--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.core.test/src/org/graalvm/compiler/core/test/StampCanonicalizerTest.java	Thu Feb 16 15:46:09 2017 -0800
@@ -0,0 +1,118 @@
+/*
+ * Copyright (c) 2012, 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 org.junit.Test;
+
+import org.graalvm.compiler.core.common.type.IntegerStamp;
+import org.graalvm.compiler.nodes.StructuredGraph;
+import org.graalvm.compiler.nodes.StructuredGraph.AllowAssumptions;
+import org.graalvm.compiler.phases.common.CanonicalizerPhase;
+import org.graalvm.compiler.phases.common.DeadCodeEliminationPhase;
+import org.graalvm.compiler.phases.tiers.PhaseContext;
+
+/**
+ * This class tests some specific patterns the stamp system should be able to canonicalize away
+ * using {@link IntegerStamp#upMask()}.
+ */
+public class StampCanonicalizerTest extends GraalCompilerTest {
+
+    public static int andStamp(int a, int b) {
+        int v = (a & 0xffff00) & (b & 0xff0000f);
+        return v & 1;
+    }
+
+    @Test
+    public void testAnd() {
+        testZeroReturn("andStamp");
+    }
+
+    public static int shiftLeftStamp1(int a) {
+        int v = a << 1;
+        return v & 1;
+    }
+
+    public static int shiftLeftStamp2(int a) {
+        int v = a << 1;
+        if (a == 17) {
+            v = a * 4;
+        }
+        return v & 1;
+    }
+
+    @Test
+    public void testShift() {
+        testZeroReturn("shiftLeftStamp1");
+        testZeroReturn("shiftLeftStamp2");
+    }
+
+    public static int upperBoundShiftStamp1(int a) {
+        int v = a & 0xffff;
+        return (v << 4) & 0xff00000;
+    }
+
+    public static int upperBoundShiftStamp2(int a) {
+        int v = a & 0xffff;
+        return (v >> 4) & 0xf000;
+    }
+
+    @Test
+    public void testUpperBoundShift() {
+        testZeroReturn("upperBoundShiftStamp1");
+        testZeroReturn("upperBoundShiftStamp2");
+    }
+
+    public static int divStamp1(int[] a) {
+        int v = a.length / 4;
+        return v & 0x80000000;
+    }
+
+    public static int divStamp2(int[] a) {
+        int v = a.length / 5;
+        return v & 0x80000000;
+    }
+
+    @Test
+    public void testDiv() {
+        testZeroReturn("divStamp1");
+        testZeroReturn("divStamp2");
+    }
+
+    public static int distinctMask(int a, int b) {
+        int x = a & 0xaaaa;
+        int y = (b & 0x5555) | 0x1;
+        return x == y ? 1 : 0;
+    }
+
+    @Test
+    public void testDistinctMask() {
+        testZeroReturn("distinctMask");
+    }
+
+    private void testZeroReturn(String methodName) {
+        StructuredGraph graph = parseEager(methodName, AllowAssumptions.YES);
+        new CanonicalizerPhase().apply(graph, new PhaseContext(getProviders()));
+        new DeadCodeEliminationPhase().apply(graph);
+        assertConstantReturn(graph, 0);
+    }
+}