Carry Flag in 8-bit Addition

Code

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

#define signbit 0x80

void add_with_carry(uint8_t a, uint8_t b, uint8_t* result, uint8_t* carry) {
    // Your logic here
    uint8_t i, reg=0, c=0, bita=0, bitb=0 ;

    for (i=0; i < 8; i++) {
        bita = a & 1;
        bitb = b & 1;
        reg = reg >> 1;

        if ((bita == 1) && (bitb == 1)) {
            if (c == 0) {
               c = 1;
                reg = (reg | 0);
            }
            else {
                c = 1;
                reg = (reg | 0x80);
            }
        }

        if ((bita == 1) && (bitb == 0)) {
            if (c == 0) {
                c = 0;
                reg = (reg | 0x80);
            }
            else {
               c = 1;
               reg = (reg | 0);
            }
        }
 
        if ((bita == 0) && (bitb == 0)) {
            if (c == 0) {
                c = 0;
                reg = (reg | 0);
            }
            else {
               c = 0;
               reg = (reg | 0x80);
            }
        }

        if ((bita == 0) && (bitb == 1)) {
            if (c == 0) {
                c = 0;
                reg = (reg | 0x80);
            }
            else {
               c = 1;
               reg = (reg | 0);
            }
        }

        a = a >> 1;
        b = b >> 1;
    }    

    *result = reg;
    *carry = c;

}

int main() {
    uint8_t a, b, result, carry;
    scanf("%hhu %hhu", &a, &b);

    add_with_carry(a, b, &result, &carry);

    printf("%u ", result);
    printf("%u", carry);
    return 0;
}

Solving Approach

add the regisers bit by bit with carry.

isolate the bits by shifting right and masking higer bits. 

put results in register from the end and shift it right