Implementing Logical Right Shift in C

Question

I\'m working on making a logical right shift function in C using only bitwise operators. Here\'s what I have:

int logical_right_shift(int x, int n)
{
    int         


        

Answer 1

Milnex's answer is great and has an awesome explanation, but the implementation unfortunately fails due to the shift by total size. Here is a working version:

int logicalShift(int x, int n) {
  int totalBitsMinusOne = (sizeof(int) * 8) - 1; // usually sizeof(int) is 4 bytes (32 bits)
  return (x >> n) & ~(((0x1 << totalBitsMinusOne) >> n) << 1);
}

To have 1 as the most significant bit, and all zeroes elsewhere, we need to shift 0x1 by number of bits - 1. I am submitting my own answer because my edit to the accepted answer was somehow rejected.