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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

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 *

 * 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).

 *

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 * 2 along with this work; if not, write to the Free Software Foundation,

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 */

/*

 * @test

 * @bug 8159016

 * @summary Tests correct dominator information after over-unrolling a loop.

 * @requires vm.gc == "Parallel" | vm.gc == "null"

 *

 * @run main/othervm -XX:+IgnoreUnrecognizedVMOptions -Xcomp -XX:-TieredCompilation

 *                   -XX:-UseG1GC -XX:+UseParallelGC

 *                   compiler.loopopts.TestOverunrolling

 */

package compiler.loopopts;

public class TestOverunrolling {

    public static Object test(int arg) {

        Object arr[] = new Object[3];

        int lim = (arg & 3);

        // The pre loop is executed for one iteration, initializing p[0].

        // The main loop is unrolled twice, initializing p[1], p[2], p[3] and p[4].

        // The p[3] and p[4] stores are always out of bounds and removed. However,

        // C2 is unable to remove the "over-unrolled", dead main loop. As a result,

        // there is a control path from the main loop to the post loop without a

        // memory path (because the last store was replaced by TOP). We crash

        // because we use a memory edge from a non-dominating region.

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

            arr[i] = new Object();

        }

        // Avoid EA

        return arr;

    }

    public static void main(String args[]) {

        for (int i = 0; i < 42; ++i) {

            test(i);

        }

    }

}