TestCopyOfBrokenAntiDependency.java

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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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/**
 * @test
 * @bug 8238384
 * @summary CTW: C2 compilation fails with "assert(store != load->find_exact_control(load->in(0))) failed: dependence cycle found"
 *
 * @run main/othervm -XX:-BackgroundCompilation TestCopyOfBrokenAntiDependency
 *
 */

import java.util.Arrays;

public class TestCopyOfBrokenAntiDependency {

    public static void main(String[] args) {
        for (int i = 0; i < 20_000; i++) {
            test(100);
        }
    }

    private static Object test(int length) {
        Object[] src  = new Object[length]; // non escaping
        final Object[] dst = Arrays.copyOf(src, 10); // can't be removed
        final Object[] dst2 = Arrays.copyOf(dst, 100);
        // load is control dependent on membar from previous copyOf
        // but has memory edge to first copyOf.
        final Object v = dst[0];
        return v;
    }
}