--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.core.test/src/org/graalvm/compiler/core/test/MonitorGraphTest.java	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,117 @@
+/*
+ * Copyright (c) 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.core.test;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import org.graalvm.compiler.graph.Node;
+import org.graalvm.compiler.graph.iterators.NodeIterable;
+import org.graalvm.compiler.nodes.ConstantNode;
+import org.graalvm.compiler.nodes.FrameState;
+import org.graalvm.compiler.nodes.Invoke;
+import org.graalvm.compiler.nodes.ParameterNode;
+import org.graalvm.compiler.nodes.StructuredGraph;
+import org.graalvm.compiler.nodes.StructuredGraph.AllowAssumptions;
+import org.graalvm.compiler.nodes.java.MonitorExitNode;
+import org.graalvm.compiler.phases.common.CanonicalizerPhase;
+import org.graalvm.compiler.phases.common.DeadCodeEliminationPhase;
+import org.graalvm.compiler.phases.common.inlining.InliningPhase;
+import org.graalvm.compiler.phases.tiers.HighTierContext;
+
+/**
+ * In the following tests, the usages of local variable "a" are replaced with the integer constant
+ * 0. Then canonicalization is applied and it is verified that the resulting graph is equal to the
+ * graph of the method that just has a "return 1" statement in it.
+ */
+public class MonitorGraphTest extends GraalCompilerTest {
+
+    private static final String REFERENCE_SNIPPET = "referenceSnippet";
+
+    @SuppressWarnings("all")
+    public static synchronized int referenceSnippet(int a) {
+        return 1;
+    }
+
+    public static int const1() {
+        return 1;
+    }
+
+    @Test
+    public void test1() {
+        test("test1Snippet");
+    }
+
+    @SuppressWarnings("all")
+    public static synchronized int test1Snippet(int a) {
+        return const1();
+    }
+
+    @Test
+    public void test2() {
+        StructuredGraph graph = parseAndProcess("test2Snippet");
+        NodeIterable<MonitorExitNode> monitors = graph.getNodes(MonitorExitNode.TYPE);
+        Assert.assertEquals(1, monitors.count());
+        Assert.assertEquals(monitors.first().stateAfter().bci, 3);
+    }
+
+    @SuppressWarnings("all")
+    public static int test2Snippet(int a) {
+        return const2();
+    }
+
+    public static synchronized int const2() {
+        return 1;
+    }
+
+    private StructuredGraph parseAndProcess(String snippet) {
+        StructuredGraph graph = parseEager(snippet, AllowAssumptions.NO);
+        ParameterNode param = graph.getNodes(ParameterNode.TYPE).first();
+        if (param != null) {
+            ConstantNode constant = ConstantNode.forInt(0, graph);
+            for (Node n : param.usages().snapshot()) {
+                if (!(n instanceof FrameState)) {
+                    n.replaceFirstInput(param, constant);
+                }
+            }
+        }
+        Map<Invoke, Double> hints = new HashMap<>();
+        for (Invoke invoke : graph.getInvokes()) {
+            hints.put(invoke, 1000d);
+        }
+        HighTierContext context = getDefaultHighTierContext();
+        new InliningPhase(hints, new CanonicalizerPhase()).apply(graph, context);
+        new CanonicalizerPhase().apply(graph, context);
+        new DeadCodeEliminationPhase().apply(graph);
+        return graph;
+    }
+
+    private void test(String snippet) {
+        StructuredGraph graph = parseAndProcess(snippet);
+        StructuredGraph referenceGraph = parseEager(REFERENCE_SNIPPET, AllowAssumptions.NO);
+        assertEquals(referenceGraph, graph);
+    }
+}