Order of local variable allocation on the stack

I’ve no idea why GCC organizes its stack the way it does (though I guess you could crack open its source or this paper and find out), but I can tell you how to guarantee the order of specific stack variables if for some reason you need to. Simply put them in a struct:

void function1() {
    struct {
        int x;
        int y;
        int z;
        int *ret;
    } locals;
}

If my memory serves me correctly, spec guarantees that &ret > &z > &y > &x. I left my K&R at work so I can’t quote chapter and verse though.