faiss/docs/html/hamming_8h_source.html

689 lines
88 KiB
HTML

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/xhtml;charset=UTF-8"/>
<meta http-equiv="X-UA-Compatible" content="IE=9"/>
<meta name="generator" content="Doxygen 1.8.5"/>
<title>Faiss: /tmp/faiss/hamming.h Source File</title>
<link href="tabs.css" rel="stylesheet" type="text/css"/>
<script type="text/javascript" src="jquery.js"></script>
<script type="text/javascript" src="dynsections.js"></script>
<link href="search/search.css" rel="stylesheet" type="text/css"/>
<script type="text/javascript" src="search/search.js"></script>
<script type="text/javascript">
$(document).ready(function() { searchBox.OnSelectItem(0); });
</script>
<link href="doxygen.css" rel="stylesheet" type="text/css" />
</head>
<body>
<div id="top"><!-- do not remove this div, it is closed by doxygen! -->
<div id="titlearea">
<table cellspacing="0" cellpadding="0">
<tbody>
<tr style="height: 56px;">
<td style="padding-left: 0.5em;">
<div id="projectname">Faiss
</div>
</td>
</tr>
</tbody>
</table>
</div>
<!-- end header part -->
<!-- Generated by Doxygen 1.8.5 -->
<script type="text/javascript">
var searchBox = new SearchBox("searchBox", "search",false,'Search');
</script>
<div id="navrow1" class="tabs">
<ul class="tablist">
<li><a href="index.html"><span>Main&#160;Page</span></a></li>
<li><a href="namespaces.html"><span>Namespaces</span></a></li>
<li><a href="annotated.html"><span>Classes</span></a></li>
<li class="current"><a href="files.html"><span>Files</span></a></li>
<li>
<div id="MSearchBox" class="MSearchBoxInactive">
<span class="left">
<img id="MSearchSelect" src="search/mag_sel.png"
onmouseover="return searchBox.OnSearchSelectShow()"
onmouseout="return searchBox.OnSearchSelectHide()"
alt=""/>
<input type="text" id="MSearchField" value="Search" accesskey="S"
onfocus="searchBox.OnSearchFieldFocus(true)"
onblur="searchBox.OnSearchFieldFocus(false)"
onkeyup="searchBox.OnSearchFieldChange(event)"/>
</span><span class="right">
<a id="MSearchClose" href="javascript:searchBox.CloseResultsWindow()"><img id="MSearchCloseImg" border="0" src="search/close.png" alt=""/></a>
</span>
</div>
</li>
</ul>
</div>
<div id="navrow2" class="tabs2">
<ul class="tablist">
<li><a href="files.html"><span>File&#160;List</span></a></li>
</ul>
</div>
</div><!-- top -->
<!-- window showing the filter options -->
<div id="MSearchSelectWindow"
onmouseover="return searchBox.OnSearchSelectShow()"
onmouseout="return searchBox.OnSearchSelectHide()"
onkeydown="return searchBox.OnSearchSelectKey(event)">
<a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(0)"><span class="SelectionMark">&#160;</span>All</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(1)"><span class="SelectionMark">&#160;</span>Classes</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(2)"><span class="SelectionMark">&#160;</span>Namespaces</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(3)"><span class="SelectionMark">&#160;</span>Functions</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(4)"><span class="SelectionMark">&#160;</span>Variables</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(5)"><span class="SelectionMark">&#160;</span>Typedefs</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(6)"><span class="SelectionMark">&#160;</span>Enumerations</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(7)"><span class="SelectionMark">&#160;</span>Enumerator</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(8)"><span class="SelectionMark">&#160;</span>Friends</a></div>
<!-- iframe showing the search results (closed by default) -->
<div id="MSearchResultsWindow">
<iframe src="javascript:void(0)" frameborder="0"
name="MSearchResults" id="MSearchResults">
</iframe>
</div>
<div class="header">
<div class="headertitle">
<div class="title">/tmp/faiss/hamming.h</div> </div>
</div><!--header-->
<div class="contents">
<div class="fragment"><div class="line"><a name="l00001"></a><span class="lineno"> 1</span>&#160;<span class="comment">/**</span></div>
<div class="line"><a name="l00002"></a><span class="lineno"> 2</span>&#160;<span class="comment"> * Copyright (c) 2015-present, Facebook, Inc.</span></div>
<div class="line"><a name="l00003"></a><span class="lineno"> 3</span>&#160;<span class="comment"> * All rights reserved.</span></div>
<div class="line"><a name="l00004"></a><span class="lineno"> 4</span>&#160;<span class="comment"> *</span></div>
<div class="line"><a name="l00005"></a><span class="lineno"> 5</span>&#160;<span class="comment"> * This source code is licensed under the BSD+Patents license found in the</span></div>
<div class="line"><a name="l00006"></a><span class="lineno"> 6</span>&#160;<span class="comment"> * LICENSE file in the root directory of this source tree.</span></div>
<div class="line"><a name="l00007"></a><span class="lineno"> 7</span>&#160;<span class="comment"> */</span></div>
<div class="line"><a name="l00008"></a><span class="lineno"> 8</span>&#160;</div>
<div class="line"><a name="l00009"></a><span class="lineno"> 9</span>&#160;<span class="comment">// -*- c++ -*-</span></div>
<div class="line"><a name="l00010"></a><span class="lineno"> 10</span>&#160;</div>
<div class="line"><a name="l00011"></a><span class="lineno"> 11</span>&#160;<span class="comment">/*</span></div>
<div class="line"><a name="l00012"></a><span class="lineno"> 12</span>&#160;<span class="comment"> * Hamming distances. The binary vector dimensionality should be a multiple</span></div>
<div class="line"><a name="l00013"></a><span class="lineno"> 13</span>&#160;<span class="comment"> * of 64, as the elementary operations operate on words. If you really need</span></div>
<div class="line"><a name="l00014"></a><span class="lineno"> 14</span>&#160;<span class="comment"> * other sizes, just pad with 0s (this is done by function fvecs2bitvecs).</span></div>
<div class="line"><a name="l00015"></a><span class="lineno"> 15</span>&#160;<span class="comment"> *</span></div>
<div class="line"><a name="l00016"></a><span class="lineno"> 16</span>&#160;<span class="comment"> * User-defined type hamdis_t is used for distances because at this time</span></div>
<div class="line"><a name="l00017"></a><span class="lineno"> 17</span>&#160;<span class="comment"> * it is still uncler clear how we will need to balance</span></div>
<div class="line"><a name="l00018"></a><span class="lineno"> 18</span>&#160;<span class="comment"> * - flexibility in vector size (may need 16- or even 8-bit vectors)</span></div>
<div class="line"><a name="l00019"></a><span class="lineno"> 19</span>&#160;<span class="comment"> * - memory usage</span></div>
<div class="line"><a name="l00020"></a><span class="lineno"> 20</span>&#160;<span class="comment"> * - cache-misses when dealing with large volumes of data (fewer bits is better)</span></div>
<div class="line"><a name="l00021"></a><span class="lineno"> 21</span>&#160;<span class="comment"> *</span></div>
<div class="line"><a name="l00022"></a><span class="lineno"> 22</span>&#160;<span class="comment"> * hamdis_t should optimally be compatibe with one of the Torch Storage</span></div>
<div class="line"><a name="l00023"></a><span class="lineno"> 23</span>&#160;<span class="comment"> * (Byte,Short,Long) and therefore should be signed for 2-bytes and 4-bytes.</span></div>
<div class="line"><a name="l00024"></a><span class="lineno"> 24</span>&#160;<span class="comment"> */</span></div>
<div class="line"><a name="l00025"></a><span class="lineno"> 25</span>&#160;</div>
<div class="line"><a name="l00026"></a><span class="lineno"> 26</span>&#160;<span class="preprocessor">#ifndef FAISS_hamming_h</span></div>
<div class="line"><a name="l00027"></a><span class="lineno"> 27</span>&#160;<span class="preprocessor"></span><span class="preprocessor">#define FAISS_hamming_h</span></div>
<div class="line"><a name="l00028"></a><span class="lineno"> 28</span>&#160;<span class="preprocessor"></span></div>
<div class="line"><a name="l00029"></a><span class="lineno"> 29</span>&#160;</div>
<div class="line"><a name="l00030"></a><span class="lineno"> 30</span>&#160;<span class="preprocessor">#include &lt;stdint.h&gt;</span></div>
<div class="line"><a name="l00031"></a><span class="lineno"> 31</span>&#160;</div>
<div class="line"><a name="l00032"></a><span class="lineno"> 32</span>&#160;<span class="preprocessor">#include &quot;Heap.h&quot;</span></div>
<div class="line"><a name="l00033"></a><span class="lineno"> 33</span>&#160;</div>
<div class="line"><a name="l00034"></a><span class="lineno"> 34</span>&#160;</div>
<div class="line"><a name="l00035"></a><span class="lineno"> 35</span>&#160;<span class="comment">/* The Hamming distance type should be exportable to Lua Tensor, which</span></div>
<div class="line"><a name="l00036"></a><span class="lineno"> 36</span>&#160;<span class="comment"> excludes most unsigned type */</span></div>
<div class="line"><a name="l00037"></a><span class="lineno"> 37</span>&#160;<span class="keyword">typedef</span> int32_t hamdis_t;</div>
<div class="line"><a name="l00038"></a><span class="lineno"> 38</span>&#160;</div>
<div class="line"><a name="l00039"></a><span class="lineno"> 39</span>&#160;<span class="keyword">namespace </span>faiss {</div>
<div class="line"><a name="l00040"></a><span class="lineno"> 40</span>&#160;</div>
<div class="line"><a name="l00041"></a><span class="lineno"> 41</span>&#160;</div>
<div class="line"><a name="l00042"></a><span class="lineno"> 42</span>&#160;<span class="keyword">extern</span> <span class="keywordtype">size_t</span> hamming_batch_size;</div>
<div class="line"><a name="l00043"></a><span class="lineno"> 43</span>&#160;</div>
<div class="line"><a name="l00044"></a><span class="lineno"> 44</span>&#160;<span class="keyword">inline</span> <span class="keywordtype">int</span> popcount64(uint64_t x) {</div>
<div class="line"><a name="l00045"></a><span class="lineno"> 45</span>&#160; <span class="keywordflow">return</span> __builtin_popcountl(x);</div>
<div class="line"><a name="l00046"></a><span class="lineno"> 46</span>&#160;}</div>
<div class="line"><a name="l00047"></a><span class="lineno"> 47</span>&#160;</div>
<div class="line"><a name="l00048"></a><span class="lineno"> 48</span>&#160;<span class="comment"></span></div>
<div class="line"><a name="l00049"></a><span class="lineno"> 49</span>&#160;<span class="comment">/** Compute a set of Hamming distances between na and nb binary vectors</span></div>
<div class="line"><a name="l00050"></a><span class="lineno"> 50</span>&#160;<span class="comment"> *</span></div>
<div class="line"><a name="l00051"></a><span class="lineno"> 51</span>&#160;<span class="comment"> * @param a size na * nbytespercode</span></div>
<div class="line"><a name="l00052"></a><span class="lineno"> 52</span>&#160;<span class="comment"> * @param b size nb * nbytespercode</span></div>
