--- /dev/null	2018-10-01 08:15:51.125839210 +0200
+++ new/test/hotspot/jtreg/compiler/codegen/TestTrichotomyExpressions.java	2018-10-01 11:16:32.363836271 +0200
@@ -0,0 +1,645 @@
+/*
+ * Copyright (c) 2018, 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.
+ */
+
+/**
+ * @test
+ * @bug 8210215
+ * @summary Test that C2 correctly optimizes trichotomy expressions.
+ * @library /test/lib
+ * @run main/othervm -XX:-TieredCompilation -Xbatch
+ *                   -XX:CompileCommand=dontinline,compiler.codegen.TestTrichotomyExpressions::test*
+ *                   compiler.codegen.TestTrichotomyExpressions
+ * @run main/othervm -XX:-TieredCompilation -Xcomp
+ *                   -XX:CompileCommand=dontinline,compiler.codegen.TestTrichotomyExpressions::test*
+ *                   compiler.codegen.TestTrichotomyExpressions
+ */
+
+package compiler.codegen;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+import java.lang.reflect.Method;
+
+import jdk.test.lib.Asserts;
+
+enum Operation { SMALLER, SMALLER_EQUAL, EQUAL, GREATER_EQUAL, GREATER, ALWAYS_FALSE }
+
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.METHOD)
+@interface Test {
+    Operation op();
+}
+
+public class TestTrichotomyExpressions {
+
+    public static int compare1(int a, int b) {
+        return (a < b) ? -1 : (a == b) ? 0 : 1; 
+    }
+
+    public static int compare2(int a, int b) {
+        return (a < b) ? -1 : (a <= b) ? 0 : 1; 
+    }
+
+    public static int compare3(int a, int b) {
+        return (a < b) ? -1 : (a > b) ? 1 : 0; 
+    }
+
+    public static int compare4(int a, int b) {
+        return (a > b) ? 1 : (a < b) ? -1 : 0; 
+    }
+
+    public static int compare5(int a, int b) {
+        return (a > b) ? 1 : (a == b) ? 0 : -1; 
+    }
+
+    public static int compare6(int a, int b) {
+        return (a > b) ? 1 : (a >= b) ? 0 : -1; 
+    }
+
+    public static int compare7(int a, int b) {
+        return (a == b) ? 0 : (a < b) ? -1 : 1; 
+    }
+
+    public static int compare8(int a, int b) {
+        return (a == b) ? 0 : (a <= b) ? -1 : 1; 
+    }
+
+    public static int compare9(int a, int b) {
+        return (a == b) ? 0 : (a > b) ? 1 : -1; 
+    }
+
+    public static int compare10(int a, int b) {
+        return (a == b) ? 0 : (a >= b) ? 1 : -1; 
+    }
+
+    public static int compare11(int a, int b) {
+        return (a >= b) ? 1 : (a > b) ? 2 : -1; 
+    }
+
+    public static int compare12(int a, int b) {
+        return (a <= b) ? 1 : (a < b) ? 2 : -1; 
+    }
+
+    public static int compare13(int a, int b) {
+        return (a == b) ? 1 : (a == b) ? 2 : -1; 
+    }
+
+    public static int compare14(int a, int b) {
+        return (a != b) ? 1 : (a < b) ? 2 : -1; 
+    }
+
+
+
+    @Test(op = Operation.SMALLER)
+    public static boolean testSmaller1(int a, int b) {
+        return compare1(a, b) == -1;
+    }
+
+    @Test(op = Operation.SMALLER)
+    public static boolean testSmaller2(int a, int b) {
+        return compare1(a, b) < 0;
+    }
+
+    @Test(op = Operation.SMALLER)
+    public static boolean testSmaller3(int a, int b) {
+        return compare1(a, b) <= -1;
+    }
+
+    @Test(op = Operation.SMALLER)
+    public static boolean testSmaller4(int a, int b) {
+        return compare2(a, b) == -1;
+    }
+
+    @Test(op = Operation.SMALLER)
+    public static boolean testSmaller5(int a, int b) {
+        return compare2(a, b) < 0;
+    }
+
+    @Test(op = Operation.SMALLER)
+    public static boolean testSmaller6(int a, int b) {
+        return compare2(a, b) <= -1;
+    }
+
+    @Test(op = Operation.SMALLER)
+    public static boolean testSmaller7(int a, int b) {
+        return compare3(a, b) == -1;
+    }
+
+    @Test(op = Operation.SMALLER)
+    public static boolean testSmaller8(int a, int b) {
+        return compare3(a, b) < 0;
+    }
+
+    @Test(op = Operation.SMALLER)
+    public static boolean testSmaller9(int a, int b) {
+        return compare3(a, b) <= -1;
+    }
+
+    @Test(op = Operation.SMALLER)
+    public static boolean testSmaller10(int a, int b) {
+        return compare4(a, b) == -1;
+    }
+
+    @Test(op = Operation.SMALLER)
+    public static boolean testSmaller11(int a, int b) {
+        return compare4(a, b) < 0;
+    }
+
+    @Test(op = Operation.SMALLER)
+    public static boolean testSmaller12(int a, int b) {
+        return compare4(a, b) <= -1;
+    }
+
+    @Test(op = Operation.SMALLER)
+    public static boolean testSmaller13(int a, int b) {
+        return compare5(a, b) == -1;
+    }
+
+    @Test(op = Operation.SMALLER)
+    public static boolean testSmaller14(int a, int b) {
+        return compare5(a, b) < 0;
+    }
+
+    @Test(op = Operation.SMALLER)
+    public static boolean testSmaller15(int a, int b) {
+        return compare5(a, b) <= -1;
+    }
+
+    @Test(op = Operation.SMALLER)
+    public static boolean testSmaller16(int a, int b) {
+        return compare6(a, b) == -1;
+    }
+
+    @Test(op = Operation.SMALLER)
+    public static boolean testSmaller17(int a, int b) {
+        return compare6(a, b) < 0;
+    }
+
+    @Test(op = Operation.SMALLER)
+    public static boolean testSmaller18(int a, int b) {
+        return compare6(a, b) <= -1;
+    }
+
+    @Test(op = Operation.SMALLER)
+    public static boolean testSmaller19(int a, int b) {
+        return compare7(a, b) == -1;
+    }
+
+    @Test(op = Operation.SMALLER)
+    public static boolean testSmaller20(int a, int b) {
+        return compare7(a, b) < 0;
+    }
+
+    @Test(op = Operation.SMALLER)
+    public static boolean testSmaller21(int a, int b) {
+        return compare7(a, b) <= -1;
+    }
+
+    @Test(op = Operation.SMALLER)
+    public static boolean testSmaller22(int a, int b) {
+        return compare8(a, b) == -1;
+    }
+
+    @Test(op = Operation.SMALLER)
+    public static boolean testSmaller23(int a, int b) {
+        return compare8(a, b) < 0;
+    }
+
+    @Test(op = Operation.SMALLER)
+    public static boolean testSmaller24(int a, int b) {
+        return compare8(a, b) <= -1;
+    }
+
+    @Test(op = Operation.SMALLER)
+    public static boolean testSmaller25(int a, int b) {
+        return compare9(a, b) == -1;
+    }
+
+    @Test(op = Operation.SMALLER)
+    public static boolean testSmaller26(int a, int b) {
+        return compare9(a, b) < 0;
+    }
+
+    @Test(op = Operation.SMALLER)
+    public static boolean testSmaller27(int a, int b) {
+        return compare9(a, b) <= -1;
+    }
+
+    @Test(op = Operation.SMALLER)
+    public static boolean testSmaller28(int a, int b) {
+        return compare10(a, b) == -1;
+    }
+
+    @Test(op = Operation.SMALLER)
+    public static boolean testSmaller29(int a, int b) {
+        return compare10(a, b) < 0;
+    }
+
+    @Test(op = Operation.SMALLER)
+    public static boolean testSmaller30(int a, int b) {
+        return compare10(a, b) <= -1;
+    }
+
+
+    @Test(op = Operation.SMALLER_EQUAL)
+    public static boolean testSmallerEqual1(int a, int b) {
+        return compare1(a, b) <= 0;
+    }
+
+    @Test(op = Operation.SMALLER_EQUAL)
+    public static boolean testSmallerEqual2(int a, int b) {
+        return compare2(a, b) <= 0;
+    }
+
+    @Test(op = Operation.SMALLER_EQUAL)
