reorganize the scalar quantizer code for dynamic dispatch#4849
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…spatch Summary: Split the SIMD-gated template specializations out of ScalarQuantizer.cpp into per-SIMD compilation units and wire up the Dynamic Dispatch (DD) infrastructure (`COMPILE_SIMD_*`, `with_simd_level`, `DISPATCH_SIMDLevel`). This follows the established pattern from `pq_code_distance/` and `distances/`. **New files:** - `sq_impl.h` — declares `sq_select_quantizer<SL>`, `sq_select_distance_computer<SL>`, `sq_select_InvertedListScanner<SL>` - `sq-inl.h` — private implementation header with shared template bodies (`select_quantizer_1_body`, `select_distance_computer_body`, `select_InvertedListScanner_body`) and scanner class templates (`IVFSQScannerIP`, `IVFSQScannerL2`) - `sq-generic.cpp` — `SIMDLevel::NONE` specializations (always compiled) - `sq-avx2.cpp` — `SIMDLevel::AVX2` specializations (`d%8` alignment) - `sq-avx512.cpp` — `SIMDLevel::AVX512` + `AVX512_SPR` forwarding - `sq-neon.cpp` — `SIMDLevel::ARM_NEON` specializations (`d%8` alignment) **Modified files:** - `ScalarQuantizer.cpp` — rewritten to use `with_simd_level` dispatch with nullptr-fallback to NONE - `quantizers.h`, `distance_computers.h` — lint formatting only - `xplat.bzl`, `CMakeLists.txt` — register new SIMD files and headers Each per-SIMD factory returns `nullptr` when the dimension doesn't align, and the caller falls back to NONE. This avoids ODR issues from instantiating `<NONE>` templates in multiple TUs. The sub-headers (codecs.h, quantizers.h, similarities.h, distance_computers.h) keep their original compiler-defined guards (`__AVX512F__`, `__AVX2__`, `USE_NEON`, etc.) because `COMPILE_SIMD_*` macros are globally visible in DD mode but the SIMD intrinsics are only available in per-SIMD TUs. The `USE_*` macros are now defined in `sq-inl.h`. Differential Revision: D94375408
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…search#4849) Summary: Pull Request resolved: facebookresearch#4849 This version introduces a cleaner separation between the SIMD templatized code. It also avoids multiple levels of indirection that existed in the original diff. The dispatching functions are now in sq-dispatch.h, which is piloted by a macro that tells it which SIMD level to instanciate. ScalarQuantizer.cpp instanciates level NONE and the sq-XXX.cpp versions instanciate the other SIMD levels. Differential Revision: D94588394
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…search#4849) Summary: Pull Request resolved: facebookresearch#4849 This version introduces a cleaner separation between the SIMD templatized code. It also avoids multiple levels of indirection that existed in the original diff. The dispatching functions are now in sq-dispatch.h, which is piloted by a macro that tells it which SIMD level to instanciate. ScalarQuantizer.cpp instanciates level NONE and the sq-XXX.cpp versions instanciate the other SIMD levels. Differential Revision: D94588394
mdouze
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…search#4849) Summary: Pull Request resolved: facebookresearch#4849 This version introduces a cleaner separation between the SIMD templatized code. It also avoids multiple levels of indirection that existed in the original diff. The dispatching functions are now in sq-dispatch.h, which is piloted by a macro that tells it which SIMD level to instanciate. ScalarQuantizer.cpp instanciates level NONE and the sq-XXX.cpp versions instanciate the other SIMD levels. Differential Revision: D94588394
mdouze
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Mar 2, 2026
…search#4849) Summary: Pull Request resolved: facebookresearch#4849 This version introduces a cleaner separation between the SIMD templatized code. It also avoids multiple levels of indirection that existed in the original diff. The dispatching functions are now in sq-dispatch.h, which is piloted by a macro that tells it which SIMD level to instanciate. ScalarQuantizer.cpp instanciates level NONE and the sq-XXX.cpp versions instanciate the other SIMD levels. Differential Revision: D94588394
…search#4849) Summary: Pull Request resolved: facebookresearch#4849 This version introduces a cleaner separation between the SIMD templatized code. It also avoids multiple levels of indirection that existed in the original diff. The dispatching functions are now in sq-dispatch.h, which is piloted by a macro that tells it which SIMD level to instanciate. ScalarQuantizer.cpp instanciates level NONE and the sq-XXX.cpp versions instanciate the other SIMD levels. Differential Revision: D94588394
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Summary:
This version introduces a cleaner separation between the SIMD templatized code.
It also avoids multiple levels of indirection that existed in the original diff.
The dispatching functions are now in sq-dispatch.h, which is piloted by a macro that tells it which SIMD level to instanciate.
ScalarQuantizer.cpp instanciates level NONE and the sq-XXX.cpp versions instanciate the other SIMD levels.
Differential Revision: D94588394