| /* |
| * Copyright (c) 2017, 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 |
| * @bug 8179678 |
| * @summary ArrayCopy with same src and dst can cause incorrect execution or compiler crash |
| * |
| * @run main/othervm -XX:CompileCommand=compileonly,TestACSameSrcDst::test* TestACSameSrcDst |
| * |
| */ |
| |
| public class TestACSameSrcDst { |
| |
| static int test1(int[] src, int[] dst) { |
| System.arraycopy(src, 5, dst, 0, 10); |
| // this shouldn't be transformed to src[5] because the copy |
| // can modify src[5] if src and dst are the same. |
| return dst[0]; |
| } |
| |
| static int test2(int[] src) { |
| System.arraycopy(src, 0, src, 0, 10); |
| // same source and destination. If load from destination is |
| // transformed to load of source, the compiler performs that |
| // optimization in an infinite loop. |
| return src[0]; |
| } |
| |
| static int test3() { |
| int[] src = new int[15]; |
| src[5] = 0x42; |
| System.arraycopy(src, 5, src, 0, 10); |
| // That load can't bypass the arraycopy |
| return src[0]; |
| } |
| |
| static int test4() { |
| int[] src = new int[15]; |
| System.arraycopy(src, 0, src, 5, 10); |
| return src[0]; |
| } |
| |
| // The dst[0] load can't bypass the arraycopy. After ArrayCopyNode |
| // is expanded, C2 looks for a stub call on the control paths of |
| // the array copy subgraph to decide whether the load's memory |
| // input can bypass the arraycopy. This test verifies the case of |
| // a source array that's not declared as an array. |
| static int test5(Object src, int l, boolean flag) { |
| int[] dst = new int[10]; |
| if (flag) { |
| dst[0] = 0x42; |
| System.arraycopy(src, 0, dst, 0, l); |
| return dst[0]; |
| } |
| return 0; |
| } |
| |
| public static void main(String[] args) { |
| int[] array = new int[15]; |
| for (int i = 0; i < 20000; i++) { |
| int res; |
| for (int j = 0; j < array.length; j++) { |
| array[j] = j; |
| } |
| int expected = array[5]; |
| res = test1(array, array); |
| if (res != expected) { |
| throw new RuntimeException("bad result: " + res + " != " + expected); |
| } |
| test2(array); |
| res = test3(); |
| if (res != 0x42) { |
| throw new RuntimeException("bad result: " + res + " != " + 0x42); |
| } |
| test4(); |
| for (int j = 0; j < array.length; j++) { |
| array[j] = j; |
| } |
| res = test5(array, 10, (i%2) == 0); |
| if (res != 0) { |
| throw new RuntimeException("bad result: " + res + " != " + 0); |
| } |
| } |
| } |
| } |