https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87373
--- Comment #5 from Richard Earnshaw <rearnsha at gcc dot gnu.org> --- It's not clear what behaviour you think is 'proper' for a packed struct with a volatile member. Since packed is a GNU extension, there's nothing in the C (or C++) standards that you can call upon to reach a reasonable expectation, and anything that is left must be down to either the GNU manuals or good luck. In this case I don't think the GNU manuals say anything specific about this case either (since that would imply knowing how each supported architecture handles misaligned memory accesses.
