Arithmetic.cpp

#include <bits/stdc++.h>
using namespace std;

int flag_on_off_8bit_ADD(int &val1)
{
	if ((val1 & 15) + (val1 & 15) > 15)
		AC = 1;
	int val = val1 + val1;
	if (val > 255)
	{
		CF = 1;
		val -= 256;
	}
	if (!val)
		ZF = 1;
	int parity_checker_bit = 1;
	int parity_counter = 0;
	for (int i = 0; i < 8; ++i)
	{
		if (parity_checker_bit & val)
			++parity_counter;
		parity_checker_bit <<= 1;
	}
	PF = 1;
	if (parity_counter & 1)
		PF = 0;
	if (val < 0)
		SF = 1;
	return val;
}

int flag_on_off_8bit_ADD(int &val1, int &val2)
{
	if ((val1 & 15) + (val2 & 15) > 15)
		AC = 1;
	int val = val1 + val2;
	if (val > 255)
	{
		CF = 1;
		val -= 256;
	}
	if (!val)
		ZF = 1;
	int parity_checker_bit = 1;
	int parity_counter = 0;
	for (int i = 0; i < 8; ++i)
	{
		if (parity_checker_bit & val)
			++parity_counter;
		parity_checker_bit <<= 1;
	}
	PF = 1;
	if (parity_counter & 1)
		PF = 0;
	if (val < 0)
		SF = 1;
	return val;
}

int flag_on_off_8bit_SUB(int &val1, int &val2)
{
	if (val1 < val2)
		SF = CF = 1;
	int tmp_val2 = val2 ^ 255;
	++tmp_val2;
	if ((val1 & 15) + (tmp_val2 & 15) > 15)
		AC = 1;
	int val = val1 - val2;
	int parity_checker_bit = 1;
	int parity_counter = 0;
	for (int i = 0; i < 8; ++i)
	{
		if (parity_checker_bit & val)
			++parity_counter;
		parity_checker_bit <<= 1;
	}
	PF = 1;
	if (parity_counter & 1)
		PF = 0;
	if (!val)
		ZF = 1;
	if (val < 0)
	{
		val *= -1;
	}
	return val;
}

int flag_on_off_8bit_SUB(int &val1)
{
	PF = 1;
	ZF = 1;
	return 0;
}

void ADD(string &user_instruction)
{
	SF = 0, ZF = 0, AC = 0, PF = 0, CF = 0;
	switch (user_instruction[4])
	{
	case 'A':
		A = flag_on_off_8bit_ADD(A);
		break;
	case 'B':
		A = flag_on_off_8bit_ADD(A, B);
		break;
	case 'C':
		A = flag_on_off_8bit_ADD(A, C);
		break;
	case 'D':
		A = flag_on_off_8bit_ADD(A, D);
		break;
	case 'E':
		A = flag_on_off_8bit_ADD(A, E);
		break;
	case 'H':
		A = flag_on_off_8bit_ADD(A, H);
		break;
	case 'L':
		A = flag_on_off_8bit_ADD(A, L);
		break;
	default:
		error = 1;
		cout << "You found a bug!\n";
	}
}

void ADI(string &user_instruction)
{
	SF = 0, ZF = 0, AC = 0, PF = 0, CF = 0;
	string hex_number = "";
	hex_number.push_back(user_instruction[4]);
	hex_number.push_back(user_instruction[5]);
	int tmp = hex_to_dec(hex_number);
	A = flag_on_off_8bit_ADD(A, tmp);
}

void SUI(string &user_instruction)
{
	SF = 0, ZF = 0, AC = 0, PF = 0, CF = 0;
	string hex_number = "";
	hex_number.push_back(user_instruction[4]);
	hex_number.push_back(user_instruction[5]);
	int tmp = hex_to_dec(hex_number);
	A = flag_on_off_8bit_SUB(A, tmp);
}

void SUB(string &user_instruction)
{
	SF = 0, ZF = 0, AC = 0, PF = 0, CF = 0;
	switch (user_instruction[4])
	{
	case 'A':
		A = flag_on_off_8bit_SUB(A);
		break;
	case 'B':
		A = flag_on_off_8bit_SUB(A, B);
		break;
	case 'C':
		A = flag_on_off_8bit_SUB(A, C);
		break;
	case 'D':
		A = flag_on_off_8bit_SUB(A, D);
		break;
	case 'E':
		A = flag_on_off_8bit_SUB(A, E);
		break;
	case 'H':
		A = flag_on_off_8bit_SUB(A, H);
		break;
	case 'L':
		A = flag_on_off_8bit_SUB(A, L);
		break;
	default:
		error = 1;
		cout << "You found a bug!\n";
	}
}

void DCR(string &user_instruction)
{
	bool tmp_CF = CF;
	SF = 0, ZF = 0, AC = 0, PF = 0;
	int tmp = 1;
	switch (user_instruction[4])
	{
	case 'A':
		A = flag_on_off_8bit_SUB(A, tmp);
		break;
	case 'B':
		B = flag_on_off_8bit_SUB(B, tmp);
		break;
	case 'C':
		C = flag_on_off_8bit_SUB(C, tmp);
		break;
	case 'D':
		D = flag_on_off_8bit_SUB(D, tmp);
		break;
	case 'E':
		E = flag_on_off_8bit_SUB(E, tmp);
		break;
	case 'H':
		H = flag_on_off_8bit_SUB(H, tmp);
		break;
	case 'L':
		L = flag_on_off_8bit_SUB(L, tmp);
		break;
	default:
		error = 1;
		cout << "You found a bug!\n";
	}
	CF = tmp_CF;
}

