quill-fastsort-simd

Single-threaded radix sort backend for quill-sort. Portable C++17 build, compiling natively on macOS (arm64/x86_64), Linux (x86_64/aarch64) and Windows.

Provides the entry points quill._backends.SimdCompanionBackend (backend name simd_companion) probes for:

sort_i64  sort_u64  sort_i32
sort_u32  sort_f64  sort_f32

Each sorts a contiguous, writable numpy buffer of the matching dtype in place, ascending. The kernel is quillcore::serial_sort — a single-threaded 8-bit LSD radix sort. It is the SIMD-friendly companion with a conservative min_n in quill, so small arrays fall back to the dispatcher's default path.

• Never-lose: results are identical to np.sort on NaN-free numeric data (verified exhaustively against np.sort across dtypes, sizes and adversarial distributions). NaN is stripped by the Quill dispatcher before any kernel runs.

Build

pip install .            # needs only a C++17 compiler

The sort kernels are header-only (src/quill_core.hpp, a synced copy of companions/_core/quill_core.hpp — run companions/sync_core.sh after editing the canonical core). No numpy headers or third-party libraries are required.