https://gcc.gnu.org/bugzilla/show_bug.cgi?id=51017
--- Comment #19 from Alexander Peslyak <solar-gcc at openwall dot com> --- (In reply to Alexander Peslyak from comment #17) > Should we create a new bug for the unnecessary and non-optional use of > unaligned load instructions for source code like this, or is this considered > the new intended behavior despite of the major slowdown on such CPUs? > (Presumably not only for JtR. I'd expect this to affect many programs.) Upon further analysis, I now think that this was my fault, and (presumably) not common in other programs. What I had was differing definition vs. declaration, so a bug. The lack of alignment specification in the declaration of the struct essentially told (newer) GCC not to assume alignment - to an extent greater than e.g. a pointer would. As far as I can tell, GCC does not currently produce unaligned load instructions (so assumes that SSE* vectors are properly aligned) when all it has is a pointer coming from another object file. I think that's the common scenario, whereas mine was uncommon (and incorrect). So let's focus on PRE only.
