1 /*
2 * Copyright (c) 2024 Alibaba Group Holding Limited. 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 package compiler.c2.irTests.scalarReplacement;
25
26 import compiler.lib.ir_framework.*;
27
28 /*
29 * @test
30 * @bug 8333334
31 * @summary Tests that dead barrier control flows do not affect the scalar replacement.
32 * @library /test/lib /
33 * @requires vm.compiler2.enabled
34 * @requires vm.gc.G1
35 * @run driver compiler.c2.irTests.scalarReplacement.ScalarReplacementWithGCBarrierTests
36 */
37 public class ScalarReplacementWithGCBarrierTests {
38 static class List {
39 public Node head;
40
41 public void push(int value) {
42 Node n = new Node();
43 n.value = value;
44 n.next = head;
45 head = n;
46 }
47
48 @ForceInline
49 public Iter iter() {
50 Iter iter = new Iter();
51 iter.list = this;
52 iter.n = head;
53 iter.sum = 0;
54 return iter;
55 }
56 }
57
58 static class Node {
59 public int value;
60 public Node next;
61 }
62
63 static class Iter {
64 public List list;
65 public Node n;
66 public Integer sum;
67
68 @ForceInline
69 public boolean next() {
70 int lastSum = sum;
71 while (sum - lastSum < 1000) {
72 while (n != null && n.value < 30) n = n.next;
73 if (n == null) return false;
74 sum += n.value;
75 n = n.next;
76 }
77 return true;
78 }
79 }
80
81 private static final int SIZE = 1000;
82
83 public static void main(String[] args) {
84 // Must use G1 GC to ensure there is a pre-barrier
85 // before the first field write.
86 TestFramework.runWithFlags("-XX:+UseG1GC");
87 }
88
89 @Run(test = "testScalarReplacementWithGCBarrier")
90 private void runner() {
91 List list = new List();
92 for (int i = 0; i < SIZE; i++) {
93 list.push(i);
94 }
95 testScalarReplacementWithGCBarrier(list);
96 }
97
98 // Allocation of `Iter iter` should be eliminated by scalar replacement, and
99 // the allocation of `Integer sum` can not be eliminated, so there should be
100 // 1 allocation after allocations and locks elimination.
101 //
102 // Before the patch of JDK-8333334, both allocations of `Iter` and `Integer`
103 // could not be eliminated.
104 @Test
105 @IR(phase = { CompilePhase.AFTER_PARSING }, counts = { IRNode.ALLOC, "1" })
106 @IR(phase = { CompilePhase.INCREMENTAL_BOXING_INLINE }, counts = { IRNode.ALLOC, "2" })
107 @IR(phase = { CompilePhase.ITER_GVN_AFTER_ELIMINATION }, counts = { IRNode.ALLOC, "1" })
108 private int testScalarReplacementWithGCBarrier(List list) {
109 Iter iter = list.iter();
110 while (true) {
111 while (iter.next()) {}
112 if (list.head == null) break;
113 list.head = list.head.next;
114 iter.n = list.head;
115 }
116 return iter.sum;
117 }
118 }