Sure, unaligned access to memory is always expensive (on architectures that allow it at all). But I'm talking about retrieving the 9th to 16th bit of a word, w

Sure, unaligned access to memory is always expensive (on architectures that allow it at all). But I'm talking about retrieving the 9th to 16th bit of a word, which is a little different. x86 does this just fine/quickly, because bytes are addressable.