--- /dev/null	2016-05-31 09:42:47.975716356 -0700
+++ new/src/jdk.vm.compiler/share/classes/org.graalvm.compiler.nodes/src/org/graalvm/compiler/nodes/spi/VirtualizerTool.java	2016-12-09 00:56:03.754699864 -0800
@@ -0,0 +1,158 @@
+/*
+ * Copyright (c) 2011, 2015, 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.nodes.spi;
+
+import java.util.List;
+
+import org.graalvm.compiler.graph.Node;
+import org.graalvm.compiler.nodes.ValueNode;
+import org.graalvm.compiler.nodes.java.MonitorIdNode;
+import org.graalvm.compiler.nodes.virtual.VirtualObjectNode;
+
+import jdk.vm.ci.meta.ConstantReflectionProvider;
+import jdk.vm.ci.meta.JavaConstant;
+import jdk.vm.ci.meta.JavaKind;
+import jdk.vm.ci.meta.MetaAccessProvider;
+
+/**
+ * This tool can be used to query the current state (normal/virtualized/re-materialized) of values
+ * and to describe the actions that would be taken for this state.
+ *
+ * See also {@link Virtualizable}.
+ */
+public interface VirtualizerTool {
+
+    /**
+     * @return the {@link MetaAccessProvider} associated with the current compilation.
+     */
+    MetaAccessProvider getMetaAccessProvider();
+
+    /**
+     * @return the {@link ConstantReflectionProvider} associated with the current compilation, which
+     *         can be used to access {@link JavaConstant}s.
+     */
+    ConstantReflectionProvider getConstantReflectionProvider();
+
+    /**
+     * This method should be used to query the maximum size of virtualized objects before attempting
+     * virtualization.
+     *
+     * @return the maximum number of entries for virtualized objects.
+     */
+    int getMaximumEntryCount();
+
+    // methods working on virtualized/materialized objects
+
+    /**
+     * Introduces a new virtual object to the current state.
+     *
+     * @param virtualObject the new virtual object.
+     * @param entryState the initial state of the virtual object's fields.
+     * @param locks the initial locking depths.
+     * @param ensureVirtualized true if this object needs to stay virtual
+     */
+    void createVirtualObject(VirtualObjectNode virtualObject, ValueNode[] entryState, List<MonitorIdNode> locks, boolean ensureVirtualized);
+
+    /**
+     * Returns a VirtualObjectNode if the given value is aliased with a virtual object that is still
+     * virtual, the materialized value of the given value is aliased with a virtual object that was
+     * materialized, the replacement if the give value was replaced, otherwise the given value.
+     *
+     * Replacements via {@link #replaceWithValue(ValueNode)} are not immediately committed. This
+     * method can be used to determine if a value was replaced by another one (e.g., a load field by
+     * the loaded value).
+     */
+    ValueNode getAlias(ValueNode value);
+
+    /**
+     * Sets the entry (field or array element) with the given index in the virtualized object.
+     *
+     * @param index the index to be set.
+     * @param value the new value for the given index.
+     * @param unsafe if true, then mismatching value {@link JavaKind}s will be accepted.
+     */
+    void setVirtualEntry(VirtualObjectNode virtualObject, int index, ValueNode value, boolean unsafe);
+
+    ValueNode getEntry(VirtualObjectNode virtualObject, int index);
+
+    void addLock(VirtualObjectNode virtualObject, MonitorIdNode monitorId);
+
+    MonitorIdNode removeLock(VirtualObjectNode virtualObject);
+
+    void setEnsureVirtualized(VirtualObjectNode virtualObject, boolean ensureVirtualized);
+
+    boolean getEnsureVirtualized(VirtualObjectNode virtualObject);
+
+    // operations on the current node
+
+    /**
+     * Deletes the current node and replaces it with the given virtualized object.
+     *
+     * @param virtualObject the virtualized object that should replace the current node.
+     */
+    void replaceWithVirtual(VirtualObjectNode virtualObject);
+
+    /**
+     * Deletes the current node and replaces it with the given value.
+     *
+     * @param replacement the value that should replace the current node.
+     */
+    void replaceWithValue(ValueNode replacement);
+
+    /**
+     * Deletes the current node.
+     */
+    void delete();
+
+    /**
+     * Replaces an input of the current node.
+     *
+     * @param oldInput the old input value.
+     * @param replacement the new input value.
+     */
+    void replaceFirstInput(Node oldInput, Node replacement);
+
+    /**
+     * Adds the given node to the graph.This action will only be performed when, and if, the changes
+     * are committed.
+     *
+     * @param node the node to add.
+     */
+    void addNode(ValueNode node);
+
+    /**
+     * This method performs either {@link #replaceWithValue(ValueNode)} or
+     * {@link #replaceWithVirtual(VirtualObjectNode)}, depending on the given value.
+     *
+     * @param value the replacement value
+     */
+    void replaceWith(ValueNode value);
+
+    /**
+     *
+     * If state is virtual, materialization is performed for the given state.
+     *
+     * @return true if materialization happened, false if not.
+     */
+    boolean ensureMaterialized(VirtualObjectNode virtualObject);
+}