Quiver v0.7.0

Quiver v0.7.0 — Apple M2 performance closure, sub-byte unpack, release-path repair

The single-machine performance story is closed: every Apple M2 operation shape dispatches to the
fastest correct implementation with committed evidence, and this is the first tag whose release
pipeline ran green end to end — full CI gate, three-platform differential sweep, 4.5 h
differential fuzz, MSan (fixed this release, R-19), LSan — and published its artifacts.

What changed?

• Vectorized sub-byte bit-unpack (widths 1–7) promoted to production dispatch: 6.9×–11.0×
  over the scalar gather on Apple M2, exact ⌈n·w/8⌉ read bound preserved and guard-page proven.
• Evidence-gated delegations on aarch64: 64-bit compare bitmap and 8-byte elementwise
  arithmetic run the compiler's code where it measured faster (parity verified at every registered
  shape); narrow-width compare (i8/i16/i32) measured and stays handwritten (2.8×/1.6×/1.1× wins).
• Complete Apple M2 paired benchmark grid: 53 shapes, zero unknowns; dense-i64-sum parity and
  null-masked wins up to 8.39× recorded honestly.
• Nightly MSan leg fixed (R-19 closed): the release publish path is live for the first time.
• Full details: CHANGELOG ·
  release notes.

Did the API change?

No. All public signatures unchanged (the M10 freeze audit remains clean). Dispatch behavior
changes only in which backend runs for the affected shapes; results are bit-identical everywhere.

Which platforms passed?

Linux x86-64 (GCC 13/14, Clang 17/19), Linux ARM64 (GCC 14, Clang 19), macOS ARM64 (Apple Clang)
— full suite. AVX-512 correctness under Intel SDE (-spr, -skx). MSVC amalgamation (tier-2,
default /arch, two documented exclusions). The matrix with compiles/tested/measured kept
distinct: compatibility.

Which machines were measured?

One: Apple M2 (apple-m2-mba, secondary platform, no PMU). Every number above is from that
machine's committed ledger and no cross-CPU claim is made. Registering an x86 machine is the most
valuable contribution the project can receive:
#38 / #39.

What remains unverified?

Native AVX-512 performance (no hardware), x86 performance generally, Windows performance; v1.0
certification is deferred until the multi-machine coverage and regression gates can run (R-06).
The status report keeps
the full honest list.

How do I install it?

• Two files, one command (attached below): download quiver.h + quiver.cpp, then
  c++ -std=c++23 -O3 your_app.cpp quiver.cpp — the
  30-second quickstart
  was compile-run verified against these exact artifacts.
• CMake: FetchContent from this tag, or find_package(Quiver CONFIG) after install.
• vcpkg / Conan Center submissions are staged
  (#40, #41).

Verifying the artifacts

SHA256SUMS covers every attached file; each artifact carries a GitHub build-provenance
attestation: gh attestation verify <file> --repo div0rce/quiver. Both were verified before this
release was published.