Determine the sign of a 32 bit int

Question

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

Answer 1

Why do you need to use bitwise operators for that?

int get_sign(int value)
{
    return (value < 0) ? -1 : (int)(value != 0);
}

If you absolutely have to use bitwise operators, then you can use the & operator to check for negative values, no shifting needed:

int get_sign(int value)
{
    return (value & 0x80000000) ? -1 : (int)(value != 0);
}

If you want to shift:

int get_sign(int value)
{
    return ((value >> 31) & 1) ? -1 : (int)(value != 0);
}

Answer 2

Dimitri's idea could be simplified to (!!x) - ((x >> 30) & 2)

And just to give one more cryptic solution:

~!x & ((-((unsigned) x >> 31)) | !!x)