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| <li class="navelem"><a class="el" href="dir_82f3a10095a8f2296c0cf5c491a57b02.html">cpc</a></li><li class="navelem"><a class="el" href="dir_fabb7854c43508dcbf81254d1daad42f.html">include</a></li> </ul> |
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| <div class="title">cpc_util.hpp</div> </div> |
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| <div class="fragment"><div class="line"><a name="l00001"></a><span class="lineno"> 1</span> <span class="comment">/*</span></div> |
| <div class="line"><a name="l00002"></a><span class="lineno"> 2</span> <span class="comment"> * Licensed to the Apache Software Foundation (ASF) under one</span></div> |
| <div class="line"><a name="l00003"></a><span class="lineno"> 3</span> <span class="comment"> * or more contributor license agreements. See the NOTICE file</span></div> |
| <div class="line"><a name="l00004"></a><span class="lineno"> 4</span> <span class="comment"> * distributed with this work for additional information</span></div> |
| <div class="line"><a name="l00005"></a><span class="lineno"> 5</span> <span class="comment"> * regarding copyright ownership. The ASF licenses this file</span></div> |
| <div class="line"><a name="l00006"></a><span class="lineno"> 6</span> <span class="comment"> * to you under the Apache License, Version 2.0 (the</span></div> |
| <div class="line"><a name="l00007"></a><span class="lineno"> 7</span> <span class="comment"> * "License"); you may not use this file except in compliance</span></div> |
| <div class="line"><a name="l00008"></a><span class="lineno"> 8</span> <span class="comment"> * with the License. You may obtain a copy of the License at</span></div> |
| <div class="line"><a name="l00009"></a><span class="lineno"> 9</span> <span class="comment"> *</span></div> |
| <div class="line"><a name="l00010"></a><span class="lineno"> 10</span> <span class="comment"> * http://www.apache.org/licenses/LICENSE-2.0</span></div> |
| <div class="line"><a name="l00011"></a><span class="lineno"> 11</span> <span class="comment"> *</span></div> |
| <div class="line"><a name="l00012"></a><span class="lineno"> 12</span> <span class="comment"> * Unless required by applicable law or agreed to in writing,</span></div> |
| <div class="line"><a name="l00013"></a><span class="lineno"> 13</span> <span class="comment"> * software distributed under the License is distributed on an</span></div> |
| <div class="line"><a name="l00014"></a><span class="lineno"> 14</span> <span class="comment"> * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY</span></div> |
| <div class="line"><a name="l00015"></a><span class="lineno"> 15</span> <span class="comment"> * KIND, either express or implied. See the License for the</span></div> |
| <div class="line"><a name="l00016"></a><span class="lineno"> 16</span> <span class="comment"> * specific language governing permissions and limitations</span></div> |
| <div class="line"><a name="l00017"></a><span class="lineno"> 17</span> <span class="comment"> * under the License.</span></div> |
| <div class="line"><a name="l00018"></a><span class="lineno"> 18</span> <span class="comment"> */</span></div> |
| <div class="line"><a name="l00019"></a><span class="lineno"> 19</span>  </div> |
| <div class="line"><a name="l00020"></a><span class="lineno"> 20</span> <span class="preprocessor">#ifndef CPC_UTIL_HPP_</span></div> |
| <div class="line"><a name="l00021"></a><span class="lineno"> 21</span> <span class="preprocessor">#define CPC_UTIL_HPP_</span></div> |
| <div class="line"><a name="l00022"></a><span class="lineno"> 22</span>  </div> |
| <div class="line"><a name="l00023"></a><span class="lineno"> 23</span> <span class="preprocessor">#include <stdexcept></span></div> |
| <div class="line"><a name="l00024"></a><span class="lineno"> 24</span>  </div> |
