On Sat, 5 Jun 2010 23:51:14 -0700, John McCall <rjmcc...@apple.com> wrote: > I just want to point out here that overflow is not undefined on unsigned > integers in C, so if you're reasoning based on abstract program semantics, > you cannot assume unsigned overflow does not occur. (((unsigned) x)-1 >= > UINT_MAX) has a valid solution at x == 0U. Signed overflow has undefined > behavior, so (((int) x)-1 >= INT_MAX) has no solutions given a valid > program. > > John.
Interesting, I didn't know that. I'm sure some people use the (platform and compiler-dependent) signed wraparound too. I guess I would want the "tautology-checking" behavior should be enabled/disabled by a compiler flag in the long run, but for now should I disable it, and perhaps just wait for another checker as Zhongxing said? _______________________________________________ cfe-commits mailing list cfe-commits@cs.uiuc.edu http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits
