Replace Bit Field in a 32-bit Register

Code

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

uint32_t replace_field(uint32_t reg, uint32_t val, uint8_t pos, uint8_t len) {
    uint32_t res=0,bit;
    int i;
    int p=pos;
    for(i=0;i<len;i++){
        bit=(val>>i)&1;
        res|=(bit<<pos);
        pos=pos+1;
        }

    for(i=p;i<(p+len);i++){
        reg&=~(1<<i);
    }
    reg|=res;
    
        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