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<div class="title">fp16_emu.cu</div> </div>
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<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">/**</span></div>
<div class="line"><a name="l00003"></a><span class="lineno"> 3</span>&#160;<span class="comment"> * Copyright (c) 2015-present, Facebook, Inc.</span></div>
<div class="line"><a name="l00004"></a><span class="lineno"> 4</span>&#160;<span class="comment"> * All rights reserved.</span></div>
<div class="line"><a name="l00005"></a><span class="lineno"> 5</span>&#160;<span class="comment"> *</span></div>
<div class="line"><a name="l00006"></a><span class="lineno"> 6</span>&#160;<span class="comment"> * This source code is licensed under the CC-by-NC license found in the</span></div>
<div class="line"><a name="l00007"></a><span class="lineno"> 7</span>&#160;<span class="comment"> * LICENSE file in the root directory of this source tree.</span></div>
<div class="line"><a name="l00008"></a><span class="lineno"> 8</span>&#160;<span class="comment"> */</span></div>
<div class="line"><a name="l00009"></a><span class="lineno"> 9</span>&#160;</div>
<div class="line"><a name="l00010"></a><span class="lineno"> 10</span>&#160;<span class="comment">// from Nvidia cuDNN library samples; modified to compile within faiss</span></div>
<div class="line"><a name="l00011"></a><span class="lineno"> 11</span>&#160;</div>
<div class="line"><a name="l00012"></a><span class="lineno"> 12</span>&#160;<span class="preprocessor">#include &quot;fp16_emu.cuh&quot;</span></div>
<div class="line"><a name="l00013"></a><span class="lineno"> 13</span>&#160;</div>
<div class="line"><a name="l00014"></a><span class="lineno"> 14</span>&#160;<span class="keyword">namespace </span>faiss { <span class="keyword">namespace </span>gpu {</div>
<div class="line"><a name="l00015"></a><span class="lineno"> 15</span>&#160;</div>
<div class="line"><a name="l00016"></a><span class="lineno"> 16</span>&#160;<span class="comment">/*</span></div>
<div class="line"><a name="l00017"></a><span class="lineno"> 17</span>&#160;<span class="comment"> * Copyright 1993-2014 NVIDIA Corporation. All rights reserved.</span></div>
<div class="line"><a name="l00018"></a><span class="lineno"> 18</span>&#160;<span class="comment"> *</span></div>
<div class="line"><a name="l00019"></a><span class="lineno"> 19</span>&#160;<span class="comment"> * NOTICE TO LICENSEE:</span></div>
<div class="line"><a name="l00020"></a><span class="lineno"> 20</span>&#160;<span class="comment"> *</span></div>
<div class="line"><a name="l00021"></a><span class="lineno"> 21</span>&#160;<span class="comment"> * This source code and/or documentation (&quot;Licensed Deliverables&quot;) are</span></div>
<div class="line"><a name="l00022"></a><span class="lineno"> 22</span>&#160;<span class="comment"> * subject to NVIDIA intellectual property rights under U.S. and</span></div>
<div class="line"><a name="l00023"></a><span class="lineno"> 23</span>&#160;<span class="comment"> * international Copyright laws.</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;<span class="comment"> * These Licensed Deliverables contained herein is PROPRIETARY and</span></div>
<div class="line"><a name="l00026"></a><span class="lineno"> 26</span>&#160;<span class="comment"> * CONFIDENTIAL to NVIDIA and is being provided under the terms and</span></div>
<div class="line"><a name="l00027"></a><span class="lineno"> 27</span>&#160;<span class="comment"> * conditions of a form of NVIDIA software license agreement by and</span></div>
<div class="line"><a name="l00028"></a><span class="lineno"> 28</span>&#160;<span class="comment"> * between NVIDIA and Licensee (&quot;License Agreement&quot;) or electronically</span></div>
<div class="line"><a name="l00029"></a><span class="lineno"> 29</span>&#160;<span class="comment"> * accepted by Licensee. Notwithstanding any terms or conditions to</span></div>
<div class="line"><a name="l00030"></a><span class="lineno"> 30</span>&#160;<span class="comment"> * the contrary in the License Agreement, reproduction or disclosure</span></div>
