wuleiwuleiwulei opened a new pull request, #10066:
URL: https://github.com/apache/arrow-rs/pull/10066
Add a runtime-detected SVE gather path to RleDecoder::get_batch_with_dict.
On AArch64, NEON has no gather instruction and SVE is not part of the baseline
ISA, so a portable binary cannot autovectorise the dictionary lookup to a
hardware gather. This adds an inline-assembly SVE kernel, gated by a cached
`is_aarch64_feature_detected!("sve")` check, that gathers 4- and 8-byte
dictionary values.
The gather slots in at the existing `get_unchecked` site introduced in #9746
and reuses its hoisted max-reduction bounds check, so it adds no new
per-element checks. It is gated on `!needs_drop::<T>()` since the kernel copies
raw element bytes, and falls back to the scalar loop for every other type,
width, or when SVE is unavailable. Non-AArch64 targets are unchanged.
# Which issue does this PR close?
<!--
We generally require a GitHub issue to be filed for all bug fixes and
enhancements and this helps us generate change logs for our releases. You can
link an issue to this PR using the GitHub syntax.
-->
- Closes #10036 .
# Rationale for this change
<!--
Why are you proposing this change? If this is already explained clearly in
the issue then this section is not needed.
Explaining clearly why changes are proposed helps reviewers understand your
changes and offer better suggestions for fixes.
-->
# What changes are included in this PR?
<!--
There is no need to duplicate the description in the issue here but it is
sometimes worth providing a summary of the individual changes in this PR.
-->
# Are these changes tested?
<!--
We typically require tests for all PRs in order to:
1. Prevent the code from being accidentally broken by subsequent changes
2. Serve as another way to document the expected behavior of the code
If tests are not included in your PR, please explain why (for example, are
they covered by existing tests)?
If this PR claims a performance improvement, please include evidence such as
benchmark results.
-->
# Are there any user-facing changes?
<!--
If there are user-facing changes then we may require documentation to be
updated before approving the PR.
If there are any breaking changes to public APIs, please call them out.
-->
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
