--- /dev/null	2017-01-22 10:16:57.869617664 -0800
+++ new/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.nodes/src/org/graalvm/compiler/nodes/memory/FloatableAccessNode.java	2017-02-15 17:07:45.856575125 -0800
@@ -0,0 +1,69 @@
+/*
+ * Copyright (c) 2013, 2016, 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.memory;
+
+import org.graalvm.compiler.core.common.LocationIdentity;
+import org.graalvm.compiler.core.common.type.Stamp;
+import org.graalvm.compiler.graph.NodeClass;
+import org.graalvm.compiler.nodeinfo.NodeInfo;
+import org.graalvm.compiler.nodes.FrameState;
+import org.graalvm.compiler.nodes.extended.GuardingNode;
+import org.graalvm.compiler.nodes.memory.address.AddressNode;
+
+/**
+ * An {@link FixedAccessNode} that can be converted to a {@link FloatingAccessNode}.
+ */
+@NodeInfo
+public abstract class FloatableAccessNode extends FixedAccessNode {
+    public static final NodeClass<FloatableAccessNode> TYPE = NodeClass.create(FloatableAccessNode.class);
+
+    protected FloatableAccessNode(NodeClass<? extends FloatableAccessNode> c, AddressNode address, LocationIdentity location, Stamp stamp) {
+        super(c, address, location, stamp);
+    }
+
+    protected FloatableAccessNode(NodeClass<? extends FloatableAccessNode> c, AddressNode address, LocationIdentity location, Stamp stamp, GuardingNode guard, BarrierType barrierType) {
+        super(c, address, location, stamp, guard, barrierType, false, null);
+    }
+
+    protected FloatableAccessNode(NodeClass<? extends FloatableAccessNode> c, AddressNode address, LocationIdentity location, Stamp stamp, GuardingNode guard, BarrierType barrierType,
+                    boolean nullCheck, FrameState stateBefore) {
+        super(c, address, location, stamp, guard, barrierType, nullCheck, stateBefore);
+    }
+
+    public abstract FloatingAccessNode asFloatingNode(MemoryNode lastLocationAccess);
+
+    protected boolean forceFixed;
+
+    public void setForceFixed(boolean flag) {
+        this.forceFixed = flag;
+    }
+
+    /**
+     * AccessNodes can float only if their location identities are not ANY_LOCATION. Furthermore, in
+     * case G1 is enabled any access (read) to the java.lang.ref.Reference.referent field which has
+     * an attached write barrier with pre-semantics can not also float.
+     */
+    public boolean canFloat() {
+        return !forceFixed && getLocationIdentity().isSingle() && getBarrierType() == BarrierType.NONE;
+    }
+}