[OT] The Usual Arithmetic Confusions

[Walter Bright]

Amusingly, how signed division is done when a signed divide instruction is not 
available is to save the signs of the operands, negate them to unsigned, do the 
unsigned divide, then negate the result according to the original signs.

Unsigned operations are the core of how CPUs work, the signed computations are 
another layer on top of that.