1 /* 2 * Copyright (c) 2014, 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 * @test 26 * @bug 8054478 27 * @summary dead backbranch in main loop results in erroneous array access 28 * 29 * @run main/othervm -Xcomp 30 * -XX:CompileCommand=compileonly,compiler.loopopts.TestDeadBackbranchArrayAccess::* 31 * compiler.loopopts.TestDeadBackbranchArrayAccess 32 */ 33 34 package compiler.loopopts; 35 36 public class TestDeadBackbranchArrayAccess { 37 static char[] pattern0 = {0}; 38 static char[] pattern1 = {1}; 39 test(char[] array)40 static void test(char[] array) { 41 if (pattern1 == null) return; 42 43 int i = 0; 44 int pos = 0; 45 char c = array[pos]; 46 47 while (i >= 0 && (c == pattern0[i] || c == pattern1[i])) { 48 i--; 49 pos--; 50 if (pos != -1) { 51 c = array[pos]; 52 } 53 } 54 } 55 main(String[] args)56 public static void main(String[] args) { 57 for (int i = 0; i < 1000000; i++) { 58 test(new char[1]); 59 } 60 } 61 } 62