Question

In C when you do something like this:

char var = 1;

while(1)
{
  var = var << 1;
}

In the 8th iteration the “<<” operator will shift out the 1 and var will be 0. I need to perform a shift in order to mantain the bit shifting. In other words I need this:

initial —– 00000001

1st shift — 00000010

2nd shift – 00000100

3rd shift – 00001000

4th shift – 00010000

5th shift — 00100000

6th shift — 01000000

7th shift – 10000000

8th shift – 00000001 (At the 8th shift the one automatically start again)

Is there something equivalent to “<<” but to achieve this?

Answer 1

Yes, you can use a circular shift. (Although it isn’t a built-in C operation, but it is a CPU instruction on x86 CPUs)