Macro-Based Register Config Helper

Code

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


#define enableMask (((1<<1)-1)<<0)
#define modeMask (((1<<2)-1)<<1)
#define speedMask (((1<<3)-1)<<3)
// Define macros here
#define SET_BITFIELD(src,mask,pos,val) src = ((src & ~(mask))| \
                                              ((val <<pos) & mask)\
                                             ) 
#define CLEAR_BITFIELD(src,mask) src = (src & ~(mask))
uint16_t build_register(uint8_t enable, uint8_t mode, uint8_t speed) {
    // Use macros to set fields
    uint16_t val=0;
    SET_BITFIELD(val,enableMask,0,enable);
    SET_BITFIELD(val,modeMask,1,mode);
    SET_BITFIELD(val,speedMask,3,speed);
    return val;
}

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