+    public static boolean testSmallerEqual3(int a, int b) {
+        return compare3(a, b) <= 0;
+    }
+
+    @Test(op = Operation.SMALLER_EQUAL)
+    public static boolean testSmallerEqual4(int a, int b) {
+        return compare4(a, b) <= 0;
+    }
+
+    @Test(op = Operation.SMALLER_EQUAL)
+    public static boolean testSmallerEqual5(int a, int b) {
+        return compare5(a, b) <= 0;
+    }
+
+    @Test(op = Operation.SMALLER_EQUAL)
+    public static boolean testSmallerEqual6(int a, int b) {
+        return compare6(a, b) <= 0;
+    }
+
+    @Test(op = Operation.SMALLER_EQUAL)
+    public static boolean testSmallerEqual7(int a, int b) {
+        return compare7(a, b) <= 0;
+    }
+
+    @Test(op = Operation.SMALLER_EQUAL)
+    public static boolean testSmallerEqual8(int a, int b) {
+        return compare8(a, b) <= 0;
+    }
+
+    @Test(op = Operation.SMALLER_EQUAL)
+    public static boolean testSmallerEqual9(int a, int b) {
+        return compare9(a, b) <= 0;
+    }
+
+    @Test(op = Operation.SMALLER_EQUAL)
+    public static boolean testSmallerEqual10(int a, int b) {
+        return compare10(a, b) <= 0;
+    }
+
+
+    @Test(op = Operation.EQUAL)
+    public static boolean testEqual1(int a, int b) {
+        return compare1(a, b) == 0;
+    }
+
+    @Test(op = Operation.EQUAL)
+    public static boolean testEqual2(int a, int b) {
+        return compare2(a, b) == 0;
+    }
+
+    @Test(op = Operation.EQUAL)
+    public static boolean testEqual3(int a, int b) {
+        return compare3(a, b) == 0;
+    }
+
+    @Test(op = Operation.EQUAL)
+    public static boolean testEqual4(int a, int b) {
+        return compare4(a, b) == 0;
+    }
+
+    @Test(op = Operation.EQUAL)
+    public static boolean testEqual5(int a, int b) {
+        return compare5(a, b) == 0;
+    }
+
+    @Test(op = Operation.EQUAL)
+    public static boolean testEqual6(int a, int b) {
+        return compare6(a, b) == 0;
+    }
+
+    @Test(op = Operation.EQUAL)
+    public static boolean testEqual7(int a, int b) {
+        return compare7(a, b) == 0;
+    }
+
+    @Test(op = Operation.EQUAL)
+    public static boolean testEqual8(int a, int b) {
+        return compare8(a, b) == 0;
+    }
+
+    @Test(op = Operation.EQUAL)
+    public static boolean testEqual9(int a, int b) {
+        return compare9(a, b) == 0;
+    }
+
+    @Test(op = Operation.EQUAL)
+    public static boolean testEqual10(int a, int b) {
+        return compare10(a, b) == 0;
+    }
+
+
+    @Test(op = Operation.GREATER_EQUAL)
+    public static boolean testGreaterEqual1(int a, int b) {
+        return compare1(a, b) >= 0;
+    }
+
+    @Test(op = Operation.GREATER_EQUAL)
+    public static boolean testGreaterEqual2(int a, int b) {
+        return compare2(a, b) >= 0;
+    }
+
+    @Test(op = Operation.GREATER_EQUAL)
+    public static boolean testGreaterEqual3(int a, int b) {
+        return compare3(a, b) >= 0;
+    }
+
+    @Test(op = Operation.GREATER_EQUAL)
+    public static boolean testGreaterEqual4(int a, int b) {
+        return compare4(a, b) >= 0;
+    }
+
+    @Test(op = Operation.GREATER_EQUAL)
+    public static boolean testGreaterEqual5(int a, int b) {
+        return compare5(a, b) >= 0;
+    }
+
+    @Test(op = Operation.GREATER_EQUAL)
+    public static boolean testGreaterEqual6(int a, int b) {
+        return compare6(a, b) >= 0;
+    }
+
+    @Test(op = Operation.GREATER_EQUAL)
+    public static boolean testGreaterEqual7(int a, int b) {
+        return compare7(a, b) >= 0;
+    }
+
+    @Test(op = Operation.GREATER_EQUAL)
+    public static boolean testGreaterEqual8(int a, int b) {
