github.com/weaviate/weaviate@v1.24.6/adapters/repos/db/vector/hnsw/distancer/asm/dot_inline.go (about)

     1  //                           _       _
     2  // __      _____  __ ___   ___  __ _| |_ ___
     3  // \ \ /\ / / _ \/ _` \ \ / / |/ _` | __/ _ \
     4  //  \ V  V /  __/ (_| |\ V /| | (_| | ||  __/
     5  //   \_/\_/ \___|\__,_| \_/ |_|\__,_|\__\___|
     6  //
     7  //  Copyright © 2016 - 2024 Weaviate B.V. All rights reserved.
     8  //
     9  //  CONTACT: hello@weaviate.io
    10  //
    11  
    12  package asm
    13  
    14  // Experiment with inlining and flattening the L2Squared distancer.
    15  // Theoretically, this should be faster than the loop version for small vectors
    16  // - it avoids the loop overhead
    17  // - it eliminates the bounds check by reversing the iteration
    18  // - it allows dot2, dot4 and dot6 to be inlined (the other ones are too large)
    19  // See go tool compile -d=ssa/check_bce/debug=1 -m dot_inline.go
    20  
    21  func dot2(x []float32, y []float32) float32 {
    22  	sum := x[1]*y[1] + x[0]*y[0]
    23  
    24  	return sum
    25  }
    26  
    27  func dot4(x []float32, y []float32) float32 {
    28  	sum := x[3]*y[3] + x[2]*y[2]
    29  
    30  	return dot2(x, y) + sum
    31  }
    32  
    33  func dot6(x []float32, y []float32) float32 {
    34  	sum := x[5]*y[5] + x[4]*y[4]
    35  
    36  	return dot4(x, y) + sum
    37  }
    38  
    39  func dot8(x []float32, y []float32) float32 {
    40  	sum := x[7]*y[7] + x[6]*y[6]
    41  
    42  	return dot6(x, y) + sum
    43  }
    44  
    45  func dot10(x []float32, y []float32) float32 {
    46  	sum := x[9]*y[9] + x[8]*y[8] + x[7]*y[7] + x[6]*y[6]
    47  
    48  	return dot6(x, y) + sum
    49  }
    50  
    51  func dot12(x []float32, y []float32) float32 {
    52  	sum := x[11]*y[11] + x[10]*y[10] + x[9]*y[9] + x[8]*y[8] + x[7]*y[7] + x[6]*y[6]
    53  
    54  	return dot6(x, y) + sum
    55  }