Macro-Based Register Config Helper

Code

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

// Define macros here
#define ENABLE(temp_reg,enable) ((temp_reg)|=(1<<0))

#define MODE(temp_reg,mode) do{ \
                                                                    if(mode & (1<<0))   \
                                                                        temp_reg|=(1<<1);   \
                                                                    if(mode & (1<<1)){      \   
                                                                        temp_reg|=(1<<2);   \
                                                                     }  \
                                                                }while(0)   

#define SPEED(temp_reg,speed) do{   \
                                                                    if(speed & (1<<0))   \
                                                                        temp_reg|=(1<<3);   \
                                                                    if(speed & (1<<1)){     \   
                                                                         temp_reg|=(1<<4);   \
                                                                    }  \
                                                                    if(speed & (1<<2)){     \
                                                                        temp_reg|=(1<<5);   \
                                                                    }   \
                                                                }while(0)   

uint16_t build_register(uint8_t enable, uint8_t mode, uint8_t speed) {
    // Use macros to set fields
    uint16_t temp_reg;
    if(enable == 1){
        ENABLE(temp_reg,enable);
    }
    MODE(temp_reg,mode);
    SPEED(temp_reg,speed);
    return temp_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