| <!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="Source of the Rust file `/root/.cargo/registry/src/github.com-1ecc6299db9ec823/libm-0.2.7/src/math/lgammaf_r.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>lgammaf_r.rs - source</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceSerif4-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../FiraSans-Regular.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../FiraSans-Medium.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceCodePro-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceSerif4-Bold.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceCodePro-Semibold.ttf.woff2"><link rel="stylesheet" href="../../../normalize.css"><link rel="stylesheet" href="../../../rustdoc.css" id="mainThemeStyle"><link rel="stylesheet" href="../../../ayu.css" disabled><link rel="stylesheet" href="../../../dark.css" disabled><link rel="stylesheet" href="../../../light.css" id="themeStyle"><script id="default-settings" ></script><script src="../../../storage.js"></script><script defer src="../../../source-script.js"></script><script defer src="../../../source-files.js"></script><script defer src="../../../main.js"></script><noscript><link rel="stylesheet" href="../../../noscript.css"></noscript><link rel="alternate icon" type="image/png" href="../../../favicon-16x16.png"><link rel="alternate icon" type="image/png" href="../../../favicon-32x32.png"><link rel="icon" type="image/svg+xml" href="../../../favicon.svg"></head><body class="rustdoc source"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"><a class="sidebar-logo" href="../../../libm/index.html"><div class="logo-container"><img class="rust-logo" src="../../../rust-logo.svg" alt="logo"></div></a></nav><main><div class="width-limiter"><nav class="sub"><a class="sub-logo-container" href="../../../libm/index.html"><img class="rust-logo" src="../../../rust-logo.svg" alt="logo"></a><form class="search-form"><div class="search-container"><span></span><input class="search-input" name="search" autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"><div id="help-button" title="help" tabindex="-1"><a href="../../../help.html">?</a></div><div id="settings-menu" tabindex="-1"><a href="../../../settings.html" title="settings"><img width="22" height="22" alt="Change settings" src="../../../wheel.svg"></a></div></div></form></nav><section id="main-content" class="content"><div class="example-wrap"><pre class="src-line-numbers"><span id="1">1</span> |
| <span id="2">2</span> |
| <span id="3">3</span> |
| <span id="4">4</span> |
| <span id="5">5</span> |
| <span id="6">6</span> |
| <span id="7">7</span> |
| <span id="8">8</span> |
| <span id="9">9</span> |
| <span id="10">10</span> |
| <span id="11">11</span> |
| <span id="12">12</span> |
| <span id="13">13</span> |
| <span id="14">14</span> |
| <span id="15">15</span> |
| <span id="16">16</span> |
| <span id="17">17</span> |
| <span id="18">18</span> |
| <span id="19">19</span> |
| <span id="20">20</span> |
| <span id="21">21</span> |
| <span id="22">22</span> |
| <span id="23">23</span> |
| <span id="24">24</span> |
| <span id="25">25</span> |
| <span id="26">26</span> |
| <span id="27">27</span> |
| <span id="28">28</span> |
| <span id="29">29</span> |
| <span id="30">30</span> |
| <span id="31">31</span> |
| <span id="32">32</span> |
| <span id="33">33</span> |
| <span id="34">34</span> |
| <span id="35">35</span> |
| <span id="36">36</span> |
