Mercurial > hg > graal-compiler
diff graal/com.oracle.max.cri/src/com/sun/cri/bytecode/Bytes.java @ 3733:e233f5660da4
Added Java files from Maxine project.
author | Thomas Wuerthinger <thomas.wuerthinger@oracle.com> |
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date | Sat, 17 Dec 2011 19:59:18 +0100 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/graal/com.oracle.max.cri/src/com/sun/cri/bytecode/Bytes.java Sat Dec 17 19:59:18 2011 +0100 @@ -0,0 +1,93 @@ +/* + * Copyright (c) 2009, 2011, Oracle and/or its affiliates. All rights reserved. + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * This code is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 only, as + * published by the Free Software Foundation. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA + * or visit www.oracle.com if you need additional information or have any + * questions. + */ +package com.sun.cri.bytecode; + +/** + * A collection of utility methods for dealing with bytes, particularly in byte arrays. + */ +public class Bytes { + /** + * Gets a signed 1-byte value. + * @param data the array containing the data + * @param bci the start index of the value to retrieve + * @return the signed 1-byte value at index {@code bci} in array {@code data} + */ + public static int beS1(byte[] data, int bci) { + return data[bci]; + } + + /** + * Gets a signed 2-byte big-endian value. + * @param data the array containing the data + * @param bci the start index of the value to retrieve + * @return the signed 2-byte, big-endian, value at index {@code bci} in array {@code data} + */ + public static int beS2(byte[] data, int bci) { + return (data[bci] << 8) | (data[bci + 1] & 0xff); + } + + /** + * Gets an unsigned 1-byte value. + * @param data the array containing the data + * @param bci the start index of the value to retrieve + * @return the unsigned 1-byte value at index {@code bci} in array {@code data} + */ + public static int beU1(byte[] data, int bci) { + return data[bci] & 0xff; + } + + /** + * Gets an unsigned 2-byte big-endian value. + * @param data the array containing the data + * @param bci the start index of the value to retrieve + * @return the unsigned 2-byte, big-endian, value at index {@code bci} in array {@code data} + */ + public static int beU2(byte[] data, int bci) { + return ((data[bci] & 0xff) << 8) | (data[bci + 1] & 0xff); + } + + /** + * Gets a signed 4-byte big-endian value. + * @param data the array containing the data + * @param bci the start index of the value to retrieve + * @return the signed 4-byte, big-endian, value at index {@code bci} in array {@code data} + */ + public static int beS4(byte[] data, int bci) { + return (data[bci] << 24) | ((data[bci + 1] & 0xff) << 16) | ((data[bci + 2] & 0xff) << 8) | (data[bci + 3] & 0xff); + } + + /** + * Gets either a signed 2-byte or a signed 4-byte big-endian value. + * @param data the array containing the data + * @param bci the start index of the value to retrieve + * @param fourByte if true, this method will return a 4-byte value + * @return the signed 2 or 4-byte, big-endian, value at index {@code bci} in array {@code data} + */ + public static int beSVar(byte[] data, int bci, boolean fourByte) { + if (fourByte) { + return beS4(data, bci); + } else { + return beS2(data, bci); + } + } +}