notImplemented();
    private final void requestRegister(Register reg, Item it) {        X86RegisterPool pool = eContext.getPool();                // check item doesn't already use register        if (!it.uses(reg)) {            if (!pool.isFree(reg)) {                notImplemented();                //TODO: spill register; make sure that the stack items                 // and floating items are handled correctly            }            pool.request(reg, it);        }    }