OPCODES = {}


def add_opcode(*opcode_names):
    def wrapped(func):
        for name in opcode_names:
            OPCODES[name] = func

    return wrapped


################################################################################

# Stack


@add_opcode('push', 'pushq')
def push(emu, value):
    emu.pushToStack(emu.getVal(value))


@add_opcode('pop', 'popq')
def pop(emu, target_reg):
    emu.registers[target_reg] = emu.popFromStack()
    emu.changedRegisters((target_reg, 'change'))


# Arithmetic


@add_opcode('mov', 'movq')
def mov(emu, from_reg, target_reg):
    emu.registers[target_reg] = emu.getVal(from_reg)
    emu.changedRegisters((target_reg, 'change'))


@add_opcode('add', 'addq')
def add(emu, add_val, target_reg):
    emu.registers[target_reg] += emu.getVal(add_val)
    emu.changedRegisters((target_reg, 'change'))


@add_opcode('sub', 'subq')
def sub(emu, sub_val, target_reg):
    emu.registers[target_reg] -= emu.getVal(sub_val)
    emu.changedRegisters((target_reg, 'change'))


# Comparison and conditional jumping


@add_opcode('cmp', 'cmpq')
def comp(emu, val1, val2):
    emu.compareVal(val1, val2)


@add_opcode('jg')
def jg(emu, label):
    emu.jump(label, g=True)


@add_opcode('jl')
def jl(emu, label):
    emu.jump(label, l=True)


@add_opcode('je')
def je(emu, label):
    emu.jump(label, e=True)


@add_opcode('jge')
def jge(emu, label):
    emu.jump(label, 'or', g=True, e=True)


@add_opcode('jle')
def jle(emu, label):
    emu.jump(label, 'or', l=True, e=True)


@add_opcode('jne')
def jne(emu, label):
    emu.jump(label, e=False)


# Unconditional Jumping


@add_opcode('jmp')
def jmp(emu, label):
    emu.registers['%rip'] = emu.labels[label]


@add_opcode('call')
def call(emu, label):
    emu.pushToStack(emu.registers['%rip'] + 1)
    emu.registers['%rip'] = emu.labels[label]


@add_opcode('leave')
def leave(emu):
    emu.registers['%rsp'] = emu.registers['%rbp']
    emu.registers['%rbp'] = emu.popFromStack()


@add_opcode('ret')
def ret(emu):
    emu.registers['%rip'] = emu.popFromStack()