Bit Operations using Macros

Code

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

// Define bitwise macros here
#define SET_BIT(reg, bit)     ((reg) |= (1U << (bit)))
#define CLEAR_BIT(reg, bit)   ((reg) &= ~(1U << (bit)))
#define TOGGLE_BIT(reg, bit)  ((reg) ^= (1U << (bit)))

uint8_t modify_register(uint8_t reg) {
    SET_BIT(reg, 2);     // Set bit 2
    SET_BIT(reg, 7);     // Set bit 7
    CLEAR_BIT(reg, 3);   // Clear bit 3
    TOGGLE_BIT(reg, 5);  // Toggle bit 5
    return reg;
}

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

Solving Approach

1. Set bits 2 and 7 using bitwise OR (|) to ensure those bits are 1, regardless of their initial state.
2. Clear bit 3 using bitwise AND (&) with an inverted mask to force that bit to 0.
3. Toggle bit 5 using bitwise XOR (^) to flip its current state—0 becomes 1, and 1 becomes 0.

Each operation uses a macro for readability and maintainability, making the code clean and hardware-friendly.