<div class="line"><a name="l00053"></a><span class="lineno"> 53</span>&#160;<span class="comment"> * @param nbytespercode should be multiple of 8</span></div>
<div class="line"><a name="l00054"></a><span class="lineno"> 54</span>&#160;<span class="comment"> * @param dis output distances, size na * nb</span></div>
<div class="line"><a name="l00055"></a><span class="lineno"> 55</span>&#160;<span class="comment"> */</span></div>
<div class="line"><a name="l00056"></a><span class="lineno"> 56</span>&#160;<span class="keywordtype">void</span> hammings (</div>
<div class="line"><a name="l00057"></a><span class="lineno"> 57</span>&#160; <span class="keyword">const</span> uint8_t * a,</div>
<div class="line"><a name="l00058"></a><span class="lineno"> 58</span>&#160; <span class="keyword">const</span> uint8_t * b,</div>
<div class="line"><a name="l00059"></a><span class="lineno"> 59</span>&#160; <span class="keywordtype">size_t</span> na, <span class="keywordtype">size_t</span> nb,</div>
<div class="line"><a name="l00060"></a><span class="lineno"> 60</span>&#160; <span class="keywordtype">size_t</span> nbytespercode,</div>
<div class="line"><a name="l00061"></a><span class="lineno"> 61</span>&#160; hamdis_t * dis);</div>
<div class="line"><a name="l00062"></a><span class="lineno"> 62</span>&#160;</div>
<div class="line"><a name="l00063"></a><span class="lineno"> 63</span>&#160;<span class="keywordtype">void</span> bitvec_print (<span class="keyword">const</span> uint8_t * b, <span class="keywordtype">size_t</span> d);</div>
<div class="line"><a name="l00064"></a><span class="lineno"> 64</span>&#160;</div>
<div class="line"><a name="l00065"></a><span class="lineno"> 65</span>&#160;</div>
<div class="line"><a name="l00066"></a><span class="lineno"> 66</span>&#160;<span class="comment">/* Functions for casting vectors of regular types to compact bits.</span></div>
<div class="line"><a name="l00067"></a><span class="lineno"> 67</span>&#160;<span class="comment"> They assume proper allocation done beforehand, meaning that b</span></div>
<div class="line"><a name="l00068"></a><span class="lineno"> 68</span>&#160;<span class="comment"> should be be able to receive as many bits as x may produce. */</span></div>
<div class="line"><a name="l00069"></a><span class="lineno"> 69</span>&#160;</div>
<div class="line"><a name="l00070"></a><span class="lineno"> 70</span>&#160;<span class="comment">/* Makes an array of bits from the signs of a float array. The length</span></div>
<div class="line"><a name="l00071"></a><span class="lineno"> 71</span>&#160;<span class="comment"> of the output array b is rounded up to byte size (allocate</span></div>
<div class="line"><a name="l00072"></a><span class="lineno"> 72</span>&#160;<span class="comment"> accordingly) */</span></div>
<div class="line"><a name="l00073"></a><span class="lineno"> 73</span>&#160;<span class="keywordtype">void</span> fvecs2bitvecs (</div>
<div class="line"><a name="l00074"></a><span class="lineno"> 74</span>&#160; <span class="keyword">const</span> <span class="keywordtype">float</span> * x,</div>
<div class="line"><a name="l00075"></a><span class="lineno"> 75</span>&#160; uint8_t * b,</div>
<div class="line"><a name="l00076"></a><span class="lineno"> 76</span>&#160; <span class="keywordtype">size_t</span> d,</div>
<div class="line"><a name="l00077"></a><span class="lineno"> 77</span>&#160; <span class="keywordtype">size_t</span> n);</div>
<div class="line"><a name="l00078"></a><span class="lineno"> 78</span>&#160;</div>
<div class="line"><a name="l00079"></a><span class="lineno"> 79</span>&#160;</div>
<div class="line"><a name="l00080"></a><span class="lineno"> 80</span>&#160;<span class="keywordtype">void</span> fvec2bitvec (<span class="keyword">const</span> <span class="keywordtype">float</span> * x, uint8_t * b, <span class="keywordtype">size_t</span> d);</div>
<div class="line"><a name="l00081"></a><span class="lineno"> 81</span>&#160;</div>
<div class="line"><a name="l00082"></a><span class="lineno"> 82</span>&#160;</div>
<div class="line"><a name="l00083"></a><span class="lineno"> 83</span>&#160;<span class="comment"></span></div>
<div class="line"><a name="l00084"></a><span class="lineno"> 84</span>&#160;<span class="comment">/** Return the k smallest Hamming distances for a set of binary query vectors,</span></div>
<div class="line"><a name="l00085"></a><span class="lineno"> 85</span>&#160;<span class="comment"> * using a max heap.</span></div>
<div class="line"><a name="l00086"></a><span class="lineno"> 86</span>&#160;<span class="comment"> * @param a queries, size ha-&gt;nh * ncodes</span></div>
<div class="line"><a name="l00087"></a><span class="lineno"> 87</span>&#160;<span class="comment"> * @param b database, size nb * ncodes</span></div>
<div class="line"><a name="l00088"></a><span class="lineno"> 88</span>&#160;<span class="comment"> * @param nb number of database vectors</span></div>
<div class="line"><a name="l00089"></a><span class="lineno"> 89</span>&#160;<span class="comment"> * @param ncodes size of the binary codes (bytes)</span></div>
<div class="line"><a name="l00090"></a><span class="lineno"> 90</span>&#160;<span class="comment"> * @param ordered if != 0: order the results by decreasing distance</span></div>
<div class="line"><a name="l00091"></a><span class="lineno"> 91</span>&#160;<span class="comment"> * (may be bottleneck for k/n &gt; 0.01) */</span></div>
<div class="line"><a name="l00092"></a><span class="lineno"> 92</span>&#160;<span class="keywordtype">void</span> <a class="code" href="namespacefaiss.html#aef2e95991f435b0103db0efe07edff81">hammings_knn_hc</a> (</div>
<div class="line"><a name="l00093"></a><span class="lineno"> 93</span>&#160; int_maxheap_array_t * ha,</div>
<div class="line"><a name="l00094"></a><span class="lineno"> 94</span>&#160; <span class="keyword">const</span> uint8_t * a,</div>
<div class="line"><a name="l00095"></a><span class="lineno"> 95</span>&#160; <span class="keyword">const</span> uint8_t * b,</div>
<div class="line"><a name="l00096"></a><span class="lineno"> 96</span>&#160; <span class="keywordtype">size_t</span> nb,</div>
<div class="line"><a name="l00097"></a><span class="lineno"> 97</span>&#160; <span class="keywordtype">size_t</span> ncodes,</div>
<div class="line"><a name="l00098"></a><span class="lineno"> 98</span>&#160; <span class="keywordtype">int</span> ordered);</div>
<div class="line"><a name="l00099"></a><span class="lineno"> 99</span>&#160;</div>
<div class="line"><a name="l00100"></a><span class="lineno"> 100</span>&#160;<span class="comment">/* Legacy alias to hammings_knn_hc. */</span></div>
<div class="line"><a name="l00101"></a><span class="lineno"> 101</span>&#160;<span class="keywordtype">void</span> hammings_knn (</div>
<div class="line"><a name="l00102"></a><span class="lineno"> 102</span>&#160; int_maxheap_array_t * ha,</div>
<div class="line"><a name="l00103"></a><span class="lineno"> 103</span>&#160; <span class="keyword">const</span> uint8_t * a,</div>
<div class="line"><a name="l00104"></a><span class="lineno"> 104</span>&#160; <span class="keyword">const</span> uint8_t * b,</div>
<div class="line"><a name="l00105"></a><span class="lineno"> 105</span>&#160; <span class="keywordtype">size_t</span> nb,</div>
<div class="line"><a name="l00106"></a><span class="lineno"> 106</span>&#160; <span class="keywordtype">size_t</span> ncodes,</div>
<div class="line"><a name="l00107"></a><span class="lineno"> 107</span>&#160; <span class="keywordtype">int</span> ordered);</div>
<div class="line"><a name="l00108"></a><span class="lineno"> 108</span>&#160;<span class="comment"></span></div>
<div class="line"><a name="l00109"></a><span class="lineno"> 109</span>&#160;<span class="comment">/** Return the k smallest Hamming distances for a set of binary query vectors,</span></div>
<div class="line"><a name="l00110"></a><span class="lineno"> 110</span>&#160;<span class="comment"> * using counting max.</span></div>
<div class="line"><a name="l00111"></a><span class="lineno"> 111</span>&#160;<span class="comment"> * @param a queries, size na * ncodes</span></div>
<div class="line"><a name="l00112"></a><span class="lineno"> 112</span>&#160;<span class="comment"> * @param b database, size nb * ncodes</span></div>
<div class="line"><a name="l00113"></a><span class="lineno"> 113</span>&#160;<span class="comment"> * @param na number of query vectors</span></div>
<div class="line"><a name="l00114"></a><span class="lineno"> 114</span>&#160;<span class="comment"> * @param nb number of database vectors</span></div>
<div class="line"><a name="l00115"></a><span class="lineno"> 115</span>&#160;<span class="comment"> * @param k number of vectors/distances to return</span></div>
<div class="line"><a name="l00116"></a><span class="lineno"> 116</span>&#160;<span class="comment"> * @param ncodes size of the binary codes (bytes)</span></div>
<div class="line"><a name="l00117"></a><span class="lineno"> 117</span>&#160;<span class="comment"> * @param distances output distances from each query vector to its k nearest</span></div>
<div class="line"><a name="l00118"></a><span class="lineno"> 118</span>&#160;<span class="comment"> * neighbors</span></div>
<div class="line"><a name="l00119"></a><span class="lineno"> 119</span>&#160;<span class="comment"> * @param labels output ids of the k nearest neighbors to each query vector</span></div>
<div class="line"><a name="l00120"></a><span class="lineno"> 120</span>&#160;<span class="comment"> */</span></div>
<div class="line"><a name="l00121"></a><span class="lineno"> 121</span>&#160;<span class="keywordtype">void</span> <a class="code" href="namespacefaiss.html#aa9ac586642ba474949a007546ab05592">hammings_knn_mc</a> (</div>
<div class="line"><a name="l00122"></a><span class="lineno"> 122</span>&#160; <span class="keyword">const</span> uint8_t * a,</div>
<div class="line"><a name="l00123"></a><span class="lineno"> 123</span>&#160; <span class="keyword">const</span> uint8_t * b,</div>
<div class="line"><a name="l00124"></a><span class="lineno"> 124</span>&#160; <span class="keywordtype">size_t</span> na,</div>
<div class="line"><a name="l00125"></a><span class="lineno"> 125</span>&#160; <span class="keywordtype">size_t</span> nb,</div>
<div class="line"><a name="l00126"></a><span class="lineno"> 126</span>&#160; <span class="keywordtype">size_t</span> k,</div>
<div class="line"><a name="l00127"></a><span class="lineno"> 127</span>&#160; <span class="keywordtype">size_t</span> ncodes,</div>
<div class="line"><a name="l00128"></a><span class="lineno"> 128</span>&#160; int32_t *distances,</div>
<div class="line"><a name="l00129"></a><span class="lineno"> 129</span>&#160; <span class="keywordtype">long</span> *labels);</div>
