--- /dev/null	2017-01-22 10:16:57.869617664 -0800
+++ new/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.lir.test/src/org/graalvm/compiler/lir/test/CompositeValueReplacementTest1.java	2017-02-15 17:05:15.092037429 -0800
@@ -0,0 +1,160 @@
+/*
+ * Copyright (c) 2014, 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.test;
+
+import static org.graalvm.compiler.lir.LIRInstruction.OperandFlag.COMPOSITE;
+import static org.graalvm.compiler.lir.LIRInstruction.OperandFlag.REG;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.fail;
+
+import java.util.EnumSet;
+
+import org.junit.Test;
+
+import org.graalvm.compiler.core.common.LIRKind;
+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 org.graalvm.compiler.lir.LIRInstructionClass;
+import org.graalvm.compiler.lir.asm.CompilationResultBuilder;
+
+import jdk.vm.ci.meta.Value;
+
+/**
+ * This test verifies that {@link CompositeValue}s are immutable, i.e. that a write to a component
+ * of a {@link CompositeValue} results in a new {@link CompositeValue}.
+ */
+public class CompositeValueReplacementTest1 {
+
+    private static class TestCompositeValue extends CompositeValue {
+
+        @Component({REG, OperandFlag.ILLEGAL}) protected Value value;
+
+        TestCompositeValue(Value value) {
+            super(LIRKind.Illegal);
+            this.value = value;
+        }
+
+        private static final EnumSet<OperandFlag> flags = EnumSet.of(OperandFlag.REG, OperandFlag.ILLEGAL);
+
+        @Override
+        public CompositeValue forEachComponent(LIRInstruction inst, OperandMode mode, InstructionValueProcedure proc) {
+            Value newValue = proc.doValue(inst, value, mode, flags);
+            if (!value.identityEquals(newValue)) {
+                return new TestCompositeValue(newValue);
+            }
+            return this;
+        }
+
+        @Override
+        protected void visitEachComponent(LIRInstruction inst, OperandMode mode, InstructionValueConsumer proc) {
+            proc.visitValue(inst, value, mode, flags);
+        }
+    }
+
+    private static class DummyValue extends Value {
+
+        private final int id;
+        private static int counter = 1;
+
+        protected DummyValue() {
+            super(LIRKind.Illegal);
+            this.id = counter++;
+        }
+
+        @Override
+        public int hashCode() {
+            final int prime = 31;
+            int result = super.hashCode();
+            result = prime * result + id;
+            return result;
+        }
+
+        @Override
+        public boolean equals(Object obj) {
+            if (this == obj) {
+                return true;
+            }
+            if (!super.equals(obj)) {
+                return false;
+            }
+            if (getClass() != obj.getClass()) {
+                return false;
+            }
+            DummyValue other = (DummyValue) obj;
+            if (id != other.id) {
+                return false;
+            }
+            return true;
+        }
+
+        @Override
+        public String toString() {
+            return "DummyValue [id=" + id + "]";
+        }
+
+    }
+
+    private static final class TestOp extends LIRInstruction {
+        public static final LIRInstructionClass<TestOp> TYPE = LIRInstructionClass.create(TestOp.class);
+
+        @Use({COMPOSITE}) protected TestCompositeValue compValue;
+
+        TestOp(TestCompositeValue compValue) {
+            super(TYPE);
+            this.compValue = compValue;
+        }
+
+        @Override
+        public void emitCode(CompilationResultBuilder crb) {
+            fail("should not reach!");
+        }
+
+    }
+
+    @Test
+    public void replaceCompValueTest0() {
+        DummyValue dummyValue1 = new DummyValue();
+        DummyValue dummyValue2 = new DummyValue();
+        DummyValue dummyValue3 = new DummyValue();
+        TestCompositeValue compValue1 = new TestCompositeValue(dummyValue1);
+        LIRInstruction op1 = new TestOp(compValue1);
+        LIRInstruction op2 = new TestOp(compValue1);
+
+        op1.forEachInput((instruction, value, mode, flags) -> {
+            assertEquals(dummyValue1, value);
+            return dummyValue2;
+        });
+
+        op2.forEachInput((instruction, value, mode, flags) -> {
+            assertEquals(dummyValue1, value);
+            return dummyValue3;
+        });
+
+        op1.visitEachInput((instruction, value, mode, flags) -> assertEquals(dummyValue2, value));
+        op2.visitEachInput((instruction, value, mode, flags) -> assertEquals(dummyValue3, value));
+    }
+}