Extract Even Bits Only from 32-bit Register

Code

#include <stdio.h>
#include <stdint.h>

uint32_t extract_even_bits(uint32_t reg) {
    uint32_t x = reg & 0x55555555u;   // mask even bits (binary 0101...)
    
    x = (x | (x >> 1)) & 0x33333333u;
    x = (x | (x >> 2)) & 0x0F0F0F0Fu;
    x = (x | (x >> 4)) & 0x00FF00FFu;
    x = (x | (x >> 8)) & 0x0000FFFFu;
    
    return (uint16_t)x;
}

int main() {
    uint32_t reg;
    scanf("%u", &reg);
    printf("%u", extract_even_bits(reg));
    return 0;
}

Solving Approach