Mercurial > hg > graal-jvmci-8

comparison graal/Compiler/src/com/sun/c1x/asm/Buffer.java @ 2507:9ec15d6914ca

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Pull over of compiler from maxine repository.
author Thomas Wuerthinger <thomas@wuerthinger.net>
date Wed, 27 Apr 2011 11:43:22 +0200
parents
children
comparison
equal deleted inserted replaced
2506:4a3bf8a5bf41 2507:9ec15d6914ca
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.sun.c1x.asm;
24
25 import java.util.*;
26
27 import com.sun.c1x.*;
28 import com.sun.cri.bytecode.*;
29 import com.sun.cri.ci.CiArchitecture.ByteOrder;
30
31 /**
32 *
33 * @author Thomas Wuerthinger
34 */
35 public final class Buffer {
36
37 private byte[] data;
38 private int position;
39 private int mark = -1;
40
41 private final ByteOrder byteOrder;
42
43 public Buffer(ByteOrder byteOrder) {
44 this.byteOrder = byteOrder;
45 this.data = new byte[C1XOptions.InitialCodeBufferSize];
46 }
47
48 public void reset() {
49 position = 0;
50 mark = -1;
51 }
52
53 /**
54 * Closes this buffer. No extra data can be written to this buffer after this call.
55 *
56 * @param trimmedCopy if {@code true}, then a copy of the underlying byte array up to (but not including)
57 * {@code position()} is returned
58 * @return the data in this buffer or a trimmed copy if {@code trimmedCopy} is {@code true}
59 */
60 public byte[] close(boolean trimmedCopy) {
61 byte[] result = trimmedCopy ? Arrays.copyOf(data, position()) : data;
62 data = null;
63 return result;
64 }
65
66 public int emitBytes(byte[] arr, int off, int len) {
67 assert data != null : "must not use buffer after calling finished!";
68 int oldPos = position;
69 ensureSize(position + len);
70 System.arraycopy(arr, off, data, position, len);
71 position += len;
72 return oldPos;
73 }
74
75 public int emitByte(int b) {
76 int oldPos = position;
77 position = emitByte(b, oldPos);
78 return oldPos;
79 }
80
81 public int emitShort(int b) {
82 int oldPos = position;
83 position = emitShort(b, oldPos);
84 return oldPos;
85 }
86
87 public int emitInt(int b) {
88 int oldPos = position;
89 position = emitInt(b, oldPos);
90 return oldPos;
91 }
92
93 public int emitLong(long b) {
94 int oldPos = position;
95 position = emitLong(b, oldPos);
96 return oldPos;
97 }
98
99 private boolean isByte(int b) {
100 return b == (b & 0xFF);
101 }
102
103 private boolean isShort(int s) {
104 return s == (s & 0xFFFF);
105 }
106
107 /**
108 * Places a bookmark at the {@linkplain #position() current position}.
109 *
110 * @return the previously placed bookmark or {@code -1} if there was no bookmark
111 */
112 public int mark() {
113 int mark = this.mark;
114 this.mark = position;
115 return mark;
116 }
117
118 private void ensureSize(int length) {
119 if (length >= data.length) {
120 data = Arrays.copyOf(data, data.length * 4);
121 C1XMetrics.CodeBufferCopies++;
122 }
123 }
124
125 public int emitByte(int b, int pos) {
126 assert data != null : "must not use buffer after calling finished!";
127 assert isByte(b);
128 ensureSize(pos + 1);
129 data[pos++] = (byte) b;
130 return pos;
131 }
132
133 public int emitShort(int b, int pos) {
134 assert data != null : "must not use buffer after calling finished!";
135 assert isShort(b);
136 ensureSize(pos + 2);
137 if (byteOrder == ByteOrder.BigEndian) {
