--- /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/EffectsBlockState.java	2017-02-15 17:09:35.914393628 -0800
@@ -0,0 +1,93 @@
+/*
+ * Copyright (c) 2011, 2012, 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 java.util.Iterator;
+import java.util.Map;
+
+public abstract class EffectsBlockState<T extends EffectsBlockState<T>> {
+
+    /*
+     * This flag specifies whether this path that leads to this block is unreachable.
+     */
+    private boolean dead;
+
+    public EffectsBlockState() {
+        // emtpy
+    }
+
+    public EffectsBlockState(EffectsBlockState<T> other) {
+        this.dead = other.dead;
+    }
+
+    @Override
+    public String toString() {
+        return "";
+    }
+
+    protected abstract boolean equivalentTo(T other);
+
+    public boolean isDead() {
+        return dead;
+    }
+
+    public void markAsDead() {
+        this.dead = true;
+    }
+
+    protected static <K, V> boolean compareMaps(Map<K, V> left, Map<K, V> right) {
+        if (left.size() != right.size()) {
+            return false;
+        }
+        return compareMapsNoSize(left, right);
+    }
+
+    protected static <K, V> boolean compareMapsNoSize(Map<K, V> left, Map<K, V> right) {
+        if (left == right) {
+            return true;
+        }
+        for (Map.Entry<K, V> entry : right.entrySet()) {
+            K key = entry.getKey();
+            V value = entry.getValue();
+            assert value != null;
+            V otherValue = left.get(key);
+            if (otherValue != value && !value.equals(otherValue)) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    protected static <U, V> void meetMaps(Map<U, V> target, Map<U, V> source) {
+        Iterator<Map.Entry<U, V>> iter = target.entrySet().iterator();
+        while (iter.hasNext()) {
+            Map.Entry<U, V> entry = iter.next();
+            if (source.containsKey(entry.getKey())) {
+                assert source.get(entry.getKey()) == entry.getValue();
+            } else {
+                iter.remove();
+            }
+        }
+    }
+
+}