1 /* 2 * Copyright 2015 SAP AG. 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 8080190 27 * @key regression 28 * @summary Test that the rotate distance used in the rotate instruction is properly masked with 0x1f 29 * @run main/othervm -Xbatch -XX:-UseOnStackReplacement IntRotateWithImmediate 30 * @author volker.simonis@gmail.com 31 */ 32 33 public class IntRotateWithImmediate { 34 35 // This is currently the same as Integer.rotateRight() 36 static int rotateRight(int i, int distance) { 37 // On some architectures (i.e. x86_64 and ppc64) the following computation is 38 // matched in the .ad file into a single MachNode which emmits a single rotate 39 // machine instruction. It is important that the shift amount is masked to match 40 // corresponding immediate width in the native instruction. On x86_64 the rotate 41 // left instruction ('rol') encodes an 8-bit immediate while the corresponding 42 // 'rotlwi' instruction on Power only encodes a 5-bit immediate. 43 return ((i >>> distance) | (i << -distance)); 44 } 45 46 static int compute(int x) { 47 return rotateRight(x, 3); 48 } 49 50 public static void main(String args[]) { 51 int val = 4096; 52 53 int firstResult = compute(val); 54 55 for (int i = 0; i < 100000; i++) { 56 int newResult = compute(val); 57 if (firstResult != newResult) { 58 throw new InternalError(firstResult + " != " + newResult); 59 } 60 } 61 System.out.println("OK"); 62 } 63 64 }