Mercurial > hg > graal-jvmci-8
diff graal/com.oracle.max.asm/src/com/oracle/max/asm/Buffer.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 |
parents | |
children | bc8527f3071c |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/graal/com.oracle.max.asm/src/com/oracle/max/asm/Buffer.java Sat Dec 17 19:59:18 2011 +0100 @@ -0,0 +1,235 @@ +/* + * 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.oracle.max.asm; + +import java.util.*; + +/** + * Code buffer management for the assembler. Support for little endian and big endian architectures is implemented using subclasses. + */ +public abstract class Buffer { + protected byte[] data; + protected int position; + + public Buffer() { + data = new byte[AsmOptions.InitialCodeBufferSize]; + } + + public void reset() { + position = 0; + } + + public int position() { + return position; + } + + public void setPosition(int position) { + assert position >= 0 && position <= data.length; + this.position = position; + } + + /** + * Closes this buffer. No extra data can be written to this buffer after + * this call. + * + * @param trimmedCopy + * if {@code true}, then a copy of the underlying byte array up + * to (but not including) {@code position()} is returned + * @return the data in this buffer or a trimmed copy if {@code trimmedCopy} + * is {@code true} + */ + public byte[] close(boolean trimmedCopy) { + byte[] result = trimmedCopy ? Arrays.copyOf(data, position()) : data; + data = null; + return result; + } + + public byte[] copyData(int start, int end) { + return Arrays.copyOfRange(data, start, end); + } + + /** + * Copies the data from this buffer into a given array. + * + * @param dst + * the destination array + * @param off + * starting position in {@code dst} + * @param len + * number of bytes to copy + */ + public void copyInto(byte[] dst, int off, int len) { + System.arraycopy(data, 0, dst, off, len); + } + + protected void ensureSize(int length) { + if (length >= data.length) { + data = Arrays.copyOf(data, length * 4); + } + } + + public void emitBytes(byte[] arr, int off, int len) { + ensureSize(position + len); + System.arraycopy(arr, off, data, position, len); + position += len; + } + + public void emitByte(int b) { + position = emitByte(b, position); + } + + public void emitShort(int b) { + position = emitShort(b, position); + } + + public void emitInt(int b) { + position = emitInt(b, position); + } + + public void emitLong(long b) { + position = emitLong(b, position); + } + + public int emitByte(int b, int pos) { + assert NumUtil.isUByte(b); + ensureSize(pos + 1); + data[pos++] = (byte) (b & 0xFF); + return pos; + } + + public abstract int emitShort(int b, int pos); + + public abstract int emitInt(int b, int pos); + + public abstract int emitLong(long b, int pos); + + public int getByte(int pos) { + return data[pos] & 0xff; + } + + public abstract int getShort(int pos); + + public abstract int getInt(int pos); + + public static final class BigEndian extends Buffer { + @Override + public int emitShort(int b, int pos) { + assert NumUtil.isUShort(b); + ensureSize(pos + 2); + data[pos++] = (byte) ((b >> 8) & 0xFF); + data[pos++] = (byte) (b & 0xFF); + return pos; + } + + @Override + public int emitInt(int b, int pos) { + ensureSize(pos + 4); + data[pos++] = (byte) ((b >> 24) & 0xFF); + data[pos++] = (byte) ((b >> 16) & 0xFF); + data[pos++] = (byte) ((b >> 8) & 0xFF); + data[pos++] = (byte) (b & 0xFF); + return pos; + } + + @Override + public int emitLong(long b, int pos) { + ensureSize(pos + 8); + data[pos++] = (byte) ((b >> 56) & 0xFF); + data[pos++] = (byte) ((b >> 48) & 0xFF); + data[pos++] = (byte) ((b >> 40) & 0xFF); + data[pos++] = (byte) ((b >> 32) & 0xFF); + data[pos++] = (byte) ((b >> 24) & 0xFF); + data[pos++] = (byte) ((b >> 16) & 0xFF); + data[pos++] = (byte) ((b >> 8) & 0xFF); + data[pos++] = (byte) (b & 0xFF); + return pos; + } + + @Override + public int getShort(int pos) { + return + (data[pos + 0] & 0xff) << 8 | + (data[pos + 1] & 0xff) << 0; + } + + @Override + public int getInt(int pos) { + return + (data[pos + 0] & 0xff) << 24 | + (data[pos + 1] & 0xff) << 16 | + (data[pos + 2] & 0xff) << 8 | + (data[pos + 3] & 0xff) << 0; + } + } + + public static final class LittleEndian extends Buffer { + @Override + public int emitShort(int b, int pos) { + assert NumUtil.isUShort(b); + ensureSize(pos + 2); + data[pos++] = (byte) (b & 0xFF); + data[pos++] = (byte) ((b >> 8) & 0xFF); + return pos; + } + + @Override + public int emitInt(int b, int pos) { + ensureSize(pos + 4); + data[pos++] = (byte) (b & 0xFF); + data[pos++] = (byte) ((b >> 8) & 0xFF); + data[pos++] = (byte) ((b >> 16) & 0xFF); + data[pos++] = (byte) ((b >> 24) & 0xFF); + return pos; + } + + @Override + public int emitLong(long b, int pos) { + ensureSize(pos + 8); + data[pos++] = (byte) (b & 0xFF); + data[pos++] = (byte) ((b >> 8) & 0xFF); + data[pos++] = (byte) ((b >> 16) & 0xFF); + data[pos++] = (byte) ((b >> 24) & 0xFF); + data[pos++] = (byte) ((b >> 32) & 0xFF); + data[pos++] = (byte) ((b >> 40) & 0xFF); + data[pos++] = (byte) ((b >> 48) & 0xFF); + data[pos++] = (byte) ((b >> 56) & 0xFF); + return pos; + } + + @Override + public int getShort(int pos) { + return + (data[pos + 1] & 0xff) << 8 | + (data[pos + 0] & 0xff) << 0; + } + + @Override + public int getInt(int pos) { + return + (data[pos + 3] & 0xff) << 24 | + (data[pos + 2] & 0xff) << 16 | + (data[pos + 1] & 0xff) << 8 | + (data[pos + 0] & 0xff) << 0; + } + } +}