Files
Ivan PleshkovandClaude Fable 5 4aa8066b75 Turbo4 batched scan (#10362)
* TurboQuantizer::score_precomputed_batch: score a contiguous run of vectors

Batch counterpart of `score_precomputed` for vectors stored back to
back at `quantized_size()`: the width's kernel scores the whole run of
codes in one `dotprod_batch` call, then a second pass applies each
vector's extras.  L1 dequantizes per vector and stays a plain loop.

Tested against per-vector `score_precomputed` for every width,
distance, and mode over run lengths that leave every group remainder.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* EncodedStorage::for_each_run: serve consecutive offsets as contiguous runs

`for_each_run(offsets, callback(first, count, bytes))` splits the
offsets into maximal runs of consecutive ids the storage can serve
from one contiguous slice, so a sequential scan resolves chunk lookups
and reads once per run instead of once per vector.  The default serves
every vector as its own run; `for_each_consecutive_run` is the shared
run detection for storages that override it, with a per-run cap for
chunk boundaries.  The test storage overrides it (its data is one flat
buffer).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* EncodedVectors::score_points: batched scoring entry point, run-batched for TQ

`score_points(query, offsets, scores)` scores a batch of points.  The
default keeps the per-vector loop the scorers run today, so SQ/PQ/BQ
are unchanged.  TurboQuant overrides it: on RAM/mmap storages it walks
`for_each_run` and scores each contiguous run with one
`score_precomputed_batch` call, hoisting the score inversion out of
the loop; backends with async reads keep the pipelined per-vector
path.  Non-consecutive offsets degrade to single-vector runs, so
scattered access keeps its previous cost.

Integration test: `score_points` vs `score_point` for every bit width
and mode, Dot and inverted L2, over sequential, scattered and
descending id orders.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* Quantized storages: for_each_run over their contiguous regions

The RAM storage and both chunked mmap storages cap runs at their chunk
boundary and serve each run with one `get_many`; the single-file mmap
storage serves any run as one sequential read.  Unit test on the RAM
storage: runs cover every offset once, in order, with bytes identical
to per-point reads, across the internal chunk boundary.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* QuantizedQueryScorer: score batches through EncodedVectors::score_points

Routes `score_stored_batch` through the batched entry point, so
TurboQuant-as-quantization scans score contiguous runs with one kernel
call per run; SQ/PQ/BQ keep the per-vector loop via the default.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* TurboScoring::score_query_batch: run-batched scoring for Turbo4 storages

Adds the batch counterpart of `score_query_bytes` to the trait, with
one shared implementation over the storage's `EncodedStorage`:
consecutive ids are coalesced into contiguous runs, each run scored by
a single `score_precomputed_batch` call, and the metric sign applied
once over the batch.  Backends with async reads keep the pipelined
per-vector path.  `TurboQueryScorer::score_stored_batch` now calls it.

The batch-vs-single storage test grows to 8192 vectors so a full
ascending scan crosses a chunk boundary of the chunked backend, and
runs that scan on the chunked, mmap and io_uring backends.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* score_precomputed_batch: keep the extras pass in L1

The kernel pass and the extras pass now alternate over sub-runs of 64
vectors instead of each covering the whole run: for a run of several
hundred vectors the second pass otherwise refetched every vector's
extras from L2.  Measured with 512-vector runs from the full-scan
driver at dim 512: the regression against 64-vector runs went from
+11 % to +2 %.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* Bench: exhaustive search over Turbo4 storages through the plain-index driver

`turbo4_full_scan` runs `BatchFilteredSearcher::peek_top_visible` —
the exact path of a non-indexed search — over 200k normalized random
vectors for Turbo4 as datatype (appendable chunked, in RAM) and Turbo4
as quantization (over a RAM dense storage), at dims 64 to 1024, so the
fixed per-point cost of the scan driver is measured next to the kernel.
`TURBO_SCAN_DIMS=64,128` narrows the dims while iterating.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
2026-09-02 11:41:07 +02:00
..
2026-09-02 11:41:07 +02:00