http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47297
--- Comment #1 from joseph at codesourcery dot com <joseph at codesourcery dot com> 2011-01-14 17:04:30 UTC --- On Fri, 14 Jan 2011, mateusz at loskot dot net wrote: > In spite of the fact the behavior is undefined, I suspect the intent > is to be consistent (which appears to be for lots of other > values I have tried), but they are not. No, the intent is not to be consistent. (The intent is that each instance of such a conversion executed in the abstract machine results in an unspecified value, as per C99 Annex F, rather than more fully optimizing based on undefined behavior, but not for anything more consistent than producing unspecified values.)