/*

 * 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

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 */

/**

 * @test

 * @bug 8054478

 * @summary dead backbranch in main loop results in erroneous array access

 *

 * @run main/othervm -Xcomp

 *      -XX:CompileCommand=compileonly,compiler.loopopts.TestDeadBackbranchArrayAccess::*

 *      compiler.loopopts.TestDeadBackbranchArrayAccess

 */

package compiler.loopopts;

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]);

        }

    }

}