<div class="line"><a name="l00130"></a><span class="lineno"> 130</span>&#160;</div>
<div class="line"><a name="l00131"></a><span class="lineno"> 131</span>&#160;<span class="comment">/* Counting the number of matches or of cross-matches (without returning them)</span></div>
<div class="line"><a name="l00132"></a><span class="lineno"> 132</span>&#160;<span class="comment"> For use with function that assume pre-allocated memory */</span></div>
<div class="line"><a name="l00133"></a><span class="lineno"> 133</span>&#160;<span class="keywordtype">void</span> hamming_count_thres (</div>
<div class="line"><a name="l00134"></a><span class="lineno"> 134</span>&#160; <span class="keyword">const</span> uint8_t * bs1,</div>
<div class="line"><a name="l00135"></a><span class="lineno"> 135</span>&#160; <span class="keyword">const</span> uint8_t * bs2,</div>
<div class="line"><a name="l00136"></a><span class="lineno"> 136</span>&#160; <span class="keywordtype">size_t</span> n1,</div>
<div class="line"><a name="l00137"></a><span class="lineno"> 137</span>&#160; <span class="keywordtype">size_t</span> n2,</div>
<div class="line"><a name="l00138"></a><span class="lineno"> 138</span>&#160; hamdis_t ht,</div>
<div class="line"><a name="l00139"></a><span class="lineno"> 139</span>&#160; <span class="keywordtype">size_t</span> ncodes,</div>
<div class="line"><a name="l00140"></a><span class="lineno"> 140</span>&#160; <span class="keywordtype">size_t</span> * nptr);</div>
<div class="line"><a name="l00141"></a><span class="lineno"> 141</span>&#160;</div>
<div class="line"><a name="l00142"></a><span class="lineno"> 142</span>&#160;<span class="comment">/* Return all Hamming distances/index passing a thres. Pre-allocation of output</span></div>
<div class="line"><a name="l00143"></a><span class="lineno"> 143</span>&#160;<span class="comment"> is required. Use hamming_count_thres to determine the proper size. */</span></div>
<div class="line"><a name="l00144"></a><span class="lineno"> 144</span>&#160;<span class="keywordtype">size_t</span> match_hamming_thres (</div>
<div class="line"><a name="l00145"></a><span class="lineno"> 145</span>&#160; <span class="keyword">const</span> uint8_t * bs1,</div>
<div class="line"><a name="l00146"></a><span class="lineno"> 146</span>&#160; <span class="keyword">const</span> uint8_t * bs2,</div>
<div class="line"><a name="l00147"></a><span class="lineno"> 147</span>&#160; <span class="keywordtype">size_t</span> n1,</div>
<div class="line"><a name="l00148"></a><span class="lineno"> 148</span>&#160; <span class="keywordtype">size_t</span> n2,</div>
<div class="line"><a name="l00149"></a><span class="lineno"> 149</span>&#160; hamdis_t ht,</div>
<div class="line"><a name="l00150"></a><span class="lineno"> 150</span>&#160; <span class="keywordtype">size_t</span> ncodes,</div>
<div class="line"><a name="l00151"></a><span class="lineno"> 151</span>&#160; <span class="keywordtype">long</span> * idx,</div>
<div class="line"><a name="l00152"></a><span class="lineno"> 152</span>&#160; hamdis_t * dis);</div>
<div class="line"><a name="l00153"></a><span class="lineno"> 153</span>&#160;</div>
<div class="line"><a name="l00154"></a><span class="lineno"> 154</span>&#160;<span class="comment">/* Cross-matching in a set of vectors */</span></div>
<div class="line"><a name="l00155"></a><span class="lineno"> 155</span>&#160;<span class="keywordtype">void</span> crosshamming_count_thres (</div>
<div class="line"><a name="l00156"></a><span class="lineno"> 156</span>&#160; <span class="keyword">const</span> uint8_t * dbs,</div>
<div class="line"><a name="l00157"></a><span class="lineno"> 157</span>&#160; <span class="keywordtype">size_t</span> n,</div>
<div class="line"><a name="l00158"></a><span class="lineno"> 158</span>&#160; hamdis_t ht,</div>
<div class="line"><a name="l00159"></a><span class="lineno"> 159</span>&#160; <span class="keywordtype">size_t</span> ncodes,</div>
<div class="line"><a name="l00160"></a><span class="lineno"> 160</span>&#160; <span class="keywordtype">size_t</span> * nptr);</div>
<div class="line"><a name="l00161"></a><span class="lineno"> 161</span>&#160;</div>
<div class="line"><a name="l00162"></a><span class="lineno"> 162</span>&#160;</div>
<div class="line"><a name="l00163"></a><span class="lineno"> 163</span>&#160;<span class="comment">/* compute the Hamming distances between two codewords of nwords*64 bits */</span></div>
<div class="line"><a name="l00164"></a><span class="lineno"> 164</span>&#160;hamdis_t hamming (</div>
<div class="line"><a name="l00165"></a><span class="lineno"> 165</span>&#160; <span class="keyword">const</span> uint64_t * bs1,</div>
<div class="line"><a name="l00166"></a><span class="lineno"> 166</span>&#160; <span class="keyword">const</span> uint64_t * bs2,</div>
<div class="line"><a name="l00167"></a><span class="lineno"> 167</span>&#160; <span class="keywordtype">size_t</span> nwords);</div>
<div class="line"><a name="l00168"></a><span class="lineno"> 168</span>&#160;</div>
<div class="line"><a name="l00169"></a><span class="lineno"> 169</span>&#160;</div>
<div class="line"><a name="l00170"></a><span class="lineno"> 170</span>&#160;</div>
<div class="line"><a name="l00171"></a><span class="lineno"> 171</span>&#160;</div>
<div class="line"><a name="l00172"></a><span class="lineno"> 172</span>&#160;<span class="comment">/******************************************************************</span></div>
<div class="line"><a name="l00173"></a><span class="lineno"> 173</span>&#160;<span class="comment"> * The HammingComputer series of classes compares a single code of</span></div>
<div class="line"><a name="l00174"></a><span class="lineno"> 174</span>&#160;<span class="comment"> * size 4 to 32 to incoming codes. They are intended for use as a</span></div>
<div class="line"><a name="l00175"></a><span class="lineno"> 175</span>&#160;<span class="comment"> * template class where it would be inefficient to switch on the code</span></div>
<div class="line"><a name="l00176"></a><span class="lineno"> 176</span>&#160;<span class="comment"> * size in the inner loop. Hopefully the compiler will inline the</span></div>
<div class="line"><a name="l00177"></a><span class="lineno"> 177</span>&#160;<span class="comment"> * hamming() functions and put the a0, a1, ... in registers.</span></div>
<div class="line"><a name="l00178"></a><span class="lineno"> 178</span>&#160;<span class="comment"> ******************************************************************/</span></div>
<div class="line"><a name="l00179"></a><span class="lineno"> 179</span>&#160;</div>
<div class="line"><a name="l00180"></a><span class="lineno"> 180</span>&#160;</div>
<div class="line"><a name="l00181"></a><span class="lineno"><a class="line" href="structfaiss_1_1HammingComputer4.html"> 181</a></span>&#160;<span class="keyword">struct </span><a class="code" href="structfaiss_1_1HammingComputer4.html">HammingComputer4</a> {</div>
<div class="line"><a name="l00182"></a><span class="lineno"> 182</span>&#160; uint32_t a0;</div>
<div class="line"><a name="l00183"></a><span class="lineno"> 183</span>&#160;</div>
<div class="line"><a name="l00184"></a><span class="lineno"> 184</span>&#160; <a class="code" href="structfaiss_1_1HammingComputer4.html">HammingComputer4</a> () {}</div>
<div class="line"><a name="l00185"></a><span class="lineno"> 185</span>&#160;</div>
<div class="line"><a name="l00186"></a><span class="lineno"> 186</span>&#160; <a class="code" href="structfaiss_1_1HammingComputer4.html">HammingComputer4</a> (<span class="keyword">const</span> uint8_t *a, <span class="keywordtype">int</span> code_size) {</div>
<div class="line"><a name="l00187"></a><span class="lineno"> 187</span>&#160; set (a, code_size);</div>
<div class="line"><a name="l00188"></a><span class="lineno"> 188</span>&#160; }</div>
<div class="line"><a name="l00189"></a><span class="lineno"> 189</span>&#160;</div>
<div class="line"><a name="l00190"></a><span class="lineno"> 190</span>&#160; <span class="keywordtype">void</span> set (<span class="keyword">const</span> uint8_t *a, <span class="keywordtype">int</span> code_size) {</div>
<div class="line"><a name="l00191"></a><span class="lineno"> 191</span>&#160; assert (code_size == 4);</div>
<div class="line"><a name="l00192"></a><span class="lineno"> 192</span>&#160; a0 = *(uint32_t *)a;</div>
<div class="line"><a name="l00193"></a><span class="lineno"> 193</span>&#160; }</div>
<div class="line"><a name="l00194"></a><span class="lineno"> 194</span>&#160;</div>
<div class="line"><a name="l00195"></a><span class="lineno"> 195</span>&#160; <span class="keyword">inline</span> <span class="keywordtype">int</span> hamming (<span class="keyword">const</span> uint8_t *b)<span class="keyword"> const </span>{</div>
<div class="line"><a name="l00196"></a><span class="lineno"> 196</span>&#160; <span class="keywordflow">return</span> popcount64 (*(uint32_t *)b ^ a0);</div>
<div class="line"><a name="l00197"></a><span class="lineno"> 197</span>&#160; }</div>
<div class="line"><a name="l00198"></a><span class="lineno"> 198</span>&#160;</div>
<div class="line"><a name="l00199"></a><span class="lineno"> 199</span>&#160;};</div>
<div class="line"><a name="l00200"></a><span class="lineno"> 200</span>&#160;</div>
<div class="line"><a name="l00201"></a><span class="lineno"><a class="line" href="structfaiss_1_1HammingComputer8.html"> 201</a></span>&#160;<span class="keyword">struct </span><a class="code" href="structfaiss_1_1HammingComputer8.html">HammingComputer8</a> {</div>
<div class="line"><a name="l00202"></a><span class="lineno"> 202</span>&#160; uint64_t a0;</div>
<div class="line"><a name="l00203"></a><span class="lineno"> 203</span>&#160;</div>
<div class="line"><a name="l00204"></a><span class="lineno"> 204</span>&#160; <a class="code" href="structfaiss_1_1HammingComputer8.html">HammingComputer8</a> () {}</div>
<div class="line"><a name="l00205"></a><span class="lineno"> 205</span>&#160;</div>
<div class="line"><a name="l00206"></a><span class="lineno"> 206</span>&#160; <a class="code" href="structfaiss_1_1HammingComputer8.html">HammingComputer8</a> (<span class="keyword">const</span> uint8_t *a, <span class="keywordtype">int</span> code_size) {</div>
<div class="line"><a name="l00207"></a><span class="lineno"> 207</span>&#160; set (a, code_size);</div>
<div class="line"><a name="l00208"></a><span class="lineno"> 208</span>&#160; }</div>
<div class="line"><a name="l00209"></a><span class="lineno"> 209</span>&#160;</div>
<div class="line"><a name="l00210"></a><span class="lineno"> 210</span>&#160; <span class="keywordtype">void</span> set (<span class="keyword">const</span> uint8_t *a, <span class="keywordtype">int</span> code_size) {</div>
<div class="line"><a name="l00211"></a><span class="lineno"> 211</span>&#160; assert (code_size == 8);</div>
