Extract and Modify Field in a 32-bit Register

Code

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

uint32_t update_register(uint32_t reg) {

    uint32_t mask = ((1u << 5) - 1) << 10;

    uint32_t field = (reg >> 10) & 0x1F;   // FIXED

    if (field < 31) {
        field++;

        reg &= ~mask;           // clear old field
        reg |= (field << 10);   // insert new field
    }

    return reg;
}

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

Solving Approach