def _signed_add(self, a, b, c=0) -> int:
self._reset()
value = a + b + c
# self.carry = (value + 2 ** 31) > max_32_bits
self.overflow = BinaryUtils.overflow(value)
self.carry, value = BinaryUtils.add_2cb(a, b, c)
self.overflow = BinaryUtils.overflow_msb(a, b, value)
result = self._value_common(value)
return result
def _value_common(self, value: int) -> int:
value = int(value)
self.zero = value == 0
self.negative = BinaryUtils.msb(value)
if value > max_32_bits_signed or value < min_32_bits_signed:
raise ValueError
return value
def _unsigned_add(self, a, b, value: int) -> int:
self._reset()
self.carry = value > max_32_bits
self.negative = BinaryUtils.msb(a)
if value > max_32_bits:
value = value - max_32_bits
return value
def test_add_2cb():
assert BinaryUtils.add_2cb(0, 0) == (False, 0)
assert BinaryUtils.add_2cb(0, -1) == (False, -1)
assert BinaryUtils.add_2cb(0, min_32_bits_signed) == (False, min_32_bits_signed)
assert BinaryUtils.add_2cb(0, max_32_bits_signed) == (False, max_32_bits_signed)
assert BinaryUtils.add_2cb(min_32_bits_signed, min_32_bits_signed) == (True, 0)
assert BinaryUtils.add_2cb(-1, -1) == (True, -1 -1)
def test_positive():
assert BinaryUtils.to_2cb(0) == '0' * 32
assert BinaryUtils.to_2cb(1) == ('0' * 31 + '1')
assert BinaryUtils.to_2cb(max_32_bits_signed) == ('0' + '1' * 31)
def test_msb():
assert BinaryUtils.msb(1) == 0
assert BinaryUtils.msb(0) == 0
assert BinaryUtils.msb(-1) == 1
def test_negation():
assert BinaryUtils.neg('1' * 32) == '0' * 32
assert BinaryUtils.neg('0' * 32) == '1' * 32
def test_negative():
assert BinaryUtils.to_2cb(-1) == ('1' * 32)
assert BinaryUtils.to_2cb(min_32_bits_signed) == ('1' + '0' * 31)
def _from_binary(cls, value):
if value[0] == '0':
return int(value, 2)
neg = int(BinaryUtils.neg(value), 2)
return -(neg + 1)