<div class="line"><a name="l00212"></a><span class="lineno"> 212</span>&#160; a0 = *(uint64_t *)a;</div>
<div class="line"><a name="l00213"></a><span class="lineno"> 213</span>&#160; }</div>
<div class="line"><a name="l00214"></a><span class="lineno"> 214</span>&#160;</div>
<div class="line"><a name="l00215"></a><span class="lineno"> 215</span>&#160; <span class="keyword">inline</span> <span class="keywordtype">int</span> hamming (<span class="keyword">const</span> uint8_t *b)<span class="keyword"> const </span>{</div>
<div class="line"><a name="l00216"></a><span class="lineno"> 216</span>&#160; <span class="keywordflow">return</span> popcount64 (*(uint64_t *)b ^ a0);</div>
<div class="line"><a name="l00217"></a><span class="lineno"> 217</span>&#160; }</div>
<div class="line"><a name="l00218"></a><span class="lineno"> 218</span>&#160;</div>
<div class="line"><a name="l00219"></a><span class="lineno"> 219</span>&#160;};</div>
<div class="line"><a name="l00220"></a><span class="lineno"> 220</span>&#160;</div>
<div class="line"><a name="l00221"></a><span class="lineno"> 221</span>&#160;</div>
<div class="line"><a name="l00222"></a><span class="lineno"><a class="line" href="structfaiss_1_1HammingComputer16.html"> 222</a></span>&#160;<span class="keyword">struct </span><a class="code" href="structfaiss_1_1HammingComputer16.html">HammingComputer16</a> {</div>
<div class="line"><a name="l00223"></a><span class="lineno"> 223</span>&#160; uint64_t a0, a1;</div>
<div class="line"><a name="l00224"></a><span class="lineno"> 224</span>&#160;</div>
<div class="line"><a name="l00225"></a><span class="lineno"> 225</span>&#160; <a class="code" href="structfaiss_1_1HammingComputer16.html">HammingComputer16</a> () {}</div>
<div class="line"><a name="l00226"></a><span class="lineno"> 226</span>&#160;</div>
<div class="line"><a name="l00227"></a><span class="lineno"> 227</span>&#160; <a class="code" href="structfaiss_1_1HammingComputer16.html">HammingComputer16</a> (<span class="keyword">const</span> uint8_t *a8, <span class="keywordtype">int</span> code_size) {</div>
<div class="line"><a name="l00228"></a><span class="lineno"> 228</span>&#160; set (a8, code_size);</div>
<div class="line"><a name="l00229"></a><span class="lineno"> 229</span>&#160; }</div>
<div class="line"><a name="l00230"></a><span class="lineno"> 230</span>&#160;</div>
<div class="line"><a name="l00231"></a><span class="lineno"> 231</span>&#160; <span class="keywordtype">void</span> set (<span class="keyword">const</span> uint8_t *a8, <span class="keywordtype">int</span> code_size) {</div>
<div class="line"><a name="l00232"></a><span class="lineno"> 232</span>&#160; assert (code_size == 16);</div>
<div class="line"><a name="l00233"></a><span class="lineno"> 233</span>&#160; <span class="keyword">const</span> uint64_t *a = (uint64_t *)a8;</div>
<div class="line"><a name="l00234"></a><span class="lineno"> 234</span>&#160; a0 = a[0]; a1 = a[1];</div>
<div class="line"><a name="l00235"></a><span class="lineno"> 235</span>&#160; }</div>
<div class="line"><a name="l00236"></a><span class="lineno"> 236</span>&#160;</div>
<div class="line"><a name="l00237"></a><span class="lineno"> 237</span>&#160; <span class="keyword">inline</span> <span class="keywordtype">int</span> hamming (<span class="keyword">const</span> uint8_t *b8)<span class="keyword"> const </span>{</div>
<div class="line"><a name="l00238"></a><span class="lineno"> 238</span>&#160; <span class="keyword">const</span> uint64_t *b = (uint64_t *)b8;</div>
<div class="line"><a name="l00239"></a><span class="lineno"> 239</span>&#160; <span class="keywordflow">return</span> popcount64 (b[0] ^ a0) + popcount64 (b[1] ^ a1);</div>
<div class="line"><a name="l00240"></a><span class="lineno"> 240</span>&#160; }</div>
<div class="line"><a name="l00241"></a><span class="lineno"> 241</span>&#160;</div>
<div class="line"><a name="l00242"></a><span class="lineno"> 242</span>&#160;};</div>
<div class="line"><a name="l00243"></a><span class="lineno"> 243</span>&#160;</div>
<div class="line"><a name="l00244"></a><span class="lineno"> 244</span>&#160;<span class="comment">// when applied to an array, 1/2 of the 64-bit accesses are unaligned.</span></div>
<div class="line"><a name="l00245"></a><span class="lineno"> 245</span>&#160;<span class="comment">// This incurs a penalty of ~10% wrt. fully aligned accesses.</span></div>
<div class="line"><a name="l00246"></a><span class="lineno"><a class="line" href="structfaiss_1_1HammingComputer20.html"> 246</a></span>&#160;<span class="keyword">struct </span><a class="code" href="structfaiss_1_1HammingComputer20.html">HammingComputer20</a> {</div>
<div class="line"><a name="l00247"></a><span class="lineno"> 247</span>&#160; uint64_t a0, a1;</div>
<div class="line"><a name="l00248"></a><span class="lineno"> 248</span>&#160; uint32_t a2;</div>
<div class="line"><a name="l00249"></a><span class="lineno"> 249</span>&#160;</div>
<div class="line"><a name="l00250"></a><span class="lineno"> 250</span>&#160; <a class="code" href="structfaiss_1_1HammingComputer20.html">HammingComputer20</a> () {}</div>
<div class="line"><a name="l00251"></a><span class="lineno"> 251</span>&#160;</div>
<div class="line"><a name="l00252"></a><span class="lineno"> 252</span>&#160; <a class="code" href="structfaiss_1_1HammingComputer20.html">HammingComputer20</a> (<span class="keyword">const</span> uint8_t *a8, <span class="keywordtype">int</span> code_size) {</div>
<div class="line"><a name="l00253"></a><span class="lineno"> 253</span>&#160; set (a8, code_size);</div>
<div class="line"><a name="l00254"></a><span class="lineno"> 254</span>&#160; }</div>
<div class="line"><a name="l00255"></a><span class="lineno"> 255</span>&#160;</div>
<div class="line"><a name="l00256"></a><span class="lineno"> 256</span>&#160; <span class="keywordtype">void</span> set (<span class="keyword">const</span> uint8_t *a8, <span class="keywordtype">int</span> code_size) {</div>
<div class="line"><a name="l00257"></a><span class="lineno"> 257</span>&#160; assert (code_size == 20);</div>
<div class="line"><a name="l00258"></a><span class="lineno"> 258</span>&#160; <span class="keyword">const</span> uint64_t *a = (uint64_t *)a8;</div>
<div class="line"><a name="l00259"></a><span class="lineno"> 259</span>&#160; a0 = a[0]; a1 = a[1]; a2 = a[2];</div>
<div class="line"><a name="l00260"></a><span class="lineno"> 260</span>&#160; }</div>
<div class="line"><a name="l00261"></a><span class="lineno"> 261</span>&#160;</div>
<div class="line"><a name="l00262"></a><span class="lineno"> 262</span>&#160; <span class="keyword">inline</span> <span class="keywordtype">int</span> hamming (<span class="keyword">const</span> uint8_t *b8)<span class="keyword"> const </span>{</div>
<div class="line"><a name="l00263"></a><span class="lineno"> 263</span>&#160; <span class="keyword">const</span> uint64_t *b = (uint64_t *)b8;</div>
<div class="line"><a name="l00264"></a><span class="lineno"> 264</span>&#160; <span class="keywordflow">return</span> popcount64 (b[0] ^ a0) + popcount64 (b[1] ^ a1) +</div>
<div class="line"><a name="l00265"></a><span class="lineno"> 265</span>&#160; popcount64 (*(uint32_t*)(b + 2) ^ a2);</div>
<div class="line"><a name="l00266"></a><span class="lineno"> 266</span>&#160; }</div>
<div class="line"><a name="l00267"></a><span class="lineno"> 267</span>&#160;};</div>
<div class="line"><a name="l00268"></a><span class="lineno"> 268</span>&#160;</div>
<div class="line"><a name="l00269"></a><span class="lineno"><a class="line" href="structfaiss_1_1HammingComputer32.html"> 269</a></span>&#160;<span class="keyword">struct </span><a class="code" href="structfaiss_1_1HammingComputer32.html">HammingComputer32</a> {</div>
<div class="line"><a name="l00270"></a><span class="lineno"> 270</span>&#160; uint64_t a0, a1, a2, a3;</div>
<div class="line"><a name="l00271"></a><span class="lineno"> 271</span>&#160;</div>
<div class="line"><a name="l00272"></a><span class="lineno"> 272</span>&#160; <a class="code" href="structfaiss_1_1HammingComputer32.html">HammingComputer32</a> () {}</div>
<div class="line"><a name="l00273"></a><span class="lineno"> 273</span>&#160;</div>
<div class="line"><a name="l00274"></a><span class="lineno"> 274</span>&#160; <a class="code" href="structfaiss_1_1HammingComputer32.html">HammingComputer32</a> (<span class="keyword">const</span> uint8_t *a8, <span class="keywordtype">int</span> code_size) {</div>
<div class="line"><a name="l00275"></a><span class="lineno"> 275</span>&#160; set (a8, code_size);</div>
<div class="line"><a name="l00276"></a><span class="lineno"> 276</span>&#160; }</div>
<div class="line"><a name="l00277"></a><span class="lineno"> 277</span>&#160;</div>
<div class="line"><a name="l00278"></a><span class="lineno"> 278</span>&#160; <span class="keywordtype">void</span> set (<span class="keyword">const</span> uint8_t *a8, <span class="keywordtype">int</span> code_size) {</div>
<div class="line"><a name="l00279"></a><span class="lineno"> 279</span>&#160; assert (code_size == 32);</div>
<div class="line"><a name="l00280"></a><span class="lineno"> 280</span>&#160; <span class="keyword">const</span> uint64_t *a = (uint64_t *)a8;</div>
<div class="line"><a name="l00281"></a><span class="lineno"> 281</span>&#160; a0 = a[0]; a1 = a[1]; a2 = a[2]; a3 = a[3];</div>
<div class="line"><a name="l00282"></a><span class="lineno"> 282</span>&#160; }</div>
<div class="line"><a name="l00283"></a><span class="lineno"> 283</span>&#160;</div>
<div class="line"><a name="l00284"></a><span class="lineno"> 284</span>&#160; <span class="keyword">inline</span> <span class="keywordtype">int</span> hamming (<span class="keyword">const</span> uint8_t *b8)<span class="keyword"> const </span>{</div>
<div class="line"><a name="l00285"></a><span class="lineno"> 285</span>&#160; <span class="keyword">const</span> uint64_t *b = (uint64_t *)b8;</div>
<div class="line"><a name="l00286"></a><span class="lineno"> 286</span>&#160; <span class="keywordflow">return</span> popcount64 (b[0] ^ a0) + popcount64 (b[1] ^ a1) +</div>
<div class="line"><a name="l00287"></a><span class="lineno"> 287</span>&#160; popcount64 (b[2] ^ a2) + popcount64 (b[3] ^ a3);</div>
<div class="line"><a name="l00288"></a><span class="lineno"> 288</span>&#160; }</div>
<div class="line"><a name="l00289"></a><span class="lineno"> 289</span>&#160;</div>
<div class="line"><a name="l00290"></a><span class="lineno"> 290</span>&#160;};</div>
<div class="line"><a name="l00291"></a><span class="lineno"> 291</span>&#160;</div>
<div class="line"><a name="l00292"></a><span class="lineno"><a class="line" href="structfaiss_1_1HammingComputer64.html"> 292</a></span>&#160;<span class="keyword">struct </span><a class="code" href="structfaiss_1_1HammingComputer64.html">HammingComputer64</a> {</div>
