July 25, 2009
11:28 p.m.
Maximum alignment currently on x86 is 16 bytes for SSE vector types. Next year AVX will add 32 byte types and while they are supposed to work OK with 16 byte alignment, performance will be better with 32 byte alignment.
That doesn't really matter. What matters is the platform's ABI, i.e. what the maximum alignment is that the compiler gives, and what the alignment of a malloc() result is. That is unlikely to change even if x86 evolves. Regards, Martin