It seems to me that it is worthwhile to fix [problems caused by overflow]

But what's the point? If your code is going that close to the limits, it is already non-portable. If you really do need to go that close to the limits, use a datatype whose behaviour is precisely specified and portable like Int32 or use one with no overflow issues like Integer. Int is the wrong tool for the job so it's no wonder it does badly. -- Alastair Reid