<div class="line"><a name="l00293"></a><span class="lineno"> 293</span>&#160; uint64_t a0, a1, a2, a3, a4, a5, a6, a7;</div>
<div class="line"><a name="l00294"></a><span class="lineno"> 294</span>&#160;</div>
<div class="line"><a name="l00295"></a><span class="lineno"> 295</span>&#160; <a class="code" href="structfaiss_1_1HammingComputer64.html">HammingComputer64</a> () {}</div>
<div class="line"><a name="l00296"></a><span class="lineno"> 296</span>&#160;</div>
<div class="line"><a name="l00297"></a><span class="lineno"> 297</span>&#160; <a class="code" href="structfaiss_1_1HammingComputer64.html">HammingComputer64</a> (<span class="keyword">const</span> uint8_t *a8, <span class="keywordtype">int</span> code_size) {</div>
<div class="line"><a name="l00298"></a><span class="lineno"> 298</span>&#160; set (a8, code_size);</div>
<div class="line"><a name="l00299"></a><span class="lineno"> 299</span>&#160; }</div>
<div class="line"><a name="l00300"></a><span class="lineno"> 300</span>&#160;</div>
<div class="line"><a name="l00301"></a><span class="lineno"> 301</span>&#160; <span class="keywordtype">void</span> set (<span class="keyword">const</span> uint8_t *a8, <span class="keywordtype">int</span> code_size) {</div>
<div class="line"><a name="l00302"></a><span class="lineno"> 302</span>&#160; assert (code_size == 64);</div>
<div class="line"><a name="l00303"></a><span class="lineno"> 303</span>&#160; <span class="keyword">const</span> uint64_t *a = (uint64_t *)a8;</div>
<div class="line"><a name="l00304"></a><span class="lineno"> 304</span>&#160; a0 = a[0]; a1 = a[1]; a2 = a[2]; a3 = a[3];</div>
<div class="line"><a name="l00305"></a><span class="lineno"> 305</span>&#160; a4 = a[4]; a5 = a[5]; a6 = a[6]; a7 = a[7];</div>
<div class="line"><a name="l00306"></a><span class="lineno"> 306</span>&#160; }</div>
<div class="line"><a name="l00307"></a><span class="lineno"> 307</span>&#160;</div>
<div class="line"><a name="l00308"></a><span class="lineno"> 308</span>&#160; <span class="keyword">inline</span> <span class="keywordtype">int</span> hamming (<span class="keyword">const</span> uint8_t *b8)<span class="keyword"> const </span>{</div>
<div class="line"><a name="l00309"></a><span class="lineno"> 309</span>&#160; <span class="keyword">const</span> uint64_t *b = (uint64_t *)b8;</div>
<div class="line"><a name="l00310"></a><span class="lineno"> 310</span>&#160; <span class="keywordflow">return</span> popcount64 (b[0] ^ a0) + popcount64 (b[1] ^ a1) +</div>
<div class="line"><a name="l00311"></a><span class="lineno"> 311</span>&#160; popcount64 (b[2] ^ a2) + popcount64 (b[3] ^ a3) +</div>
<div class="line"><a name="l00312"></a><span class="lineno"> 312</span>&#160; popcount64 (b[4] ^ a4) + popcount64 (b[5] ^ a5) +</div>
<div class="line"><a name="l00313"></a><span class="lineno"> 313</span>&#160; popcount64 (b[6] ^ a6) + popcount64 (b[7] ^ a7);</div>
<div class="line"><a name="l00314"></a><span class="lineno"> 314</span>&#160; }</div>
<div class="line"><a name="l00315"></a><span class="lineno"> 315</span>&#160;</div>
<div class="line"><a name="l00316"></a><span class="lineno"> 316</span>&#160;};</div>
<div class="line"><a name="l00317"></a><span class="lineno"> 317</span>&#160;</div>
<div class="line"><a name="l00318"></a><span class="lineno"> 318</span>&#160;<span class="comment">// very inefficient...</span></div>
<div class="line"><a name="l00319"></a><span class="lineno"><a class="line" href="structfaiss_1_1HammingComputerDefault.html"> 319</a></span>&#160;<span class="keyword">struct </span><a class="code" href="structfaiss_1_1HammingComputerDefault.html">HammingComputerDefault</a> {</div>
<div class="line"><a name="l00320"></a><span class="lineno"> 320</span>&#160; <span class="keyword">const</span> uint8_t *a;</div>
<div class="line"><a name="l00321"></a><span class="lineno"> 321</span>&#160; <span class="keywordtype">int</span> n;</div>
<div class="line"><a name="l00322"></a><span class="lineno"> 322</span>&#160;</div>
<div class="line"><a name="l00323"></a><span class="lineno"> 323</span>&#160; <a class="code" href="structfaiss_1_1HammingComputerDefault.html">HammingComputerDefault</a> () {}</div>
<div class="line"><a name="l00324"></a><span class="lineno"> 324</span>&#160;</div>
<div class="line"><a name="l00325"></a><span class="lineno"> 325</span>&#160; <a class="code" href="structfaiss_1_1HammingComputerDefault.html">HammingComputerDefault</a> (<span class="keyword">const</span> uint8_t *a8, <span class="keywordtype">int</span> code_size) {</div>
<div class="line"><a name="l00326"></a><span class="lineno"> 326</span>&#160; set (a8, code_size);</div>
<div class="line"><a name="l00327"></a><span class="lineno"> 327</span>&#160; }</div>
<div class="line"><a name="l00328"></a><span class="lineno"> 328</span>&#160;</div>
<div class="line"><a name="l00329"></a><span class="lineno"> 329</span>&#160; <span class="keywordtype">void</span> set (<span class="keyword">const</span> uint8_t *a8, <span class="keywordtype">int</span> code_size) {</div>
<div class="line"><a name="l00330"></a><span class="lineno"> 330</span>&#160; a = a8;</div>
<div class="line"><a name="l00331"></a><span class="lineno"> 331</span>&#160; n = code_size;</div>
<div class="line"><a name="l00332"></a><span class="lineno"> 332</span>&#160; }</div>
<div class="line"><a name="l00333"></a><span class="lineno"> 333</span>&#160;</div>
<div class="line"><a name="l00334"></a><span class="lineno"> 334</span>&#160; <span class="keywordtype">int</span> hamming (<span class="keyword">const</span> uint8_t *b8)<span class="keyword"> const </span>{</div>
<div class="line"><a name="l00335"></a><span class="lineno"> 335</span>&#160; <span class="keywordtype">int</span> accu = 0;</div>
<div class="line"><a name="l00336"></a><span class="lineno"> 336</span>&#160; <span class="keywordflow">for</span> (<span class="keywordtype">int</span> i = 0; i &lt; n; i++)</div>
<div class="line"><a name="l00337"></a><span class="lineno"> 337</span>&#160; accu += popcount64 (a[i] ^ b8[i]);</div>
<div class="line"><a name="l00338"></a><span class="lineno"> 338</span>&#160; <span class="keywordflow">return</span> accu;</div>
<div class="line"><a name="l00339"></a><span class="lineno"> 339</span>&#160; }</div>
<div class="line"><a name="l00340"></a><span class="lineno"> 340</span>&#160;</div>
<div class="line"><a name="l00341"></a><span class="lineno"> 341</span>&#160;};</div>
<div class="line"><a name="l00342"></a><span class="lineno"> 342</span>&#160;</div>
<div class="line"><a name="l00343"></a><span class="lineno"> 343</span>&#160;</div>
<div class="line"><a name="l00344"></a><span class="lineno"><a class="line" href="structfaiss_1_1HammingComputerM8.html"> 344</a></span>&#160;<span class="keyword">struct </span><a class="code" href="structfaiss_1_1HammingComputerM8.html">HammingComputerM8</a> {</div>
<div class="line"><a name="l00345"></a><span class="lineno"> 345</span>&#160; <span class="keyword">const</span> uint64_t *a;</div>
<div class="line"><a name="l00346"></a><span class="lineno"> 346</span>&#160; <span class="keywordtype">int</span> n;</div>
<div class="line"><a name="l00347"></a><span class="lineno"> 347</span>&#160;</div>
<div class="line"><a name="l00348"></a><span class="lineno"> 348</span>&#160; <a class="code" href="structfaiss_1_1HammingComputerM8.html">HammingComputerM8</a> () {}</div>
<div class="line"><a name="l00349"></a><span class="lineno"> 349</span>&#160;</div>
<div class="line"><a name="l00350"></a><span class="lineno"> 350</span>&#160; <a class="code" href="structfaiss_1_1HammingComputerM8.html">HammingComputerM8</a> (<span class="keyword">const</span> uint8_t *a8, <span class="keywordtype">int</span> code_size) {</div>
<div class="line"><a name="l00351"></a><span class="lineno"> 351</span>&#160; set (a8, code_size);</div>
<div class="line"><a name="l00352"></a><span class="lineno"> 352</span>&#160; }</div>
<div class="line"><a name="l00353"></a><span class="lineno"> 353</span>&#160;</div>
<div class="line"><a name="l00354"></a><span class="lineno"> 354</span>&#160; <span class="keywordtype">void</span> set (<span class="keyword">const</span> uint8_t *a8, <span class="keywordtype">int</span> code_size) {</div>
<div class="line"><a name="l00355"></a><span class="lineno"> 355</span>&#160; assert (code_size % 8 == 0);</div>
<div class="line"><a name="l00356"></a><span class="lineno"> 356</span>&#160; a = (uint64_t *)a8;</div>
<div class="line"><a name="l00357"></a><span class="lineno"> 357</span>&#160; n = code_size / 8;</div>
<div class="line"><a name="l00358"></a><span class="lineno"> 358</span>&#160; }</div>
<div class="line"><a name="l00359"></a><span class="lineno"> 359</span>&#160;</div>
<div class="line"><a name="l00360"></a><span class="lineno"> 360</span>&#160; <span class="keywordtype">int</span> hamming (<span class="keyword">const</span> uint8_t *b8)<span class="keyword"> const </span>{</div>
<div class="line"><a name="l00361"></a><span class="lineno"> 361</span>&#160; <span class="keyword">const</span> uint64_t *b = (uint64_t *)b8;</div>
<div class="line"><a name="l00362"></a><span class="lineno"> 362</span>&#160; <span class="keywordtype">int</span> accu = 0;</div>
<div class="line"><a name="l00363"></a><span class="lineno"> 363</span>&#160; <span class="keywordflow">for</span> (<span class="keywordtype">int</span> i = 0; i &lt; n; i++)</div>
<div class="line"><a name="l00364"></a><span class="lineno"> 364</span>&#160; accu += popcount64 (a[i] ^ b[i]);</div>
<div class="line"><a name="l00365"></a><span class="lineno"> 365</span>&#160; <span class="keywordflow">return</span> accu;</div>
<div class="line"><a name="l00366"></a><span class="lineno"> 366</span>&#160; }</div>
<div class="line"><a name="l00367"></a><span class="lineno"> 367</span>&#160;</div>
<div class="line"><a name="l00368"></a><span class="lineno"> 368</span>&#160;};</div>
<div class="line"><a name="l00369"></a><span class="lineno"> 369</span>&#160;</div>
<div class="line"><a name="l00370"></a><span class="lineno"> 370</span>&#160;<span class="comment">// even more inefficient!</span></div>
<div class="line"><a name="l00371"></a><span class="lineno"><a class="line" href="structfaiss_1_1HammingComputerM4.html"> 371</a></span>&#160;<span class="keyword">struct </span><a class="code" href="structfaiss_1_1HammingComputerM4.html">HammingComputerM4</a> {</div>
<div class="line"><a name="l00372"></a><span class="lineno"> 372</span>&#160; <span class="keyword">const</span> uint32_t *a;</div>
<div class="line"><a name="l00373"></a><span class="lineno"> 373</span>&#160; <span class="keywordtype">int</span> n;</div>
<div class="line"><a name="l00374"></a><span class="lineno"> 374</span>&#160;</div>
<div class="line"><a name="l00375"></a><span class="lineno"> 375</span>&#160; <a class="code" href="structfaiss_1_1HammingComputerM4.html">HammingComputerM4</a> () {}</div>
<div class="line"><a name="l00376"></a><span class="lineno"> 376</span>&#160;</div>
<div class="line"><a name="l00377"></a><span class="lineno"> 377</span>&#160; <a class="code" href="structfaiss_1_1HammingComputerM4.html">HammingComputerM4</a> (<span class="keyword">const</span> uint8_t *a4, <span class="keywordtype">int</span> code_size) {</div>
<div class="line"><a name="l00378"></a><span class="lineno"> 378</span>&#160; set (a4, code_size);</div>
<div class="line"><a name="l00379"></a><span class="lineno"> 379</span>&#160; }</div>
<div class="line"><a name="l00380"></a><span class="lineno"> 380</span>&#160;</div>
<div class="line"><a name="l00381"></a><span class="lineno"> 381</span>&#160; <span class="keywordtype">void</span> set (<span class="keyword">const</span> uint8_t *a4, <span class="keywordtype">int</span> code_size) {</div>
<div class="line"><a name="l00382"></a><span class="lineno"> 382</span>&#160; assert (code_size % 4 == 0);</div>
<div class="line"><a name="l00383"></a><span class="lineno"> 383</span>&#160; a = (uint32_t *)a4;</div>
<div class="line"><a name="l00384"></a><span class="lineno"> 384</span>&#160; n = code_size / 4;</div>
<div class="line"><a name="l00385"></a><span class="lineno"> 385</span>&#160; }</div>
<div class="line"><a name="l00386"></a><span class="lineno"> 386</span>&#160;</div>
<div class="line"><a name="l00387"></a><span class="lineno"> 387</span>&#160; <span class="keywordtype">int</span> hamming (<span class="keyword">const</span> uint8_t *b8)<span class="keyword"> const </span>{</div>
<div class="line"><a name="l00388"></a><span class="lineno"> 388</span>&#160; <span class="keyword">const</span> uint32_t *b = (uint32_t *)b8;</div>
<div class="line"><a name="l00389"></a><span class="lineno"> 389</span>&#160; <span class="keywordtype">int</span> accu = 0;</div>
<div class="line"><a name="l00390"></a><span class="lineno"> 390</span>&#160; <span class="keywordflow">for</span> (<span class="keywordtype">int</span> i = 0; i &lt; n; i++)</div>
<div class="line"><a name="l00391"></a><span class="lineno"> 391</span>&#160; accu += popcount64 (a[i] ^ b[i]);</div>
<div class="line"><a name="l00392"></a><span class="lineno"> 392</span>&#160; <span class="keywordflow">return</span> accu;</div>
<div class="line"><a name="l00393"></a><span class="lineno"> 393</span>&#160; }</div>
<div class="line"><a name="l00394"></a><span class="lineno"> 394</span>&#160;</div>
<div class="line"><a name="l00395"></a><span class="lineno"> 395</span>&#160;};</div>
<div class="line"><a name="l00396"></a><span class="lineno"> 396</span>&#160;</div>
<div class="line"><a name="l00397"></a><span class="lineno"> 397</span>&#160;<span class="comment">/***************************************************************************</span></div>
<div class="line"><a name="l00398"></a><span class="lineno"> 398</span>&#160;<span class="comment"> * Equivalence with a template class when code size is known at compile time</span></div>
<div class="line"><a name="l00399"></a><span class="lineno"> 399</span>&#160;<span class="comment"> **************************************************************************/</span></div>
<div class="line"><a name="l00400"></a><span class="lineno"> 400</span>&#160;</div>
<div class="line"><a name="l00401"></a><span class="lineno"> 401</span>&#160;<span class="comment">// default template</span></div>
<div class="line"><a name="l00402"></a><span class="lineno"> 402</span>&#160;<span class="keyword">template</span>&lt;<span class="keywordtype">int</span> CODE_SIZE&gt;</div>
<div class="line"><a name="l00403"></a><span class="lineno"><a class="line" href="structfaiss_1_1HammingComputer.html"> 403</a></span>&#160;<span class="keyword">struct </span><a class="code" href="structfaiss_1_1HammingComputer.html">HammingComputer</a>: <a class="code" href="structfaiss_1_1HammingComputerM8.html">HammingComputerM8</a> {</div>
<div class="line"><a name="l00404"></a><span class="lineno"> 404</span>&#160; <a class="code" href="structfaiss_1_1HammingComputer.html">HammingComputer</a> (<span class="keyword">const</span> uint8_t *a, <span class="keywordtype">int</span> code_size):</div>
<div class="line"><a name="l00405"></a><span class="lineno"> 405</span>&#160; <a class="code" href="structfaiss_1_1HammingComputerM8.html">HammingComputerM8</a>(a, code_size) {}</div>
<div class="line"><a name="l00406"></a><span class="lineno"> 406</span>&#160;};</div>
<div class="line"><a name="l00407"></a><span class="lineno"> 407</span>&#160;</div>
<div class="line"><a name="l00408"></a><span class="lineno"> 408</span>&#160;<span class="preprocessor">#define SPECIALIZED_HC(CODE_SIZE) \</span></div>
<div class="line"><a name="l00409"></a><span class="lineno"> 409</span>&#160;<span class="preprocessor"> template&lt;&gt; struct HammingComputer&lt;CODE_SIZE&gt;: \</span></div>
<div class="line"><a name="l00410"></a><span class="lineno"> 410</span>&#160;<span class="preprocessor"> HammingComputer ## CODE_SIZE { \</span></div>
<div class="line"><a name="l00411"></a><span class="lineno"> 411</span>&#160;<span class="preprocessor"> HammingComputer (const uint8_t *a): \</span></div>
<div class="line"><a name="l00412"></a><span class="lineno"> 412</span>&#160;<span class="preprocessor"> HammingComputer ## CODE_SIZE(a, CODE_SIZE) {} \</span></div>
<div class="line"><a name="l00413"></a><span class="lineno"> 413</span>&#160;<span class="preprocessor"> }</span></div>
<div class="line"><a name="l00414"></a><span class="lineno"> 414</span>&#160;<span class="preprocessor"></span></div>
<div class="line"><a name="l00415"></a><span class="lineno"> 415</span>&#160;SPECIALIZED_HC(4);</div>
<div class="line"><a name="l00416"></a><span class="lineno"> 416</span>&#160;SPECIALIZED_HC(8);</div>
<div class="line"><a name="l00417"></a><span class="lineno"> 417</span>&#160;SPECIALIZED_HC(16);</div>
<div class="line"><a name="l00418"></a><span class="lineno"> 418</span>&#160;SPECIALIZED_HC(20);</div>
<div class="line"><a name="l00419"></a><span class="lineno"> 419</span>&#160;SPECIALIZED_HC(32);</div>
<div class="line"><a name="l00420"></a><span class="lineno"> 420</span>&#160;SPECIALIZED_HC(64);</div>
<div class="line"><a name="l00421"></a><span class="lineno"> 421</span>&#160;</div>
<div class="line"><a name="l00422"></a><span class="lineno"> 422</span>&#160;<span class="preprocessor">#undef SPECIALIZED_HC</span></div>
<div class="line"><a name="l00423"></a><span class="lineno"> 423</span>&#160;<span class="preprocessor"></span></div>
<div class="line"><a name="l00424"></a><span class="lineno"> 424</span>&#160;</div>
<div class="line"><a name="l00425"></a><span class="lineno"> 425</span>&#160;<span class="comment">/***************************************************************************</span></div>
<div class="line"><a name="l00426"></a><span class="lineno"> 426</span>&#160;<span class="comment"> * generalized Hamming = number of bytes that are different between</span></div>
<div class="line"><a name="l00427"></a><span class="lineno"> 427</span>&#160;<span class="comment"> * two codes.</span></div>
<div class="line"><a name="l00428"></a><span class="lineno"> 428</span>&#160;<span class="comment"> ***************************************************************************/</span></div>
<div class="line"><a name="l00429"></a><span class="lineno"> 429</span>&#160;</div>
<div class="line"><a name="l00430"></a><span class="lineno"> 430</span>&#160;</div>
<div class="line"><a name="l00431"></a><span class="lineno"> 431</span>&#160;<span class="keyword">inline</span> <span class="keywordtype">int</span> generalized_hamming_64 (uint64_t a) {</div>
<div class="line"><a name="l00432"></a><span class="lineno"> 432</span>&#160; a |= a &gt;&gt; 1;</div>
<div class="line"><a name="l00433"></a><span class="lineno"> 433</span>&#160; a |= a &gt;&gt; 2;</div>
<div class="line"><a name="l00434"></a><span class="lineno"> 434</span>&#160; a |= a &gt;&gt; 4;</div>
<div class="line"><a name="l00435"></a><span class="lineno"> 435</span>&#160; a &amp;= 0x0101010101010101UL;</div>
<div class="line"><a name="l00436"></a><span class="lineno"> 436</span>&#160; <span class="keywordflow">return</span> popcount64 (a);</div>
<div class="line"><a name="l00437"></a><span class="lineno"> 437</span>&#160;}</div>
<div class="line"><a name="l00438"></a><span class="lineno"> 438</span>&#160;</div>
<div class="line"><a name="l00439"></a><span class="lineno"> 439</span>&#160;</div>
<div class="line"><a name="l00440"></a><span class="lineno"><a class="line" href="structfaiss_1_1GenHammingComputer8.html"> 440</a></span>&#160;<span class="keyword">struct </span><a class="code" href="structfaiss_1_1GenHammingComputer8.html">GenHammingComputer8</a> {</div>
<div class="line"><a name="l00441"></a><span class="lineno"> 441</span>&#160; uint64_t a0;</div>
<div class="line"><a name="l00442"></a><span class="lineno"> 442</span>&#160;</div>
<div class="line"><a name="l00443"></a><span class="lineno"> 443</span>&#160; <a class="code" href="structfaiss_1_1GenHammingComputer8.html">GenHammingComputer8</a> (<span class="keyword">const</span> uint8_t *a, <span class="keywordtype">int</span> code_size) {</div>
<div class="line"><a name="l00444"></a><span class="lineno"> 444</span>&#160; assert (code_size == 8);</div>
<div class="line"><a name="l00445"></a><span class="lineno"> 445</span>&#160; a0 = *(uint64_t *)a;</div>
<div class="line"><a name="l00446"></a><span class="lineno"> 446</span>&#160; }</div>
<div class="line"><a name="l00447"></a><span class="lineno"> 447</span>&#160;</div>
<div class="line"><a name="l00448"></a><span class="lineno"> 448</span>&#160; <span class="keyword">inline</span> <span class="keywordtype">int</span> hamming (<span class="keyword">const</span> uint8_t *b)<span class="keyword"> const </span>{</div>
<div class="line"><a name="l00449"></a><span class="lineno"> 449</span>&#160; <span class="keywordflow">return</span> generalized_hamming_64 (*(uint64_t *)b ^ a0);</div>
<div class="line"><a name="l00450"></a><span class="lineno"> 450</span>&#160; }</div>
<div class="line"><a name="l00451"></a><span class="lineno"> 451</span>&#160;</div>
<div class="line"><a name="l00452"></a><span class="lineno"> 452</span>&#160;};</div>
<div class="line"><a name="l00453"></a><span class="lineno"> 453</span>&#160;</div>
<div class="line"><a name="l00454"></a><span class="lineno"> 454</span>&#160;</div>
<div class="line"><a name="l00455"></a><span class="lineno"><a class="line" href="structfaiss_1_1GenHammingComputer16.html"> 455</a></span>&#160;<span class="keyword">struct </span><a class="code" href="structfaiss_1_1GenHammingComputer16.html">GenHammingComputer16</a> {</div>
<div class="line"><a name="l00456"></a><span class="lineno"> 456</span>&#160; uint64_t a0, a1;</div>