+        return compare8(a, b) >= 0;
+    }
+
+    @Test(op = Operation.GREATER_EQUAL)
+    public static boolean testGreaterEqual9(int a, int b) {
+        return compare9(a, b) >= 0;
+    }
+
+    @Test(op = Operation.GREATER_EQUAL)
+    public static boolean testGreaterEqual10(int a, int b) {
+        return compare10(a, b) >= 0;
+    }
+
+
+    @Test(op = Operation.GREATER)
+    public static boolean testGreater1(int a, int b) {
+        return compare1(a, b) == 1;
+    }
+
+    @Test(op = Operation.GREATER)
+    public static boolean testGreater2(int a, int b) {
+        return compare1(a, b) > 0;
+    }
+
+    @Test(op = Operation.GREATER)
+    public static boolean testGreater3(int a, int b) {
+        return compare1(a, b) >= 1;
+    }
+
+    @Test(op = Operation.GREATER)
+    public static boolean testGreater4(int a, int b) {
+        return compare2(a, b) == 1;
+    }
+
+    @Test(op = Operation.GREATER)
+    public static boolean testGreater5(int a, int b) {
+        return compare2(a, b) > 0;
+    }
+
+    @Test(op = Operation.GREATER)
+    public static boolean testGreater6(int a, int b) {
+        return compare2(a, b) >= 1;
+    }
+
+    @Test(op = Operation.GREATER)
+    public static boolean testGreater7(int a, int b) {
+        return compare3(a, b) == 1;
+    }
+
+    @Test(op = Operation.GREATER)
+    public static boolean testGreater8(int a, int b) {
+        return compare3(a, b) > 0;
+    }
+
+    @Test(op = Operation.GREATER)
+    public static boolean testGreater9(int a, int b) {
+        return compare3(a, b) >= 1;
+    }
+
+    @Test(op = Operation.GREATER)
+    public static boolean testGreater10(int a, int b) {
+        return compare4(a, b) == 1;
+    }
+
+    @Test(op = Operation.GREATER)
+    public static boolean testGreater11(int a, int b) {
+        return compare4(a, b) > 0;
+    }
+
+    @Test(op = Operation.GREATER)
+    public static boolean testGreater12(int a, int b) {
+        return compare4(a, b) >= 1;
+    }
+
+    @Test(op = Operation.GREATER)
+    public static boolean testGreater13(int a, int b) {
+        return compare5(a, b) == 1;
+    }
+
+    @Test(op = Operation.GREATER)
+    public static boolean testGreater14(int a, int b) {
+        return compare5(a, b) > 0;
+    }
+
+    @Test(op = Operation.GREATER)
+    public static boolean testGreater15(int a, int b) {
+        return compare5(a, b) >= 1;
+    }
+
+    @Test(op = Operation.GREATER)
+    public static boolean testGreater16(int a, int b) {
+        return compare6(a, b) == 1;
+    }
+
+    @Test(op = Operation.GREATER)
+    public static boolean testGreater17(int a, int b) {
+        return compare6(a, b) > 0;
+    }
+
+    @Test(op = Operation.GREATER)
+    public static boolean testGreater18(int a, int b) {
+        return compare6(a, b) >= 1;
+    }
+
+    @Test(op = Operation.GREATER)
+    public static boolean testGreater19(int a, int b) {
+        return compare7(a, b) == 1;
+    }
+
+    @Test(op = Operation.GREATER)
+    public static boolean testGreater20(int a, int b) {
+        return compare7(a, b) > 0;
+    }
+
+    @Test(op = Operation.GREATER)
+    public static boolean testGreater21(int a, int b) {
+        return compare7(a, b) >= 1;
+    }
+
+    @Test(op = Operation.GREATER)
+    public static boolean testGreater22(int a, int b) {
+        return compare8(a, b) == 1;
+    }
+
+    @Test(op = Operation.GREATER)
+    public static boolean testGreater23(int a, int b) {
+        return compare8(a, b) > 0;
+    }
+
+    @Test(op = Operation.GREATER)
+    public static boolean testGreater24(int a, int b) {
