On 2013-09-25 22:29:58 -0400, James K. Lowden wrote: > You mean that a naïve rendering of the source code implies an overflow > where none might exist in the actual emitted object code. And, > presumably, the converse: that even if the source is written such that > there logically can't be an overflow, the compiler might render object > code that does. The converse is forbidden. > I saw recommendations here for -ftrapv, said to be broken (?), > defined only for signed integer operations, [...] It's defined only for signed integer operations, because there are never overflows with unsigned integer operations (except for conversions from floating-point types). -- Vincent Lefèvre <vincent@xxxxxxxxxx> - Web: <http://www.vinc17.net/> 100% accessible validated (X)HTML - Blog: <http://www.vinc17.net/blog/> Work: CR INRIA - computer arithmetic / AriC project (LIP, ENS-Lyon)