| <span id="37">37</span> |
| <span id="38">38</span> |
| <span id="39">39</span> |
| <span id="40">40</span> |
| <span id="41">41</span> |
| <span id="42">42</span> |
| <span id="43">43</span> |
| <span id="44">44</span> |
| <span id="45">45</span> |
| <span id="46">46</span> |
| <span id="47">47</span> |
| <span id="48">48</span> |
| <span id="49">49</span> |
| <span id="50">50</span> |
| <span id="51">51</span> |
| <span id="52">52</span> |
| <span id="53">53</span> |
| <span id="54">54</span> |
| <span id="55">55</span> |
| <span id="56">56</span> |
| <span id="57">57</span> |
| <span id="58">58</span> |
| <span id="59">59</span> |
| <span id="60">60</span> |
| <span id="61">61</span> |
| <span id="62">62</span> |
| <span id="63">63</span> |
| <span id="64">64</span> |
| <span id="65">65</span> |
| <span id="66">66</span> |
| <span id="67">67</span> |
| <span id="68">68</span> |
| <span id="69">69</span> |
| <span id="70">70</span> |
| <span id="71">71</span> |
| <span id="72">72</span> |
| <span id="73">73</span> |
| <span id="74">74</span> |
| <span id="75">75</span> |
| <span id="76">76</span> |
| <span id="77">77</span> |
| <span id="78">78</span> |
| <span id="79">79</span> |
| <span id="80">80</span> |
| <span id="81">81</span> |
| <span id="82">82</span> |
| <span id="83">83</span> |
| <span id="84">84</span> |
| <span id="85">85</span> |
| <span id="86">86</span> |
| <span id="87">87</span> |
| <span id="88">88</span> |
| <span id="89">89</span> |
| <span id="90">90</span> |
| <span id="91">91</span> |
| <span id="92">92</span> |
| <span id="93">93</span> |
| <span id="94">94</span> |
| <span id="95">95</span> |
| <span id="96">96</span> |
| <span id="97">97</span> |
| <span id="98">98</span> |
| <span id="99">99</span> |
| <span id="100">100</span> |
| <span id="101">101</span> |
| <span id="102">102</span> |
| <span id="103">103</span> |
| <span id="104">104</span> |
| <span id="105">105</span> |
| <span id="106">106</span> |
| <span id="107">107</span> |
| <span id="108">108</span> |
| <span id="109">109</span> |
| <span id="110">110</span> |
| <span id="111">111</span> |
| <span id="112">112</span> |
| <span id="113">113</span> |
| <span id="114">114</span> |
| <span id="115">115</span> |
| <span id="116">116</span> |
| <span id="117">117</span> |
| <span id="118">118</span> |
| <span id="119">119</span> |
| <span id="120">120</span> |
| <span id="121">121</span> |
| <span id="122">122</span> |
| <span id="123">123</span> |
| <span id="124">124</span> |
| <span id="125">125</span> |
| <span id="126">126</span> |
| <span id="127">127</span> |
| <span id="128">128</span> |
| <span id="129">129</span> |
| <span id="130">130</span> |
| <span id="131">131</span> |
| <span id="132">132</span> |
| <span id="133">133</span> |
| <span id="134">134</span> |
| <span id="135">135</span> |
| <span id="136">136</span> |
| <span id="137">137</span> |
| <span id="138">138</span> |
| <span id="139">139</span> |
| <span id="140">140</span> |
| <span id="141">141</span> |
| <span id="142">142</span> |
| <span id="143">143</span> |
| <span id="144">144</span> |
| <span id="145">145</span> |
| <span id="146">146</span> |
| <span id="147">147</span> |
| <span id="148">148</span> |
| <span id="149">149</span> |
| <span id="150">150</span> |
| <span id="151">151</span> |
| <span id="152">152</span> |
| <span id="153">153</span> |
| <span id="154">154</span> |
| <span id="155">155</span> |