| <div class="line"><a name="l00025"></a><span class="lineno"> 25</span> <span class="keyword">namespace </span><a class="code" href="namespacedatasketches.html">datasketches</a> {</div> |
| <div class="line"><a name="l00026"></a><span class="lineno"> 26</span>  </div> |
| <div class="line"><a name="l00027"></a><span class="lineno"> 27</span> <span class="keyword">static</span> <span class="keyword">inline</span> uint64_t divide_longs_rounding_up(uint64_t x, uint64_t y) {</div> |
| <div class="line"><a name="l00028"></a><span class="lineno"> 28</span>  <span class="keywordflow">if</span> (y == 0) <span class="keywordflow">throw</span> std::invalid_argument(<span class="stringliteral">"divide_longs_rounding_up: bad argument"</span>);</div> |
| <div class="line"><a name="l00029"></a><span class="lineno"> 29</span>  <span class="keyword">const</span> uint64_t quotient = x / y;</div> |
| <div class="line"><a name="l00030"></a><span class="lineno"> 30</span>  <span class="keywordflow">if</span> (quotient * y == x) <span class="keywordflow">return</span> (quotient);</div> |
| <div class="line"><a name="l00031"></a><span class="lineno"> 31</span>  <span class="keywordflow">else</span> <span class="keywordflow">return</span> quotient + 1;</div> |
| <div class="line"><a name="l00032"></a><span class="lineno"> 32</span> }</div> |
| <div class="line"><a name="l00033"></a><span class="lineno"> 33</span>  </div> |
| <div class="line"><a name="l00034"></a><span class="lineno"> 34</span> <span class="keyword">static</span> <span class="keyword">inline</span> uint8_t floor_log2_of_long(uint64_t x) {</div> |
| <div class="line"><a name="l00035"></a><span class="lineno"> 35</span>  <span class="keywordflow">if</span> (x < 1) <span class="keywordflow">throw</span> std::invalid_argument(<span class="stringliteral">"floor_log2_of_long: bad argument"</span>);</div> |
| <div class="line"><a name="l00036"></a><span class="lineno"> 36</span>  uint8_t p = 0;</div> |
| <div class="line"><a name="l00037"></a><span class="lineno"> 37</span>  uint64_t y = 1;</div> |
| <div class="line"><a name="l00038"></a><span class="lineno"> 38</span>  <span class="keywordflow">while</span> (<span class="keyword">true</span>) {</div> |
| <div class="line"><a name="l00039"></a><span class="lineno"> 39</span>  <span class="keywordflow">if</span> (y == x) <span class="keywordflow">return</span> p;</div> |
| <div class="line"><a name="l00040"></a><span class="lineno"> 40</span>  <span class="keywordflow">if</span> (y > x) <span class="keywordflow">return</span> p - 1;</div> |
| <div class="line"><a name="l00041"></a><span class="lineno"> 41</span>  p += 1;</div> |
| <div class="line"><a name="l00042"></a><span class="lineno"> 42</span>  y <<= 1;</div> |
| <div class="line"><a name="l00043"></a><span class="lineno"> 43</span>  }</div> |
| <div class="line"><a name="l00044"></a><span class="lineno"> 44</span> }</div> |
| <div class="line"><a name="l00045"></a><span class="lineno"> 45</span>  </div> |
| <div class="line"><a name="l00046"></a><span class="lineno"> 46</span> <span class="comment">// This place-holder code was inadequate because it caused</span></div> |
| <div class="line"><a name="l00047"></a><span class="lineno"> 47</span> <span class="comment">// the cost of the post-merge get_result() operation to be O(C)</span></div> |
| <div class="line"><a name="l00048"></a><span class="lineno"> 48</span> <span class="comment">// instead of O(K). It did have the advantage of being</span></div> |
| <div class="line"><a name="l00049"></a><span class="lineno"> 49</span> <span class="comment">// very simple and trustworthy during initial testing.</span></div> |
| <div class="line"><a name="l00050"></a><span class="lineno"> 50</span> <span class="keyword">static</span> <span class="keyword">inline</span> uint64_t wegner_count_bits_set_in_matrix(<span class="keyword">const</span> uint64_t* array, <span class="keywordtype">size_t</span> length) {</div> |
