On Thu, Oct 13, 2011 at 4:54 PM, Andi Kleen <a...@firstfloor.org> wrote: > Artem Shinkarov <artyom.shinkar...@gmail.com> writes: >> >> 1) Currently in C we cannot provide information that an array is >> aligned to a certain number. The problem is hidden in the fact, that > > Have you considered doing it the other way round: when an optimization > needs something to be aligned, make the declaration aligned? > > -Andi
Andi, I can't realistically imagine how could it work. The problem is that for an arbitrary arr[x], I have no idea whether it should be aligned or not. what if arr = ptr + 5; v = *(vec *) arr; I can make arr aligned, because it would be better for performance, but obviously, the pointer expression breaks this alignment. But the code is valid, because unaligned move is still possible. So I think that checking is a more conservative approach. Or I am missing someting? Thanks, Artem. > -- > a...@linux.intel.com -- Speaking for myself only >
