/* 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 11N.
*
* @author Julien Névo
*/
public class InstructionFormat11N extends Instruction
implements IOneRegisterInstruction, ILiteralInstruction {
/**
* Instruction size in bytes.
*/
private static final int INSTRUCTION_SIZE = 2;
private int registerA;
private int literalB;
@Override
public int getRegisterA() {
return registerA;
}
@Override
public int getLiteral() {
return literalB;
}
/**
* 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 LiteralB encoded in the given 16-bit opcode.
* @return the LiteralB.
*/
public static int getLiteralB(int opcode) {
return ((byte)(opcode >> 8)) >> 4; // Needs to keep the sign.
}
/**
* 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 literal to store.
*/
public InstructionFormat11N(int opcode, int destinationRegister, int var) {
super(opcode);
registerA = destinationRegister;
literalB = var;
Instruction.test4BitsLimit(registerA);
Instruction.test4BitsLimit(literalB);
}
@Override
public int getSize() {
return INSTRUCTION_SIZE;
}
@Override
public void write(ByteVector out, ConstantPool constantPool) {
test4BitsLimit(registerA);
int firstShort = ((literalB & 0xf) << 12) + ((registerA & 0xf) << 8) + opcodeByte;
out.putShort(firstShort);
}
}