`dot_i8` had an AVX2 kernel and a scalar fallback, so on aarch64 the
quantised HNSW index ran the scalar loop. It now dispatches to one of
two NEON kernels:
- `dot_i8_dotprod`: the ARMv8.2 dot-product instruction, `SDOT`, which
multiplies and accumulates sixteen i8 pairs into four i32 lanes per
instruction. Present on Cortex-A76 and later (Raspberry Pi 5, current
Android phones), Neoverse-N1 (Graviton2, Ampere Altra) and every Apple
Silicon generation. Issued as inline assembly because the `vdotq_s32`
intrinsic is still behind the unstable `stdarch_neon_dotprod` feature;
inline asm is stable on aarch64.
- `dot_i8`: plain NEON for cores without the extension — `vmull_s8`
widens to i16 (even -128 * -128 fits) and `vpadalq_s16` folds adjacent
pairs into i32 accumulators, so nothing overflows.
Selected at runtime with `is_aarch64_feature_detected!("dotprod")`.
Verified on a Raspberry Pi 5 (Cortex-A76, `asimddp` present), not just
compiled — the aarch64 code is cfg'd out on x86, so x86 CI never builds
or lints it:
- both kernels bit-exact against scalar at every length, tails and
extremes included. Each is tested directly rather than through
dispatch, because dispatch only takes one path on a given CPU: on the
Pi, testing through it alone would never have run the plain-NEON
fallback at all.
- mutation-checked: dropping the SDOT kernel's second accumulator fails
at length 32, and using the low half twice in the NEON kernel fails at
length 16 — the first lengths that exercise each.
- the ANN suite passes, including int8 recall against ground truth.
- clippy clean with -D warnings on aarch64.
Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
The int8-quantised HNSW index compared vectors with a scalar loop that
the compiler vectorised for the x86-64 baseline (SSE2), while the f32
path it was measured against goes through `clawhdf5-accel` and runs
AVX2. So the ~13% throughput cost recorded for `quantized_index` was a
missing kernel rather than a property of int8.
`clawhdf5_accel::dot_i8` adds a scalar fallback and an AVX2 path:
sign-extend each 16-byte half to i16, then `madd_epi16`, which
multiplies and sums adjacent pairs straight into i32 lanes. It is
dispatched through the same detected backend as the f32 kernels, and
the index now calls it.
Integer arithmetic, so the SIMD path must agree with scalar bit for
bit — tested at lengths that are and are not multiples of the block,
and at the -128 extreme for overflow.
Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
Bump all workspace crates, the node package and pyproject to 2.5.0, fold the
two unreleased sections together and add upgrade notes for the behaviour
changes.
Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
Bump all workspace crates, the node package and pyproject to 2.4.0, finalize
the changelog and add upgrade notes for the search behaviour changes.
Co-Authored-By: Claude Fable 5.1 <[email protected]>
- Cosine distance was 1 - dot/(|a||b|), re-deriving both norms on every
evaluation in the innermost loop of build and search. The index now stores
unit vectors (prepared at build, insert, graph load and HDF5 load; the query
once per search) and uses 1 - dot. Zero vectors stay zero, giving distance 1
as before. Returned distances are unchanged.
- search_layer allocated a HashSet of visited nodes per call. It is now an
epoch-stamped u32 array in thread-local scratch, reused across calls, so
search(&self) stays shareable between threads.
- clawhdf5-accel caches the detected SIMD backend in a OnceLock.
Recall is identical. Build 2.75 -> 1.89 s (10K), ~38 -> 21 s (100K); QPS at
ef=64 22.7K -> 39K (10K), 10.4K -> 14K (100K).
Co-Authored-By: Claude Fable 5.1 <[email protected]>
Bump all workspace crates, the node package and pyproject to 2.3.0, finalize
the changelog and add upgrade notes for the behaviour changes.
Co-Authored-By: Claude Fable 5.1 <[email protected]>
Formatting only. cargo fmt --check was already failing on main (accel SIMD
kernels, agent, format, migrate, bench); CI now enforces it.
