Thanks for the interest in this article (I am the author of this article). @vinx13 answer this correctly. It is not restricted on skylake. try_reorder and try_unroll_vec is to make AutoTVM tune and try to find the best loop order / schedule primitives so that we could improve loop locality and performance. try_unroll_vec will decide whether we unroll / vectorize axis. For example, unroll maybe is not always better than unroll, because unroll will result in producing more instructions and maybe can not be hold in instruction cache so that we get worse performance. So try_unroll_vec is one better solution.