Set Specific Bits in a 32-bit Register

Code

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

uint32_t set_bits(uint32_t reg, uint8_t pos, uint8_t len) {
    
    // crude way
    // for(uint8_t i=pos ;i < (len+pos); i++){
     //   reg |= (1 << i);
   // }

   uint32_t mask = ((1 << len)- 1u) << pos;
   reg |= mask;

    return reg;
}

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

Solving Approach