/* * Copyright (c) 2015, Oracle and/or its affiliates. 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 * @bug 8086046 * @summary load bypasses arraycopy that sets the value after the ArrayCopyNode is expanded * @run main/othervm -XX:-BackgroundCompilation -XX:-UseOnStackReplacement -XX:CompileCommand=dontinline,TestLoadBypassArrayCopy::test_helper -XX:-TieredCompilation TestLoadBypassArrayCopy * */ public class TestLoadBypassArrayCopy { static long i; static boolean test_helper() { i++; if ((i%10) == 0) { return false; } return true; } static int test(int[] src, int len, boolean flag) { int[] dest = new int[10]; int res = 0; while (test_helper()) { System.arraycopy(src, 0, dest, 0, len); // predicate moved out of loop so control of following // load is not the ArrayCopyNode. Otherwise, if the memory // of the load is changed and the control is set to the // ArrayCopyNode the graph is unschedulable and the test // doesn't fail. if (flag) { } // The memory of this load shouldn't bypass the arraycopy res = dest[0]; } return res; } static public void main(String[] args) { int[] src = new int[10]; src[0] = 0x42; for (int i = 0; i < 20000; i++) { int res = test(src, 10, false); if (res != src[0]) { throw new RuntimeException("test failed"); } } } }