1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
|
/*
* Copyright (c) 2020, 2021, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
/*
* @test
* @bug 8249607 8260420
* @library /test/lib
* @summary A LoadNode is pinned in split_if_with_blocks_post() on a loop exit node x that is part of a strip mined loop. It has a late control y outside
the outer strip mined loop. After pre-main-post, the dominator chain of y does not include x anymore resulting in an assertion failure.
* @run main/othervm -Xbatch -XX:CompileCommand=compileonly,compiler.loopopts.TestSplitIfPinnedLoadInStripMinedLoop::*
* compiler.loopopts.TestSplitIfPinnedLoadInStripMinedLoop
*/
package compiler.loopopts;
import jdk.test.lib.Asserts;
public class TestSplitIfPinnedLoadInStripMinedLoop {
public boolean bFld = false;
public short sFld = 4;
public static int iFld = 5;
public static float fFld= 6.0f;
public static int iArrFld[] = new int[400];
public void test1() {
int x = 7;
int y = 8;
int a = 9;
float f = 10.0f;
double d = 11.0f;
double dArr[] = new double[400];
for (int i = 16; i < 350; i++) {
for (int j = 1; j < 75; j++) {
for (int k = 1; k < 3; k++) {
}
f = j * 6;
y = j;
try {
x = (y / 148);
} catch (ArithmeticException a_e) {}
if (bFld) {
break;
}
dArr[1] = 4;
}
for (int k = 75; k > i; k--) {
iArrFld[k] = 5;
}
for (int k = 4; k < 75; k++) {
f -= fFld;
// The LoadSNode for sFld is cloned in split_if_with_blocks_post() for each use such that they can float out of the loop. All control
// inputs of the clone are set to the latest control of the original LoadSNode which in this case is the StoreSNode for iFld that is
// aninput to a MergeMemNode which is an input to the SafePointNode in the outer strip mined loop. Both these nodes are not part
// of the loop body and thus the StoreNode is also not part of the loop anymore. This means that all the new LoadNode clones get
// the loop exit l inside the outer strip mined loop as control input. Some of these clones (**) have a late control outside of
// this outer strip mined loop. The dominator chain from the controls nodes of (**) contain l. However, after pre-main-post, we
// insert additional Region nodes but do not account for these control inputs of the LoadSNodes. They remain unchanged and still
// have l as control input. As a consequence, we do not find l on the dominator chains from the control nodes of (**) anymore
// resulting in a dominator assertion failure.
iFld = sFld;
}
switch ((i % 8) + 27) {
case 27:
if (bFld) {
for (a = 1; a < 75; a++) {
iFld += 6; // (**)
}
} else {
d -= x;
}
break;
case 28:
iFld = y;
// Fall through
case 33:
case 34:
iFld -= (int)d; // (**)
break;
}
}
}
static class MyClass {
int x = 42;
}
int res = 0;
// The obj1.x load has two uses: The 'res' store and the return. After cloning, both loads end up in the
// OuterStripMinedLoop which triggers an assert in LoopNode::verify_strip_mined:
// assert(found_sfpt) failed: no node in loop that's not input to safepoint
int test2(MyClass obj1, MyClass obj2) {
for (int i = 0; i < 10; ++i) {
for (int j = 0; j < 10; ++j) {
obj2.x = 42; // Prevents obj1.x load from floating up because obj2 could alias obj1
res = obj1.x;
}
for (int j = 0; j < 10_000; ++j) {
}
}
return res;
}
// Same as test2 but with reference to outer loop induction variable 'i' and different order of instructions.
// Triggers an assert in PhaseIdealLoop::build_loop_late_post_work if loop strip mining verification is disabled:
// assert(false) failed: Bad graph detected in build_loop_late
int test3(MyClass obj1, MyClass obj2) {
for (int i = 0; i < 10; ++i) {
for (int j = 0; j < 10; ++j) {
res = obj1.x + i;
obj2.x = 42;
}
for (int j = 0; j < 10_000; ++j) {
}
}
return res;
}
// Same as test2 but with reference to inner loop induction variable 'j' and different order of instructions.
// Triggers an assert in PhaseCFG::insert_anti_dependences if loop strip mining verification is disabled:
// assert(!LCA_orig->dominates(pred_block) || early->dominates(pred_block)) failed: early is high enough
int test4(MyClass obj1, MyClass obj2) {
for (int i = 0; i < 10; ++i) {
for (int j = 0; j < 10; ++j) {
res = obj1.x + j;
obj2.x = 42;
}
for (int j = 0; j < 10_000; ++j) {
}
}
return res;
}
public static void main(String[] strArr) {
TestSplitIfPinnedLoadInStripMinedLoop t = new TestSplitIfPinnedLoadInStripMinedLoop();
MyClass obj = new MyClass();
for (int i = 0; i < 10; i++) {
t.test1();
int res = t.test2(obj, obj);
Asserts.assertEquals(res, t.res);
Asserts.assertEquals(res, 42);
res = t.test3(obj, obj);
Asserts.assertEquals(res, t.res);
Asserts.assertEquals(res, 51);
res = t.test4(obj, obj);
Asserts.assertEquals(res, t.res);
Asserts.assertEquals(res, 51);
}
}
}
|
