http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43311
--- Comment #4 from Richard Guenther <rguenth at gcc dot gnu.org> 2012-01-25
11:13:40 UTC ---
(In reply to comment #3)
> Does the following code have undefined behavior?
>
> typedef struct { unsigned char b1, b2; } __attribute__((aligned(8))) S;
> void f( S const* s, unsigned char* b1, unsigned char* b2 )
> {
> *b1 = s->b1;
> *b2 = s->b2;
> }
>
> int main()
> {
> S s = { 1, 2 };
> f(&s, &s.b2, &s.b2);
> return s.b2 != 1;
> }
No, s.b2 should be 1.
