On Wed, Mar 2, 2011 at 2:49 AM, Eli Friedman <eli.fried...@gmail.com> wrote: > PR9350: increment/decrement of char (and anything else narrower than int) > can't overflow due to promotion rules; emit a wrapping add for those cases.
The addition may not be able to overflow, but if the result is not representable in the (signed) character type it's converted to then "either the result is implementation-defined or an implementation-defined signal is raised" [C99 6.3.1.3p3]. However, I'm not fluent enough in standardese to know whether that allows a non-wrapping add to be used in this case. Is 'undef' a valid implementation-defined result? (Also, I didn't check C89 or any C++ standards) _______________________________________________ cfe-commits mailing list cfe-commits@cs.uiuc.edu http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits
