Macro-Based Register Config Helper

Code

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

// Define macros here
#define ENABLE(reg,en) reg=reg|en
#define mode_b(reg,mo) reg=reg|mo<<1
#define speed_b(reg,sp) reg=reg|sp<<3
#define reserved_b reg=reg & ~(3<<6)


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_b(reg,mode) ;
    speed_b(reg,speed) ;
    reserved_b;
    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