void INR(string &user_instruction)
{
	bool tmp_CF = CF;
	SF = 0, ZF = 0, AC = 0, PF = 0;
	int tmp = 1;
	switch (user_instruction[4])
	{
	case 'A':
		A = flag_on_off_8bit_ADD(A, tmp);
		break;
	case 'B':
		B = flag_on_off_8bit_ADD(B, tmp);
		break;
	case 'C':
		C = flag_on_off_8bit_ADD(C, tmp);
		break;
	case 'D':
		D = flag_on_off_8bit_ADD(D, tmp);
		break;
	case 'E':
		E = flag_on_off_8bit_ADD(E, tmp);
		break;
	case 'H':
		H = flag_on_off_8bit_ADD(H, tmp);
		break;
	case 'L':
		L = flag_on_off_8bit_ADD(L, tmp);
		break;
	default:
		error = 1;
		cout << "You found a bug!\n";
	}
	CF = tmp_CF;
}

void INX(string &user_instruction)
{
	SF = 0, ZF = 0, AC = 0, PF = 0, CF = 0;
	int temp;
	switch (user_instruction[4])
	{
	case 'B':
		temp = hex_to_dec(dec_to_hex(B) + dec_to_hex(C));
		break;
	case 'D':
		temp = hex_to_dec(dec_to_hex(D) + dec_to_hex(E));
		break;
	case 'H':
		temp = hex_to_dec(dec_to_hex(H) + dec_to_hex(L));
		break;
	default:
		error = 1;
		cout << "You found a bug!\n";
	}
	++temp;
	if (temp > hex_to_dec("FFFF"))
		temp -= hex_to_dec("FFFF");
	string val = dec_to_hex16(temp);
	string address1 = "", address2 = "";
	for (int i = 0; i <= 1; ++i)
		address1.push_back(val[i]);
	for (int i = 2; i <= 3; ++i)
		address2.push_back(val[i]);
	switch (user_instruction[4])
	{
	case 'B':
		C = hex_to_dec(address2);
		B = hex_to_dec(address1);
		break;
	case 'D':
		E = hex_to_dec(address2);
		D = hex_to_dec(address1);
		break;
	case 'H':
		L = hex_to_dec(address2);
		H = hex_to_dec(address1);
		break;
	default:
		error = 1;
		cout << "You found a bug!\n";
	}
}

void DCX(string &user_instruction)
{
	SF = 0, ZF = 0, AC = 0, PF = 0, CF = 0;
	int temp;
	switch (user_instruction[4])
	{
	case 'B':
		temp = hex_to_dec(dec_to_hex(B) + dec_to_hex(C));
		break;
	case 'D':
		temp = hex_to_dec(dec_to_hex(D) + dec_to_hex(E));
		break;
	case 'H':
		temp = hex_to_dec(dec_to_hex(H) + dec_to_hex(L));
		break;
	default:
		error = 1;
		cout << "You found a bug!\n";
	}
	--temp;
	cout << temp << "\n";
	if (temp < 0)
		temp *= -1;
	cout << temp << "\n";
	string val = dec_to_hex16(temp);
	string address1 = "", address2 = "";
	for (int i = 0; i <= 1; ++i)
		address1.push_back(val[i]);
	for (int i = 2; i <= 3; ++i)
		address2.push_back(val[i]);
	switch (user_instruction[4])
	{
	case 'B':
		C = hex_to_dec(address2);
		B = hex_to_dec(address1);
		break;
	case 'D':
		E = hex_to_dec(address2);
		D = hex_to_dec(address1);
		break;
	case 'H':
		L = hex_to_dec(address2);
		H = hex_to_dec(address1);
		break;
	default:
		error = 1;
		cout << "You found a bug!\n";
	}
}

void DAD(string &user_instruction)
{
	SF = 0, ZF = 0, AC = 0, PF = 0, CF = 0;
	int val1 = hex_to_dec(dec_to_hex(H) + dec_to_hex(L)), val2;
	switch (user_instruction[4])
	{
	case 'B':
		val2 = hex_to_dec(dec_to_hex(B) + dec_to_hex(C));
		break;
	case 'D':
		val2 = hex_to_dec(dec_to_hex(D) + dec_to_hex(E));
		break;
	case 'H':
		val2 = val1;
		break;
	default:
		error = 1;
		cout << "You found a bug!\n";
	}
	val1 += val2;
	if (val1 > hex_to_dec("FFFF"))
	{
		CF = 1;
		val1 -= hex_to_dec("FFFF") + 1;
	}
	cout << val1 << "\n";
	string val = dec_to_hex16(val1);
	cout << val << "\n";
	string address1 = "", address2 = "";
	for (int i = 0; i <= 1; ++i)
		address1.push_back(val[i]);
	for (int i = 2; i <= 3; ++i)
		address2.push_back(val[i]);
	cout << address1 << " " << address2 << "\n";
	L = hex_to_dec(address2);
	H = hex_to_dec(address1);
}