On 04/22/2013 11:12 AM, Warlich, Christof wrote: > ketmar wrote: >> 0x7fffffc0 can'be exactly represented in float, 'cause there is some >> bits occupied by exponent. so it is rounded so some other number, which >> is unfortunately too big to be converted to int. therefore conversion >> triggers undefined behavior. > > Yes, that's what I suspected after I tried Andrew's example. > >> change float to double and everything will be fine. > > I guess that only shifts the problem to (much) higher numbers. > > After all, this reminds be a bit of a hack lawver: A legal loophole > shamelessly capitalizing upon ;-). At least, it violates the golden > principle of "least surprise", being said to be an essential part of > good software design. What do you think the conversion should do in this case? I find the current behaviour to be the least surprising. > Anyhow, as I really need to deal with such situations: Is there a way > to catch such conversion errors without cluttering the code with checks > that test if still being within the range of a conversion or not? Skimming > the paper linked by David suggests that it should be possible to > install trap handlers for this purpose. Does anyone know how to do this > with gcc? Just define your own conversion function. Any program that tries to convert an out-of-range value and then uses the result is buggy anyway. Andrew.