<div class="line"><a name="l00031"></a><span class="lineno"> 31</span>&#160;<span class="comment"> * of the Licensed Deliverables to any third party without the express</span></div>
<div class="line"><a name="l00032"></a><span class="lineno"> 32</span>&#160;<span class="comment"> * written consent of NVIDIA is prohibited.</span></div>
<div class="line"><a name="l00033"></a><span class="lineno"> 33</span>&#160;<span class="comment"> *</span></div>
<div class="line"><a name="l00034"></a><span class="lineno"> 34</span>&#160;<span class="comment"> * NOTWITHSTANDING ANY TERMS OR CONDITIONS TO THE CONTRARY IN THE</span></div>
<div class="line"><a name="l00035"></a><span class="lineno"> 35</span>&#160;<span class="comment"> * LICENSE AGREEMENT, NVIDIA MAKES NO REPRESENTATION ABOUT THE</span></div>
<div class="line"><a name="l00036"></a><span class="lineno"> 36</span>&#160;<span class="comment"> * SUITABILITY OF THESE LICENSED DELIVERABLES FOR ANY PURPOSE. IT IS</span></div>
<div class="line"><a name="l00037"></a><span class="lineno"> 37</span>&#160;<span class="comment"> * PROVIDED &quot;AS IS&quot; WITHOUT EXPRESS OR IMPLIED WARRANTY OF ANY KIND.</span></div>
<div class="line"><a name="l00038"></a><span class="lineno"> 38</span>&#160;<span class="comment"> * NVIDIA DISCLAIMS ALL WARRANTIES WITH REGARD TO THESE LICENSED</span></div>
<div class="line"><a name="l00039"></a><span class="lineno"> 39</span>&#160;<span class="comment"> * DELIVERABLES, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY,</span></div>
<div class="line"><a name="l00040"></a><span class="lineno"> 40</span>&#160;<span class="comment"> * NONINFRINGEMENT, AND FITNESS FOR A PARTICULAR PURPOSE.</span></div>
<div class="line"><a name="l00041"></a><span class="lineno"> 41</span>&#160;<span class="comment"> * NOTWITHSTANDING ANY TERMS OR CONDITIONS TO THE CONTRARY IN THE</span></div>
<div class="line"><a name="l00042"></a><span class="lineno"> 42</span>&#160;<span class="comment"> * LICENSE AGREEMENT, IN NO EVENT SHALL NVIDIA BE LIABLE FOR ANY</span></div>
<div class="line"><a name="l00043"></a><span class="lineno"> 43</span>&#160;<span class="comment"> * SPECIAL, INDIRECT, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, OR ANY</span></div>
<div class="line"><a name="l00044"></a><span class="lineno"> 44</span>&#160;<span class="comment"> * DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,</span></div>
<div class="line"><a name="l00045"></a><span class="lineno"> 45</span>&#160;<span class="comment"> * WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS</span></div>
<div class="line"><a name="l00046"></a><span class="lineno"> 46</span>&#160;<span class="comment"> * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE</span></div>
<div class="line"><a name="l00047"></a><span class="lineno"> 47</span>&#160;<span class="comment"> * OF THESE LICENSED DELIVERABLES.</span></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"> * U.S. Government End Users. These Licensed Deliverables are a</span></div>
<div class="line"><a name="l00050"></a><span class="lineno"> 50</span>&#160;<span class="comment"> * &quot;commercial item&quot; as that term is defined at 48 C.F.R. 2.101 (OCT</span></div>
<div class="line"><a name="l00051"></a><span class="lineno"> 51</span>&#160;<span class="comment"> * 1995), consisting of &quot;commercial computer software&quot; and &quot;commercial</span></div>
<div class="line"><a name="l00052"></a><span class="lineno"> 52</span>&#160;<span class="comment"> * computer software documentation&quot; as such terms are used in 48</span></div>
<div class="line"><a name="l00053"></a><span class="lineno"> 53</span>&#160;<span class="comment"> * C.F.R. 12.212 (SEPT 1995) and is provided to the U.S. Government</span></div>
<div class="line"><a name="l00054"></a><span class="lineno"> 54</span>&#160;<span class="comment"> * only as a commercial end item. Consistent with 48 C.F.R.12.212 and</span></div>
<div class="line"><a name="l00055"></a><span class="lineno"> 55</span>&#160;<span class="comment"> * 48 C.F.R. 227.7202-1 through 227.7202-4 (JUNE 1995), all</span></div>
