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 *
29 * @run main/othervm -Xbatch -XX:-TieredCompilation
30 * -XX:CompileCommand=dontinline,compiler.codegen.BitTests::*
31 * compiler.codegen.BitTests
32 * @run main/othervm -Xbatch -XX:+TieredCompilation -XX:TieredStopAtLevel=1
33 * compiler.codegen.BitTests
34 * @run main/othervm -Xbatch -XX:+TieredCompilation
35 * compiler.codegen.BitTests
36 */
37
38 package compiler.codegen;
39
40 // Try to ensure that the bit test instructions TBZ/TBNZ, TST/TSTW
41 // don't generate incorrect code. We can't guarantee that C2 will use
42 // bit test instructions for this test and it's not a bug if it
43 // doesn't. However, these test cases are ideal candidates for each
44 // of the instruction forms.
45 public class BitTests {
46
47 private final XorShift r = new XorShift();
48
49 private final long increment(long ctr) {
50 return ctr + 1;
51 }
52
53 private final int increment(int ctr) {
54 return ctr + 1;
55 }
56
57 private final long testIntSignedBranch(long counter) {
58 if ((int) r.nextLong() < 0) {
59 counter = increment(counter);
60 }
61 return counter;
62 }
63
64 private final long testLongSignedBranch(long counter) {
65 if (r.nextLong() < 0) {
66 counter = increment(counter);
67 }
68 return counter;
69 }
70
71 private final long testIntBitBranch(long counter) {
72 if (((int) r.nextLong() & (1 << 27)) != 0) {
73 counter = increment(counter);
74 }
75 if (((int) r.nextLong() & (1 << 27)) != 0) {
76 counter = increment(counter);
77 }
78 return counter;
79 }
80
81 private final long testLongBitBranch(long counter) {
82 if ((r.nextLong() & (1l << 50)) != 0) {
83 counter = increment(counter);
84 }
85 if ((r.nextLong() & (1l << 50)) != 0) {
86 counter = increment(counter);
87 }
88 return counter;
89 }
90
91 private final long testLongMaskBranch(long counter) {
92 if (((r.nextLong() & 0x0800000000l) != 0)) {
93 counter++;
94 }
95 return counter;
96 }
97
98 private final long testIntMaskBranch(long counter) {
99 if ((((int) r.nextLong() & 0x08) != 0)) {
100 counter++;
101 }
102 return counter;
103 }
104
105 private final long testLongMaskBranch(long counter, long mask) {
106 if (((r.nextLong() & mask) != 0)) {
107 counter++;
108 }
109 return counter;
110 }
111
112 private final long testIntMaskBranch(long counter, int mask) {
113 if ((((int) r.nextLong() & mask) != 0)) {
114 counter++;
115 }
116 return counter;
117 }
118
119 private final long step(long counter) {
120 counter = testIntSignedBranch(counter);
121 counter = testLongSignedBranch(counter);
122 counter = testIntBitBranch(counter);
123 counter = testLongBitBranch(counter);
124 counter = testIntMaskBranch(counter);
125 counter = testLongMaskBranch(counter);
126 counter = testIntMaskBranch(counter, 0x8000);
127 counter = testLongMaskBranch(counter, 0x800000000l);
128 return counter;
129 }
130
131
132 private final long finalBits = 3;
133
134 private long bits = 7;
135
136 public static void main(String[] args) {
137 BitTests t = new BitTests();
138
139 long counter = 0;
140 for (int i = 0; i < 10000000; i++) {
141 counter = t.step((int) counter);
142 }
143 if (counter != 50001495) {
144 System.err.println("FAILED: counter = " + counter + ", should be 50001495.");
145 System.exit(97);
146 }
147 System.out.println("PASSED");
148 }
149
150 // Marsaglia's xor-shift generator, used here because it is
151 // reproducible across all Java implementations. It is also very
152 // fast.
153 static class XorShift {
154
155 private long y;
156
157 XorShift() {
158 y = 2463534242l;
159 }
160
161 public long nextLong() {
162 y ^= (y << 13);
163 y ^= (y >>> 17);
164 return (y ^= (y << 5));
165
166 }
167 }
168 }