1 /* 2 * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 24 /* 25 * @test 26 * @bug 8086046 27 * @summary load bypasses arraycopy that sets the value after the ArrayCopyNode is expanded 28 * @run main/othervm -XX:-BackgroundCompilation -XX:-UseOnStackReplacement -XX:CompileCommand=dontinline,TestLoadBypassArrayCopy::test_helper -XX:-TieredCompilation TestLoadBypassArrayCopy 29 * 30 */ 31 32 public class TestLoadBypassArrayCopy { 33 34 static long i; 35 static boolean test_helper() { 36 i++; 37 if ((i%10) == 0) { 38 return false; 39 } 40 return true; 41 } 42 43 static int test(int[] src, int len, boolean flag) { 44 int[] dest = new int[10]; 45 int res = 0; 46 while (test_helper()) { 47 System.arraycopy(src, 0, dest, 0, len); 48 // predicate moved out of loop so control of following 49 // load is not the ArrayCopyNode. Otherwise, if the memory 50 // of the load is changed and the control is set to the 51 // ArrayCopyNode the graph is unschedulable and the test 52 // doesn't fail. 53 if (flag) { 54 } 55 // The memory of this load shouldn't bypass the arraycopy 56 res = dest[0]; 57 } 58 return res; 59 } 60 61 static public void main(String[] args) { 62 int[] src = new int[10]; 63 src[0] = 0x42; 64 for (int i = 0; i < 20000; i++) { 65 int res = test(src, 10, false); 66 if (res != src[0]) { 67 throw new RuntimeException("test failed"); 68 } 69 } 70 } 71 }