How does a processor negate an integer?
Option 1 is how I've seen it and how I've designed it for integer inversion.
The &quot;add 1&quot; takes one cycle and the bit inversion is absorbed in the same cycle.
For subtraction, the same adder with inverter is used, and the &quot;add 1&quot; is applied through the carry-in for the LSB, and so it costs no extra cycles.

From https://cs.wellesley.edu/~cs240/f16/assignments/circuits/circuits.html