> > * Paul Schlie: > > >> (Without -fwrapv, integer overflow is undefined, and subsequent range > >> checks can be optimized away, so that it might cause erroneous > >> behavior.) > > > > - Since for all practical purposes most (if not all) target's use > > 2's complement integer representations which naturally "wrap", might > > it be simply best to presume that all do "wrap" by default, but allow > > -fnowrapv to disable it if ever required by the odd target/language? > > Enabling -fwrapv disables quite a few optimizations on signed integer > types in C code. OTOH, you should compile most real-world C code with > -fwrapv anyway. See my security advisory on incorrect overflow > checking in C; this is a rather widespread issue, even in new code.
No they should be using -ftrapv instead which traps on overflow and then make sure they are not trapping when testing. Thanks, Andrew Pinski