<div class="line"><a name="l00457"></a><span class="lineno"> 457</span>&#160; <a class="code" href="structfaiss_1_1GenHammingComputer16.html">GenHammingComputer16</a> (<span class="keyword">const</span> uint8_t *a8, <span class="keywordtype">int</span> code_size) {</div>
<div class="line"><a name="l00458"></a><span class="lineno"> 458</span>&#160; assert (code_size == 16);</div>
<div class="line"><a name="l00459"></a><span class="lineno"> 459</span>&#160; <span class="keyword">const</span> uint64_t *a = (uint64_t *)a8;</div>
<div class="line"><a name="l00460"></a><span class="lineno"> 460</span>&#160; a0 = a[0]; a1 = a[1];</div>
<div class="line"><a name="l00461"></a><span class="lineno"> 461</span>&#160; }</div>
<div class="line"><a name="l00462"></a><span class="lineno"> 462</span>&#160;</div>
<div class="line"><a name="l00463"></a><span class="lineno"> 463</span>&#160; <span class="keyword">inline</span> <span class="keywordtype">int</span> hamming (<span class="keyword">const</span> uint8_t *b8)<span class="keyword"> const </span>{</div>
<div class="line"><a name="l00464"></a><span class="lineno"> 464</span>&#160; <span class="keyword">const</span> uint64_t *b = (uint64_t *)b8;</div>
<div class="line"><a name="l00465"></a><span class="lineno"> 465</span>&#160; <span class="keywordflow">return</span> generalized_hamming_64 (b[0] ^ a0) +</div>
<div class="line"><a name="l00466"></a><span class="lineno"> 466</span>&#160; generalized_hamming_64 (b[1] ^ a1);</div>
<div class="line"><a name="l00467"></a><span class="lineno"> 467</span>&#160; }</div>
<div class="line"><a name="l00468"></a><span class="lineno"> 468</span>&#160;</div>
<div class="line"><a name="l00469"></a><span class="lineno"> 469</span>&#160;};</div>
<div class="line"><a name="l00470"></a><span class="lineno"> 470</span>&#160;</div>
<div class="line"><a name="l00471"></a><span class="lineno"><a class="line" href="structfaiss_1_1GenHammingComputer32.html"> 471</a></span>&#160;<span class="keyword">struct </span><a class="code" href="structfaiss_1_1GenHammingComputer32.html">GenHammingComputer32</a> {</div>
<div class="line"><a name="l00472"></a><span class="lineno"> 472</span>&#160; uint64_t a0, a1, a2, a3;</div>
<div class="line"><a name="l00473"></a><span class="lineno"> 473</span>&#160;</div>
<div class="line"><a name="l00474"></a><span class="lineno"> 474</span>&#160; <a class="code" href="structfaiss_1_1GenHammingComputer32.html">GenHammingComputer32</a> (<span class="keyword">const</span> uint8_t *a8, <span class="keywordtype">int</span> code_size) {</div>
<div class="line"><a name="l00475"></a><span class="lineno"> 475</span>&#160; assert (code_size == 32);</div>
<div class="line"><a name="l00476"></a><span class="lineno"> 476</span>&#160; <span class="keyword">const</span> uint64_t *a = (uint64_t *)a8;</div>
<div class="line"><a name="l00477"></a><span class="lineno"> 477</span>&#160; a0 = a[0]; a1 = a[1]; a2 = a[2]; a3 = a[3];</div>
<div class="line"><a name="l00478"></a><span class="lineno"> 478</span>&#160; }</div>
<div class="line"><a name="l00479"></a><span class="lineno"> 479</span>&#160;</div>
<div class="line"><a name="l00480"></a><span class="lineno"> 480</span>&#160; <span class="keyword">inline</span> <span class="keywordtype">int</span> hamming (<span class="keyword">const</span> uint8_t *b8)<span class="keyword"> const </span>{</div>
<div class="line"><a name="l00481"></a><span class="lineno"> 481</span>&#160; <span class="keyword">const</span> uint64_t *b = (uint64_t *)b8;</div>
<div class="line"><a name="l00482"></a><span class="lineno"> 482</span>&#160; <span class="keywordflow">return</span> generalized_hamming_64 (b[0] ^ a0) +</div>
<div class="line"><a name="l00483"></a><span class="lineno"> 483</span>&#160; generalized_hamming_64 (b[1] ^ a1) +</div>
<div class="line"><a name="l00484"></a><span class="lineno"> 484</span>&#160; generalized_hamming_64 (b[2] ^ a2) +</div>
<div class="line"><a name="l00485"></a><span class="lineno"> 485</span>&#160; generalized_hamming_64 (b[3] ^ a3);</div>
<div class="line"><a name="l00486"></a><span class="lineno"> 486</span>&#160; }</div>
<div class="line"><a name="l00487"></a><span class="lineno"> 487</span>&#160;</div>
<div class="line"><a name="l00488"></a><span class="lineno"> 488</span>&#160;};</div>
<div class="line"><a name="l00489"></a><span class="lineno"> 489</span>&#160;</div>
<div class="line"><a name="l00490"></a><span class="lineno"><a class="line" href="structfaiss_1_1GenHammingComputerM8.html"> 490</a></span>&#160;<span class="keyword">struct </span><a class="code" href="structfaiss_1_1GenHammingComputerM8.html">GenHammingComputerM8</a> {</div>
<div class="line"><a name="l00491"></a><span class="lineno"> 491</span>&#160; <span class="keyword">const</span> uint64_t *a;</div>
<div class="line"><a name="l00492"></a><span class="lineno"> 492</span>&#160; <span class="keywordtype">int</span> n;</div>
<div class="line"><a name="l00493"></a><span class="lineno"> 493</span>&#160;</div>
<div class="line"><a name="l00494"></a><span class="lineno"> 494</span>&#160; <a class="code" href="structfaiss_1_1GenHammingComputerM8.html">GenHammingComputerM8</a> (<span class="keyword">const</span> uint8_t *a8, <span class="keywordtype">int</span> code_size) {</div>
<div class="line"><a name="l00495"></a><span class="lineno"> 495</span>&#160; assert (code_size % 8 == 0);</div>
<div class="line"><a name="l00496"></a><span class="lineno"> 496</span>&#160; a = (uint64_t *)a8;</div>
<div class="line"><a name="l00497"></a><span class="lineno"> 497</span>&#160; n = code_size / 8;</div>
<div class="line"><a name="l00498"></a><span class="lineno"> 498</span>&#160; }</div>
<div class="line"><a name="l00499"></a><span class="lineno"> 499</span>&#160;</div>
<div class="line"><a name="l00500"></a><span class="lineno"> 500</span>&#160; <span class="keywordtype">int</span> hamming (<span class="keyword">const</span> uint8_t *b8)<span class="keyword"> const </span>{</div>
<div class="line"><a name="l00501"></a><span class="lineno"> 501</span>&#160; <span class="keyword">const</span> uint64_t *b = (uint64_t *)b8;</div>
<div class="line"><a name="l00502"></a><span class="lineno"> 502</span>&#160; <span class="keywordtype">int</span> accu = 0;</div>
<div class="line"><a name="l00503"></a><span class="lineno"> 503</span>&#160; <span class="keywordflow">for</span> (<span class="keywordtype">int</span> i = 0; i &lt; n; i++)</div>
<div class="line"><a name="l00504"></a><span class="lineno"> 504</span>&#160; accu += generalized_hamming_64 (a[i] ^ b[i]);</div>
<div class="line"><a name="l00505"></a><span class="lineno"> 505</span>&#160; <span class="keywordflow">return</span> accu;</div>
<div class="line"><a name="l00506"></a><span class="lineno"> 506</span>&#160; }</div>
<div class="line"><a name="l00507"></a><span class="lineno"> 507</span>&#160;</div>
<div class="line"><a name="l00508"></a><span class="lineno"> 508</span>&#160;};</div>
<div class="line"><a name="l00509"></a><span class="lineno"> 509</span>&#160;</div>
<div class="line"><a name="l00510"></a><span class="lineno"> 510</span>&#160;<span class="comment"></span></div>
<div class="line"><a name="l00511"></a><span class="lineno"> 511</span>&#160;<span class="comment">/** generalized Hamming distances (= count number of code bytes that</span></div>
<div class="line"><a name="l00512"></a><span class="lineno"> 512</span>&#160;<span class="comment"> are the same) */</span></div>
<div class="line"><a name="l00513"></a><span class="lineno"> 513</span>&#160;<span class="keywordtype">void</span> <a class="code" href="namespacefaiss.html#a9c1131631ad4314ba716372fe0d1dea6">generalized_hammings_knn_hc</a> (</div>
<div class="line"><a name="l00514"></a><span class="lineno"> 514</span>&#160; <a class="code" href="structfaiss_1_1HeapArray.html">int_maxheap_array_t</a> * ha,</div>
<div class="line"><a name="l00515"></a><span class="lineno"> 515</span>&#160; <span class="keyword">const</span> uint8_t * a,</div>
<div class="line"><a name="l00516"></a><span class="lineno"> 516</span>&#160; <span class="keyword">const</span> uint8_t * b,</div>
<div class="line"><a name="l00517"></a><span class="lineno"> 517</span>&#160; <span class="keywordtype">size_t</span> nb,</div>
<div class="line"><a name="l00518"></a><span class="lineno"> 518</span>&#160; <span class="keywordtype">size_t</span> code_size,</div>
<div class="line"><a name="l00519"></a><span class="lineno"> 519</span>&#160; <span class="keywordtype">int</span> ordered = <span class="keyword">true</span>);</div>
<div class="line"><a name="l00520"></a><span class="lineno"> 520</span>&#160;</div>
<div class="line"><a name="l00521"></a><span class="lineno"> 521</span>&#160;</div>
<div class="line"><a name="l00522"></a><span class="lineno"> 522</span>&#160;<span class="comment"></span></div>
<div class="line"><a name="l00523"></a><span class="lineno"> 523</span>&#160;<span class="comment">/** This class maintains a list of best distances seen so far.</span></div>
<div class="line"><a name="l00524"></a><span class="lineno"> 524</span>&#160;<span class="comment"> *</span></div>
<div class="line"><a name="l00525"></a><span class="lineno"> 525</span>&#160;<span class="comment"> * Since the distances are in a limited range (0 to nbit), the</span></div>
<div class="line"><a name="l00526"></a><span class="lineno"> 526</span>&#160;<span class="comment"> * object maintains one list per possible distance, and fills</span></div>
<div class="line"><a name="l00527"></a><span class="lineno"> 527</span>&#160;<span class="comment"> * in only the n-first lists, such that the sum of sizes of the</span></div>
<div class="line"><a name="l00528"></a><span class="lineno"> 528</span>&#160;<span class="comment"> * n lists is below k.</span></div>
<div class="line"><a name="l00529"></a><span class="lineno"> 529</span>&#160;<span class="comment"> */</span></div>
<div class="line"><a name="l00530"></a><span class="lineno"> 530</span>&#160;<span class="keyword">template</span>&lt;<span class="keyword">class</span> HammingComputer&gt;</div>
<div class="line"><a name="l00531"></a><span class="lineno"><a class="line" href="structfaiss_1_1HCounterState.html"> 531</a></span>&#160;<span class="keyword">struct </span><a class="code" href="structfaiss_1_1HCounterState.html">HCounterState</a> {</div>
<div class="line"><a name="l00532"></a><span class="lineno"> 532</span>&#160; <span class="keywordtype">int</span> *counters;</div>
<div class="line"><a name="l00533"></a><span class="lineno"> 533</span>&#160; <span class="keywordtype">long</span> *ids_per_dis;</div>
<div class="line"><a name="l00534"></a><span class="lineno"> 534</span>&#160;</div>
<div class="line"><a name="l00535"></a><span class="lineno"> 535</span>&#160; <a class="code" href="structfaiss_1_1HammingComputer.html">HammingComputer</a> hc;</div>
