Function drutil_insert_get_mem_addr_ex 

pub unsafe extern "C" fn drutil_insert_get_mem_addr_ex(
    drcontext: *mut c_void,
    bb: *mut instrlist_t,
    where_: *mut instr_t,
    memref: opnd_t,
    dst: reg_id_t,
    scratch: reg_id_t,
    scratch_used: *mut bool_,
) -> bool_

Identical to drutil_insert_get_mem_addr() except it returns in the optional OUT parameter \p scratch_used whether or not \p scratch was written to.