Ok yes!! This is perfectly clear now, thanks. I didn't know, very interesting and a smart optimisation of cache lines use! I've also read that the processors

Ok yes!! This is perfectly clear now, thanks. I didn't know, very interesting and a smart optimisation of cache lines use! I've also read that the processors are able to ask words (of a cache line) in different orders, and so ask for hot words first. It may help a little if this kind of structure was not aligned in an optimized fashion. Doesn't work for HW prefetch, though.