Add Neon implementation of is_sorted_until
#6018
Open
+133
−9
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
AlexGuteniev
approved these changes
Jan 16, 2026
StephanTLavavej
added
performance
StephanTLavavej
approved these changes
Jan 17, 2026
| if constexpr (_Traits::_Vectorized) { | ||
| const size_t _Total_size_bytes = _Byte_length(_First, _Last); | ||
|
|
||
| const auto _Cmp_gt_wrap = [](const auto _Right, const auto _Left) noexcept { |
Member
There was a problem hiding this comment.
No change requested: This parameter order does non-Newtonian things to my brain but I suppose it is consistent with the code below.
Contributor
There was a problem hiding this comment.
On instruction level, both ISAs have the GT mnemonic and not LT mnemonic.
So on intrinsics level lt is weird, and SSE4,2/AVX2 doesn't even have them (SSE2 does though).
For C++ the default predicate is std::less,
We need to bridge these two somehow. Ideally that this part would stand out.
By putting it into the least comfortable place we ensure it stands out.
Contributor
There was a problem hiding this comment.
(See also Pearl River Necklace bridge)
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
3 participants
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
This PR adds a vectorized implementation of
is_sorted_untilusing Neon intrinsics 🚀Performance numbers (speedup figure relative to the existing, non-manually vectorized code - higher is better)