/*

 * Copyright (c) 2018, Red Hat, Inc. 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 8193130

 * @summary Bad graph when unrolled loop bounds conflicts with range checks

 *

 * @run main/othervm IterationSplitPredicateInconsistency

 * @run main/othervm -XX:-UseLoopPredicate IterationSplitPredicateInconsistency

 *

 */

public class IterationSplitPredicateInconsistency {

    static volatile int barrier;

    // Pollute profile so loop appears to run for a large number of iterations

    static boolean test1_helper(int start, int stop, double[] array1, double[] array2, int exit) {

        for (int i = start; i < stop; i++) {

            array1[i] = array2[i];

            if (i == exit) {

                return true;

            }

            barrier = 0x42;

        }

        return false;

    }

    static double[] test1(int start, double[] array2, int exit) {

        double[] array1 = new double[10];

        // Predication moves range checks out of loop and

        // pre/main/post loops are created. The main loop is unrolled

        // several times to the point where it's never executed but

        // compiler can't tell from the loop bounds alone. The lower

        // bound of the loop is negative and would cause range checks

        // (that were removed from the loop body) to fail.

        if (test1_helper(start, 5, array1, array2, exit)) {

            return null;

        }

        return array1;

    }

    // Same as above with other combinations of increasing/decreasing

    // loops, positive/negative stride

    static boolean test2_helper(int start, int stop, double[] array1, double[] array2, int exit) {

        for (int i = start-1; i >= stop; i--) {

            array1[i] = array2[i];

            if (i == exit) {

                return true;

            }

            barrier = 0x42;

        }

        return false;

    }

    static double[] test2(int start, double[] array2, int exit) {

        double[] array1 = new double[10];

        if (test2_helper(start, 0, array1, array2, exit)) {

            return null;

        }

        return array1;

    }

    static boolean test3_helper(int start, int stop, double[] array1, double[] array2, int exit) {

        for (int i = start; i < stop; i++) {

            array1[stop-i-1] = array2[stop-i-1];

            if (i == exit) {

                return true;

            }

            barrier = 0x42;

        }

        return false;

    }

    static double[] test3(int start, double[] array2, int exit) {

        double[] array1 = new double[5];

        if (test3_helper(start, 5, array1, array2, exit)) {

            return null;

        }

        return array1;

    }

    static boolean test4_helper(int start, int stop, int from, double[] array1, double[] array2, int exit) {

        for (int i = start-1; i >= stop; i--) {

            array1[from-i-1] = array2[from-i-1];

            if (i == exit) {

                return true;

            }

            barrier = 0x42;

        }

        return false;

    }

    static double[] test4(int start, double[] array2, int exit) {

        double[] array1 = new double[5];

        if (test4_helper(start, 0, 5, array1, array2, exit)) {

            return null;

        }

        return array1;

    }

    public static void main(String[] args) {

        double[] array2 = new double[10];

        double[] array3 = new double[1000];

        for (int i = 0; i < 20_000; i++) {

            test1_helper(0, 1000, array3, array3, 998);

            test1(0, array2, 999);

            test1(0, array2, 4);

            test2_helper(1000, 0, array3, array3, 1);

            test2(5, array2, 999);

            test2(5, array2, 1);

            test3_helper(0, 1000, array3, array3, 998);

            test3(0, array2, 999);

            test3(0, array2, 4);

            test4_helper(1000, 0, 1000, array3, array3, 1);

            test4(5, array2, 999);

            test4(5, array2, 1);

        }

    }

}