2009/6/4 . . <pkejjy@xxxxxxxxx>: > If so, that would be a bad performance decision in this > multicore world, where memory footprint size matters much more than > alignment, generally speaking. > But sharing of cache lines between unrelated things can be even worse. And as you said, the point is to make the 64-bit ints properly aligned when arrays of the type are used. There are numerous architectures which cannot read mis-aligned types, and those that can are usually fairly slow at it -- especially when then end up straddling cache lines, as an array of 17-byte structs certainly would, at some point. There is, iirc, an __attribute__ that'll let you pack it, if you insist. Do you have profiler feedback that says it actually matters?
