I think in the short term, companies that develop these things will behave ethically without any oversight (by making machines "enjoy" what they are doing) because doing something else would be inefficient or counterproductive. Why would you make an expensive thinking machine miserable? Humans that are happy are way more productive - and machines that are based off humans will be as well.
In the long term, if and when these things become mass-produced and cheap, people may want to do terrible things to them, in the same vein as animal torture. That may be when laws get put in place to protect them.
In the long term, if and when these things become mass-produced and cheap, people may want to do terrible things to them, in the same vein as animal torture. That may be when laws get put in place to protect them.