test/hotspot/jtreg/compiler/loopstripmining/TestConservativeAntiDep.java

/*
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
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 * 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.
 *
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 */

/**
 * @test
 * @bug 8231550
 * @summary C2: ShouldNotReachHere() in verify_strip_mined_scheduling
 *
 * @run main/othervm -XX:-BackgroundCompilation -XX:LoopMaxUnroll=0 TestConservativeAntiDep
 *
 */

import java.lang.reflect.Array;
import java.util.Arrays;

public class TestConservativeAntiDep {
    private static long longField;

    public static void main(String[] args) throws InstantiationException, IllegalAccessException {
        for (int i = 0; i < 20_000; i++) {
            test1(A.class);
            test2(B.class);
        }
    }

    private static int test1(Class klass) {
        Object[] in = (Object[])Array.newInstance(klass, 100);

        Object[] o = in;
        int v = 1;
        // CountedLoop has control dependent CastPP
        for (int i = 0; i < 100 ; i++) {
            longField = i; // sunk in outer strip mined loop
            o = (A[]) o;
            v *= 2;
        }

        // LoadRange cannot float higher than CountedLoop (because of
        // CastPP) and is found anti-dependent with long store so
        // scheduled in outer strip mined loop
        return v + o.length;
    }

    private static int test2(Class klass) throws IllegalAccessException, InstantiationException {
        A in = (A)klass.newInstance();

        A o = in;
        int v = 1;
        // CountedLoop has control dependent CastPP
        for (int i = 0; i < 100 ; i++) {
            longField = i;  // sunk in outer strip mined loop
            o = (B) o;
            v *= 2;
        }

        // Load cannot float higher than CountedLoop (because of
        // CastPP) and is found anti-dependent with long store so
        // scheduled in outer strip mined loop
        return v + o.intField;
    }

    private static class A {
        int intField;
        public A() {}
    }

    private static class B extends A {
        public B() {}
    }
}