void abort(void);
int b = 1;
int foo() {
    int a;
    int c;
    a = 0xff;
    for (; b; b--) {
        c = 1;
        asm("" ::"r"(c));
        c = (signed char)a;
    }
    if (c != -1)
        abort();
    return c;
}
int main() {
    foo();
    return 0;
}
