1 /*
2 * Copyright (c) 2015, 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 8144028
27 * @summary Use AArch64 bit-test instructions in C2
28 * @modules java.base
29 * @run main/othervm -Xbatch -XX:CompileCommand=dontinline,BitTests::* -XX:-TieredCompilation BitTests
30 * @run main/othervm -Xbatch -XX:+TieredCompilation -XX:TieredStopAtLevel=1 BitTests
31 * @run main/othervm -Xbatch -XX:+TieredCompilation BitTests
32 *
33 */
34
35 // Try to ensure that the bit test instructions TBZ/TBNZ, TST/TSTW
36 // don't generate incorrect code. We can't guarantee that C2 will use
37 // bit test instructions for this test and it's not a bug if it
38 // doesn't. However, these test cases are ideal candidates for each
39 // of the instruction forms.
40 public class BitTests {
41
42 private final XorShift r = new XorShift();
43
44 private final long increment(long ctr) {
45 return ctr + 1;
46 }
47
48 private final int increment(int ctr) {
49 return ctr + 1;
50 }
51
52 private final long testIntSignedBranch(long counter) {
53 if ((int)r.nextLong() < 0) {
54 counter = increment(counter);
55 }
56 return counter;
57 }
58
59 private final long testLongSignedBranch(long counter) {
60 if (r.nextLong() < 0) {
61 counter = increment(counter);
62 }
63 return counter;
64 }
65
66 private final long testIntBitBranch(long counter) {
67 if (((int)r.nextLong() & (1 << 27)) != 0) {
68 counter = increment(counter);
69 }
70 if (((int)r.nextLong() & (1 << 27)) != 0) {
71 counter = increment(counter);
72 }
73 return counter;
74 }
75
76 private final long testLongBitBranch(long counter) {
77 if ((r.nextLong() & (1l << 50)) != 0) {
78 counter = increment(counter);
79 }
80 if ((r.nextLong() & (1l << 50)) != 0) {
81 counter = increment(counter);
82 }
83 return counter;
84 }
85
86 private final long testLongMaskBranch(long counter) {
87 if (((r.nextLong() & 0x0800000000l) != 0)) {
88 counter++;
89 }
90 return counter;
91 }
92
93 private final long testIntMaskBranch(long counter) {
94 if ((((int)r.nextLong() & 0x08) != 0)) {
95 counter++;
96 }
97 return counter;
98 }
99
100 private final long testLongMaskBranch(long counter, long mask) {
101 if (((r.nextLong() & mask) != 0)) {
102 counter++;
103 }
104 return counter;
105 }
106
107 private final long testIntMaskBranch(long counter, int mask) {
108 if ((((int)r.nextLong() & mask) != 0)) {
109 counter++;
110 }
111 return counter;
112 }
113
114 private final long step(long counter) {
115 counter = testIntSignedBranch(counter);
116 counter = testLongSignedBranch(counter);
117 counter = testIntBitBranch(counter);
118 counter = testLongBitBranch(counter);
119 counter = testIntMaskBranch(counter);
120 counter = testLongMaskBranch(counter);
121 counter = testIntMaskBranch(counter, 0x8000);
122 counter = testLongMaskBranch(counter, 0x800000000l);
123 return counter;
124 }
125
126
127 private final long finalBits = 3;
128
129 private long bits = 7;
130
131 public static void main(String[] args) {
132 BitTests t = new BitTests();
133
134 long counter = 0;
135 for (int i = 0; i < 10000000; i++) {
136 counter = t.step((int) counter);
137 }
138 if (counter != 50001495) {
139 System.err.println("FAILED: counter = " + counter + ", should be 50001495.");
140 System.exit(97);
141 }
142 System.out.println("PASSED");
143 }
144
145 }
146
147 // Marsaglia's xor-shift generator, used here because it is
148 // reproducible across all Java implementations. It is also very
149 // fast.
150 class XorShift {
151
152 private long y;
153
154 XorShift() {
155 y = 2463534242l;
156 }
157
158 public long nextLong() {
159 y ^= (y << 13);
160 y ^= (y >>> 17);
161 return (y ^= (y << 5));
162
163 }
164 }