| <span id="156">156</span> |
| <span id="157">157</span> |
| <span id="158">158</span> |
| <span id="159">159</span> |
| <span id="160">160</span> |
| <span id="161">161</span> |
| <span id="162">162</span> |
| <span id="163">163</span> |
| <span id="164">164</span> |
| <span id="165">165</span> |
| <span id="166">166</span> |
| <span id="167">167</span> |
| <span id="168">168</span> |
| <span id="169">169</span> |
| <span id="170">170</span> |
| <span id="171">171</span> |
| <span id="172">172</span> |
| <span id="173">173</span> |
| <span id="174">174</span> |
| <span id="175">175</span> |
| <span id="176">176</span> |
| <span id="177">177</span> |
| <span id="178">178</span> |
| <span id="179">179</span> |
| <span id="180">180</span> |
| <span id="181">181</span> |
| <span id="182">182</span> |
| <span id="183">183</span> |
| <span id="184">184</span> |
| <span id="185">185</span> |
| <span id="186">186</span> |
| <span id="187">187</span> |
| <span id="188">188</span> |
| <span id="189">189</span> |
| <span id="190">190</span> |
| <span id="191">191</span> |
| <span id="192">192</span> |
| <span id="193">193</span> |
| <span id="194">194</span> |
| <span id="195">195</span> |
| <span id="196">196</span> |
| <span id="197">197</span> |
| <span id="198">198</span> |
| <span id="199">199</span> |
| <span id="200">200</span> |
| <span id="201">201</span> |
| <span id="202">202</span> |
| <span id="203">203</span> |
| <span id="204">204</span> |
| <span id="205">205</span> |
| <span id="206">206</span> |
| <span id="207">207</span> |
| <span id="208">208</span> |
| <span id="209">209</span> |
| <span id="210">210</span> |
| <span id="211">211</span> |
| <span id="212">212</span> |
| <span id="213">213</span> |
| <span id="214">214</span> |
| <span id="215">215</span> |
| <span id="216">216</span> |
| <span id="217">217</span> |
| <span id="218">218</span> |
| <span id="219">219</span> |
| <span id="220">220</span> |
| <span id="221">221</span> |
| <span id="222">222</span> |
| <span id="223">223</span> |
| <span id="224">224</span> |
| <span id="225">225</span> |
| <span id="226">226</span> |
| <span id="227">227</span> |
| <span id="228">228</span> |
| <span id="229">229</span> |
| <span id="230">230</span> |
| <span id="231">231</span> |
| <span id="232">232</span> |
| <span id="233">233</span> |
| <span id="234">234</span> |
| <span id="235">235</span> |
| <span id="236">236</span> |
| <span id="237">237</span> |
| <span id="238">238</span> |
| <span id="239">239</span> |
| <span id="240">240</span> |
| <span id="241">241</span> |
| <span id="242">242</span> |
| <span id="243">243</span> |
| <span id="244">244</span> |
| <span id="245">245</span> |
| <span id="246">246</span> |
| <span id="247">247</span> |
| <span id="248">248</span> |
| <span id="249">249</span> |
| <span id="250">250</span> |
| <span id="251">251</span> |
| <span id="252">252</span> |
| <span id="253">253</span> |
| <span id="254">254</span> |
| <span id="255">255</span> |
| </pre><pre class="rust"><code><span class="comment">/* origin: FreeBSD /usr/src/lib/msun/src/e_lgammaf_r.c */ |
| /* |
| * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. |
| */ |
| /* |
| * ==================================================== |
| * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. |
| * |
| * Developed at SunPro, a Sun Microsystems, Inc. business. |
| * Permission to use, copy, modify, and distribute this |
