overflow_test.c

#include <stdio.h>
#include <limits.h>

int main(void) {
    int a = ((INT_MAX) / 2);
    int b = ((INT_MAX) / 2) + 2;

    long x = (long)(a + b);

    printf("x = %d\na = %d\tb = %d\n", x, a, b);
    printf("(x^a) >= 0: %d\n", ((x^a) >= 0));
    printf("(x^b) >= 0: %d\n", ((x^b) >= 0));

    x = (long)((unsigned long)a + b);

    printf("(x^a) >= 0: %d\n", ((x^a) >= 0));
    printf("(x^b) >= 0: %d\n", ((x^b) >= 0));

    a = ((INT_MAX) / 2) + 2;
    b = ((INT_MAX) / 2);

    x = (long)(a + b);

    printf("x = %d\na = %d\tb = %d\n", x, a, b);
    printf("(x^a) >= 0: %d\n", ((x^a) >= 0));
    printf("(x^b) >= 0: %d\n", ((x^b) >= 0));

    x = (long)((unsigned long)a + b);

    printf("(x^a) >= 0: %d\n", ((x^a) >= 0));
    printf("(x^b) >= 0: %d\n", ((x^b) >= 0));

    long c = ((LONG_MAX) / 2);
    long d = ((LONG_MAX) / 2) + 2;

    x = (long)(c + d);

    printf("x = %ld\nc = %ld\td = %ld\n", x, c, d);
    printf("(x^c) >= 0: %ld\n", ((x^c) >= 0));
    printf("(x^d) >= 0: %ld\n", ((x^d) >= 0));

    x = (long)((unsigned long)c + d);

    printf("(x^c) >= 0: %ld\n", ((x^c) >= 0));
    printf("(x^d) >= 0: %ld\n", ((x^d) >= 0));

    c = ((LONG_MAX) / 2) + 2;
    d = ((LONG_MAX) / 2);

    x = (long)(c + d);

    printf("x = %ld\nc = %ld\td = %ld\n", x, c, d);
    printf("(x^c) >= 0: %ld\n", ((x^c) >= 0));
    printf("(x^d) >= 0: %ld\n", ((x^d) >= 0));

    x = (long)((unsigned long)c + d);

    printf("(x^c) >= 0: %ld\n", ((x^c) >= 0));
    printf("(x^d) >= 0: %ld\n", ((x^d) >= 0));

    return 0;
}
/*
output:
    x = -2147483648
    a = 1073741823  b = 1073741825
    (x^a) >= 0: 0
    (x^b) >= 0: 0
    (x^a) >= 0: 1
    (x^b) >= 0: 1
    x = -2147483648
    a = 1073741825  b = 1073741823
    (x^a) >= 0: 0
    (x^b) >= 0: 0
    (x^a) >= 0: 1
    (x^b) >= 0: 1
    x = -9223372036854775808
    c = 4611686018427387903 d = 4611686018427387905
    (x^c) >= 0: 0
    (x^d) >= 0: 0
    (x^c) >= 0: 0
    (x^d) >= 0: 0
    x = -9223372036854775808
    c = 4611686018427387905 d = 4611686018427387903
    (x^c) >= 0: 0
    (x^d) >= 0: 0
    (x^c) >= 0: 0
    (x^d) >= 0: 0
*/