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 mask = (1u << len) - 1;     // Step 1: mask create
    reg &= ~(mask << pos);               // Step 2: clear the field
    reg |= (val & mask) << pos;          // Step 3: insert new value
    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