Using ONLY:
! ~ & ^ | + << >>
NO LOOPS
I need to determine the sign of a 32 bit integer and I need to return 1 if positive, 0 if 0 and -1 if ne
What about:
int getsign(int n)
{
return (!!n) + (~((n >> 30) & 2) + 1);
}
..for 32-bit signed int, 2's complement only.
!!n
gives 1 if n
is nonzero.
((n >> 30) & 2)
gives 2 iff the high bit (sign) is set. The bitwise NOT and +1 take the 2's complement of this, giving -2 or 0.
Adding gives -1 (1 + -2) for negative values, 0 (0 + 0) for zero, and +1 (1 + 0) for positive values.