--- /dev/null	2017-01-22 10:16:57.869617664 -0800
+++ new/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.lir/src/org/graalvm/compiler/lir/alloc/trace/ShadowedRegisterValue.java	2017-02-15 17:05:33.613840021 -0800
@@ -0,0 +1,106 @@
+/*
+ * Copyright (c) 2015, 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.lir.alloc.trace;
+
+import static org.graalvm.compiler.lir.LIRInstruction.OperandFlag.REG;
+import static org.graalvm.compiler.lir.LIRInstruction.OperandFlag.STACK;
+
+import java.util.EnumSet;
+
+import org.graalvm.compiler.lir.CompositeValue;
+import org.graalvm.compiler.lir.InstructionValueConsumer;
+import org.graalvm.compiler.lir.InstructionValueProcedure;
+import org.graalvm.compiler.lir.LIRInstruction;
+import org.graalvm.compiler.lir.LIRInstruction.OperandFlag;
+import org.graalvm.compiler.lir.LIRInstruction.OperandMode;
+
+import jdk.vm.ci.code.RegisterValue;
+import jdk.vm.ci.meta.AllocatableValue;
+
+/**
+ * Represents a {@link #register} which has a shadow copy on the {@link #stackslot stack}.
+ */
+public final class ShadowedRegisterValue extends CompositeValue {
+    private static final EnumSet<OperandFlag> registerFlags = EnumSet.of(REG);
+    private static final EnumSet<OperandFlag> stackslotFlags = EnumSet.of(STACK);
+
+    @Component({REG}) protected RegisterValue register;
+    @Component({STACK}) protected AllocatableValue stackslot;
+
+    public ShadowedRegisterValue(RegisterValue register, AllocatableValue stackslot) {
+        super(register.getValueKind());
+        assert (register.getValueKind().equals(stackslot.getValueKind()));
+        this.register = register;
+        this.stackslot = stackslot;
+    }
+
+    public RegisterValue getRegister() {
+        return register;
+    }
+
+    public AllocatableValue getStackSlot() {
+        return stackslot;
+    }
+
+    @Override
+    public CompositeValue forEachComponent(LIRInstruction inst, OperandMode mode, InstructionValueProcedure proc) {
+        RegisterValue newRegister = (RegisterValue) proc.doValue(inst, register, mode, registerFlags);
+        AllocatableValue newStackSlot = (AllocatableValue) proc.doValue(inst, stackslot, mode, stackslotFlags);
+        if (register.equals(newRegister) || stackslot.equals(newStackSlot)) {
+            return this;
+        }
+        return new ShadowedRegisterValue(newRegister, newStackSlot);
+    }
+
+    @Override
+    protected void visitEachComponent(LIRInstruction inst, OperandMode mode, InstructionValueConsumer proc) {
+        proc.visitValue(inst, register, mode, registerFlags);
+        proc.visitValue(inst, stackslot, mode, stackslotFlags);
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (obj == null) {
+            return false;
+        }
+        if (this == obj) {
+            return true;
+        }
+        if (getClass() != obj.getClass()) {
+            return false;
+        }
+        ShadowedRegisterValue other = (ShadowedRegisterValue) obj;
+        assert register != null;
+        assert stackslot != null;
+        assert other.register != null;
+        assert other.stackslot != null;
+        if (!register.equals(other.register)) {
+            return false;
+        }
+        if (!stackslot.equals(other.stackslot)) {
+            return false;
+        }
+        return true;
+    }
+
+}