/*

 * Copyright (c) 2015, 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 8077504

 * @summary Unsafe load can loose control dependency and cause crash

 * @modules java.base/jdk.internal.misc:+open

 *

 * @run main/othervm -XX:-BackgroundCompilation -XX:-UseOnStackReplacement

 *                   compiler.unsafe.TestUnsafeLoadControl

 */

package compiler.unsafe;

import jdk.internal.misc.Unsafe;

import java.lang.reflect.Field;

public class TestUnsafeLoadControl {

    private static final Unsafe UNSAFE;

    static {

        try {

            Field unsafeField = Unsafe.class.getDeclaredField("theUnsafe");

            unsafeField.setAccessible(true);

            UNSAFE = (Unsafe) unsafeField.get(null);

        } catch(Exception e) {

            throw new RuntimeException(e);

        }

    }

    static int val;

    static void test1(int[] a, boolean[] flags, boolean flag, long j) {

        for (int i = 0; i < 10; i++) {

            if (flags[i]) {

                if (flag) {

                    long address = (j << 2) + UNSAFE.ARRAY_INT_BASE_OFFSET;

                    int v = UNSAFE.getInt(a, address);

                    val = v;

                }

            }

        }

    }

    static int test2(int[] a, boolean[] flags, boolean flag, long j) {

        int sum = 0;

        for (int i = 0; i < 10; i++) {

            if (flags[i]) {

                if (flag) {

                    long address = (j << 2) + UNSAFE.ARRAY_INT_BASE_OFFSET;

                    int v = UNSAFE.getInt(a, address);

                    if (v == 0) {

                        sum++;

                    }

                }

            }

        }

        return sum;

    }

    static public void main(String[] args) {

        boolean[] flags = new boolean[10];

        for (int i = 0; i < flags.length; i++) {

            flags[i] = true;

        }

        int[] array = new int[10];

        for (int i = 0; i < 20000; i++) {

            test1(array, flags, true, 0);

        }

        for (int i = 0; i < flags.length; i++) {

            flags[i] = false;

        }

        test1(array, flags, true, Long.MAX_VALUE/4);

        for (int i = 0; i < flags.length; i++) {

            flags[i] = true;

        }

        for (int i = 0; i < 20000; i++) {

            test2(array, flags, true, 0);

        }

        for (int i = 0; i < flags.length; i++) {

            flags[i] = false;

        }

        test2(array, flags, true, Long.MAX_VALUE/4);

    }

}