https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61502
--- Comment #13 from joseph at codesourcery dot com <joseph at codesourcery dot com> --- On Wed, 22 Oct 2014, Keith.S.Thompson at gmail dot com wrote: > Do you believe that the authors of the standard meant it the way you do? The "authors of the standard" are an amorphous group over 30 years and I don't think a single intent can meaningfully be assigned to them. In recent years, the general position has included: * C is a high-level language supporting a wide range of implementations, not just ones with a conventional linear address space and otherwise conventional direct mappings to machine operations; * edge cases should generally be resolved in the way that is convenient for optimization rather than the way that is simplest to specify. For the latter, see for example the discussion in the Parma minutes of instability of uninitialized variables with automatic storage duration. That is, if you have unsigned char a; // uninitialized, inside a function unsigned char b = a; unsigned char c = b; then even if there isn't undefined behavior, there is no requirement (given no further assignments to b or c) for b == c, or for the value of b == c to stay unchanged, or for the values of b and c to remain unchanged. (As another example, C11 chose to make INT_MIN % -1 explicitly undefined for implementation convenience, even though users might think the value is obviously 0.)
