Macro-Based Register Config Helper

Code

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

// Define macros here
#define enable(reg, c)(reg |= (c<<0b0000))
#define mode(reg, c)(reg |= (c<<0b0001))
#define speed(reg, c)(reg |= (c<<0b0011))

uint16_t build_register(uint8_t enable, uint8_t mode, uint8_t speed) {
    // Use macros to set fields
 uint16_t reg = 0;
 enable(reg, enable);
 mode(reg, mode);
 speed(reg, speed);

    return reg;
}

int main() {
    uint8_t enable, mode, speed;
    scanf("%hhu %hhu %hhu", &enable, &mode, &speed);

    uint16_t reg = build_register(enable, mode, speed);
    printf("%u", reg);
    return 0;
}

Solving Approach