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 119 <a href="_n_e_math_8h.xhtml">Go to the documentation of this file.</a><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) 2016, 2017 ARM Limited.</span></div><div class="line"><a name="l00003"></a><span class="lineno">    3</span>&#160;<span class="comment"> *</span></div><div class="line"><a name="l00004"></a><span class="lineno">    4</span>&#160;<span class="comment"> * SPDX-License-Identifier: MIT</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"> * Permission is hereby granted, free of charge, to any person obtaining a copy</span></div><div class="line"><a name="l00007"></a><span class="lineno">    7</span>&#160;<span class="comment"> * of this software and associated documentation files (the &quot;Software&quot;), to</span></div><div class="line"><a name="l00008"></a><span class="lineno">    8</span>&#160;<span class="comment"> * deal in the Software without restriction, including without limitation the</span></div><div class="line"><a name="l00009"></a><span class="lineno">    9</span>&#160;<span class="comment"> * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or</span></div><div class="line"><a name="l00010"></a><span class="lineno">   10</span>&#160;<span class="comment"> * sell copies of the Software, and to permit persons to whom the Software is</span></div><div class="line"><a name="l00011"></a><span class="lineno">   11</span>&#160;<span class="comment"> * furnished to do so, subject to the following conditions:</span></div><div class="line"><a name="l00012"></a><span class="lineno">   12</span>&#160;<span class="comment"> *</span></div><div class="line"><a name="l00013"></a><span class="lineno">   13</span>&#160;<span class="comment"> * The above copyright notice and this permission notice shall be included in all</span></div><div class="line"><a name="l00014"></a><span class="lineno">   14</span>&#160;<span class="comment"> * copies or substantial portions of the Software.</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"> * THE SOFTWARE IS PROVIDED &quot;AS IS&quot;, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR</span></div><div class="line"><a name="l00017"></a><span class="lineno">   17</span>&#160;<span class="comment"> * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,</span></div><div class="line"><a name="l00018"></a><span class="lineno">   18</span>&#160;<span class="comment"> * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE</span></div><div class="line"><a name="l00019"></a><span class="lineno">   19</span>&#160;<span class="comment"> * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER</span></div><div class="line"><a name="l00020"></a><span class="lineno">   20</span>&#160;<span class="comment"> * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,</span></div><div class="line"><a name="l00021"></a><span class="lineno">   21</span>&#160;<span class="comment"> * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE</span></div><div class="line"><a name="l00022"></a><span class="lineno">   22</span>&#160;<span class="comment"> * SOFTWARE.</span></div><div class="line"><a name="l00023"></a><span class="lineno">   23</span>&#160;<span class="comment"> */</span></div><div class="line"><a name="l00024"></a><span class="lineno">   24</span>&#160;<span class="preprocessor">#ifndef __ARM_COMPUTE_NEMATH_H__</span></div><div class="line"><a name="l00025"></a><span class="lineno">   25</span>&#160;<span class="preprocessor">#define __ARM_COMPUTE_NEMATH_H__</span></div><div class="line"><a name="l00026"></a><span class="lineno">   26</span>&#160;</div><div class="line"><a name="l00027"></a><span class="lineno">   27</span>&#160;<span class="preprocessor">#include &lt;arm_neon.h&gt;</span></div><div class="line"><a name="l00028"></a><span class="lineno">   28</span>&#160;</div><div class="line"><a name="l00029"></a><span class="lineno">   29</span>&#160;<span class="keyword">namespace </span><a class="code" href="namespacearm__compute.xhtml">arm_compute</a></div><div