/* * Copyright (c) 2021, 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 8262739 * @summary Test correct insertion of anti-dependencies after String inflation. * @run main/othervm -Xbatch * compiler.controldependency.TestAntiDependencyAfterStringInflation */ package compiler.controldependency; public class TestAntiDependencyAfterStringInflation { static String reverseString(String str) { int size = str.length(); char[] buffer = new char[size]; reverse(str, buffer, size); return new String(buffer, 0, size); } static void reverse(String str, char[] buffer, int size) { // Inflate String.value byte[] to char[] str.getChars(0, size, buffer, 0); // Reverse String by copying buffer elements. This will fail // if C2 does not insert anti-dependencies between loads/stores. int half = size / 2; for (int l = 0, r = size - 1; l < half; l++, r--) { char tmp = buffer[l]; buffer[l] = buffer[r]; buffer[r] = tmp; } } public static void main(String[] args) throws Exception { for (int i = 0; i < 50_000; i++) { String res = reverseString("0123456789"); if (!res.equals("9876543210")) { throw new RuntimeException("Unexpected result: " + res); } } } }