1 /*
2 * Copyright (c) 2015, Oracle and/or its affiliates. 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 /**
26 * @test
27 * @bug 8078497
28 * @summary Tests correct alignment of vectors with loop invariant offset.
29 * @modules java.base/jdk.internal.misc
30 * @library /testlibrary
31 * @run main compiler.loopopts.superword.TestVectorizationWithInvariant
32 */
33
34 package compiler.loopopts.superword;
35
36 import jdk.internal.misc.Unsafe;
37 import jdk.test.lib.Utils;
38
39 public class TestVectorizationWithInvariant {
40
41 private static Unsafe unsafe;
42 private static final long BYTE_ARRAY_OFFSET;
43 private static final long CHAR_ARRAY_OFFSET;
44
45 static {
46 unsafe = Utils.getUnsafe();
47 BYTE_ARRAY_OFFSET = unsafe.arrayBaseOffset(byte[].class);
48 CHAR_ARRAY_OFFSET = unsafe.arrayBaseOffset(char[].class);
49 }
50
51 public static void main(String[] args) throws Exception {
52 byte[] byte_array1 = new byte[1000];
53 byte[] byte_array2 = new byte[1000];
54 char[] char_array = new char[1000];
55
56 for (int i = 0; i < 20_000; ++i) {
57 copyByteToChar(byte_array1, byte_array2, char_array, 1);
58 copyCharToByte(char_array, byte_array1, 1);
59 copyCharToByteAligned(char_array, byte_array1);
60 copyCharToByteUnaligned(char_array, byte_array1);
61 }
62 }
63
64 /*
65 * Copy multiple consecutive chars from a byte array to a given offset in a char array
66 * to trigger C2's superword optimization. The offset in the byte array is independent
67 * of the loop induction variable and can be set to an arbitrary value. It may then not
68 * be possible to both align the LoadUS and the StoreC operations. Therefore, vectorization
69 * should only be done in this case if unaligned memory accesses are allowed.
70 */
71 public static void copyByteToChar(byte[] src1, byte[] src2, char[] dst, int off) {
72 off = (int) BYTE_ARRAY_OFFSET + (off << 1);
73 byte[] src = src1;
74 for (int i = (int) CHAR_ARRAY_OFFSET; i < 100; i = i + 8) {
75 // Copy 8 chars from src to dst
76 unsafe.putChar(dst, i + 0, unsafe.getChar(src, off + 0));
77 unsafe.putChar(dst, i + 2, unsafe.getChar(src, off + 2));
78 unsafe.putChar(dst, i + 4, unsafe.getChar(src, off + 4));
79 unsafe.putChar(dst, i + 6, unsafe.getChar(src, off + 6));
80 unsafe.putChar(dst, i + 8, unsafe.getChar(src, off + 8));
81 unsafe.putChar(dst, i + 10, unsafe.getChar(src, off + 10));
82 unsafe.putChar(dst, i + 12, unsafe.getChar(src, off + 12));
83 unsafe.putChar(dst, i + 14, unsafe.getChar(src, off + 14));
84
85 // Prevent loop invariant code motion of char read.
86 src = (src == src1) ? src2 : src1;
87 }
88 }
89
90 /*
91 * Copy multiple consecutive chars from a char array to a given offset in a byte array
92 * to trigger C2's superword optimization. Checks for similar problems as 'copyByteToChar'.
93 */
94 public static void copyCharToByte(char[] src, byte[] dst, int off) {
95 off = (int) BYTE_ARRAY_OFFSET + (off << 1);
96 for (int i = 0; i < 100; i = i + 8) {
97 // Copy 8 chars from src to dst
98 unsafe.putChar(dst, off + 0, src[i + 0]);
99 unsafe.putChar(dst, off + 2, src[i + 1]);
100 unsafe.putChar(dst, off + 4, src[i + 2]);
101 unsafe.putChar(dst, off + 6, src[i + 3]);
102 unsafe.putChar(dst, off + 8, src[i + 4]);
103 unsafe.putChar(dst, off + 10, src[i + 5]);
104 unsafe.putChar(dst, off + 12, src[i + 6]);
105 unsafe.putChar(dst, off + 14, src[i + 7]);
106 }
107 }
108
109 /*
110 * Variant of copyCharToByte with a constant destination array offset.
111 * The loop should always be vectorized because both the LoadUS and StoreC
112 * operations can be aligned.
113 */
114 public static void copyCharToByteAligned(char[] src, byte[] dst) {
115 final int off = (int) BYTE_ARRAY_OFFSET;
116 for (int i = 8; i < 100; i = i + 8) {
117 // Copy 8 chars from src to dst
118 unsafe.putChar(dst, off + 0, src[i + 0]);
119 unsafe.putChar(dst, off + 2, src[i + 1]);
120 unsafe.putChar(dst, off + 4, src[i + 2]);
121 unsafe.putChar(dst, off + 6, src[i + 3]);
122 unsafe.putChar(dst, off + 8, src[i + 4]);
123 unsafe.putChar(dst, off + 10, src[i + 5]);
124 unsafe.putChar(dst, off + 12, src[i + 6]);
125 unsafe.putChar(dst, off + 14, src[i + 7]);
126 }
127 }
128
129 /*
130 * Variant of copyCharToByte with a constant destination array offset. The
131 * loop should only be vectorized if unaligned memory operations are allowed
132 * because not both the LoadUS and the StoreC can be aligned.
133 */
134 public static void copyCharToByteUnaligned(char[] src, byte[] dst) {
135 final int off = (int) BYTE_ARRAY_OFFSET + 2;
136 for (int i = 0; i < 100; i = i + 8) {
137 // Copy 8 chars from src to dst
138 unsafe.putChar(dst, off + 0, src[i + 0]);
139 unsafe.putChar(dst, off + 2, src[i + 1]);
140 unsafe.putChar(dst, off + 4, src[i + 2]);
141 unsafe.putChar(dst, off + 6, src[i + 3]);
142 unsafe.putChar(dst, off + 8, src[i + 4]);
143 unsafe.putChar(dst, off + 10, src[i + 5]);
144 unsafe.putChar(dst, off + 12, src[i + 6]);
145 unsafe.putChar(dst, off + 14, src[i + 7]);
146 }
147 }
148 }