class="line"><a name="l00030"></a><span class="lineno">   30</span>&#160;{</div><div class="line"><a name="l00031"></a><span class="lineno">   31</span>&#160;<span class="comment">/* Exponent polynomial coefficients */</span></div><div class="line"><a name="l00032"></a><span class="lineno"><a class="line" href="namespacearm__compute.xhtml#a869945609357fa552d94eb16f7aad4e9">   32</a></span>&#160;<span class="keyword">const</span> std::array&lt;float32x4_t, 8&gt; <a class="code" href="namespacearm__compute.xhtml#a869945609357fa552d94eb16f7aad4e9">exp_tab</a> =</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;        vdupq_n_f32(1.f),</div><div class="line"><a name="l00036"></a><span class="lineno">   36</span>&#160;        vdupq_n_f32(0.0416598916054f),</div><div class="line"><a name="l00037"></a><span class="lineno">   37</span>&#160;        vdupq_n_f32(0.500000596046f),</div><div class="line"><a name="l00038"></a><span class="lineno">   38</span>&#160;        vdupq_n_f32(0.0014122662833f),</div><div class="line"><a name="l00039"></a><span class="lineno">   39</span>&#160;        vdupq_n_f32(1.00000011921f),</div><div class="line"><a name="l00040"></a><span class="lineno">   40</span>&#160;        vdupq_n_f32(0.00833693705499f),</div><div class="line"><a name="l00041"></a><span class="lineno">   41</span>&#160;        vdupq_n_f32(0.166665703058f),</div><div class="line"><a name="l00042"></a><span class="lineno">   42</span>&#160;        vdupq_n_f32(0.000195780929062f),</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;};</div><div class="line"><a name="l00045"></a><span class="lineno">   45</span>&#160;</div><div class="line"><a name="l00046"></a><span class="lineno">   46</span>&#160;<span class="comment">/* Logarithm polynomial coefficients */</span></div><div class="line"><a name="l00047"></a><span class="lineno"><a class="line" href="namespacearm__compute.xhtml#a48fb9cf404e8f7043235bf14105c9793">   47</a></span>&#160;<span class="keyword">const</span> std::array&lt;float32x4_t, 8&gt; <a class="code" href="namespacearm__compute.xhtml#a48fb9cf404e8f7043235bf14105c9793">log_tab</a> =</div><div class="line"><a name="l00048"></a><span class="lineno">   48</span>&#160;{</div><div class="line"><a name="l00049"></a><span class="lineno">   49</span>&#160;    {</div><div class="line"><a name="l00050"></a><span class="lineno">   50</span>&#160;        vdupq_n_f32(-2.29561495781f),</div><div class="line"><a name="l00051"></a><span class="lineno">   51</span>&#160;        vdupq_n_f32(-2.47071170807f),</div><div class="line"><a name="l00052"></a><span class="lineno">   52</span>&#160;        vdupq_n_f32(-5.68692588806f),</div><div class="line"><a name="l00053"></a><span class="lineno">   53</span>&#160;        vdupq_n_f32(-0.165253549814f),</div><div class="line"><a name="l00054"></a><span class="lineno">   54</span>&#160;        vdupq_n_f32(5.17591238022f),</div><div class="line"><a name="l00055"></a><span class="lineno">   55</span>&#160;        vdupq_n_f32(0.844007015228f),</div><div class="line"><a name="l00056"></a><span class="lineno">   56</span>&#160;        vdupq_n_f32(4.58445882797f),</div><div class="line"><a name="l00057"></a><span class="lineno">   57</span>&#160;        vdupq_n_f32(0.0141278216615f),</div><div class="line"><a name="l00058"></a><span class="lineno">   58</span>&#160;    }</div><div class="line"><a name="l00059"></a><span class="lineno">   59</span>&#160;};</div><div class="line"><a name="l00060"></a><span class="lineno">   60</span>&#160;</div><div class="line"><a name="l00067"></a><span class="lineno"><a class="line" href="namespacearm__compute.xhtml#aab4b53a52d617f05420711425f20ed4b">   67</a></span>&#160;<span class="keyword">inline</span> float32x4_t <a class="code" href="namespacearm__compute.xhtml#aab4b53a52d617f05420711425f20ed4b">vinvsqrt_f32</a>(float32x4_t x)</div><div class="line"><a name="l00068"></a><span class="lineno">   68</span>&#160;{</div><div class="line"><a name="l00069"></a><span class="lineno">   69</span>&#160;    