Bit Operations using Macros

Code

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

#define SET(r) r|=132
#define CLEAR(r) r=r&~(1<<3)
#define TOG(r) r^=1<<5

uint8_t modify_register(uint8_t reg) {
    SET(reg);
    CLEAR(reg);
    TOG(reg);

    return reg;
}

int main() {
    uint8_t reg;
    scanf("%hhu", &reg);
    printf("%u", modify_register(reg));
    return 0;
}

Solving Approach