1 /*
2  * Copyright (c) 2020, 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 8245714
27  * @requires vm.compiler2.enabled
28  * @summary "Bad graph detected in build_loop_late" when loads are pinned on loop limit check uncommon branch
29  *
30  * @run main/othervm -XX:-BackgroundCompilation -XX:ArrayCopyLoadStoreMaxElem=0 TestBadControlLoopLimitCheck
31  */
32 
33 public class TestBadControlLoopLimitCheck {
main(String[] args)34     public static void main(String[] args) {
35         int[] int_array = {0, 0};
36         A[] obj_array = {new A(), new A()};
37         for (int i = 0; i < 20_000; i++) {
38             test1(int_array, 0, 10, false);
39             test_helper(42);
40             test2(obj_array, 0, 10, false);
41         }
42     }
43 
test1(int[] a, int start, int stop, boolean flag)44     private static int test1(int[] a, int start, int stop, boolean flag) {
45         int[] b = new int[2]; // non escaping allocation
46         System.arraycopy(a, 0, b, 0, 2); // optimized out
47         int v = 1;
48         int j = 0;
49         for (; j < 10; j++);
50         int inc = test_helper(j); // delay transformation to counted loop
51         // loop limit check here has loads pinned on unc branch
52         for (int i = start; i < stop; i += inc) {
53             v *= 2;
54         }
55         if (flag) {
56             v += b[0] + b[1];
57         }
58         return v;
59     }
60 
test2(A[] a, int start, int stop, boolean flag)61     private static int test2(A[] a, int start, int stop, boolean flag) {
62         A[] b = new A[2]; // non escaping allocation
63         System.arraycopy(a, 0, b, 0, 2); // optimized out
64         int v = 1;
65         int j = 0;
66         for (; j < 10; j++);
67         int inc = test_helper(j); // delay transformation to counted loop
68         // loop limit check here has loads pinned on unc branch
69         for (int i = start; i < stop; i += inc) {
70             v *= 2;
71         }
72         if (flag) {
73             v += b[0].f + b[1].f;
74         }
75         return v;
76     }
77 
78     static class A {
79         int f;
80     }
81 
test_helper(int j)82     static int test_helper(int j) {
83         return j == 10 ? 10 : 1;
84     }
85 }
86