#include "../Iinstr.hpp"


class Cldh : public Iinstr {
	public:
		Cldh();
		void evalInstr();
		void execInstr();
		std::string toString();
		Iinstr* getNew();
};

/**
 * Name:      create_instruction
 * Purpose:   if compiled as shared library, this functions creates the 
              instruction object

 * Returns:   pointer to instruction object
 */
extern "C" Iinstr* create_instruction() {
    return new Cldh();
}

Iinstr* Cldh::getNew()
{
    return new Cldh();
}

/**
 * Name:      destroy_instruction
 * Purpose:   if compiled as shared library, this functions destoys the 
              instruction object

 * Parameter: IInstruction - the instruction object to delete
 */
extern "C" void destroy_instruction(Iinstr* p) {
    delete p;
}

Cldh::Cldh()
{
	opcode = B5(10000);
	name = "ldh";
}

void Cldh::evalInstr()
{
	this->m_s = true;

	dynamic_bitset<> immb = argbits;
	immb.resize(15);
	this->m_imm = this->generate15ImmSign(immb.to_ulong());

	argbits >>= 15;
	m_ra = this->getRegister(argbits);
	argbits >>= 4;
	m_rd = this->getRegister(argbits);

}

#include <iomanip>
#define AS_HEX std::hex << setw(8) << setfill('0')

void Cldh::execInstr()
{
	//cout << "should exec " << this->toString() << endl;
	CDat val = this->m_cpu->getRegister(this->m_ra);
	val += m_imm;
	MEMORY_ADDRESS temp = (val & (~(BYTE_COUNT-1)));
	CDat offset = val-temp;
	if(offset%2 == 1) {
		cerr << "you try to get an invalid halfword!" << endl;
		return;
	}
	val = this->m_cpu->getRAM(temp);
	val = (val >> (offset*8)) & ( ((1<<16)-1));
	CDat dest = this->m_cpu->getRegister(this->m_rd);
	dest = dest & (~((1<<16)-1));
	dest = dest | val;
	this->m_cpu->setRegister(this->m_rd,dest);
}

std::string Cldh::toString()
{
	stringstream op;
	op << this->getName();

	op << this->getConditionFlag() << " r" << m_rd << ", " << m_imm << "(r" <<  m_ra << ")";

	return op.str();
}