* Sam Ravnborg (s...@ravnborg.org) wrote: > > > > If my memory serves me correctly, I think "long long" is aligned on 4 bytes > > on > > ppc32, but on 8 bytes on x86_32 (yeah, that's weird). How about we create a > > #define __long_long_aligned __attribute__((__aligned__(__alignof__(long > > long)))) > > #define __u64_aligned __attribute__((__aligned__(__alignof__(long long)))) > > A bit shorter but maybe less obvious.
Yep, that would make sense. I'm tempted to try creating #defined __u64_packed_aligned __attribute__((__packed__, __aligned__(__alignof__(long long)))) in the hope that gcc sees this as a strict alignment requirement (including a max bound) rather than just a hint. From what I gather in my reading of http://gcc.gnu.org/onlinedocs/gcc/Type-Attributes.html "The aligned attribute can only increase the alignment; but you can decrease it by specifying packed as well. See below." gcc seems to support having both specified. I think this would provide the kind of alignment guarantees we really need here: both specifying the minimum _and_ maximum alignment. Thoughts ? Mathieu > > Sam -- Mathieu Desnoyers Operating System Efficiency R&D Consultant EfficiOS Inc. http://www.efficios.com -- To UNSUBSCRIBE, email to debian-kernel-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/20110119161857.GC15031@Krystal