<div class="line"><a name="l00056"></a><span class="lineno"> 56</span>&#160;<span class="comment"> * U.S. Government End Users acquire the Licensed Deliverables with</span></div>
<div class="line"><a name="l00057"></a><span class="lineno"> 57</span>&#160;<span class="comment"> * only those rights set forth herein.</span></div>
<div class="line"><a name="l00058"></a><span class="lineno"> 58</span>&#160;<span class="comment"> *</span></div>
<div class="line"><a name="l00059"></a><span class="lineno"> 59</span>&#160;<span class="comment"> * Any use of the Licensed Deliverables in individual and commercial</span></div>
<div class="line"><a name="l00060"></a><span class="lineno"> 60</span>&#160;<span class="comment"> * software must include, in the user documentation and internal</span></div>
<div class="line"><a name="l00061"></a><span class="lineno"> 61</span>&#160;<span class="comment"> * comments to the code, the above Disclaimer and U.S. Government End</span></div>
<div class="line"><a name="l00062"></a><span class="lineno"> 62</span>&#160;<span class="comment"> * Users Notice.</span></div>
<div class="line"><a name="l00063"></a><span class="lineno"> 63</span>&#160;<span class="comment"> */</span></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;<span class="comment">// Host functions for converting between FP32 and FP16 formats</span></div>
<div class="line"><a name="l00066"></a><span class="lineno"> 66</span>&#160;<span class="comment">// Paulius Micikevicius (pauliusm@nvidia.com)</span></div>
<div class="line"><a name="l00067"></a><span class="lineno"> 67</span>&#160;</div>
<div class="line"><a name="l00068"></a><span class="lineno"> 68</span>&#160;half1 cpu_float2half_rn(<span class="keywordtype">float</span> f)</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; half1 ret;</div>
<div class="line"><a name="l00071"></a><span class="lineno"> 71</span>&#160;</div>
<div class="line"><a name="l00072"></a><span class="lineno"> 72</span>&#160; <span class="keyword">union </span>{</div>
<div class="line"><a name="l00073"></a><span class="lineno"> 73</span>&#160; <span class="keywordtype">float</span> f;</div>
<div class="line"><a name="l00074"></a><span class="lineno"> 74</span>&#160; <span class="keywordtype">unsigned</span> u;</div>
<div class="line"><a name="l00075"></a><span class="lineno"> 75</span>&#160; } un;</div>
<div class="line"><a name="l00076"></a><span class="lineno"> 76</span>&#160;</div>
<div class="line"><a name="l00077"></a><span class="lineno"> 77</span>&#160; un.f = f;</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; <span class="keywordtype">unsigned</span> x = un.u;</div>
<div class="line"><a name="l00080"></a><span class="lineno"> 80</span>&#160; <span class="keywordtype">unsigned</span> u = (x &amp; 0x7fffffff), remainder, shift, lsb, lsb_s1, lsb_m1;</div>
<div class="line"><a name="l00081"></a><span class="lineno"> 81</span>&#160; <span class="keywordtype">unsigned</span> sign, exponent, mantissa;</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">// Get rid of +NaN/-NaN case first.</span></div>
<div class="line"><a name="l00084"></a><span class="lineno"> 84</span>&#160; <span class="keywordflow">if</span> (u &gt; 0x7f800000) {</div>
<div class="line"><a name="l00085"></a><span class="lineno"> 85</span>&#160; ret.x = 0x7fffU;</div>
<div class="line"><a name="l00086"></a><span class="lineno"> 86</span>&#160; <span class="keywordflow">return</span> ret;</div>
<div class="line"><a name="l00087"></a><span class="lineno"> 87</span>&#160; }</div>
<div class="line"><a name="l00088"></a><span class="lineno"> 88</span>&#160;</div>
<div class="line"><a name="l00089"></a><span class="lineno"> 89</span>&#160; sign = ((x &gt;&gt; 16) &amp; 0x8000);</div>
<div class="line"><a name="l00090"></a><span class="lineno"> 90</span>&#160;</div>
<div class="line"><a name="l00091"></a><span class="lineno"> 91</span>&#160; <span class="comment">// Get rid of +Inf/-Inf, +0/-0.</span></div>
<div class="line"><a name="l00092"></a><span class="lineno"> 92</span>&#160; <span class="keywordflow">if</span> (u &gt; 0x477fefff) {</div>
<div class="line"><a name="l00093"></a><span class="lineno"> 93</span>&#160; ret.x = sign | 0x7c00U;</div>