float32x4_t sqrt_reciprocal = vrsqrteq_f32(x);</div><div class="line"><a name="l00070"></a><span class="lineno">   70</span>&#160;    sqrt_reciprocal             = vmulq_f32(vrsqrtsq_f32(vmulq_f32(x, sqrt_reciprocal), sqrt_reciprocal), sqrt_reciprocal);</div><div class="line"><a name="l00071"></a><span class="lineno">   71</span>&#160;    sqrt_reciprocal             = vmulq_f32(vrsqrtsq_f32(vmulq_f32(x, sqrt_reciprocal), sqrt_reciprocal), sqrt_reciprocal);</div><div class="line"><a name="l00072"></a><span class="lineno">   72</span>&#160;</div><div class="line"><a name="l00073"></a><span class="lineno">   73</span>&#160;    <span class="keywordflow">return</span> sqrt_reciprocal;</div><div class="line"><a name="l00074"></a><span class="lineno">   74</span>&#160;}</div><div class="line"><a name="l00075"></a><span class="lineno">   75</span>&#160;</div><div class="line"><a name="l00082"></a><span class="lineno"><a class="line" href="namespacearm__compute.xhtml#a99d2837a875f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html#aa4e5c4d2084010ee1c68475fde882f84">vtaylor_poly_f32</a>(val, exp_tab);</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;    <span class="comment">// Reconstruct</span></div><div class="line"><a name="l00128"></a><span class="lineno">  128</span>&#160;    poly = vreinterpretq_f32_s32(vaddq_s32(vreinterpretq_s32_f32(poly), vshlq_n_s32(m, 23)));</div><div class="line"><a name="l00129"></a><span class="lineno">  129</span>&#160;</div><div class="line"><a name="l00130"></a><span class="lineno">  130</span>&#160;    <span class="keywordflow">return</span> poly;</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="l00139"></a><span class="lineno"><a class="line" href="namespacearm__compute.xhtml#afa7e6a89815b00d86c5ae6ec73d79c26">  139</a></span>&#160;<span class="keyword">inline</span> float32x4_t <a class="code" href="namespacearm__compute.xhtml#afa7e6a89815b00d86c5ae6ec73d79c26">vlog_f32</a>(<span class="keyword">const</span> float32x4_t &amp;x)</div><div class="line"><a name="l00140"></a><span class="lineno">  140</span>&#160;{</div><div class="line"><a name="l00141"></a><span class="lineno">  141</span>&#160;    <span class="keyword">static</span> <span class="keyword">const</span> int32x4_t   CONST_127 = vdupq_n_s32(127);           <span class="comment">// 127</span></div><div class="line"><a name="l00142"></a><span class="lineno">  142</span>&#160;    <span class="keyword">static</span> <span class="keyword">const</span> float32x4_t CONST_LN2 = vdupq_n_f32(0.6931471805f); <span class="comment">// ln(2)</span></div><div class="line"><a name="l00143"></a><span class="lineno">  143</span>&#160;</div><div class="line"><a name="l00144"></a><span class="lineno">  144</span>&#160;    <span class="comment">// Extract exponent</span></div><div class="line"><a name="l00145"></a><span class="lineno">  145</span>&#160;    int32x4_t   m   = vsubq_s32(vreinterpretq_s32_u32(vshrq_n_u32(vreinterpretq_u32_f32(x), 23)), CONST_127);</div><div class="line"><a name="l00146"></a><span class="lineno">  146</span>&#160;    float32x4_t val = vreinterpretq_f32_s32(vsubq_s32(vreinterpretq_s32_f32(x), vshlq_n_s32(m, 23)));</div><div class="line"><a name="l00147"></a><span class="lineno">  147</span>&#160;</div><div class="line"><a name="l00148"></a><span class="lineno">  148</span>&#160;    <span class="comment">// Polynomial Approximation</span></div><div class="line"><a name="l00149"></a><span class="lineno">  149</span>&#160;    float32x4_t poly = <a class="code" href="namespacearm__compute.xhtml#aa4e5c4d2084010ee1c68475fde882f84">vtaylor_poly_f32</a>(val, log_tab);</div><div class="line"><a name="l00150"></a><span class="lineno">  150</span>&#160;</div><div class="line"><a name="l00151"></a><span class="lineno">  151</span>&#160;    <span class="comment">// Reconstruct</span></div><div class="line"><a name="l00152"></a><span class="lineno">  152</span>&#160;    poly = vmlaq_f32(poly, vcvtq_f32_s32(m), CONST_LN2);</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="keywordflow">return</span> poly;</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="l00165"></a><span class="lineno"><a class="line" href="namespacearm__compute.xhtml#af2002ba27e8c8033e3038da708248f32">  165</a></span>&#160;<span class="keyword">inline</span> float32x4_t <a class="code" href="namespacearm__compute.xhtml#af2002ba27e8c8033e3038da708248f32">vtanh_f32</a>(<span class="keyword">const</span> float32x4_t &amp;val)</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="keyword">static</span> <span class="keyword">const</span> float32x4_t CONST_1 = vdupq_n_f32(1.f); <span class="comment">// 1.f</span></div><div class="line"><a name="l00168"></a><span class="lineno">  168</span>&#160;    <span class="keyword">static</span> <span class="keyword">const</span> float32x4_t CONST_2 = vdupq_n_f32(2.f); <span class="comment">// 2.f</span></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;    float32x4_t exp2x = <a class="code" href="namespacearm__compute.xhtml#ab61617950fb57bf883ee19fc4e219826">vexp_f32</a>(vmulq_f32(CONST_2, val));</div><div class="line"><a name="l00171"></a><span class="lineno">  171</span>&#160;    float32x4_t num   = vsubq_f32(exp2x, CONST_1);</div><div class="line"><a name="l00172"></a><span class="lineno">  172</span>&#160;    float32x4_t den   = vaddq_f32(exp2x, CONST_1);</div><div class="line"><a name="l00173"></a><span class="lineno">  173</span>&#160;    float32x4_t tanh  = vmulq_f32(num, <a class="code" href="namespacearm__compute.xhtml#a99d2837a875fc6bca19755f40205f04a">vinv_f32</a>(den));</div><div class="line"><a name="l00174"></a><span class="lineno">  174</span>&#160;    <span class="keywordflow">return</span> tanh;</div><div class="line"><a name="l00175"></a><span class="lineno">  175</span>&#160;}</div><div class="line"><a name="l00176"></a><span class="lineno">  176</span>&#160;</div><div class="line"><a name="l00186"></a><span class="lineno"><a class="line" href="namespacearm__compute.xhtml#ae0dbcd09c015bda4ab290b957d7bd6c7">  186</a></span>&#160;<span class="keyword">inline</span> float32x4_t <a class="code" href="namespacearm__compute.xhtml#ae0dbcd09c015bda4ab290b957d7bd6c7">vpowq_f32</a>(<span class="keyword">const</span> float32x4_t &amp;val, <span class="keyword">const</span> float32x4_t &amp;n)</div><div class="line"><a name="l00187"></a><span class="lineno">  187</span>&#160;{</div><div class="line"><a name="l00188"></a><span class="lineno">  188</span>&#160;    <span class="keywordflow">return</span> <a class="code" href="namespacearm__compute.xhtml#ab61617950fb57bf883ee19fc4e219826">vexp_f32</a>(vmulq_f32(n, <a class="code" href="namespacearm__compute.xhtml#afa7e6a89815b00d86c5ae6ec73d79c26">vlog_f32</a>(val)));</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;}</div><div class="line"><a name="l00191"></a><span class="lineno">  191</span>&#160;</div><div class="line"><a name="l00192"></a><span class="lineno">  192</span>&#160;<span class="preprocessor">#endif </span><span class="comment">/* __ARM_COMPUTE_NEMATH_H__ */</span><span class="preprocessor"></span></div><div class="ttc" id="namespacearm__compute_xhtml_a1ce9b523fd4f3b5bbcadcd796183455aa7fc56270e7a70fa81a5935b72eacbe29"><div class="ttname"><a href="namespacearm__compute.xhtml#a1ce9b523fd4f3b5bbcadcd796183455aa7fc56270e7a70fa81a5935b72eacbe29">arm_compute::Channel::A</a></div><div class="ttdoc">Alpha channel. </div></div>
 120 <div class="ttc" id="namespacearm__compute_xhtml_aa4e5c4d2084010ee1c68475fde882f84"><div class="ttname"><a href="namespacearm__compute.xhtml#aa4e5c4d2084010ee1c68475fde882f84">arm_compute::vtaylor_poly_f32</a></div><div class="ttdeci">float32x4_t vtaylor_poly_f32(const float32x4_t &amp;x, const std::array&lt; float32x4_t, 8 &gt; &amp;coeffs)</div><div class="ttdoc">Perform a 7th degree polynomial approximation using Estrin&amp;#39;s method. </div><div class="ttdef"><b>Definition:</b> <a href="_n_e_math_8h_source.xhtml#l00097">NEMath.h:97</a></div></div>
