Question

Is there a function in Apple’s library that can reverse the order of the bits in a short?

0000 0011 -> 1100 0000

Thanks in advance.

Method used:

unsigned int  NO_OF_BITS = sizeof(num) * 8;
unsigned int reverse_num = 0;
int i;
for (i = 0; i < NO_OF_BITS; i++)
{
    if((num & (1 << i)))
        reverse_num |= 1 << ((NO_OF_BITS - 1) - i);
}

Source: http://www.geeksforgeeks.org/archives/726

Answer 1

It sounds like you are trying to reverse the bit sequence of the give byte.

There are lots of way to do this efficiently. Have a look at http://graphics.stanford.edu/~seander/bithacks.html#BitReverseObvious

This site contains lots of tricks when working with bits.