Change sign using bitwise operators

Question

How to change the sign of int using bitwise operators? Obviously we can use x*=-1 or x/=-1. Is there any fastest way of doing this?

I did a sm

Answer 1

Java uses Complement Two representation. In order to change a sign, it means you must do a bitwise negation (it would be equivalent to xor with FFFF) and add 1.

x = ~x + 1;

I am almost sure that -x is, if anything, faster than that.