138 data[pos++] = (byte) ((b >> 8) & 0xFF);
139 data[pos++] = (byte) (b & 0xFF);
140
141 } else {
142 assert byteOrder == ByteOrder.LittleEndian;
143 data[pos++] = (byte) (b & 0xFF);
144 data[pos++] = (byte) ((b >> 8) & 0xFF);
145 }
146 return pos;
147 }
148
149 public int emitInt(int b, int pos) {
150 assert data != null : "must not use buffer after calling finished!";
151 ensureSize(pos + 4);
152 if (byteOrder == ByteOrder.BigEndian) {
153 data[pos++] = (byte) ((b >> 24) & 0xFF);
154 data[pos++] = (byte) ((b >> 16) & 0xFF);
155 data[pos++] = (byte) ((b >> 8) & 0xFF);
156 data[pos++] = (byte) (b & 0xFF);
157 } else {
158 assert byteOrder == ByteOrder.LittleEndian;
159 data[pos++] = (byte) (b & 0xFF);
160 data[pos++] = (byte) ((b >> 8) & 0xFF);
161 data[pos++] = (byte) ((b >> 16) & 0xFF);
162 data[pos++] = (byte) ((b >> 24) & 0xFF);
163 }
164 return pos;
165 }
166
167 public int emitLong(long b, int pos) {
168 assert data != null : "must not use buffer after calling finished!";
169 ensureSize(pos + 8);
170
171 if (byteOrder == ByteOrder.BigEndian) {
172 data[pos++] = (byte) ((b >> 56) & 0xFF);
173 data[pos++] = (byte) ((b >> 48) & 0xFF);
174 data[pos++] = (byte) ((b >> 40) & 0xFF);
175 data[pos++] = (byte) ((b >> 32) & 0xFF);
176 data[pos++] = (byte) ((b >> 24) & 0xFF);
177 data[pos++] = (byte) ((b >> 16) & 0xFF);
178 data[pos++] = (byte) ((b >> 8) & 0xFF);
179 data[pos++] = (byte) (b & 0xFF);
180 } else {
181 assert byteOrder == ByteOrder.LittleEndian;
182 data[pos++] = (byte) (b & 0xFF);
183 data[pos++] = (byte) ((b >> 8) & 0xFF);
184 data[pos++] = (byte) ((b >> 16) & 0xFF);
185 data[pos++] = (byte) ((b >> 24) & 0xFF);
186 data[pos++] = (byte) ((b >> 32) & 0xFF);
187 data[pos++] = (byte) ((b >> 40) & 0xFF);
188 data[pos++] = (byte) ((b >> 48) & 0xFF);
189 data[pos++] = (byte) ((b >> 56) & 0xFF);
190 }
191 return pos;
192 }
193
194 public int position() {
195 return position;
196 }
197
198 public void setPosition(int position) {
199 assert position >= 0 && position <= data.length;
200 this.position = position;
201 }
202
203 public int getByte(int pos) {
204 return Bytes.beU1(data, pos);
205 }
206
207 public int getShort(int pos) {
208 if (byteOrder == ByteOrder.BigEndian) {
209 return
210 (data[pos + 0] & 0xff) << 8 |
211 (data[pos + 1] & 0xff) << 0;
212 } else {
213 assert byteOrder == ByteOrder.LittleEndian;
214 return
215 (data[pos + 1] & 0xff) << 8 |
216 (data[pos + 0] & 0xff) << 0;
217 }
218 }
219
220 public int getInt(int pos) {
221 if (byteOrder == ByteOrder.BigEndian) {
222 return
223 (data[pos + 0] & 0xff) << 24 |
224 (data[pos + 1] & 0xff) << 16 |
225 (data[pos + 2] & 0xff) << 8 |
226 (data[pos + 3] & 0xff) << 0;
227 } else {
228 assert byteOrder == ByteOrder.LittleEndian;
229 return
230 (data[pos + 3] & 0xff) << 24 |
231 (data[pos + 2] & 0xff) << 16 |
232 (data[pos + 1] & 0xff) << 8 |
233 (data[pos + 0] & 0xff) << 0;
234 }
235 }
236
237 public byte[] copyData(int start, int end) {
238 return Arrays.copyOfRange(data, start, end);
239 }
240
241 /**
242 * Copies the data from this buffer into a given array.
243 *
244 * @param dst the destination array
245 * @param off starting position in {@code dst}
246 * @param len number of bytes to copy
247 */
248 public void copyInto(byte[] dst, int off, int len) {
249 System.arraycopy(data, 0, dst, off, len);
250 }
251 }