The attached test case contains code similar to:

    int8_t local = global_ptr->array[i].member1;
    if (local != global_ptr->member2)
    {
        /* several lines later */
	function_call(local);
    }

The code generated by the compiler loads member1 two times, into different registers. Subsequent code that refers to local (a copy of member1), uses both registers at different times.