While fancy hardware would make it faster, what you are comparing it to is a bunch of floating point and large number multiplication. I believe in this case the

While fancy hardware would make it faster, what you are comparing it to is a bunch of floating point and large number multiplication. I believe in this case they just use a look up table: If one value is 0, it is 0. If the signs are different, it is -1. If the signs are the same, it is 1. I’m sure those can be done with relatively few instructions using far less power hungry hardware.