<div class="line"><a name="l00536"></a><span class="lineno"> 536</span>&#160; <span class="keywordtype">int</span> thres;</div>
<div class="line"><a name="l00537"></a><span class="lineno"> 537</span>&#160; <span class="keywordtype">int</span> count_lt;</div>
<div class="line"><a name="l00538"></a><span class="lineno"> 538</span>&#160; <span class="keywordtype">int</span> count_eq;</div>
<div class="line"><a name="l00539"></a><span class="lineno"> 539</span>&#160; <span class="keywordtype">int</span> k;</div>
<div class="line"><a name="l00540"></a><span class="lineno"> 540</span>&#160;</div>
<div class="line"><a name="l00541"></a><span class="lineno"> 541</span>&#160; <a class="code" href="structfaiss_1_1HCounterState.html">HCounterState</a>(<span class="keywordtype">int</span> *counters, <span class="keywordtype">long</span> *ids_per_dis,</div>
<div class="line"><a name="l00542"></a><span class="lineno"> 542</span>&#160; <span class="keyword">const</span> uint8_t *x, <span class="keywordtype">int</span> d, <span class="keywordtype">int</span> k)</div>
<div class="line"><a name="l00543"></a><span class="lineno"> 543</span>&#160; : counters(counters),</div>
<div class="line"><a name="l00544"></a><span class="lineno"> 544</span>&#160; ids_per_dis(ids_per_dis),</div>
<div class="line"><a name="l00545"></a><span class="lineno"> 545</span>&#160; hc(x, d / 8),</div>
<div class="line"><a name="l00546"></a><span class="lineno"> 546</span>&#160; thres(d + 1),</div>
<div class="line"><a name="l00547"></a><span class="lineno"> 547</span>&#160; count_lt(0),</div>
<div class="line"><a name="l00548"></a><span class="lineno"> 548</span>&#160; count_eq(0),</div>
<div class="line"><a name="l00549"></a><span class="lineno"> 549</span>&#160; k(k) {}</div>
<div class="line"><a name="l00550"></a><span class="lineno"> 550</span>&#160;</div>
<div class="line"><a name="l00551"></a><span class="lineno"> 551</span>&#160; <span class="keywordtype">void</span> update_counter(<span class="keyword">const</span> uint8_t *y, <span class="keywordtype">size_t</span> j) {</div>
<div class="line"><a name="l00552"></a><span class="lineno"> 552</span>&#160; int32_t dis = hc.hamming(y);</div>
<div class="line"><a name="l00553"></a><span class="lineno"> 553</span>&#160;</div>
<div class="line"><a name="l00554"></a><span class="lineno"> 554</span>&#160; <span class="keywordflow">if</span> (dis &lt;= thres) {</div>
<div class="line"><a name="l00555"></a><span class="lineno"> 555</span>&#160; <span class="keywordflow">if</span> (dis &lt; thres) {</div>
<div class="line"><a name="l00556"></a><span class="lineno"> 556</span>&#160; ids_per_dis[dis * k + counters[dis]++] = j;</div>
<div class="line"><a name="l00557"></a><span class="lineno"> 557</span>&#160; ++count_lt;</div>
<div class="line"><a name="l00558"></a><span class="lineno"> 558</span>&#160; <span class="keywordflow">while</span> (count_lt == k &amp;&amp; thres &gt; 0) {</div>
<div class="line"><a name="l00559"></a><span class="lineno"> 559</span>&#160; --thres;</div>
<div class="line"><a name="l00560"></a><span class="lineno"> 560</span>&#160; count_eq = counters[thres];</div>
<div class="line"><a name="l00561"></a><span class="lineno"> 561</span>&#160; count_lt -= count_eq;</div>
<div class="line"><a name="l00562"></a><span class="lineno"> 562</span>&#160; }</div>
<div class="line"><a name="l00563"></a><span class="lineno"> 563</span>&#160; } <span class="keywordflow">else</span> <span class="keywordflow">if</span> (count_eq &lt; k) {</div>
<div class="line"><a name="l00564"></a><span class="lineno"> 564</span>&#160; ids_per_dis[dis * k + count_eq++] = j;</div>
<div class="line"><a name="l00565"></a><span class="lineno"> 565</span>&#160; counters[dis] = count_eq;</div>
<div class="line"><a name="l00566"></a><span class="lineno"> 566</span>&#160; }</div>
<div class="line"><a name="l00567"></a><span class="lineno"> 567</span>&#160; }</div>
<div class="line"><a name="l00568"></a><span class="lineno"> 568</span>&#160; }</div>
<div class="line"><a name="l00569"></a><span class="lineno"> 569</span>&#160;};</div>
<div class="line"><a name="l00570"></a><span class="lineno"> 570</span>&#160;</div>
<div class="line"><a name="l00571"></a><span class="lineno"> 571</span>&#160;</div>
<div class="line"><a name="l00572"></a><span class="lineno"> 572</span>&#160;} <span class="comment">// namespace faiss</span></div>
<div class="line"><a name="l00573"></a><span class="lineno"> 573</span>&#160;</div>
<div class="line"><a name="l00574"></a><span class="lineno"> 574</span>&#160;</div>
<div class="line"><a name="l00575"></a><span class="lineno"> 575</span>&#160;<span class="preprocessor">#endif </span><span class="comment">/* FAISS_hamming_h */</span><span class="preprocessor"></span></div>
<div class="ttc" id="namespacefaiss_html_aef2e95991f435b0103db0efe07edff81"><div class="ttname"><a href="namespacefaiss.html#aef2e95991f435b0103db0efe07edff81">faiss::hammings_knn_hc</a></div><div class="ttdeci">void hammings_knn_hc(int_maxheap_array_t *ha, const uint8_t *a, const uint8_t *b, size_t nb, size_t ncodes, int order)</div><div class="ttdef"><b>Definition:</b> <a href="hamming_8cpp_source.html#l00518">hamming.cpp:518</a></div></div>
<div class="ttc" id="structfaiss_1_1HammingComputerM4_html"><div class="ttname"><a href="structfaiss_1_1HammingComputerM4.html">faiss::HammingComputerM4</a></div><div class="ttdef"><b>Definition:</b> <a href="hamming_8h_source.html#l00371">hamming.h:371</a></div></div>
<div class="ttc" id="structfaiss_1_1HammingComputer_html"><div class="ttname"><a href="structfaiss_1_1HammingComputer.html">faiss::HammingComputer</a></div><div class="ttdef"><b>Definition:</b> <a href="hamming_8h_source.html#l00403">hamming.h:403</a></div></div>
<div class="ttc" id="structfaiss_1_1HammingComputer20_html"><div class="ttname"><a href="structfaiss_1_1HammingComputer20.html">faiss::HammingComputer20</a></div><div class="ttdef"><b>Definition:</b> <a href="hamming_8h_source.html#l00246">hamming.h:246</a></div></div>
<div class="ttc" id="structfaiss_1_1GenHammingComputer16_html"><div class="ttname"><a href="structfaiss_1_1GenHammingComputer16.html">faiss::GenHammingComputer16</a></div><div class="ttdef"><b>Definition:</b> <a href="hamming_8h_source.html#l00455">hamming.h:455</a></div></div>
<div class="ttc" id="structfaiss_1_1GenHammingComputer8_html"><div class="ttname"><a href="structfaiss_1_1GenHammingComputer8.html">faiss::GenHammingComputer8</a></div><div class="ttdef"><b>Definition:</b> <a href="hamming_8h_source.html#l00440">hamming.h:440</a></div></div>
<div class="ttc" id="structfaiss_1_1HCounterState_html"><div class="ttname"><a href="structfaiss_1_1HCounterState.html">faiss::HCounterState</a></div><div class="ttdef"><b>Definition:</b> <a href="hamming_8h_source.html#l00531">hamming.h:531</a></div></div>
<div class="ttc" id="namespacefaiss_html_aa9ac586642ba474949a007546ab05592"><div class="ttname"><a href="namespacefaiss.html#aa9ac586642ba474949a007546ab05592">faiss::hammings_knn_mc</a></div><div class="ttdeci">void hammings_knn_mc(const uint8_t *a, const uint8_t *b, size_t na, size_t nb, size_t k, size_t ncodes, int32_t *distances, long *labels)</div><div class="ttdef"><b>Definition:</b> <a href="hamming_8cpp_source.html#l00556">hamming.cpp:556</a></div></div>
<div class="ttc" id="structfaiss_1_1HammingComputer8_html"><div class="ttname"><a href="structfaiss_1_1HammingComputer8.html">faiss::HammingComputer8</a></div><div class="ttdef"><b>Definition:</b> <a href="hamming_8h_source.html#l00201">hamming.h:201</a></div></div>
<div class="ttc" id="structfaiss_1_1HammingComputer64_html"><div class="ttname"><a href="structfaiss_1_1HammingComputer64.html">faiss::HammingComputer64</a></div><div class="ttdef"><b>Definition:</b> <a href="hamming_8h_source.html#l00292">hamming.h:292</a></div></div>
<div class="ttc" id="structfaiss_1_1HammingComputer16_html"><div class="ttname"><a href="structfaiss_1_1HammingComputer16.html">faiss::HammingComputer16</a></div><div class="ttdef"><b>Definition:</b> <a href="hamming_8h_source.html#l00222">hamming.h:222</a></div></div>
<div class="ttc" id="structfaiss_1_1HammingComputer4_html"><div class="ttname"><a href="structfaiss_1_1HammingComputer4.html">faiss::HammingComputer4</a></div><div class="ttdef"><b>Definition:</b> <a href="hamming_8h_source.html#l00181">hamming.h:181</a></div></div>
<div class="ttc" id="structfaiss_1_1GenHammingComputerM8_html"><div class="ttname"><a href="structfaiss_1_1GenHammingComputerM8.html">faiss::GenHammingComputerM8</a></div><div class="ttdef"><b>Definition:</b> <a href="hamming_8h_source.html#l00490">hamming.h:490</a></div></div>
<div class="ttc" id="structfaiss_1_1HeapArray_html"><div class="ttname"><a href="structfaiss_1_1HeapArray.html">faiss::HeapArray</a></div><div class="ttdef"><b>Definition:</b> <a href="Heap_8h_source.html#l00350">Heap.h:350</a></div></div>
<div class="ttc" id="structfaiss_1_1HammingComputer32_html"><div class="ttname"><a href="structfaiss_1_1HammingComputer32.html">faiss::HammingComputer32</a></div><div class="ttdef"><b>Definition:</b> <a href="hamming_8h_source.html#l00269">hamming.h:269</a></div></div>
<div class="ttc" id="structfaiss_1_1GenHammingComputer32_html"><div class="ttname"><a href="structfaiss_1_1GenHammingComputer32.html">faiss::GenHammingComputer32</a></div><div class="ttdef"><b>Definition:</b> <a href="hamming_8h_source.html#l00471">hamming.h:471</a></div></div>
<div class="ttc" id="structfaiss_1_1HammingComputerDefault_html"><div class="ttname"><a href="structfaiss_1_1HammingComputerDefault.html">faiss::HammingComputerDefault</a></div><div class="ttdef"><b>Definition:</b> <a href="hamming_8h_source.html#l00319">hamming.h:319</a></div></div>
<div class="ttc" id="structfaiss_1_1HammingComputerM8_html"><div class="ttname"><a href="structfaiss_1_1HammingComputerM8.html">faiss::HammingComputerM8</a></div><div class="ttdef"><b>Definition:</b> <a href="hamming_8h_source.html#l00344">hamming.h:344</a></div></div>
<div class="ttc" id="namespacefaiss_html_a9c1131631ad4314ba716372fe0d1dea6"><div class="ttname"><a href="namespacefaiss.html#a9c1131631ad4314ba716372fe0d1dea6">faiss::generalized_hammings_knn_hc</a></div><div class="ttdeci">void generalized_hammings_knn_hc(int_maxheap_array_t *ha, const uint8_t *a, const uint8_t *b, size_t nb, size_t code_size, int ordered)</div><div class="ttdef"><b>Definition:</b> <a href="hamming_8cpp_source.html#l00729">hamming.cpp:729</a></div></div>
</div><!-- fragment --></div><!-- contents -->
<!-- start footer part -->
<hr class="footer"/><address class="footer"><small>
Generated by &#160;<a href="http://www.doxygen.org/index.html">
<img class="footer" src="doxygen.png" alt="doxygen"/>
</a> 1.8.5
</small></address>
</body>
</html>