<div class="line"><a name="l00094"></a><span class="lineno"> 94</span>&#160; <span class="keywordflow">return</span> ret;</div>
<div class="line"><a name="l00095"></a><span class="lineno"> 95</span>&#160; }</div>
<div class="line"><a name="l00096"></a><span class="lineno"> 96</span>&#160; <span class="keywordflow">if</span> (u &lt; 0x33000001) {</div>
<div class="line"><a name="l00097"></a><span class="lineno"> 97</span>&#160; ret.x = (sign | 0x0000);</div>
<div class="line"><a name="l00098"></a><span class="lineno"> 98</span>&#160; <span class="keywordflow">return</span> ret;</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;</div>
<div class="line"><a name="l00101"></a><span class="lineno"> 101</span>&#160; exponent = ((u &gt;&gt; 23) &amp; 0xff);</div>
<div class="line"><a name="l00102"></a><span class="lineno"> 102</span>&#160; mantissa = (u &amp; 0x7fffff);</div>
<div class="line"><a name="l00103"></a><span class="lineno"> 103</span>&#160;</div>
<div class="line"><a name="l00104"></a><span class="lineno"> 104</span>&#160; <span class="keywordflow">if</span> (exponent &gt; 0x70) {</div>
<div class="line"><a name="l00105"></a><span class="lineno"> 105</span>&#160; shift = 13;</div>
<div class="line"><a name="l00106"></a><span class="lineno"> 106</span>&#160; exponent -= 0x70;</div>
<div class="line"><a name="l00107"></a><span class="lineno"> 107</span>&#160; } <span class="keywordflow">else</span> {</div>
<div class="line"><a name="l00108"></a><span class="lineno"> 108</span>&#160; shift = 0x7e - exponent;</div>
<div class="line"><a name="l00109"></a><span class="lineno"> 109</span>&#160; exponent = 0;</div>
<div class="line"><a name="l00110"></a><span class="lineno"> 110</span>&#160; mantissa |= 0x800000;</div>
<div class="line"><a name="l00111"></a><span class="lineno"> 111</span>&#160; }</div>
<div class="line"><a name="l00112"></a><span class="lineno"> 112</span>&#160; lsb = (1 &lt;&lt; shift);</div>
<div class="line"><a name="l00113"></a><span class="lineno"> 113</span>&#160; lsb_s1 = (lsb &gt;&gt; 1);</div>
<div class="line"><a name="l00114"></a><span class="lineno"> 114</span>&#160; lsb_m1 = (lsb - 1);</div>
<div class="line"><a name="l00115"></a><span class="lineno"> 115</span>&#160;</div>
<div class="line"><a name="l00116"></a><span class="lineno"> 116</span>&#160; <span class="comment">// Round to nearest even.</span></div>
<div class="line"><a name="l00117"></a><span class="lineno"> 117</span>&#160; remainder = (mantissa &amp; lsb_m1);</div>
<div class="line"><a name="l00118"></a><span class="lineno"> 118</span>&#160; mantissa &gt;&gt;= shift;</div>
<div class="line"><a name="l00119"></a><span class="lineno"> 119</span>&#160; <span class="keywordflow">if</span> (remainder &gt; lsb_s1 || (remainder == lsb_s1 &amp;&amp; (mantissa &amp; 0x1))) {</div>
<div class="line"><a name="l00120"></a><span class="lineno"> 120</span>&#160; ++mantissa;</div>
<div class="line"><a name="l00121"></a><span class="lineno"> 121</span>&#160; <span class="keywordflow">if</span> (!(mantissa &amp; 0x3ff)) {</div>
<div class="line"><a name="l00122"></a><span class="lineno"> 122</span>&#160; ++exponent;</div>
<div class="line"><a name="l00123"></a><span class="lineno"> 123</span>&#160; mantissa = 0;</div>
<div class="line"><a name="l00124"></a><span class="lineno"> 124</span>&#160; }</div>
<div class="line"><a name="l00125"></a><span class="lineno"> 125</span>&#160; }</div>
<div class="line"><a name="l00126"></a><span class="lineno"> 126</span>&#160;</div>
<div class="line"><a name="l00127"></a><span class="lineno"> 127</span>&#160; ret.x = (sign | (exponent &lt;&lt; 10) | mantissa);</div>
<div class="line"><a name="l00128"></a><span class="lineno"> 128</span>&#160;</div>
<div class="line"><a name="l00129"></a><span class="lineno"> 129</span>&#160; <span class="keywordflow">return</span> ret;</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;</div>
<div class="line"><a name="l00132"></a><span class="lineno"> 132</span>&#160;</div>
<div class="line"><a name="l00133"></a><span class="lineno"> 133</span>&#160;<span class="keywordtype">float</span> cpu_half2float(half1 h)</div>