+        return compare8(a, b) >= 1;
+    }
+
+    @Test(op = Operation.GREATER)
+    public static boolean testGreater25(int a, int b) {
+        return compare9(a, b) == 1;
+    }
+
+    @Test(op = Operation.GREATER)
+    public static boolean testGreater26(int a, int b) {
+        return compare9(a, b) > 0;
+    }
+
+    @Test(op = Operation.GREATER)
+    public static boolean testGreater27(int a, int b) {
+        return compare9(a, b) >= 1;
+    }
+
+    @Test(op = Operation.GREATER)
+    public static boolean testGreater28(int a, int b) {
+        return compare10(a, b) == 1;
+    }
+
+    @Test(op = Operation.GREATER)
+    public static boolean testGreater29(int a, int b) {
+        return compare10(a, b) > 0;
+    }
+
+    @Test(op = Operation.GREATER)
+    public static boolean testGreater30(int a, int b) {
+        return compare10(a, b) >= 1;
+    }
+
+
+    @Test(op = Operation.ALWAYS_FALSE)
+    public static boolean testAlwaysFalse1(int a, int b) {
+        return compare11(a, b) == 2;
+    }
+
+    @Test(op = Operation.ALWAYS_FALSE)
+    public static boolean testAlwaysFalse2(int a, int b) {
+        return compare11(a, b) > 1;
+    }
+
+    @Test(op = Operation.ALWAYS_FALSE)
+    public static boolean testAlwaysFalse3(int a, int b) {
+        return compare11(a, b) >= 2;
+    }
+
+    @Test(op = Operation.ALWAYS_FALSE)
+    public static boolean testAlwaysFalse4(int a, int b) {
+        return compare12(a, b) == 2;
+    }
+
+    @Test(op = Operation.ALWAYS_FALSE)
+    public static boolean testAlwaysFalse5(int a, int b) {
+        return compare12(a, b) > 1;
+    }
+
+    @Test(op = Operation.ALWAYS_FALSE)
+    public static boolean testAlwaysFalse6(int a, int b) {
+        return compare12(a, b) >= 2;
+    }
+
+    @Test(op = Operation.ALWAYS_FALSE)
+    public static boolean testAlwaysFalse7(int a, int b) {
+        return compare13(a, b) == 2;
+    }
+
+    @Test(op = Operation.ALWAYS_FALSE)
+    public static boolean testAlwaysFalse8(int a, int b) {
+        return compare13(a, b) > 1;
+    }
+
+    @Test(op = Operation.ALWAYS_FALSE)
+    public static boolean testAlwaysFalse9(int a, int b) {
+        return compare13(a, b) >= 2;
+    }
+
+    @Test(op = Operation.ALWAYS_FALSE)
+    public static boolean testAlwaysFalse10(int a, int b) {
+        return compare14(a, b) == 2;
+    }
+
+    @Test(op = Operation.ALWAYS_FALSE)
+    public static boolean testAlwaysFalse11(int a, int b) {
+        return compare14(a, b) > 1;
+    }
+
+    @Test(op = Operation.ALWAYS_FALSE)
+    public static boolean testAlwaysFalse12(int a, int b) {
+        return compare14(a, b) >= 2;
+    }
+
+    public static void main(String[] args) throws Exception {
+        for (int i = 0; i < 20_000; ++i) {
+            for (Method m : TestTrichotomyExpressions.class.getMethods()) {
+                if (m.isAnnotationPresent(Test.class)) {
+                    Operation op = m.getAnnotation(Test.class).op();
+                    boolean result = (boolean)m.invoke(null, 0, 0);
+                    Asserts.assertEquals(result, (op == Operation.EQUAL || op == Operation.SMALLER_EQUAL || op == Operation.GREATER_EQUAL) ? true : false);
+                    result = (boolean)m.invoke(null, 0, 1);
+                    Asserts.assertEquals(result, (op == Operation.SMALLER || op == Operation.SMALLER_EQUAL) ? true : false);
+                    result = (boolean)m.invoke(null, 1, 0);
+                    Asserts.assertEquals(result, (op == Operation.GREATER || op == Operation.GREATER_EQUAL) ? true : false);
+                }
+            }
+        }
+    }
+}