| * software is freely granted, provided that this notice |
| * is preserved. |
| * ==================================================== |
| */ |
| |
| </span><span class="kw">use super</span>::{floorf, k_cosf, k_sinf, logf}; |
| |
| <span class="kw">const </span>PI: f32 = <span class="number">3.1415927410e+00</span>; <span class="comment">/* 0x40490fdb */ |
| </span><span class="kw">const </span>A0: f32 = <span class="number">7.7215664089e-02</span>; <span class="comment">/* 0x3d9e233f */ |
| </span><span class="kw">const </span>A1: f32 = <span class="number">3.2246702909e-01</span>; <span class="comment">/* 0x3ea51a66 */ |
| </span><span class="kw">const </span>A2: f32 = <span class="number">6.7352302372e-02</span>; <span class="comment">/* 0x3d89f001 */ |
| </span><span class="kw">const </span>A3: f32 = <span class="number">2.0580807701e-02</span>; <span class="comment">/* 0x3ca89915 */ |
| </span><span class="kw">const </span>A4: f32 = <span class="number">7.3855509982e-03</span>; <span class="comment">/* 0x3bf2027e */ |
| </span><span class="kw">const </span>A5: f32 = <span class="number">2.8905137442e-03</span>; <span class="comment">/* 0x3b3d6ec6 */ |
| </span><span class="kw">const </span>A6: f32 = <span class="number">1.1927076848e-03</span>; <span class="comment">/* 0x3a9c54a1 */ |
| </span><span class="kw">const </span>A7: f32 = <span class="number">5.1006977446e-04</span>; <span class="comment">/* 0x3a05b634 */ |
| </span><span class="kw">const </span>A8: f32 = <span class="number">2.2086278477e-04</span>; <span class="comment">/* 0x39679767 */ |
| </span><span class="kw">const </span>A9: f32 = <span class="number">1.0801156895e-04</span>; <span class="comment">/* 0x38e28445 */ |
| </span><span class="kw">const </span>A10: f32 = <span class="number">2.5214456400e-05</span>; <span class="comment">/* 0x37d383a2 */ |
| </span><span class="kw">const </span>A11: f32 = <span class="number">4.4864096708e-05</span>; <span class="comment">/* 0x383c2c75 */ |
| </span><span class="kw">const </span>TC: f32 = <span class="number">1.4616321325e+00</span>; <span class="comment">/* 0x3fbb16c3 */ |
| </span><span class="kw">const </span>TF: f32 = -<span class="number">1.2148628384e-01</span>; <span class="comment">/* 0xbdf8cdcd */ |
| /* TT = -(tail of TF) */ |
| </span><span class="kw">const </span>TT: f32 = <span class="number">6.6971006518e-09</span>; <span class="comment">/* 0x31e61c52 */ |
| </span><span class="kw">const </span>T0: f32 = <span class="number">4.8383611441e-01</span>; <span class="comment">/* 0x3ef7b95e */ |
| </span><span class="kw">const </span>T1: f32 = -<span class="number">1.4758771658e-01</span>; <span class="comment">/* 0xbe17213c */ |
| </span><span class="kw">const </span>T2: f32 = <span class="number">6.4624942839e-02</span>; <span class="comment">/* 0x3d845a15 */ |
| </span><span class="kw">const </span>T3: f32 = -<span class="number">3.2788541168e-02</span>; <span class="comment">/* 0xbd064d47 */ |
| </span><span class="kw">const </span>T4: f32 = <span class="number">1.7970675603e-02</span>; <span class="comment">/* 0x3c93373d */ |
| </span><span class="kw">const </span>T5: f32 = -<span class="number">1.0314224288e-02</span>; <span class="comment">/* 0xbc28fcfe */ |
| </span><span class="kw">const </span>T6: f32 = <span class="number">6.1005386524e-03</span>; <span class="comment">/* 0x3bc7e707 */ |
| </span><span class="kw">const </span>T7: f32 = -<span class="number">3.6845202558e-03</span>; <span class="comment">/* 0xbb7177fe */ |
