/* Software Name : AsmDex
* Version : 1.0
*
* Copyright © 2012 France Télécom
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGE.
*/
package org.ow2.asmdex.instruction;
import org.ow2.asmdex.lowLevelUtils.ByteVector;
import org.ow2.asmdex.lowLevelUtils.IDalvikValueReader;
import org.ow2.asmdex.structureWriter.ConstantPool;
/**
* Encodes and decodes an instruction built with the Dalvik format 31I.
*
* @author Julien Névo
*/
public class InstructionFormat31I extends Instruction
implements IOneRegisterInstruction, ILiteralInstruction {
private static final int INSTRUCTION_SIZE = 6; // Instruction size in bytes.
private int registerA;
private int literalB;
@Override
public int getRegisterA() {
return registerA;
}
@Override
public int getLiteral() {
return literalB;
}
/**
* Constructor of the Instruction, using a Reader to parse its bytecode.
* @param reader reader on the Instruction to parse, pointing after the 16-bit opcode.
* @param opcode 16-bit opcode.
*/
// public InstructionFormat31I(IDalvikValueReader reader, int opcode) {
// super(opcode);
//
// // The format is AA|op BBBBlo BBBBhi.
// registerA = opcodeHighOrderByte;
// literalB = (int)reader.ushort() + ((int)reader.ushort() << 16);
// //literalB = reader.sshort() + (reader.sshort() << 16);
// }
/**
* Returns the RegisterA encoded in the given 16-bit opcode.
* @return the RegisterA .
*/
public static int getRegisterA(int opcode) {
return (opcode >> 8) & 0xff;
}
/**
* Returns the LiteralB encoded where the Reader points. <i>It must be performed only once after
* having read the opcode.</i>
* @param reader reader pointing after the 16-bit opcode.
* @return the LiteralB.
*/
public static int getLiteralB(IDalvikValueReader reader) {
return reader.ushort() + (reader.ushort() << 16);
}
/**
* Skips the data of this Instruction.
* @param reader reader on the Instruction to parse, pointing after the 16-bit opcode.
*/
public static void skip(IDalvikValueReader reader) {
reader.relativeSeek(INSTRUCTION_SIZE - 2); // The first word has already been read.
}
/**
* Constructor of the Instruction by providing all the elements it's composed of.
* @param opcode 8 or 16 bits opcode.
* @param destinationRegister the destination register to store.
* @param var the literal to store.
*/
public InstructionFormat31I(int opcode, int destinationRegister, int var) {
super(opcode);
registerA = destinationRegister;
literalB = var;
}
@Override
public int getSize() {
return INSTRUCTION_SIZE;
}
// @Override
// public int[] getUsedRegisters() {
// int[] usedRegisters;
// // Pair registers or not ?
// if (opcodeByte == 0x17) {
// usedRegisters = new int[] { registerA, registerA + 1 };
// } else {
// usedRegisters = new int[] { registerA };
// }
// return usedRegisters;
// }
// @Override
// public int getNbEncodedRegisters() {
// return 1;
// }
@Override
public void write(ByteVector out, ConstantPool constantPool) {
test8BitsLimit(registerA);
out.putShort(((registerA & 0xff) << 8) + opcodeByte);
out.putShort(literalB & 0xffff);
out.putShort((literalB >> 16) & 0xffff);
}
}