Co-Authored-By: Claude Fable 5.1 <[email protected]>
Bump all workspace crates, the node package and pyproject to 2.2.0 and
finalize the changelog. The repository URL in every manifest pointed at a
GitHub location that does not resolve; use the real origin.
Co-Authored-By: Claude Fable 5.1 <[email protected]>
The SIMD migration weakened the near-zero-norm guard in all four
clawhdf5-accel cosine_similarity backends (scalar/avx2/avx512/neon)
from `denom < f32::EPSILON` to `denom == 0.0`. Vectors with a tiny
but nonzero norm (denom in (0, 1.19e-7)) fell through to dot/denom
and scored as identical instead of maximally dissimilar, diverging
from the pre-SIMD scalar loop's documented fallback behavior.
Restores the epsilon threshold in all four backends so
`1.0 - cosine_similarity(...)` in hnsw.rs::compute_distance
reproduces the old fallback exactly. Adds regression tests in
clawhdf5-accel and clawhdf5-ann locking in the near-zero-norm case.
Co-Authored-By: Claude Sonnet 5 <[email protected]>
Add [workspace.dependencies] to the root Cargo.toml for the four
duplicated-across-many-crates dependencies flagged by the earlier review:
tempfile (7 crates), criterion (6), half (4 — real version skew, clawhdf5-gpu
pinned 2.7 while others used bare 2), and serde (4). Update every consuming
crate to `dep = { workspace = true }`, preserving crate-local `optional =
true` where it already existed. half now resolves uniformly to 2.7.x
workspace-wide instead of two separate semver ranges.
Also fixed clawhdf5-filters/Cargo.toml's stale "rustyhdf5" description
while touching the file (same class of leftover rename as prior fixes).
Not touching rayon/byteorder/clap (no skew found, lower priority).
- Add .gitea/workflows/ci.yml running scripts/ci-test.sh (fmt, clippy,
test, no_std check) on push/PR to main.
- Fix stale rustyhdf5-py/rustyhdf5-format package names in
ci-test.sh/check-nostd.sh, which had been silently no-op'ing those
checks (cargo warns but doesn't fail on an unknown --exclude/-p
target).
- With those checks actually running, fix the real issues they surface:
- clippy: useless_conversion in chunked_write.rs, byte_char_slices in
global_heap.rs/object_header.rs.
- cargo fmt: apply formatting across the workspace (whitespace only).
- no_std (thumbv7em-none-eabihf) build errors in clawhdf5-format:
core::sync::atomic::AtomicU64 doesn't exist on that target (no
native 64-bit atomics) — switch profiling.rs's counters to
portable-atomic, which falls back to a CAS-based emulation there
and is a no-op wrapper elsewhere. Add missing alloc imports for
Box (filters.rs), Vec (filters_szip.rs), and format! (dict_encoding.rs)
on no_std paths. Replace f64::powi (std/libm-only) with a small
local exponentiation-by-squaring helper in the scale-offset filter.
Sweep of the docs after the v2.0.0 rename and recent changes:
- Per-crate READMEs (13 files): rename leftover rustyhdf5-*/edgehdf5-*
package names and badges to clawhdf5-*, bump usage versions to 2.1.0.
- README: update stale test badge (417 -> 1500+), workspace stats
(15 crates/72K -> 17 crates/84K), agent crate stats (20.7K/32 modules),
and add the missing clawhdf5-napi and clawhdf5-bench crates to the tree.
- CLAUDE.md: correct the CLI subcommand list (inspect/dump/index/search ->
the actual create/save/search/recall/stats/flush-wal/agents-md/export/snapshot).
No code changes. Verified there are zero todo!()/unimplemented!() macros and
no TODO/FIXME comments in the tree.
Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>
Bumps [workspace.package] and all 17 crate package versions (and internal
path-dependency requirements) from 2.0.0 to 2.1.0 for a coordinated release.
Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>
