--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.nodes.test/src/org/graalvm/compiler/nodes/test/IfNodeCanonicalizationTest.java	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,171 @@
+/*
+ * Copyright (c) 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.nodes.test;
+
+import org.junit.Assert;
+import org.junit.Ignore;
+import org.junit.Test;
+
+import org.graalvm.compiler.api.directives.GraalDirectives;
+import org.graalvm.compiler.core.test.GraalCompilerTest;
+import org.graalvm.compiler.graph.Node;
+import org.graalvm.compiler.nodes.IfNode;
+import org.graalvm.compiler.nodes.LogicNode;
+import org.graalvm.compiler.nodes.StructuredGraph;
+import org.graalvm.compiler.nodes.StructuredGraph.AllowAssumptions;
+import org.graalvm.compiler.nodes.calc.SubNode;
+import org.graalvm.compiler.phases.common.CanonicalizerPhase;
+import org.graalvm.compiler.phases.common.ConvertDeoptimizeToGuardPhase;
+import org.graalvm.compiler.phases.common.IterativeConditionalEliminationPhase;
+import org.graalvm.compiler.phases.tiers.PhaseContext;
+
+/**
+ * A few tests of expected simplifications by
+ * {@link IfNode#simplify(org.graalvm.compiler.graph.spi.SimplifierTool)}.
+ */
+public class IfNodeCanonicalizationTest extends GraalCompilerTest {
+
+    static int value;
+
+    static final byte[] testValues = {-128, -1, 0, 1, 127};
+
+    @Test
+    public void test1() {
+        /*
+         * exercise conversion of x - y < 0 into x < y, both by checking expected graph shape and
+         * that the transformed code produces the right answer.
+         */
+        test("testSnippet1", SubNode.class, 0);
+        byte[] values = new byte[4];
+        for (byte a : testValues) {
+            values[0] = a;
+            for (byte b : testValues) {
+                values[1] = b;
+                for (byte c : testValues) {
+                    values[2] = c;
+                    for (byte d : testValues) {
+                        values[3] = d;
+                        value = 2;
+                        super.test("testSnippet1", values, true);
+                        super.test("testSnippet1", values, false);
+                    }
+                }
+            }
+        }
+    }
+
+    public int testSnippet1(byte[] values, boolean test) {
+        int v = values[0] - values[1];
+        if (test) {
+            v = values[2] - values[3];
+        }
+        if (v < 0) {
+            value = 1;
+        }
+        return value;
+    }
+
+    @Test
+    public void test2() {
+        test("testSnippet2", 1);
+    }
+
+    public boolean testSnippet2(int a, int[] limit) {
+        int l = limit.length;
+        if (!(a >= 0 && a < l)) {
+            value = a;
+            return true;
+        }
+        return false;
+    }
+
+    @Ignore("currently not working because swapped case isn't handled")
+    @Test
+    public void test3() {
+        test("testSnippet3", 1);
+    }
+
+    public boolean testSnippet3(int a, int[] limit) {
+        int l = limit.length;
+        if (a < l && a >= 0) {
+            value = 9;
+            return true;
+        }
+        return false;
+    }
+
+    @Test
+    public void test4() {
+        test("testSnippet4", 1);
+    }
+
+    public boolean testSnippet4(int a, int[] limit) {
+        int l = limit.length;
+        if (a < 0) {
+            GraalDirectives.deoptimize();
+        }
+        if (a >= l) {
+            GraalDirectives.deoptimize();
+        }
+        return true;
+    }
+
+    @Ignore("Reversed conditions aren't working with guards")
+    @Test
+    public void test5() {
+        test("testSnippet5", 1);
+    }
+
+    public boolean testSnippet5(int a, int[] limit) {
+        int l = limit.length;
+        if (a >= l) {
+            GraalDirectives.deoptimize();
+        }
+        if (a < 0) {
+            GraalDirectives.deoptimize();
+        }
+        return true;
+    }
+
+    public void test(String name, int logicCount) {
+        test(name, LogicNode.class, logicCount);
+    }
+
+    public void test(String name, Class<? extends Node> expectedClass, int expectedCount) {
+        StructuredGraph graph = parseEager(name, AllowAssumptions.YES);
+
+        PhaseContext context = new PhaseContext(getProviders());
+        CanonicalizerPhase canonicalizer = new CanonicalizerPhase();
+        graph.clearAllStateAfter();
+        graph.setGuardsStage(StructuredGraph.GuardsStage.AFTER_FSA);
+        canonicalizer.apply(graph, context);
+
+        new ConvertDeoptimizeToGuardPhase().apply(graph, context);
+        // new DominatorConditionalEliminationPhase(true).apply(graph, context);
+        new IterativeConditionalEliminationPhase(canonicalizer, true).apply(graph, context);
+        canonicalizer.apply(graph, context);
+        canonicalizer.apply(graph, context);
+
+        Assert.assertEquals(expectedCount, graph.getNodes().filter(expectedClass).count());
+    }
+}