README.md

vectorcmp

This library provides functions to do comparions on many rows using AVX2's VPCMP instruction. Fallback code is transparently used if AVX(2) is not available.

VectorEquals

The easiest way to explain is to just show the fallback code.

func goVectorEquals[T uint8 | uint16 | uint32 | uint64 | float32 | float64](dst []byte, search T, rows []T) {
  clear(dst)
  for i, v := range rows {
    if search == v {
      dst[i/8] |= 1 << (i % 8)
    }
  }
}

Similar to VectorEquals we also implement VectorGreaterThan, VectorLessThan, VectorGreaterEquals and VectorLesserEquals.

Benchmark

goos: linux
goarch: amd64
pkg: github.com/hexon/vectorcmp
cpu: 13th Gen Intel(R) Core(TM) i9-13900
                              │     purego     │                avx2                 │
                              │     sec/op     │   sec/op     vs base                │
VectorEquals8-32                191765.5n ± 2%   912.5n ± 2%  -99.52% (p=0.000 n=10)
VectorGreaterThan8-32           189871.0n ± 1%   899.4n ± 1%  -99.53% (p=0.000 n=10)
VectorLessThan8-32              189939.5n ± 2%   903.3n ± 1%  -99.52% (p=0.000 n=10)
VectorGreaterEquals8-32         200345.0n ± 1%   969.2n ± 3%  -99.52% (p=0.000 n=10)
VectorLesserEquals8-32          198189.5n ± 2%   973.8n ± 3%  -99.51% (p=0.000 n=10)
VectorEquals16-32                187.738µ ± 2%   1.892µ ± 7%  -98.99% (p=0.000 n=10)
VectorGreaterThan16-32           191.861µ ± 1%   1.890µ ± 6%  -99.01% (p=0.000 n=10)
VectorLessThan16-32              189.357µ ± 2%   1.894µ ± 4%  -99.00% (p=0.000 n=10)
VectorGreaterEquals16-32         201.101µ ± 2%   2.003µ ± 5%  -99.00% (p=0.000 n=10)
VectorLesserEquals16-32          197.853µ ± 1%   1.991µ ± 5%  -98.99% (p=0.000 n=10)
VectorEquals32-32                192.640µ ± 1%   3.685µ ± 5%  -98.09% (p=0.000 n=10)
VectorEqualsFloat32-32           209.408µ ± 1%   3.156µ ± 1%  -98.49% (p=0.000 n=10)
VectorGreaterThan32-32           192.983µ ± 1%   3.717µ ± 2%  -98.07% (p=0.000 n=10)
VectorGreaterThanFloat32-32      210.209µ ± 2%   3.156µ ± 1%  -98.50% (p=0.000 n=10)
VectorLessThan32-32              188.972µ ± 1%   3.729µ ± 4%  -98.03% (p=0.000 n=10)
VectorLessThanFloat32-32         211.101µ ± 3%   3.137µ ± 2%  -98.51% (p=0.000 n=10)
VectorGreaterEquals32-32         199.521µ ± 1%   3.859µ ± 4%  -98.07% (p=0.000 n=10)
VectorGreaterEqualsFloat32-32    217.290µ ± 1%   3.179µ ± 1%  -98.54% (p=0.000 n=10)
VectorLesserEquals32-32          200.432µ ± 1%   3.907µ ± 3%  -98.05% (p=0.000 n=10)
VectorLesserEqualsFloat32-32     215.699µ ± 2%   3.167µ ± 2%  -98.53% (p=0.000 n=10)
VectorEquals64-32                194.138µ ± 2%   6.628µ ± 4%  -96.59% (p=0.000 n=10)
VectorEqualsFloat64-32           228.983µ ± 1%   6.341µ ± 1%  -97.23% (p=0.000 n=10)
VectorGreaterThan64-32           191.010µ ± 2%   7.453µ ± 3%  -96.10% (p=0.000 n=10)
VectorGreaterThanFloat64-32      205.197µ ± 1%   6.357µ ± 1%  -96.90% (p=0.000 n=10)
VectorLessThan64-32              192.766µ ± 3%   7.443µ ± 3%  -96.14% (p=0.000 n=10)
VectorLessThanFloat64-32         212.995µ ± 2%   6.323µ ± 1%  -97.03% (p=0.000 n=10)
VectorGreaterEquals64-32         203.198µ ± 2%   7.407µ ± 3%  -96.35% (p=0.000 n=10)
VectorGreaterEqualsFloat64-32    220.453µ ± 2%   6.391µ ± 2%  -97.10% (p=0.000 n=10)
VectorLesserEquals64-32          201.495µ ± 2%   7.541µ ± 3%  -96.26% (p=0.000 n=10)
VectorLesserEqualsFloat64-32     215.303µ ± 3%   6.388µ ± 2%  -97.03% (p=0.000 n=10)
geomean                            201.1µ        3.160µ       -98.43%