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comparison graal/com.oracle.graal.asm/src/com/oracle/max/asm/Buffer.java @ 6497:64b7dd2075c0

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renamed projects com.oracle.max.asm* to com.oracle.graal.asm*
author Doug Simon <doug.simon@oracle.com>
date Wed, 03 Oct 2012 17:42:12 +0200
parents graal/com.oracle.max.asm/src/com/oracle/max/asm/Buffer.java@bc8527f3071c
children
comparison
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6496:16d1411409b4 6497:64b7dd2075c0
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.max.asm;
24
25 import java.util.*;
26
27 /**
28 * Code buffer management for the assembler. Support for little endian and big endian architectures is implemented using subclasses.
29 */
30 public abstract class Buffer {
31 protected byte[] data;
32 protected int position;
33
34 public Buffer() {
35 data = new byte[AsmOptions.InitialCodeBufferSize];
36 }
37
38 public void reset() {
39 position = 0;
40 }
41
42 public int position() {
43 return position;
44 }
45
46 public void setPosition(int position) {
47 assert position >= 0 && position <= data.length;
48 this.position = position;
49 }
50
51 /**
52 * Closes this buffer. No extra data can be written to this buffer after
53 * this call.
54 *
55 * @param trimmedCopy
56 * if {@code true}, then a copy of the underlying byte array up
57 * to (but not including) {@code position()} is returned
58 * @return the data in this buffer or a trimmed copy if {@code trimmedCopy}
59 * is {@code true}
60 */
61 public byte[] close(boolean trimmedCopy) {
62 byte[] result = trimmedCopy ? Arrays.copyOf(data, position()) : data;
63 data = null;
64 return result;
65 }
66
67 public byte[] copyData(int start, int end) {
68 return Arrays.copyOfRange(data, start, end);
69 }
70
71 /**
72 * Copies the data from this buffer into a given array.
73 *
74 * @param dst
75 * the destination array
76 * @param off
77 * starting position in {@code dst}
78 * @param len
79 * number of bytes to copy
80 */
81 public void copyInto(byte[] dst, int off, int len) {
82 System.arraycopy(data, 0, dst, off, len);
83 }
84
85 protected void ensureSize(int length) {
86 if (length >= data.length) {
87 data = Arrays.copyOf(data, length * 4);
88 }
89 }
90
91 public void emitBytes(byte[] arr, int off, int len) {
92 ensureSize(position + len);
93 System.arraycopy(arr, off, data, position, len);
94 position += len;
95 }
96
97 public void emitByte(int b) {
98 position = emitByte(b, position);
99 }
100
101 public void emitShort(int b) {
102 position = emitShort(b, position);
103 }
104
105 public void emitInt(int b) {
106 position = emitInt(b, position);
107 }
108
109 public void emitLong(long b) {
110 position = emitLong(b, position);
111 }
112
113 public int emitByte(int b, int pos) {
114 assert NumUtil.isUByte(b);
115 int newPos = pos + 1;
116 ensureSize(newPos);
117 data[pos] = (byte) (b & 0xFF);
118 return newPos;
119 }
120
121 public abstract int emitShort(int b, int pos);
122
123 public abstract int emitInt(int b, int pos);
124
125 public abstract int emitLong(long b, int pos);
126
127 public int getByte(int pos) {
128 return data[pos] & 0xff;
129 }
130
131 public abstract int getShort(int pos);
132
133 public abstract int getInt(int pos);
134
135 public static final class BigEndian extends Buffer {
136 @Override
137 public int emitShort(int b, int pos) {
138 assert NumUtil.isUShort(b);
139 int newPos = pos + 2;
140 ensureSize(pos + 2);
141 data[pos] = (byte) ((b >> 8) & 0xFF);
142 data[pos + 1] = (byte) (b & 0xFF);
143 return newPos;
144 }
145
146 @Override
147 public int emitInt(int b, int pos) {
148 int newPos = pos + 4;
149 ensureSize(newPos);
150 data[pos] = (byte) ((b >> 24) & 0xFF);
151 data[pos + 1] = (byte) ((b >> 16) & 0xFF);
152 data[pos + 2] = (byte) ((b >> 8) & 0xFF);
153 data[pos + 3] = (byte) (b & 0xFF);
154 return newPos;
155 }
156
157 @Override
158 public int emitLong(long b, int pos) {
159 int newPos = pos + 8;
160 ensureSize(newPos);
161 data[pos] = (byte) ((b >> 56) & 0xFF);
162 data[pos + 1] = (byte) ((b >> 48) & 0xFF);
163 data[pos + 2] = (byte) ((b >> 40) & 0xFF);
164 data[pos + 3] = (byte) ((b >> 32) & 0xFF);
165 data[pos + 4] = (byte) ((b >> 24) & 0xFF);
166 data[pos + 5] = (byte) ((b >> 16) & 0xFF);
167 data[pos + 6] = (byte) ((b >> 8) & 0xFF);
168 data[pos + 7] = (byte) (b & 0xFF);
169 return newPos;
170 }
171
172 @Override
173 public int getShort(int pos) {
174 return
175 (data[pos + 0] & 0xff) << 8 |
176 (data[pos + 1] & 0xff) << 0;
177 }
178
179 @Override
180 public int getInt(int pos) {
181 return
182 (data[pos + 0] & 0xff) << 24 |
183 (data[pos + 1] & 0xff) << 16 |
184 (data[pos + 2] & 0xff) << 8 |
185 (data[pos + 3] & 0xff) << 0;
186 }
187 }
188
189 public static final class LittleEndian extends Buffer {
190 @Override
191 public int emitShort(int b, int pos) {
192 assert NumUtil.isUShort(b);
193 int newPos = pos + 2;
194 ensureSize(newPos);
195 data[pos] = (byte) (b & 0xFF);
196 data[pos + 1] = (byte) ((b >> 8) & 0xFF);
197 return newPos;
198 }
199
200 @Override
201 public int emitInt(int b, int pos) {
202 int newPos = pos + 4;
203 ensureSize(newPos);
204 data[pos] = (byte) (b & 0xFF);
205 data[pos + 1] = (byte) ((b >> 8) & 0xFF);
206 data[pos + 2] = (byte) ((b >> 16) & 0xFF);
207 data[pos + 3] = (byte) ((b >> 24) & 0xFF);
208 return newPos;
209 }
210
211 @Override
212 public int emitLong(long b, int pos) {
213 int newPos = pos + 8;
214 ensureSize(newPos);
215 data[pos] = (byte) (b & 0xFF);
216 data[pos + 1] = (byte) ((b >> 8) & 0xFF);
217 data[pos + 2] = (byte) ((b >> 16) & 0xFF);
218 data[pos + 3] = (byte) ((b >> 24) & 0xFF);
219 data[pos + 4] = (byte) ((b >> 32) & 0xFF);
220 data[pos + 5] = (byte) ((b >> 40) & 0xFF);
221 data[pos + 6] = (byte) ((b >> 48) & 0xFF);
222 data[pos + 7] = (byte) ((b >> 56) & 0xFF);
223 return newPos;
224 }
225
226 @Override
227 public int getShort(int pos) {
228 return
229 (data[pos + 1] & 0xff) << 8 |
230 (data[pos + 0] & 0xff) << 0;
231 }
232
233 @Override
234 public int getInt(int pos) {
235 return
236 (data[pos + 3] & 0xff) << 24 |
237 (data[pos + 2] & 0xff) << 16 |
238 (data[pos + 1] & 0xff) << 8 |
239 (data[pos + 0] & 0xff) << 0;
240 }
241 }
242 }