1/*
2 * Copyright (c) 2015 SAP SE. All rights reserved.
3 * Copyright (c) 2016, Red Hat, Inc. All rights reserved.
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This code is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 only, as
8 * published by the Free Software Foundation.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 */
24
25/*
26 * @test
27 * @bug 8080190
28 * @bug 8154537
29 * @key regression
30 * @summary Test that the rotate distance used in the rotate instruction is properly masked with 0x1f
31 *
32 * @run main/othervm -Xbatch -XX:-UseOnStackReplacement compiler.codegen.IntRotateWithImmediate
33 * @author volker.simonis@gmail.com
34 */
35
36package compiler.codegen;
37
38public class IntRotateWithImmediate {
39
40    // This is currently the same as Integer.rotateRight()
41    static int rotateRight1(int i, int distance) {
42        // On some architectures (i.e. x86_64 and ppc64) the following computation is
43        // matched in the .ad file into a single MachNode which emmits a single rotate
44        // machine instruction. It is important that the shift amount is masked to match
45        // corresponding immediate width in the native instruction. On x86_64 the rotate
46        // left instruction ('rol') encodes an 8-bit immediate while the corresponding
47        // 'rotlwi' instruction on Power only encodes a 5-bit immediate.
48        return ((i >>> distance) | (i << -distance));
49    }
50
51    static int rotateRight2(int i, int distance) {
52        return ((i >>> distance) | (i << (32 - distance)));
53    }
54
55    static int compute1(int x) {
56        return rotateRight1(x, 3);
57    }
58
59    static int compute2(int x) {
60        return rotateRight2(x, 3);
61    }
62
63    public static void main(String args[]) {
64        int val = 4096;
65
66        int firstResult = compute1(val);
67
68        for (int i = 0; i < 100000; i++) {
69            int newResult = compute1(val);
70            if (firstResult != newResult) {
71                throw new InternalError(firstResult + " != " + newResult);
72            }
73            newResult = compute2(val);
74            if (firstResult != newResult) {
75                throw new InternalError(firstResult + " != " + newResult);
76            }
77        }
78        System.out.println("OK");
79    }
80
81}
82