| <div class="line"><a name="l00051"></a><span class="lineno"> 51</span>  uint64_t pattern = 0;</div> |
| <div class="line"><a name="l00052"></a><span class="lineno"> 52</span>  uint64_t count = 0;</div> |
| <div class="line"><a name="l00053"></a><span class="lineno"> 53</span>  <span class="comment">// clock_t t0, t1;</span></div> |
| <div class="line"><a name="l00054"></a><span class="lineno"> 54</span>  <span class="comment">// t0 = clock();</span></div> |
| <div class="line"><a name="l00055"></a><span class="lineno"> 55</span>  <span class="comment">// Wegner's Bit-Counting Algorithm, CACM 3 (1960), p. 322.</span></div> |
| <div class="line"><a name="l00056"></a><span class="lineno"> 56</span>  <span class="keywordflow">for</span> (uint64_t i = 0; i < length; i++) {</div> |
| <div class="line"><a name="l00057"></a><span class="lineno"> 57</span>  pattern = array[i];</div> |
| <div class="line"><a name="l00058"></a><span class="lineno"> 58</span>  <span class="keywordflow">while</span> (pattern != 0) {</div> |
| <div class="line"><a name="l00059"></a><span class="lineno"> 59</span>  pattern &= (pattern - 1);</div> |
| <div class="line"><a name="l00060"></a><span class="lineno"> 60</span>  count++;</div> |
| <div class="line"><a name="l00061"></a><span class="lineno"> 61</span>  }</div> |
| <div class="line"><a name="l00062"></a><span class="lineno"> 62</span>  }</div> |
| <div class="line"><a name="l00063"></a><span class="lineno"> 63</span>  <span class="comment">// t1 = clock();</span></div> |
| <div class="line"><a name="l00064"></a><span class="lineno"> 64</span>  <span class="comment">// printf ("\n(Wegner CountBitsTime %.1f)\n", ((double) (t1 - t0)) / 1000.0);</span></div> |
| <div class="line"><a name="l00065"></a><span class="lineno"> 65</span>  <span class="comment">// fflush (stdout);</span></div> |
| <div class="line"><a name="l00066"></a><span class="lineno"> 66</span>  <span class="keywordflow">return</span> count;</div> |
| <div class="line"><a name="l00067"></a><span class="lineno"> 67</span> }</div> |
| <div class="line"><a name="l00068"></a><span class="lineno"> 68</span>  </div> |
| <div class="line"><a name="l00069"></a><span class="lineno"> 69</span> <span class="comment">// Note: this is an adaptation of the Java code,</span></div> |
| <div class="line"><a name="l00070"></a><span class="lineno"> 70</span> <span class="comment">// which is apparently a variation of Figure 5-2 in "Hacker's Delight"</span></div> |
| <div class="line"><a name="l00071"></a><span class="lineno"> 71</span> <span class="comment">// by Henry S. Warren.</span></div> |
| <div class="line"><a name="l00072"></a><span class="lineno"> 72</span> <span class="keyword">static</span> <span class="keyword">inline</span> uint32_t warren_bit_count(uint64_t i) {</div> |
| <div class="line"><a name="l00073"></a><span class="lineno"> 73</span>  i = i - ((i >> 1) & 0x5555555555555555ULL);</div> |
| <div class="line"><a name="l00074"></a><span class="lineno"> 74</span>  i = (i & 0x3333333333333333ULL) + ((i >> 2) & 0x3333333333333333ULL);</div> |
| <div class="line"><a name="l00075"></a><span class="lineno"> 75</span>  i = (i + (i >> 4)) & 0x0f0f0f0f0f0f0f0fULL;</div> |
| <div class="line"><a name="l00076"></a><span class="lineno"> 76</span>  i = i + (i >> 8);</div> |
| <div class="line"><a name="l00077"></a><span class="lineno"> 77</span>  i = i + (i >> 16);</div> |
| <div class="line"><a name="l00078"></a><span class="lineno"> 78</span>  i = i + (i >> 32);</div> |
| <div class="line"><a name="l00079"></a><span class="lineno"> 79</span>  <span class="keywordflow">return</span> i & 0x7f;</div> |
| <div class="line"><a name="l00080"></a><span class="lineno"> 80</span> }</div> |
| <div class="line"><a name="l00081"></a><span class="lineno"> 81</span>  </div> |
