<!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 to the Rust file `/home/mrh/.cargo/registry/src/github.com-1ecc6299db9ec823/libm-0.1.4/src/math/truncf.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>truncf.rs.html -- source</title><link rel="stylesheet" type="text/css" href="../../../normalize.css"><link rel="stylesheet" type="text/css" href="../../../rustdoc.css" id="mainThemeStyle"><link rel="stylesheet" type="text/css" href="../../../dark.css"><link rel="stylesheet" type="text/css" href="../../../light.css" id="themeStyle"><script src="../../../storage.js"></script><noscript><link rel="stylesheet" href="../../../noscript.css"></noscript><link rel="shortcut icon" href="../../../favicon.ico"><style type="text/css">#crate-search{background-image:url("../../../down-arrow.svg");}</style></head><body class="rustdoc source"><!--[if lte IE 8]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"><div class="sidebar-menu">☰</div><a href='../../../libm/index.html'><div class='logo-container'><img src='../../../rust-logo.png' alt='logo'></div></a></nav><div class="theme-picker"><button id="theme-picker" aria-label="Pick another theme!"><img src="../../../brush.svg" width="18" alt="Pick another theme!"></button><div id="theme-choices"></div></div><script src="../../../theme.js"></script><nav class="sub"><form class="search-form js-only"><div class="search-container"><div><select id="crate-search"><option value="All crates">All crates</option></select><input class="search-input" name="search" autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"></div><a id="settings-menu" href="../../../settings.html"><img src="../../../wheel.svg" width="18" alt="Change settings"></a></div></form></nav><section id="main" class="content"><pre class="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>
</pre><div class="example-wrap"><pre class="rust ">
<span class="kw">use</span> <span class="ident">core</span>::<span class="ident">f32</span>;
<span class="attribute">#[<span class="ident">inline</span>]</span>
<span class="attribute">#[<span class="ident">cfg_attr</span>(<span class="ident">all</span>(<span class="ident">test</span>, <span class="ident">assert_no_panic</span>), <span class="ident">no_panic</span>::<span class="ident">no_panic</span>)]</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">truncf</span>(<span class="ident">x</span>: <span class="ident">f32</span>) <span class="op">-</span><span class="op">></span> <span class="ident">f32</span> {
<span class="comment">// On wasm32 we know that LLVM's intrinsic will compile to an optimized</span>
<span class="comment">// `f32.trunc` native instruction, so we can leverage this for both code size</span>
<span class="comment">// and speed.</span>
<span class="macro">llvm_intrinsically_optimized</span><span class="macro">!</span> {
<span class="attribute">#[<span class="ident">cfg</span>(<span class="ident">target_arch</span> <span class="op">=</span> <span class="string">"wasm32"</span>)]</span> {
<span class="kw">return</span> <span class="kw">unsafe</span> { ::<span class="ident">core</span>::<span class="ident">intrinsics</span>::<span class="ident">truncf32</span>(<span class="ident">x</span>) }
}
}
<span class="kw">let</span> <span class="ident">x1p120</span> <span class="op">=</span> <span class="ident">f32</span>::<span class="ident">from_bits</span>(<span class="number">0x7b800000</span>); <span class="comment">// 0x1p120f === 2 ^ 120</span>
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">i</span>: <span class="ident">u32</span> <span class="op">=</span> <span class="ident">x</span>.<span class="ident">to_bits</span>();
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">e</span>: <span class="ident">i32</span> <span class="op">=</span> (<span class="ident">i</span> <span class="op">></span><span class="op">></span> <span class="number">23</span> <span class="op">&</span> <span class="number">0xff</span>) <span class="kw">as</span> <span class="ident">i32</span> <span class="op">-</span> <span class="number">0x7f</span> <span class="op">+</span> <span class="number">9</span>;
<span class="kw">let</span> <span class="ident">m</span>: <span class="ident">u32</span>;
<span class="kw">if</span> <span class="ident">e</span> <span class="op">></span><span class="op">=</span> <span class="number">23</span> <span class="op">+</span> <span class="number">9</span> {
<span class="kw">return</span> <span class="ident">x</span>;
}
<span class="kw">if</span> <span class="ident">e</span> <span class="op"><</span> <span class="number">9</span> {
<span class="ident">e</span> <span class="op">=</span> <span class="number">1</span>;
}
<span class="ident">m</span> <span class="op">=</span> <span class="op">-</span><span class="number">1i32</span> <span class="kw">as</span> <span class="ident">u32</span> <span class="op">></span><span class="op">></span> <span class="ident">e</span>;
<span class="kw">if</span> (<span class="ident">i</span> <span class="op">&</span> <span class="ident">m</span>) <span class="op">=</span><span class="op">=</span> <span class="number">0</span> {
<span class="kw">return</span> <span class="ident">x</span>;
}
<span class="macro">force_eval</span><span class="macro">!</span>(<span class="ident">x</span> <span class="op">+</span> <span class="ident">x1p120</span>);
<span class="ident">i</span> <span class="kw-2">&</span><span class="op">=</span> <span class="op">!</span><span class="ident">m</span>;
<span class="ident">f32</span>::<span class="ident">from_bits</span>(<span class="ident">i</span>)
}
<span class="attribute">#[<span class="ident">cfg</span>(<span class="ident">test</span>)]</span>
<span class="kw">mod</span> <span class="ident">tests</span> {
<span class="attribute">#[<span class="ident">test</span>]</span>
<span class="kw">fn</span> <span class="ident">sanity_check</span>() {
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="kw">super</span>::<span class="ident">truncf</span>(<span class="number">1.1</span>), <span class="number">1.0</span>);
}
}
</pre></div>
</section><section id="search" class="content hidden"></section><section class="footer"></section><aside id="help" class="hidden"><div><h1 class="hidden">Help</h1><div class="shortcuts"><h2>Keyboard Shortcuts</h2><dl><dt><kbd>?</kbd></dt><dd>Show this help dialog</dd><dt><kbd>S</kbd></dt><dd>Focus the search field</dd><dt><kbd>↑</kbd></dt><dd>Move up in search results</dd><dt><kbd>↓</kbd></dt><dd>Move down in search results</dd><dt><kbd>↹</kbd></dt><dd>Switch tab</dd><dt><kbd>⏎</kbd></dt><dd>Go to active search result</dd><dt><kbd>+</kbd></dt><dd>Expand all sections</dd><dt><kbd>-</kbd></dt><dd>Collapse all sections</dd></dl></div><div class="infos"><h2>Search Tricks</h2><p>Prefix searches with a type followed by a colon (e.g., <code>fn:</code>) to restrict the search to a given type.</p><p>Accepted types are: <code>fn</code>, <code>mod</code>, <code>struct</code>, <code>enum</code>, <code>trait</code>, <code>type</code>, <code>macro</code>, and <code>const</code>.</p><p>Search functions by type signature (e.g., <code>vec -> usize</code> or <code>* -> vec</code>)</p><p>Search multiple things at once by splitting your query with comma (e.g., <code>str,u8</code> or <code>String,struct:Vec,test</code>)</p></div></div></aside><script>window.rootPath = "../../../";window.currentCrate = "libm";</script><script src="../../../aliases.js"></script><script src="../../../main.js"></script><script src="../../../source-script.js"></script><script src="../../../source-files.js"></script><script defer src="../../../search-index.js"></script></body></html>