| </span><span class="kw">const </span>T8: f32 = <span class="number">2.2596477065e-03</span>; <span class="comment">/* 0x3b141699 */ |
| </span><span class="kw">const </span>T9: f32 = -<span class="number">1.4034647029e-03</span>; <span class="comment">/* 0xbab7f476 */ |
| </span><span class="kw">const </span>T10: f32 = <span class="number">8.8108185446e-04</span>; <span class="comment">/* 0x3a66f867 */ |
| </span><span class="kw">const </span>T11: f32 = -<span class="number">5.3859531181e-04</span>; <span class="comment">/* 0xba0d3085 */ |
| </span><span class="kw">const </span>T12: f32 = <span class="number">3.1563205994e-04</span>; <span class="comment">/* 0x39a57b6b */ |
| </span><span class="kw">const </span>T13: f32 = -<span class="number">3.1275415677e-04</span>; <span class="comment">/* 0xb9a3f927 */ |
| </span><span class="kw">const </span>T14: f32 = <span class="number">3.3552918467e-04</span>; <span class="comment">/* 0x39afe9f7 */ |
| </span><span class="kw">const </span>U0: f32 = -<span class="number">7.7215664089e-02</span>; <span class="comment">/* 0xbd9e233f */ |
| </span><span class="kw">const </span>U1: f32 = <span class="number">6.3282704353e-01</span>; <span class="comment">/* 0x3f2200f4 */ |
| </span><span class="kw">const </span>U2: f32 = <span class="number">1.4549225569e+00</span>; <span class="comment">/* 0x3fba3ae7 */ |
| </span><span class="kw">const </span>U3: f32 = <span class="number">9.7771751881e-01</span>; <span class="comment">/* 0x3f7a4bb2 */ |
| </span><span class="kw">const </span>U4: f32 = <span class="number">2.2896373272e-01</span>; <span class="comment">/* 0x3e6a7578 */ |
| </span><span class="kw">const </span>U5: f32 = <span class="number">1.3381091878e-02</span>; <span class="comment">/* 0x3c5b3c5e */ |
| </span><span class="kw">const </span>V1: f32 = <span class="number">2.4559779167e+00</span>; <span class="comment">/* 0x401d2ebe */ |
| </span><span class="kw">const </span>V2: f32 = <span class="number">2.1284897327e+00</span>; <span class="comment">/* 0x4008392d */ |
| </span><span class="kw">const </span>V3: f32 = <span class="number">7.6928514242e-01</span>; <span class="comment">/* 0x3f44efdf */ |
| </span><span class="kw">const </span>V4: f32 = <span class="number">1.0422264785e-01</span>; <span class="comment">/* 0x3dd572af */ |
| </span><span class="kw">const </span>V5: f32 = <span class="number">3.2170924824e-03</span>; <span class="comment">/* 0x3b52d5db */ |
| </span><span class="kw">const </span>S0: f32 = -<span class="number">7.7215664089e-02</span>; <span class="comment">/* 0xbd9e233f */ |
| </span><span class="kw">const </span>S1: f32 = <span class="number">2.1498242021e-01</span>; <span class="comment">/* 0x3e5c245a */ |
| </span><span class="kw">const </span>S2: f32 = <span class="number">3.2577878237e-01</span>; <span class="comment">/* 0x3ea6cc7a */ |
| </span><span class="kw">const </span>S3: f32 = <span class="number">1.4635047317e-01</span>; <span class="comment">/* 0x3e15dce6 */ |
| </span><span class="kw">const </span>S4: f32 = <span class="number">2.6642270386e-02</span>; <span class="comment">/* 0x3cda40e4 */ |
| </span><span class="kw">const </span>S5: f32 = <span class="number">1.8402845599e-03</span>; <span class="comment">/* 0x3af135b4 */ |
| </span><span class="kw">const </span>S6: f32 = <span class="number">3.1947532989e-05</span>; <span class="comment">/* 0x3805ff67 */ |