| <div class="line"><a name="l00082"></a><span class="lineno"> 82</span> <span class="keyword">static</span> <span class="keyword">inline</span> uint32_t warren_count_bits_set_in_matrix(<span class="keyword">const</span> uint64_t* array, uint32_t length) {</div> |
| <div class="line"><a name="l00083"></a><span class="lineno"> 83</span>  uint32_t count = 0;</div> |
| <div class="line"><a name="l00084"></a><span class="lineno"> 84</span>  <span class="keywordflow">for</span> (uint32_t i = 0; i < length; i++) {</div> |
| <div class="line"><a name="l00085"></a><span class="lineno"> 85</span>  count += warren_bit_count(array[i]);</div> |
| <div class="line"><a name="l00086"></a><span class="lineno"> 86</span>  }</div> |
| <div class="line"><a name="l00087"></a><span class="lineno"> 87</span>  <span class="keywordflow">return</span> count;</div> |
| <div class="line"><a name="l00088"></a><span class="lineno"> 88</span> }</div> |
| <div class="line"><a name="l00089"></a><span class="lineno"> 89</span>  </div> |
| <div class="line"><a name="l00090"></a><span class="lineno"> 90</span> <span class="comment">// This code is Figure 5-9 in "Hacker's Delight" by Henry S. Warren.</span></div> |
| <div class="line"><a name="l00091"></a><span class="lineno"> 91</span>  </div> |
| <div class="line"><a name="l00092"></a><span class="lineno"> 92</span> <span class="preprocessor">#define DATASKETCHES_CSA(h, l, a, b, c) \</span></div> |
| <div class="line"><a name="l00093"></a><span class="lineno"> 93</span> <span class="preprocessor"> { \</span></div> |
| <div class="line"><a name="l00094"></a><span class="lineno"> 94</span> <span class="preprocessor"> uint64_t u = a ^ b; \</span></div> |
| <div class="line"><a name="l00095"></a><span class="lineno"> 95</span> <span class="preprocessor"> uint64_t v = c; \</span></div> |
| <div class="line"><a name="l00096"></a><span class="lineno"> 96</span> <span class="preprocessor"> h = (a & b) | (u & v); \</span></div> |
| <div class="line"><a name="l00097"></a><span class="lineno"> 97</span> <span class="preprocessor"> l = u ^ v; \</span></div> |
| <div class="line"><a name="l00098"></a><span class="lineno"> 98</span> <span class="preprocessor"> }</span></div> |
| <div class="line"><a name="l00099"></a><span class="lineno"> 99</span>  </div> |
| <div class="line"><a name="l00100"></a><span class="lineno"> 100</span> <span class="keyword">static</span> <span class="keyword">inline</span> uint32_t count_bits_set_in_matrix(<span class="keyword">const</span> uint64_t* a, uint32_t length) {</div> |
| <div class="line"><a name="l00101"></a><span class="lineno"> 101</span>  <span class="keywordflow">if</span> ((length & 0x7) != 0) <span class="keywordflow">throw</span> std::invalid_argument(<span class="stringliteral">"the length of the array must be a multiple of 8"</span>);</div> |
| <div class="line"><a name="l00102"></a><span class="lineno"> 102</span>  uint32_t total = 0;</div> |
| <div class="line"><a name="l00103"></a><span class="lineno"> 103</span>  uint64_t ones, twos, twos_a, twos_b, fours, fours_a, fours_b, eights;</div> |
| <div class="line"><a name="l00104"></a><span class="lineno"> 104</span>  fours = twos = ones = 0;</div> |
| <div class="line"><a name="l00105"></a><span class="lineno"> 105</span>  </div> |
| <div class="line"><a name="l00106"></a><span class="lineno"> 106</span>  <span class="keywordflow">for</span> (uint32_t i = 0; i <= length - 8; i += 8) {</div> |
| <div class="line"><a name="l00107"></a><span class="lineno"> 107</span>  DATASKETCHES_CSA(twos_a, ones, ones, a[i+0], a[i+1]);</div> |
| <div class="line"><a name="l00108"></a><span class="lineno"> 108</span>  DATASKETCHES_CSA(twos_b, ones, ones, a[i+2], a[i+3]);</div> |
| <div class="line"><a name="l00109"></a><span class="lineno"> 109</span>  DATASKETCHES_CSA(fours_a, twos, twos, twos_a, twos_b);</div> |
| <div class="line"><a name="l00110"></a><span class="lineno"> 110</span>  </div> |
