[Bug tree-optimization/106131] [10/11/12/13 Regression] -fstrict-aliasing breaks normal program that does not use any pointer or reference

[18307130172 at fudan dot edu.cn via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106131

--- Comment #6 from Xue Zhenliang <18307130172 at fudan dot edu.cn> ---
I'm trying to reducing it further. Now I've eliminated the dependency on STL:

struct Pair {
    int a, b;

    Pair(const Pair &) = default;
    Pair(int _a, int _b) : a(_a), b(_b) {}
    Pair &operator=(const Pair &z) {
        a = z.a;
        b = z.b;
        return *this;
    }
};

const int &max(const int &a, const int &b) {
    return a < b ? b : a;
}

int foo(Pair x, Pair y) {
    return max(x.b, y.b);
}

int main() {
    auto f = new Pair[3] {{0, -11}, {0, -8}, {0, 2}};
    for (int i = 0; i < 1; i++) {
        f[i] = f[0];
        if(i == 0)
            f[i] = f[2];
        if (foo(f[i], f[1]) != 2)
            __builtin_abort();
    }
}