1 /* 2 * Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 /** 26 * @test 27 * @bug 6897150 28 * @summary Hotspot optimises away a valid loop 29 * 30 * @run main Test6897150 31 */ 32 33 // Should be compiled with javac from JDK1.3 to get bytecode which shows the problem. 34 public class Test6897150 { 35 public static void main(String[] args) { 36 // This works 37 loopAndPrint(Integer.MAX_VALUE -1); 38 // This doesn't 39 loopAndPrint(Integer.MAX_VALUE); 40 } 41 42 static void verify(int max, int a) { 43 if ( a != (max - 1)) { 44 System.out.println("Expected: " + (max - 1)); 45 System.out.println("Actual : " + a); 46 System.exit(97); 47 } 48 } 49 static void loopAndPrint(int max) { 50 int a = -1; 51 int i = 1; 52 for (; i < max; i++) { 53 a = i; 54 } 55 verify(max, a); 56 } 57 } 58