| <div class="line"><a name="l00111"></a><span class="lineno"> 111</span>  DATASKETCHES_CSA(twos_a, ones, ones, a[i+4], a[i+5]);</div> |
| <div class="line"><a name="l00112"></a><span class="lineno"> 112</span>  DATASKETCHES_CSA(twos_b, ones, ones, a[i+6], a[i+7]);</div> |
| <div class="line"><a name="l00113"></a><span class="lineno"> 113</span>  DATASKETCHES_CSA(fours_b, twos, twos, twos_a, twos_b);</div> |
| <div class="line"><a name="l00114"></a><span class="lineno"> 114</span>  </div> |
| <div class="line"><a name="l00115"></a><span class="lineno"> 115</span>  DATASKETCHES_CSA(eights, fours, fours, fours_a, fours_b);</div> |
| <div class="line"><a name="l00116"></a><span class="lineno"> 116</span>  </div> |
| <div class="line"><a name="l00117"></a><span class="lineno"> 117</span>  total += warren_bit_count(eights);</div> |
| <div class="line"><a name="l00118"></a><span class="lineno"> 118</span>  }</div> |
| <div class="line"><a name="l00119"></a><span class="lineno"> 119</span>  total = 8 * total + 4 * warren_bit_count(fours) + 2 * warren_bit_count(twos) + warren_bit_count(ones);</div> |
| <div class="line"><a name="l00120"></a><span class="lineno"> 120</span>  </div> |
| <div class="line"><a name="l00121"></a><span class="lineno"> 121</span>  <span class="comment">// Because I still don't fully trust this fancy version</span></div> |
| <div class="line"><a name="l00122"></a><span class="lineno"> 122</span>  <span class="comment">// assert(total == wegner_count_bits_set_in_matrix(A, length));</span></div> |
| <div class="line"><a name="l00123"></a><span class="lineno"> 123</span>  <span class="comment">//if (total != wegner_count_bits_set_in_matrix(a, length)) throw std::logic_error("count_bits_set_in_matrix error");</span></div> |
| <div class="line"><a name="l00124"></a><span class="lineno"> 124</span>  </div> |
| <div class="line"><a name="l00125"></a><span class="lineno"> 125</span>  <span class="keywordflow">return</span> total;</div> |
| <div class="line"><a name="l00126"></a><span class="lineno"> 126</span> }</div> |
| <div class="line"><a name="l00127"></a><span class="lineno"> 127</span>  </div> |
| <div class="line"><a name="l00128"></a><span class="lineno"> 128</span> <span class="preprocessor">#undef DATASKETCHES_CSA</span></div> |
| <div class="line"><a name="l00129"></a><span class="lineno"> 129</span>  </div> |
| <div class="line"><a name="l00130"></a><span class="lineno"> 130</span> <span class="comment">// Here are some timings made with quickTestMerge.c</span></div> |
| <div class="line"><a name="l00131"></a><span class="lineno"> 131</span> <span class="comment">// for the "5 5" case:</span></div> |
| <div class="line"><a name="l00132"></a><span class="lineno"> 132</span>  </div> |
| <div class="line"><a name="l00133"></a><span class="lineno"> 133</span> <span class="comment">// Wegner CountBitsTime 29.3</span></div> |
| <div class="line"><a name="l00134"></a><span class="lineno"> 134</span> <span class="comment">// Warren CountBitsTime 5.3</span></div> |
| <div class="line"><a name="l00135"></a><span class="lineno"> 135</span> <span class="comment">// CSA CountBitsTime 4.3</span></div> |
| <div class="line"><a name="l00136"></a><span class="lineno"> 136</span>  </div> |
| <div class="line"><a name="l00137"></a><span class="lineno"> 137</span> } <span class="comment">/* namespace datasketches */</span></div> |
| <div class="line"><a name="l00138"></a><span class="lineno"> 138</span>  </div> |
| <div class="line"><a name="l00139"></a><span class="lineno"> 139</span> <span class="preprocessor">#endif</span></div> |
| <div class="ttc" id="anamespacedatasketches_html"><div class="ttname"><a href="namespacedatasketches.html">datasketches</a></div><div class="ttdoc">DataSketches namespace.</div><div class="ttdef"><b>Definition:</b> binomial_bounds.hpp:38</div></div> |
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