Mercurial > hg > truffle
diff test/compiler/loopopts/TestDeadBackbranchArrayAccess.java @ 20680:5b8e0f84f00f
8054478: C2: Incorrectly compiled char[] array access crashes JVM
Summary: dead backbranch in main loop results in erroneous array access
Reviewed-by: kvn, iveresov
author | roland |
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date | Mon, 01 Dec 2014 22:27:00 +0100 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/test/compiler/loopopts/TestDeadBackbranchArrayAccess.java Mon Dec 01 22:27:00 2014 +0100 @@ -0,0 +1,58 @@ +/* + * Copyright (c) 2014, 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 8054478 + * @summary dead backbranch in main loop results in erroneous array access + * @run main/othervm -XX:CompileOnly=TestDeadBackbranchArrayAccess -Xcomp TestDeadBackbranchArrayAccess + * + */ + +public class TestDeadBackbranchArrayAccess { + static char[] pattern0 = {0}; + static char[] pattern1 = {1}; + + static void test(char[] array) { + if (pattern1 == null) return; + + int i = 0; + int pos = 0; + char c = array[pos]; + + while (i >= 0 && (c == pattern0[i] || c == pattern1[i])) { + i--; + pos--; + if (pos != -1) { + c = array[pos]; + } + } + } + + public static void main(String[] args) { + for (int i = 0; i < 1000000; i++) { + test(new char[1]); + } + } +}