Macro-Based Register Config Helper

Code

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

// Define macros here
#define SET_ENABLE_BIT(reg,x) reg |= x<<0
#define SET_MODE_VALUE(reg, x) reg|= x<<1
#define SET_SPEED_VALUE(reg, x) reg |= x<<3
#define RESERVE(reg) reg &= ~(3 << 8)

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

    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