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
38package 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.
45public 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}
169