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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * version 2 for more details (a copy is included in the LICENSE file that
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 */

/**
 * @test
 * @bug 8328107
 * @summary Barrier expanded on backedge break loop verification code
 * @requires vm.gc.Shenandoah
 *
 * @run main/othervm -XX:+UseShenandoahGC -XX:-BackgroundCompilation -XX:CompileCommand=dontinline,TestBarrierOnLoopBackedge::notInlined
 *                   -XX:+IgnoreUnrecognizedVMOptions -XX:+VerifyLoopOptimizations TestBarrierOnLoopBackedge
 * @run main/othervm -XX:+UseShenandoahGC -XX:-BackgroundCompilation -XX:CompileCommand=dontinline,TestBarrierOnLoopBackedge::notInlined
 *                   -XX:+IgnoreUnrecognizedVMOptions -XX:+VerifyLoopOptimizations -XX:-UseCountedLoopSafepoints TestBarrierOnLoopBackedge
 */

public class TestBarrierOnLoopBackedge {
    private static A field = new A();
    private static final A finalField = new A();
    private static float floatField;

    public static void main(String[] args) {
        A[] array = new A[1];
        array[0] = finalField;
        for (int i = 0; i < 20_000; i++) {
            test1();
            test2();
        }
    }

    private static void test1() {
        floatField = field.f;
        for (int i = 0; i < 1000; i++) {
            notInlined(field); // load barrier split thru phi and ends up on back edge
            if (i % 2 == 0) {
                field = finalField;
            }
        }
    }

    private static void test2() {
        A[] array = new A[1];
        notInlined(array);
        int i = 0;
        A a = array[0];
        for (;;) {
            synchronized (new Object()) {
            }
            notInlined(a);
            i++;
            if (i >= 1000) {
                break;
            }
            a = array[0]; // load barrier pinned on backedge
        }
    }

    private static void notInlined(Object a) {

    }

    private static class A {
        float f;
    }
}