1 /*
2  * Copyright (c) 2018, Red Hat, Inc. 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 8212673
27  * @summary Node::eqv_uncast() shouldn't step over load barriers unconditionally
28  * @library /test/lib /
29  * @modules java.base/jdk.internal.misc
30  *
31  * @build sun.hotspot.WhiteBox
32  * @run driver ClassFileInstaller sun.hotspot.WhiteBox
33  *                                sun.hotspot.WhiteBox$WhiteBoxPermission
34  * @run main/othervm -Xbootclasspath/a:. -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -XX:-UseOnStackReplacement -XX:-TieredCompilation -XX:-BackgroundCompilation EqvUncastStepOverBarrier
35  */
36 
37 import sun.hotspot.WhiteBox;
38 import java.lang.reflect.Method;
39 
40 public class EqvUncastStepOverBarrier {
41     static final WhiteBox WHITE_BOX = WhiteBox.getWhiteBox();
42 
43     private static Object field = new A();
44 
main(String[] args)45     public static void main(String[] args) throws Exception {
46         for (int i = 0; i < 20_000; i++) {
47             test();
48             test();
49             test_helper(null, 0);
50         }
51         Method m = EqvUncastStepOverBarrier.class.getDeclaredMethod("test");
52         WHITE_BOX.enqueueMethodForCompilation(m, 4);
53         if (!WHITE_BOX.isMethodCompiled(m, false)) {
54             throw new RuntimeException("Method compilation failed");
55         }
56     }
57 
test()58     private static Object test() {
59         Object o = field;
60         if (o == null) {}
61         for (int i = 1; i < 100; i *= 2) {
62             int j = 0;
63             for (; j < 4; j++) ;
64             o = test_helper(o, j);
65         }
66         return o;
67     }
68 
test_helper(Object o, int j)69     private static Object test_helper(Object o, int j) {
70         if (j == 4) {
71             A a = (A) o;
72             o = a;
73         } else {
74             o = new Object();
75         }
76         return o;
77     }
78 
79     private static class A {
80     }
81 }
82