signed_addition_overflow_demo.c

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

int main(void) {
    int8_t ms[] = {
        0x50,
        0x50,
        0x50,
        0x50,
        0xD0,
        0xD0,
        0xD0,
        0xD0
    };

    int8_t ns[] = {
        0x10,
        0x50,
        0x90,
        0xD0,
        0x10,
        0x50,
        0x90,
        0xD0
    };

    int result = 0;

    bool overflow = 0;
    bool carry = 0;
    bool m7 = 0;
    bool n7 = 0;
    bool c6 = 0;
    bool c7 = 0;
    bool s7 = 0;

    for (int i = 0; i < 8; i++) {
        result = (ms[i] + ns[i]) & 0xFF;
        overflow = (ms[i] ^ result) & (ns[i] ^ result) & 0x80;
        m7 = ms[i] & 0x80;
        n7 = ns[i] & 0x80;
        c6 = (ms[i] & 0x40) & (ns[i] & 0x40);
        c7 = (m7 & n7) | (c6 & (m7 | n7));
        s7 = result & 0x80;
        printf("%5d %5d %5d | %5d %5d %5d | ", m7, n7, c6, c7, s7, overflow);
        printf("%5hhu + %5hhu = %5hhu | ", ms[i], ns[i], result);
        printf("%5hhd + %5hhd = %5hhd | ", ms[i], ns[i], result);
        printf("%5hhx + %5hhx = %5hhx \n", ms[i], ns[i], result);
    }

    return 0;
}