--- /dev/null	2017-01-22 10:16:57.869617664 -0800
+++ new/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.phases.common/src/org/graalvm/compiler/phases/common/ValueAnchorCleanupPhase.java	2017-02-15 17:08:14.574832449 -0800
@@ -0,0 +1,102 @@
+/*
+ * 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.phases.common;
+
+import java.util.List;
+import java.util.Set;
+
+import org.graalvm.compiler.graph.Node;
+import org.graalvm.compiler.nodes.AbstractMergeNode;
+import org.graalvm.compiler.nodes.FixedNode;
+import org.graalvm.compiler.nodes.StartNode;
+import org.graalvm.compiler.nodes.StructuredGraph;
+import org.graalvm.compiler.nodes.ValueNode;
+import org.graalvm.compiler.nodes.extended.ValueAnchorNode;
+import org.graalvm.compiler.phases.Phase;
+import org.graalvm.compiler.phases.graph.MergeableState;
+import org.graalvm.compiler.phases.graph.SinglePassNodeIterator;
+
+/**
+ * This phase performs a bit of hygiene on {@link ValueAnchorNode} by removing inputs that have
+ * already been anchored in a dominating value anchor. Value anchors that lose their last input,
+ * have no usages and are not marked as permanent are removed.
+ */
+public class ValueAnchorCleanupPhase extends Phase {
+
+    private static class State extends MergeableState<State> implements Cloneable {
+
+        private final Set<Node> anchoredValues;
+
+        State() {
+            anchoredValues = Node.newSet();
+        }
+
+        State(State other) {
+            anchoredValues = Node.newSet(other.anchoredValues);
+        }
+
+        @Override
+        public boolean merge(AbstractMergeNode merge, List<State> withStates) {
+            for (State other : withStates) {
+                anchoredValues.retainAll(other.anchoredValues);
+            }
+            return true;
+        }
+
+        @Override
+        public State clone() {
+            return new State(this);
+        }
+    }
+
+    private static class CleanupValueAnchorsClosure extends SinglePassNodeIterator<State> {
+
+        CleanupValueAnchorsClosure(StartNode start) {
+            super(start, new State());
+        }
+
+        @Override
+        protected void node(FixedNode node) {
+            if (node instanceof ValueAnchorNode) {
+                ValueAnchorNode anchor = (ValueAnchorNode) node;
+                ValueNode anchored = anchor.getAnchoredNode();
+                if (anchored != null) {
+                    if (state.anchoredValues.contains(anchored)) {
+                        anchor.removeAnchoredNode();
+                    } else {
+                        state.anchoredValues.add(anchored);
+                    }
+                }
+                if (anchor.getAnchoredNode() == null && anchor.hasNoUsages()) {
+                    node.graph().removeFixed(anchor);
+                }
+            }
+        }
+    }
+
+    @Override
+    protected void run(StructuredGraph graph) {
+        CleanupValueAnchorsClosure closure = new CleanupValueAnchorsClosure(graph.start());
+        closure.apply();
+    }
+}