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/*
* Copyright (c) 2016, 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
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
/**
* @test TestExpandedWBLostNullCheckDep
* @summary Logic that moves a null check in the expanded barrier may cause a memory access that doesn't depend on the barrier to bypass the null check
* @key gc
* @requires vm.gc.Shenandoah & !vm.graal.enabled
* @requires vm.flavor == "server"
* @run main/othervm -XX:-BackgroundCompilation -XX:-UseOnStackReplacement -XX:-TieredCompilation
* -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC
* -XX:+StressGCM -XX:+StressLCM TestExpandedWBLostNullCheckDep
*/
public class TestExpandedWBLostNullCheckDep {
static void test(int i, int[] arr) {
// arr.length depends on a null check for arr
if (i < 0 || i >= arr.length) {
}
// The write barrier here also depends on the null check. The
// null check is moved in the barrier to enable implicit null
// checks. The null check must not be moved arr.length
arr[i] = 0x42;
}
static public void main(String[] args) {
int[] int_arr = new int[10];
for (int i = 0; i < 20000; i++) {
test(0, int_arr);
}
try {
test(0, null);
} catch (NullPointerException npe) {}
}
}
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