| </span><span class="kw">const </span>R1: f32 = <span class="number">1.3920053244e+00</span>; <span class="comment">/* 0x3fb22d3b */ |
| </span><span class="kw">const </span>R2: f32 = <span class="number">7.2193557024e-01</span>; <span class="comment">/* 0x3f38d0c5 */ |
| </span><span class="kw">const </span>R3: f32 = <span class="number">1.7193385959e-01</span>; <span class="comment">/* 0x3e300f6e */ |
| </span><span class="kw">const </span>R4: f32 = <span class="number">1.8645919859e-02</span>; <span class="comment">/* 0x3c98bf54 */ |
| </span><span class="kw">const </span>R5: f32 = <span class="number">7.7794247773e-04</span>; <span class="comment">/* 0x3a4beed6 */ |
| </span><span class="kw">const </span>R6: f32 = <span class="number">7.3266842264e-06</span>; <span class="comment">/* 0x36f5d7bd */ |
| </span><span class="kw">const </span>W0: f32 = <span class="number">4.1893854737e-01</span>; <span class="comment">/* 0x3ed67f1d */ |
| </span><span class="kw">const </span>W1: f32 = <span class="number">8.3333335817e-02</span>; <span class="comment">/* 0x3daaaaab */ |
| </span><span class="kw">const </span>W2: f32 = -<span class="number">2.7777778450e-03</span>; <span class="comment">/* 0xbb360b61 */ |
| </span><span class="kw">const </span>W3: f32 = <span class="number">7.9365057172e-04</span>; <span class="comment">/* 0x3a500cfd */ |
| </span><span class="kw">const </span>W4: f32 = -<span class="number">5.9518753551e-04</span>; <span class="comment">/* 0xba1c065c */ |
| </span><span class="kw">const </span>W5: f32 = <span class="number">8.3633989561e-04</span>; <span class="comment">/* 0x3a5b3dd2 */ |
| </span><span class="kw">const </span>W6: f32 = -<span class="number">1.6309292987e-03</span>; <span class="comment">/* 0xbad5c4e8 */ |
| |
| /* sin(PI*x) assuming x > 2^-100, if sin(PI*x)==0 the sign is arbitrary */ |
| </span><span class="kw">fn </span>sin_pi(<span class="kw-2">mut </span>x: f32) -> f32 { |
| <span class="kw">let </span><span class="kw-2">mut </span>y: f64; |
| <span class="kw">let </span><span class="kw-2">mut </span>n: isize; |
| |
| <span class="comment">/* spurious inexact if odd int */ |
| </span>x = <span class="number">2.0 </span>* (x * <span class="number">0.5 </span>- floorf(x * <span class="number">0.5</span>)); <span class="comment">/* x mod 2.0 */ |
| |
| </span>n = (x * <span class="number">4.0</span>) <span class="kw">as </span>isize; |
| n = <span class="macro">div!</span>(n + <span class="number">1</span>, <span class="number">2</span>); |
| y = (x <span class="kw">as </span>f64) - (n <span class="kw">as </span>f64) * <span class="number">0.5</span>; |
| y <span class="kw-2">*</span>= <span class="number">3.14159265358979323846</span>; |
| <span class="kw">match </span>n { |
| <span class="number">1 </span>=> k_cosf(y), |
| <span class="number">2 </span>=> k_sinf(-y), |
| <span class="number">3 </span>=> -k_cosf(y), |
| <span class="number">0 </span>| <span class="kw">_ </span>=> k_sinf(y), |
| } |
| } |
| |
| <span class="attribute">#[cfg_attr(all(test, assert_no_panic), no_panic::no_panic)] |
| </span><span class="kw">pub fn </span>lgammaf_r(<span class="kw-2">mut </span>x: f32) -> (f32, i32) { |
| <span class="kw">let </span>u = x.to_bits(); |
| <span class="kw">let </span><span class="kw-2">mut </span>t: f32; |
| <span class="kw">let </span>y: f32; |
| <span class="kw">let </span><span class="kw-2">mut </span>z: f32; |
| <span class="kw">let </span>nadj: f32; |