<div class="line"><a name="l00134"></a><span class="lineno"> 134</span>&#160;{</div>
<div class="line"><a name="l00135"></a><span class="lineno"> 135</span>&#160; <span class="keywordtype">unsigned</span> sign = ((h.x &gt;&gt; 15) &amp; 1);</div>
<div class="line"><a name="l00136"></a><span class="lineno"> 136</span>&#160; <span class="keywordtype">unsigned</span> exponent = ((h.x &gt;&gt; 10) &amp; 0x1f);</div>
<div class="line"><a name="l00137"></a><span class="lineno"> 137</span>&#160; <span class="keywordtype">unsigned</span> mantissa = ((h.x &amp; 0x3ff) &lt;&lt; 13);</div>
<div class="line"><a name="l00138"></a><span class="lineno"> 138</span>&#160;</div>
<div class="line"><a name="l00139"></a><span class="lineno"> 139</span>&#160; <span class="keywordflow">if</span> (exponent == 0x1f) { <span class="comment">/* NaN or Inf */</span></div>
<div class="line"><a name="l00140"></a><span class="lineno"> 140</span>&#160; mantissa = (mantissa ? (sign = 0, 0x7fffff) : 0);</div>
<div class="line"><a name="l00141"></a><span class="lineno"> 141</span>&#160; exponent = 0xff;</div>
<div class="line"><a name="l00142"></a><span class="lineno"> 142</span>&#160; } <span class="keywordflow">else</span> <span class="keywordflow">if</span> (!exponent) { <span class="comment">/* Denorm or Zero */</span></div>
<div class="line"><a name="l00143"></a><span class="lineno"> 143</span>&#160; <span class="keywordflow">if</span> (mantissa) {</div>
<div class="line"><a name="l00144"></a><span class="lineno"> 144</span>&#160; <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> msb;</div>
<div class="line"><a name="l00145"></a><span class="lineno"> 145</span>&#160; exponent = 0x71;</div>
<div class="line"><a name="l00146"></a><span class="lineno"> 146</span>&#160; <span class="keywordflow">do</span> {</div>
<div class="line"><a name="l00147"></a><span class="lineno"> 147</span>&#160; msb = (mantissa &amp; 0x400000);</div>
<div class="line"><a name="l00148"></a><span class="lineno"> 148</span>&#160; mantissa &lt;&lt;= 1; <span class="comment">/* normalize */</span></div>
<div class="line"><a name="l00149"></a><span class="lineno"> 149</span>&#160; --exponent;</div>
<div class="line"><a name="l00150"></a><span class="lineno"> 150</span>&#160; } <span class="keywordflow">while</span> (!msb);</div>
<div class="line"><a name="l00151"></a><span class="lineno"> 151</span>&#160; mantissa &amp;= 0x7fffff; <span class="comment">/* 1.mantissa is implicit */</span></div>
<div class="line"><a name="l00152"></a><span class="lineno"> 152</span>&#160; }</div>
<div class="line"><a name="l00153"></a><span class="lineno"> 153</span>&#160; } <span class="keywordflow">else</span> {</div>
<div class="line"><a name="l00154"></a><span class="lineno"> 154</span>&#160; exponent += 0x70;</div>
<div class="line"><a name="l00155"></a><span class="lineno"> 155</span>&#160; }</div>
<div class="line"><a name="l00156"></a><span class="lineno"> 156</span>&#160;</div>
<div class="line"><a name="l00157"></a><span class="lineno"> 157</span>&#160; <span class="keyword">union </span>{</div>
<div class="line"><a name="l00158"></a><span class="lineno"> 158</span>&#160; <span class="keywordtype">int</span> i;</div>
<div class="line"><a name="l00159"></a><span class="lineno"> 159</span>&#160; <span class="keywordtype">float</span> f;</div>
<div class="line"><a name="l00160"></a><span class="lineno"> 160</span>&#160; } un;</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; un.i = ((sign &lt;&lt; 31) | (exponent &lt;&lt; 23) | mantissa);</div>
<div class="line"><a name="l00163"></a><span class="lineno"> 163</span>&#160;</div>
<div class="line"><a name="l00164"></a><span class="lineno"> 164</span>&#160; <span class="keywordflow">return</span> un.f;</div>
<div class="line"><a name="l00165"></a><span class="lineno"> 165</span>&#160;}</div>
<div class="line"><a name="l00166"></a><span class="lineno"> 166</span>&#160;</div>
<div class="line"><a name="l00167"></a><span class="lineno"> 167</span>&#160;} } <span class="comment">// namespace</span></div>
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