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comparison graal/com.oracle.jvmci.bytecode/src/com/oracle/jvmci/bytecode/Bytes.java @ 21713:454a99ca00a9

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fixed canonicalizeprojects issues
author Doug Simon <doug.simon@oracle.com>
date Wed, 03 Jun 2015 22:13:10 +0200
parents graal/com.oracle.jvmci.bytecode/src/com/oracle/graal/bytecode/Bytes.java@1c41d00e6b2f
children
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21712:a59a0c85650a 21713:454a99ca00a9
1 /*
2 * Copyright (c) 2009, 2011, 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 package com.oracle.jvmci.bytecode;
24
25 /**
26 * A collection of utility methods for dealing with bytes, particularly in byte arrays.
27 */
28 public class Bytes {
29
30 /**
31 * Gets a signed 1-byte value.
32 *
33 * @param data the array containing the data
34 * @param bci the start index of the value to retrieve
35 * @return the signed 1-byte value at index {@code bci} in array {@code data}
36 */
37 public static int beS1(byte[] data, int bci) {
38 return data[bci];
39 }
40
41 /**
42 * Gets a signed 2-byte big-endian value.
43 *
44 * @param data the array containing the data
45 * @param bci the start index of the value to retrieve
46 * @return the signed 2-byte, big-endian, value at index {@code bci} in array {@code data}
47 */
48 public static int beS2(byte[] data, int bci) {
49 return (data[bci] << 8) | (data[bci + 1] & 0xff);
50 }
51
52 /**
53 * Gets an unsigned 1-byte value.
54 *
55 * @param data the array containing the data
56 * @param bci the start index of the value to retrieve
57 * @return the unsigned 1-byte value at index {@code bci} in array {@code data}
58 */
59 public static int beU1(byte[] data, int bci) {
60 return data[bci] & 0xff;
61 }
62
63 /**
64 * Gets an unsigned 2-byte big-endian value.
65 *
66 * @param data the array containing the data
67 * @param bci the start index of the value to retrieve
68 * @return the unsigned 2-byte, big-endian, value at index {@code bci} in array {@code data}
69 */
70 public static int beU2(byte[] data, int bci) {
71 return ((data[bci] & 0xff) << 8) | (data[bci + 1] & 0xff);
72 }
73
74 /**
75 * Gets a signed 4-byte big-endian value.
76 *
77 * @param data the array containing the data
78 * @param bci the start index of the value to retrieve
79 * @return the signed 4-byte, big-endian, value at index {@code bci} in array {@code data}
80 */
81 public static int beS4(byte[] data, int bci) {
82 return (data[bci] << 24) | ((data[bci + 1] & 0xff) << 16) | ((data[bci + 2] & 0xff) << 8) | (data[bci + 3] & 0xff);
83 }
84
85 /**
86 * Gets either a signed 2-byte or a signed 4-byte big-endian value.
87 *
88 * @param data the array containing the data
89 * @param bci the start index of the value to retrieve
90 * @param fourByte if true, this method will return a 4-byte value
91 * @return the signed 2 or 4-byte, big-endian, value at index {@code bci} in array {@code data}
92 */
93 public static int beSVar(byte[] data, int bci, boolean fourByte) {
94 if (fourByte) {
95 return beS4(data, bci);
96 } else {
97 return beS2(data, bci);
98 }
99 }
100 }