https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66194
--- Comment #10 from Evgeniy Dushistov <dushistov at mail dot ru> --- >ABI requirements are not C requirements always. This paragraph is talking >about >memory accesses but really it did not take into account other >requirements of C >correctly. But where then I can get this "C requirements", standard(C99) mention only "align requirements", but no method how to calculate them, so it may be a)ABI that gcc implement, but compiler may have more strict requirement (and you acknowledge this) b)In gcc documentation, but I can see in "C Implementation" any hints, there is only in "Extensions to the C Language Family" operator alignof, that give 4 for both x86/amd64, but it describe it as: Some machines never actually require alignment; they allow reference to any data type even at an odd address. For these machines, '__alignof__' reports the smallest alignment that GCC gives the data type, usually as mandated by the target ABI, there is no note that result of alignof is strict memory requirements of gcc, If I add note about this in texinfo, is this patch be accepted?
