MDEV-34804: mhnsw: compiler-independent choice of CPU-specific optimizations#4671
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hadeer-r wants to merge 1 commit intoMariaDB:mainfrom
Draft
MDEV-34804: mhnsw: compiler-independent choice of CPU-specific optimizations#4671hadeer-r wants to merge 1 commit intoMariaDB:mainfrom
hadeer-r wants to merge 1 commit intoMariaDB:mainfrom
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Replace GCC function multiversioning (__attribute__((target(...)))) with runtime CPU detection using function pointers. At startup, cpuid selects the optimal SIMD implementation (AVX512, AVX2) via a Vector_ops struct. Move x86 CPU detection into a separate vector_mhnsw_x86.cc, compiled with appropriate -mavx2/-mavx512 flags. This makes the dispatching work with musl libc and MSVC, which do not support GCC function multiversioning. Benchmark (1M iterations, 1024 dimensions, AVX512): 0.039602 s total, 0.039602 us per call
gkodinov
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Issue: MDEV-34804
Description
In this draft PR I test different approaches for compiler-independent CPU-specific optimization dispatching in MHNSW. Results and comparison will follow.
Progress
Function pointer:
vector_mhnsw_x86.ccBenchmark: (1M iterations, 1024 dimensions, AVX512)