--- /dev/null	2016-05-31 09:42:47.975716356 -0700
+++ new/src/jdk.vm.compiler/share/classes/org.graalvm.compiler.phases/src/org/graalvm/compiler/phases/graph/MergeableState.java	2016-12-09 00:56:27.823760790 -0800
@@ -0,0 +1,75 @@
+/*
+ * Copyright (c) 2011, 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.graph;
+
+import java.util.List;
+
+import org.graalvm.compiler.nodes.AbstractBeginNode;
+import org.graalvm.compiler.nodes.AbstractMergeNode;
+import org.graalvm.compiler.nodes.ControlSplitNode;
+import org.graalvm.compiler.nodes.LoopBeginNode;
+import org.graalvm.compiler.nodes.LoopEndNode;
+
+public abstract class MergeableState<T> {
+
+    @Override
+    public abstract T clone();
+
+    /**
+     * This method is called on merge on the state of the first branch. The {@code withStates} list
+     * contains the states of the of the other branches in the order of the merge's end nodes.
+     *
+     * @param merge the merge node
+     * @param withStates the state at the the merge's end node except the first one.
+     */
+    public abstract boolean merge(AbstractMergeNode merge, List<T> withStates);
+
+    /**
+     * This method is called before a loop is entered (before the {@link LoopBeginNode} is visited).
+     *
+     * @param loopBegin the begin node of the loop
+     */
+    public void loopBegin(LoopBeginNode loopBegin) {
+        // empty default implementation
+    }
+
+    /**
+     * This method is called after all {@link LoopEndNode}s belonging to a loop have been visited.
+     *
+     * @param loopBegin the begin node of the loop
+     * @param loopEndStates the states at the loop ends, sorted according to
+     *            {@link LoopBeginNode#orderedLoopEnds()}
+     */
+    public void loopEnds(LoopBeginNode loopBegin, List<T> loopEndStates) {
+        // empty default implementation
+    }
+
+    /**
+     * This method is called before the successors of a {@link ControlSplitNode} are visited.
+     *
+     * @param node the successor of the control split that is about to be visited
+     */
+    public void afterSplit(AbstractBeginNode node) {
+        // empty default implementation
+    }
+}