binaryfloating point
Biased representation (or excess-N, offset binary) are used for floating number representation in computers. This wiki page says
This allows high speed comparisons
Could any one explain why comparison is faster (potentially in terms of gates implementation)?
IEEE 754 floating point numbers are represented as a sign, a mantissa and an exponent.
It is possible to work with floats at a bit level, but you need to know what you're doing.
Here are some documents which explain further.
Two's compliment representation of signed integers is easy to manipulate in hardware. For example, negation (i.e. x = -x) can be performed simply by flipping all the bits in the number and adding one. Performing the same operation in raw binary (e.g. with a sign bit) usually involves a lot more work, because you must treat certain bits in the stream as special. Same goes for addition - the add operation for negative numbers is identical to the add operation for positive numbers, so no additional logic (no pun intended) is required to handle the negative case.
While this doesn't mean it's easier from your perspective, as a consumer of this data, it does lessen the design effort and complexity of the device, thus presumably making it cheaper.
Best Answer
It makes it faster because, when you need to check if A is greater than B, with bias, you can just use the usual integer comparison (using subtraction), actually interpreting the floating point bits like a normal unsigned integer (like a "reinterpret_cast" in C++), and the result will be obtained immediately.
Otherwise, you would need two steps: first comparing exponents, then comparing mantissa, and that would make it a specific processor instruction.