| <!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/sinh.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>sinh.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> |
| </pre><pre class="rust"><code><span class="kw">use super</span>::{expm1, expo2}; |
| |
| <span class="comment">// sinh(x) = (exp(x) - 1/exp(x))/2 |
| // = (exp(x)-1 + (exp(x)-1)/exp(x))/2 |
| // = x + x^3/6 + o(x^5) |
| // |
| </span><span class="attribute">#[cfg_attr(all(test, assert_no_panic), no_panic::no_panic)] |
| </span><span class="kw">pub fn </span>sinh(x: f64) -> f64 { |
| <span class="comment">// union {double f; uint64_t i;} u = {.f = x}; |
| // uint32_t w; |
| // double t, h, absx; |
| |
| </span><span class="kw">let </span><span class="kw-2">mut </span>uf: f64 = x; |
| <span class="kw">let </span><span class="kw-2">mut </span>ui: u64 = f64::to_bits(uf); |
| <span class="kw">let </span>w: u32; |
| <span class="kw">let </span>t: f64; |
| <span class="kw">let </span><span class="kw-2">mut </span>h: f64; |
| <span class="kw">let </span>absx: f64; |
| |
| h = <span class="number">0.5</span>; |
| <span class="kw">if </span>ui >> <span class="number">63 </span>!= <span class="number">0 </span>{ |
| h = -h; |
| } |
| <span class="comment">/* |x| */ |
| </span>ui &= !<span class="number">1 </span>/ <span class="number">2</span>; |
| uf = f64::from_bits(ui); |
| absx = uf; |
| w = (ui >> <span class="number">32</span>) <span class="kw">as </span>u32; |
| |
| <span class="comment">/* |x| < log(DBL_MAX) */ |
| </span><span class="kw">if </span>w < <span class="number">0x40862e42 </span>{ |
| t = expm1(absx); |
| <span class="kw">if </span>w < <span class="number">0x3ff00000 </span>{ |
| <span class="kw">if </span>w < <span class="number">0x3ff00000 </span>- (<span class="number">26 </span><< <span class="number">20</span>) { |
| <span class="comment">/* note: inexact and underflow are raised by expm1 */ |
| /* note: this branch avoids spurious underflow */ |
| </span><span class="kw">return </span>x; |
| } |
| <span class="kw">return </span>h * (<span class="number">2.0 </span>* t - t * t / (t + <span class="number">1.0</span>)); |
| } |
| <span class="comment">/* note: |x|>log(0x1p26)+eps could be just h*exp(x) */ |
| </span><span class="kw">return </span>h * (t + t / (t + <span class="number">1.0</span>)); |
| } |
| |
| <span class="comment">/* |x| > log(DBL_MAX) or nan */ |
| /* note: the result is stored to handle overflow */ |
| </span>t = <span class="number">2.0 </span>* h * expo2(absx); |
| t |
| } |
| </code></pre></div> |
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