 121 <div class="ttc" id="namespacearm__compute_xhtml_a99d2837a875fc6bca19755f40205f04a"><div class="ttname"><a href="namespacearm__compute.xhtml#a99d2837a875fc6bca19755f40205f04a">arm_compute::vinv_f32</a></div><div class="ttdeci">float32x4_t vinv_f32(const float32x4_t &amp;x)</div><div class="ttdoc">Calculate reciprocal. </div><div class="ttdef"><b>Definition:</b> <a href="_n_e_math_8h_source.xhtml#l00082">NEMath.h:82</a></div></div>
 122 <div class="ttc" id="namespacearm__compute_xhtml_a1ce9b523fd4f3b5bbcadcd796183455aa9d5ed678fe57bcca610140957afab571"><div class="ttname"><a href="namespacearm__compute.xhtml#a1ce9b523fd4f3b5bbcadcd796183455aa9d5ed678fe57bcca610140957afab571">arm_compute::Channel::B</a></div><div class="ttdoc">Blue channel. </div></div>
 123 <div class="ttc" id="namespacearm__compute_xhtml_af2002ba27e8c8033e3038da708248f32"><div class="ttname"><a href="namespacearm__compute.xhtml#af2002ba27e8c8033e3038da708248f32">arm_compute::vtanh_f32</a></div><div class="ttdeci">float32x4_t vtanh_f32(const float32x4_t &amp;val)</div><div class="ttdoc">Calculate hyperbolic tangent. </div><div class="ttdef"><b>Definition:</b> <a href="_n_e_math_8h_source.xhtml#l00165">NEMath.h:165</a></div></div>
 124 <div class="ttc" id="namespacearm__compute_xhtml"><div class="ttname"><a href="namespacearm__compute.xhtml">arm_compute</a></div><div class="ttdef"><b>Definition:</b> <a href="arm__compute_8dox_source.xhtml#l00001">arm_compute.dox:1</a></div></div>
 125 <div class="ttc" id="namespacearm__compute_xhtml_a869945609357fa552d94eb16f7aad4e9"><div class="ttname"><a href="namespacearm__compute.xhtml#a869945609357fa552d94eb16f7aad4e9">arm_compute::exp_tab</a></div><div class="ttdeci">const std::array&lt; float32x4_t, 8 &gt; exp_tab</div><div class="ttdef"><b>Definition:</b> <a href="_n_e_math_8h_source.xhtml#l00032">NEMath.h:32</a></div></div>
 126 <div class="ttc" id="namespacearm__compute_xhtml_aab4b53a52d617f05420711425f20ed4b"><div class="ttname"><a href="namespacearm__compute.xhtml#aab4b53a52d617f05420711425f20ed4b">arm_compute::vinvsqrt_f32</a></div><div class="ttdeci">float32x4_t vinvsqrt_f32(float32x4_t x)</div><div class="ttdoc">Calculate inverse square root. </div><div class="ttdef"><b>Definition:</b> <a href="_n_e_math_8h_source.xhtml#l00067">NEMath.h:67</a></div></div>
 127 <div class="ttc" id="namespacearm__compute_xhtml_afa7e6a89815b00d86c5ae6ec73d79c26"><div class="ttname"><a href="namespacearm__compute.xhtml#afa7e6a89815b00d86c5ae6ec73d79c26">arm_compute::vlog_f32</a></div><div class="ttdeci">float32x4_t vlog_f32(const float32x4_t &amp;x)</div><div class="ttdoc">Calculate logarithm. </div><div class="ttdef"><b>Definition:</b> <a href="_n_e_math_8h_source.xhtml#l00139">NEMath.h:139</a></div></div>
 128 <div class="ttc" id="namespacearm__compute_xhtml_ab61617950fb57bf883ee19fc4e219826"><div class="ttname"><a href="namespacearm__compute.xhtml#ab61617950fb57bf883ee19fc4e219826">arm_compute::vexp_f32</a></div><div class="ttdeci">float32x4_t vexp_f32(const float32x4_t &amp;x)</div><div class="ttdoc">Calculate exponential. </div><div class="ttdef"><b>Definition:</b> <a href="_n_e_math_8h_source.xhtml#l00115">NEMath.h:115</a></div></div>
 129 <div class="ttc" id="namespacearm__compute_xhtml_ae0dbcd09c015bda4ab290b957d7bd6c7"><div class="ttname"><a href="namespacearm__compute.xhtml#ae0dbcd09c015bda4ab290b957d7bd6c7">arm_compute::vpowq_f32</a></div><div class="ttdeci">float32x4_t vpowq_f32(const float32x4_t &amp;val, const float32x4_t &amp;n)</div><div class="ttdoc">Calculate n power of a number. </div><div class="ttdef"><b>Definition:</b> <a href="_n_e_math_8h_source.xhtml#l00186">NEMath.h:186</a></div></div>
 130 <div class="ttc" id="namespacearm__compute_xhtml_a48fb9cf404e8f7043235bf14105c9793"><div class="ttname"><a href="namespacearm__compute.xhtml#a48fb9cf404e8f7043235bf14105c9793">arm_compute::log_tab</a></div><div class="ttdeci">const std::array&lt; float32x4_t, 8 &gt; log_tab</div><div class="ttdef"><b>Definition:</b> <a href="_n_e_math_8h_source.xhtml#l00047">NEMath.h:47</a></div></div>
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