On Fri, 13 Sep 2024 19:45:11 GMT, Paul Sandoz <psan...@openjdk.org> wrote:
>>> Given `rearrange` with 1 vector gets wrapping indices semantics. I think we >>> should stop normalizing indices when converting a `Vector` into a >>> `VectorShuffle` (currently we wrap all out-of-bound elements to `[-VLEN, >>> 0)`). Then the rearrange with 2 vectors will also wrap similarly (all >>> indices are `& (VLEN * 2 - 1)`, then indices `[0, VLEN)` maps to the first >>> vector and indices `[VLEN, 2 * VLEN)` map to the second vector). We will >>> normalize the indices when we invoke `VectorShuffle::toVector` which I >>> think is much less used than `Vector::toShuffle`. What do you think? >> >> The guidance from Paul Sandoz and John Rose is to keep the the partial >> wrapping at shuffle construction as is for now and only change the rearrange >> and selectFrom apis. > >> >> The guidance from Paul Sandoz and John Rose is to keep the the partial >> wrapping at shuffle construction as is for now and only change the rearrange >> and selectFrom apis. > > Yes, we are trying to take smaller incremental steps. Once the we are done > with this work we can step back and discuss/review what to do about shuffles. @PaulSandoz Thanks a lot for the review and the CSR. I will look forward to Hotspot review and CSR progress/approval. ------------- PR Comment: https://git.openjdk.org/jdk/pull/20634#issuecomment-2353449454
