Replace Bit Field in a 32-bit Register

Code

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

#define set_bit(reg, index)   ((reg) | (1 << (index)))
#define clear_bit(reg, index) ((reg) & ~(1 << (index)))

uint32_t replace_field(uint32_t reg, uint32_t val, uint8_t pos, uint8_t len) {
    // Your code here
    for (int i = pos; i < pos+len; ++i) {
        reg = (val&1) ? set_bit(reg, i) : clear_bit(reg, i);
        val >>= 1;
    }
    return reg;
}

int main() {
    uint32_t reg, val;
    uint8_t pos, len;
    scanf("%u %u %hhu %hhu", &reg, &val, &pos, &len);
    printf("%u", replace_field(reg, val, pos, len));
    return 0;
}

Solving Approach