
+        }
+
+        deleteNodes(flood, graph);
+    }
+
+    private static void iterateSuccessorsAndInputs(NodeFlood flood) {
+        Node.EdgeVisitor consumer = new Node.EdgeVisitor() {
+            @Override
+            public Node apply(Node n, Node succOrInput) {
+                assert succOrInput.isAlive() : "dead successor or input " + succOrInput + " in " + n;
+                flood.add(succOrInput);
+                return succOrInput;
+            }
+        };
+        for (Node current : flood) {
+            if (current instanceof AbstractEndNode) {
+                AbstractEndNode end = (AbstractEndNode) current;
+                flood.add(end.merge());
+            } else {
+                current.applySuccessors(consumer);
+                current.applyInputs(consumer);
+            }
+        }
+    }
+
+    private static void deleteNodes(NodeFlood flood, StructuredGraph graph) {
+        Node.EdgeVisitor consumer = new Node.EdgeVisitor() {
+            @Override
+            public Node apply(Node n, Node input) {
+                if (input.isAlive() && flood.isMarked(input)) {
+                    input.removeUsage(n);
+                }
+                return input;
+            }
+        };
+
+        for (Node node : graph.getNodes()) {
+            if (!flood.isMarked(node)) {
+                node.markDeleted();
+                node.applyInputs(consumer);
+                counterNodesRemoved.increment();
+            }
+        }
+    }
+}