| <span class="kw">let </span>p: f32; |
| <span class="kw">let </span>p1: f32; |
| <span class="kw">let </span>p2: f32; |
| <span class="kw">let </span>p3: f32; |
| <span class="kw">let </span>q: f32; |
| <span class="kw">let </span><span class="kw-2">mut </span>r: f32; |
| <span class="kw">let </span>w: f32; |
| <span class="kw">let </span>ix: u32; |
| <span class="kw">let </span>i: i32; |
| <span class="kw">let </span>sign: bool; |
| <span class="kw">let </span><span class="kw-2">mut </span>signgam: i32; |
| |
| <span class="comment">/* purge off +-inf, NaN, +-0, tiny and negative arguments */ |
| </span>signgam = <span class="number">1</span>; |
| sign = (u >> <span class="number">31</span>) != <span class="number">0</span>; |
| ix = u & <span class="number">0x7fffffff</span>; |
| <span class="kw">if </span>ix >= <span class="number">0x7f800000 </span>{ |
| <span class="kw">return </span>(x * x, signgam); |
| } |
| <span class="kw">if </span>ix < <span class="number">0x35000000 </span>{ |
| <span class="comment">/* |x| < 2**-21, return -log(|x|) */ |
| </span><span class="kw">if </span>sign { |
| signgam = -<span class="number">1</span>; |
| x = -x; |
| } |
| <span class="kw">return </span>(-logf(x), signgam); |
| } |
| <span class="kw">if </span>sign { |
| x = -x; |
| t = sin_pi(x); |
| <span class="kw">if </span>t == <span class="number">0.0 </span>{ |
| <span class="comment">/* -integer */ |
| </span><span class="kw">return </span>(<span class="number">1.0 </span>/ (x - x), signgam); |
| } |
| <span class="kw">if </span>t > <span class="number">0.0 </span>{ |
| signgam = -<span class="number">1</span>; |
| } <span class="kw">else </span>{ |
| t = -t; |
| } |
| nadj = logf(PI / (t * x)); |
| } <span class="kw">else </span>{ |
| nadj = <span class="number">0.0</span>; |
| } |
| |
| <span class="comment">/* purge off 1 and 2 */ |
| </span><span class="kw">if </span>ix == <span class="number">0x3f800000 </span>|| ix == <span class="number">0x40000000 </span>{ |
| r = <span class="number">0.0</span>; |
| } |
| <span class="comment">/* for x < 2.0 */ |
| </span><span class="kw">else if </span>ix < <span class="number">0x40000000 </span>{ |
| <span class="kw">if </span>ix <= <span class="number">0x3f666666 </span>{ |
| <span class="comment">/* lgamma(x) = lgamma(x+1)-log(x) */ |
| </span>r = -logf(x); |
| <span class="kw">if </span>ix >= <span class="number">0x3f3b4a20 </span>{ |
| y = <span class="number">1.0 </span>- x; |
| i = <span class="number">0</span>; |
| } <span class="kw">else if </span>ix >= <span class="number">0x3e6d3308 </span>{ |
| y = x - (TC - <span class="number">1.0</span>); |
| i = <span class="number">1</span>; |
| } <span class="kw">else </span>{ |
| y = x; |
| i = <span class="number">2</span>; |
| } |
| } <span class="kw">else </span>{ |
| r = <span class="number">0.0</span>; |
| <span class="kw">if </span>ix >= <span class="number">0x3fdda618 </span>{ |
| <span class="comment">/* [1.7316,2] */ |
| </span>y = <span class="number">2.0 </span>- x; |
| i = <span class="number">0</span>; |
| } <span class="kw">else if </span>ix >= <span class="number">0x3F9da620 </span>{ |
| <span class="comment">/* [1.23,1.73] */ |
| </span>y = x - TC; |
| i = <span class="number">1</span>; |
| } <span class="kw">else </span>{ |
| y = x - <span class="number">1.0</span>; |
| i = <span class="number">2</span>; |
| } |
| } |
| <span class="kw">match </span>i { |
| <span class="number">0 </span>=> { |
