Two's Complement disadvantage?

5
votes

I was reading about two's complement, I understand this method is most efficient, but there might be some disadvantages too. I could not find any disadvantages, Is there any situation where the conversion to two's complement could fail to represent the number correctly?

2
twos-complement
I guess the whole electronic world rely on 2's compliment for representing numbers. It is a full proof concept and works well as long as you are working within the boundary of the available memory. - Gyanendra Dwivedi

2 Answers

5
votes

Two's complement is awesome - that's why everyone uses it. The biggest disadvantage is that if you try to negate the lowest representable value, you get an overflow. With one's complement or sign and magnitude, that doesn't happen.

1
votes

With "two complement"-notation you can't compare the size of two Integers with very simple logic operators (at lowest level hardware). Thats the reason why the exponent in IEEE Standard for Floating-Point Arithmetic (IEEE 754) is not represented in "two complement" but in "biased" notation.