On Wed, 8 Mar 2023 13:46:03 GMT, Quan Anh Mai <qa...@openjdk.org> wrote:
>> `Vector::slice` is a method at the top-level class of the Vector API that >> concatenates the 2 inputs into an intermediate composite and extracts a >> window equal to the size of the inputs into the result. It is used in vector >> conversion methods where the part number is not 0 to slice the parts to the >> correct positions. Slicing is also used in text processing such as utf8 and >> utf16 validation. x86 starting from SSSE3 has `palignr` which does vector >> slicing very efficiently. As a result, I think it is beneficial to add a C2 >> node for this operation as well as intrinsify `Vector::slice` method. >> >> A slice is currently implemented as >> `v2.rearrange(iota).blend(v1.rearrange(iota), blendMask)` which requires >> preparation of the index vector and the blending mask. Even with the >> preparations being hoisted out of the loops, microbenchmarks show >> improvement using the slice instrinsics. Some have tremendous increases in >> throughput due to the limitation that a mask of length 2 cannot currently be >> intrinsified, leading to falling back to the Java implementations. >> >> Please take a look and have some reviews. Thank you very much. > > Quan Anh Mai has updated the pull request incrementally with one additional > commit since the last revision: > > address reviews Java changes look good. The HotSpot code looks well structured but i will let others comment on the specifics. ------------- Marked as reviewed by psandoz (Reviewer). PR: https://git.openjdk.org/jdk/pull/12909