| z = y * y; |
| p1 = A0 + z * (A2 + z * (A4 + z * (A6 + z * (A8 + z * A10)))); |
| p2 = z * (A1 + z * (A3 + z * (A5 + z * (A7 + z * (A9 + z * A11))))); |
| p = y * p1 + p2; |
| r += p - <span class="number">0.5 </span>* y; |
| } |
| <span class="number">1 </span>=> { |
| z = y * y; |
| w = z * y; |
| p1 = T0 + w * (T3 + w * (T6 + w * (T9 + w * T12))); <span class="comment">/* parallel comp */ |
| </span>p2 = T1 + w * (T4 + w * (T7 + w * (T10 + w * T13))); |
| p3 = T2 + w * (T5 + w * (T8 + w * (T11 + w * T14))); |
| p = z * p1 - (TT - w * (p2 + y * p3)); |
| r += TF + p; |
| } |
| <span class="number">2 </span>=> { |
| p1 = y * (U0 + y * (U1 + y * (U2 + y * (U3 + y * (U4 + y * U5))))); |
| p2 = <span class="number">1.0 </span>+ y * (V1 + y * (V2 + y * (V3 + y * (V4 + y * V5)))); |
| r += -<span class="number">0.5 </span>* y + p1 / p2; |
| } |
| <span class="attribute">#[cfg(debug_assertions)] |
| </span><span class="kw">_ </span>=> <span class="macro">unreachable!</span>(), |
| <span class="attribute">#[cfg(not(debug_assertions))] |
| </span><span class="kw">_ </span>=> {} |
| } |
| } <span class="kw">else if </span>ix < <span class="number">0x41000000 </span>{ |
| <span class="comment">/* x < 8.0 */ |
| </span>i = x <span class="kw">as </span>i32; |
| y = x - (i <span class="kw">as </span>f32); |
| p = y * (S0 + y * (S1 + y * (S2 + y * (S3 + y * (S4 + y * (S5 + y * S6)))))); |
| q = <span class="number">1.0 </span>+ y * (R1 + y * (R2 + y * (R3 + y * (R4 + y * (R5 + y * R6))))); |
| r = <span class="number">0.5 </span>* y + p / q; |
| z = <span class="number">1.0</span>; <span class="comment">/* lgamma(1+s) = log(s) + lgamma(s) */ |
| // TODO: In C, this was implemented using switch jumps with fallthrough. |
| // Does this implementation have performance problems? |
| </span><span class="kw">if </span>i >= <span class="number">7 </span>{ |
| z <span class="kw-2">*</span>= y + <span class="number">6.0</span>; |
| } |
| <span class="kw">if </span>i >= <span class="number">6 </span>{ |
| z <span class="kw-2">*</span>= y + <span class="number">5.0</span>; |
| } |
| <span class="kw">if </span>i >= <span class="number">5 </span>{ |
| z <span class="kw-2">*</span>= y + <span class="number">4.0</span>; |
| } |
| <span class="kw">if </span>i >= <span class="number">4 </span>{ |
| z <span class="kw-2">*</span>= y + <span class="number">3.0</span>; |
| } |
| <span class="kw">if </span>i >= <span class="number">3 </span>{ |
| z <span class="kw-2">*</span>= y + <span class="number">2.0</span>; |
| r += logf(z); |
| } |
| } <span class="kw">else if </span>ix < <span class="number">0x5c800000 </span>{ |
| <span class="comment">/* 8.0 <= x < 2**58 */ |
| </span>t = logf(x); |
| z = <span class="number">1.0 </span>/ x; |
| y = z * z; |
| w = W0 + z * (W1 + y * (W2 + y * (W3 + y * (W4 + y * (W5 + y * W6))))); |
| r = (x - <span class="number">0.5</span>) * (t - <span class="number">1.0</span>) + w; |
| } <span class="kw">else </span>{ |
| <span class="comment">/* 2**58 <= x <= inf */ |
| </span>r = x * (logf(x) - <span class="number">1.0</span>); |
| } |
| <span class="kw">if </span>sign { |
| r = nadj - r; |
| } |
| <span class="kw">return </span>(r, signgam); |
| } |
| </code></pre></div> |
| </section></div></main><div id="rustdoc-vars" data-root-path="../../../" data-current-crate="libm" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0-nightly (5c8bff74b 2022-10-21)" ></div></body></html> |
