Extract and Modify Field in a 32-bit Register

Code

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

uint32_t update_register(uint32_t reg) {
    const uint32_t FIELD_SHIFT = 10;
    const uint32_t FIELD_MASK  = 0x1F; // 5 bits: 0b11111

    // 1. Extract field
    uint32_t field = (reg >> FIELD_SHIFT) & FIELD_MASK;

    // 2. Modify field
    if (field < FIELD_MASK)
    {
        field++;
    }

    // 3. Clear old field bits in register
    reg &= ~(FIELD_MASK << FIELD_SHIFT);

    // 4. Write updated field back
    reg |= (field << FIELD_SHIFT);
    return reg;
}

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

Solving Approach