https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88490
--- Comment #6 from rguenther at suse dot de <rguenther at suse dot de> --- On Fri, 14 Dec 2018, joseph at codesourcery dot com wrote: > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88490 > > --- Comment #5 from joseph at codesourcery dot com <joseph at codesourcery > dot com> --- > On Fri, 14 Dec 2018, rguenther at suse dot de wrote: > > > Note I do not think the C standard is sufficiently clear with regarding > > to restrict qualified pointers loaded from memory. > > I think this is where "Every access that modifies X shall be considered > also to modify P, for the purposes of this subclause." comes in. (See > what I said at <https://gcc.gnu.org/ml/gcc-bugs/2005-01/msg03394.html>.) > Modifying s->d[n][0] is considered to modify s->d[n], and so considered to > modify s->d, and so considered to modify s. (It's still perfectly valid > to have n == k; what's not valid is aliasing between objects accessed via > s->d[0] and s->d[1], for example.) OK, thanks for clarifying. I think we are fine implementation-wise and I have a hard time thinking of a way to improve here given we have to compute sth conservatively correct.
