/* 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.structureWriter.ConstantPool;
/**
* Encodes and decodes an instruction built with the Dalvik format 12X.
*
* @author Julien Névo
*/
public class InstructionFormat12X extends Instruction implements ITwoRegistersInstruction {
private static final int INSTRUCTION_SIZE = 2; // Instruction size in bytes.
private int registerA;
private int registerB;
@Override
public int getRegisterA() {
return registerA;
}
@Override
public int getRegisterB() {
return registerB;
}
/**
* Returns the RegisterA encoded in the given 16-bit opcode.
* @return the RegisterA .
*/
public static int getRegisterA(int opcode) {
return (opcode >> 8) & 0xf;
}
/**
* Returns the RegisterB encoded in the given 16-bit opcode.
* @return the RegisterB .
*/
public static int getRegisterB(int opcode) {
return (opcode >> 12) & 0xf;
}
/**
* 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.
* @param var the register.
*/
public InstructionFormat12X(int opcode, int destinationRegister, int var) {
super(opcode);
registerA = destinationRegister;
registerB = var;
Instruction.test4BitsLimit(registerA);
Instruction.test4BitsLimit(registerB);
}
// @Override
// public int[] getUsedRegisters() {
// int[] usedRegisters;
// // Pair registers or not ?
// switch (opcodeByte) {
// case 0x04:
// case 0x7d:
// case 0x7e:
// case 0x80:
// case 0x81:
// case 0x83:
// case 0x86:
// case 0x88:
// case 0x89:
// case 0x8b:
// case 0x8c:
// case 0xbb:
// case 0xbc:
// case 0xbd:
// case 0xbe:
// case 0xbf:
// case 0xc0:
// case 0xc1:
// case 0xc2:
// case 0xc3:
// case 0xc4:
// case 0xc5:
// case 0xcb:
// case 0xcc:
// case 0xcd:
// case 0xce:
// case 0xcf:
// usedRegisters = new int[] { registerA, registerA + 1, registerB, registerB + 1 };
// break;
// default:
// usedRegisters = new int[] { registerA, registerB };
// }
//
// return usedRegisters;
// }
// @Override
// public int getNbEncodedRegisters() {
// return 2;
// }
@Override
public int getSize() {
return INSTRUCTION_SIZE;
}
@Override
public void write(ByteVector out, ConstantPool constantPool) {
test4BitsLimit(registerA | registerB);
int firstShort = ((registerB & 0xf) << 12) + ((registerA & 0xf) << 8) + opcodeByte;
out.putShort(firstShort);
}
}