Extract and Modify Field in a 32-bit Register

Code

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

uint32_t update_register(uint32_t reg) {
    uint8_t mask = (reg >> 8) & 0xFF;
    uint8_t a = mask;
    a = a << 1;
    a = a >> 3;
    if(a >= 31)
    {
        return reg;
    }
    reg = reg + 1024;
    return reg;
}

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

Solving Approach