| <!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 `/home/runner/.cargo/registry/src/github.com-1ecc6299db9ec823/libm-0.2.1/src/math/rem_pio2f.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>rem_pio2f.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" type="text/css" href="../../../normalize.css"><link rel="stylesheet" type="text/css" href="../../../rustdoc.css" id="mainThemeStyle"><link rel="stylesheet" type="text/css" href="../../../ayu.css" disabled><link rel="stylesheet" type="text/css" href="../../../dark.css" disabled><link rel="stylesheet" type="text/css" href="../../../light.css" id="themeStyle"><script id="default-settings" ></script><script src="../../../storage.js"></script><script src="../../../crates.js"></script><script defer src="../../../main.js"></script><script defer src="../../../source-script.js"></script><script defer src="../../../source-files.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"><div class="sidebar-menu" role="button">☰</div><a class="sidebar-logo" href="../../../libm/index.html"><div class="logo-container"><img class="rust-logo" src="../../../rust-logo.png" alt="logo"></div> |
| </a></nav><main><div class="width-limiter"><div class="sub-container"><a class="sub-logo-container" href="../../../libm/index.html"><img class="rust-logo" src="../../../rust-logo.png" alt="logo"></a><nav class="sub"><div class="theme-picker"><button id="theme-picker" aria-label="Pick another theme!" aria-haspopup="menu" title="themes"><img width="18" height="18" alt="Pick another theme!" src="../../../brush.svg"></button><div id="theme-choices" role="menu"></div></div><form class="search-form"><div class="search-container"><div> |
| <input class="search-input" name="search" autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"></div><button type="button" id="help-button" title="help">?</button><a id="settings-menu" href="../../../settings.html" title="settings"><img width="18" height="18" alt="Change settings" src="../../../wheel.svg"></a></div></form></nav></div><section id="main-content" class="content"><div class="example-wrap"><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> |
| <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> |
| </pre><pre class="rust"><code><span class="comment">/* origin: FreeBSD /usr/src/lib/msun/src/e_rem_pio2f.c */</span> |
| <span class="comment">/* |
| * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. |
| * Debugged and optimized by Bruce D. Evans. |
| */</span> |
| <span class="comment">/* |
| * ==================================================== |
| * 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</span> <span class="ident"><span class="kw">super</span>::rem_pio2_large</span>; |
| |
| <span class="kw">use</span> <span class="ident">core::f64</span>; |
| |
| <span class="kw">const</span> <span class="ident">TOINT</span>: <span class="ident">f64</span> <span class="op">=</span> <span class="number">1.5</span> <span class="op">/</span> <span class="ident">f64::EPSILON</span>; |
| |
| <span class="doccomment">/// 53 bits of 2/pi</span> |
| <span class="kw">const</span> <span class="ident">INV_PIO2</span>: <span class="ident">f64</span> <span class="op">=</span> <span class="number">6.36619772367581382433e-01</span>; <span class="comment">/* 0x3FE45F30, 0x6DC9C883 */</span> |
| <span class="doccomment">/// first 25 bits of pi/2</span> |
| <span class="kw">const</span> <span class="ident">PIO2_1</span>: <span class="ident">f64</span> <span class="op">=</span> <span class="number">1.57079631090164184570e+00</span>; <span class="comment">/* 0x3FF921FB, 0x50000000 */</span> |
| <span class="doccomment">/// pi/2 - pio2_1</span> |
| <span class="kw">const</span> <span class="ident">PIO2_1T</span>: <span class="ident">f64</span> <span class="op">=</span> <span class="number">1.58932547735281966916e-08</span>; <span class="comment">/* 0x3E5110b4, 0x611A6263 */</span> |
| |
| <span class="doccomment">/// Return the remainder of x rem pi/2 in *y</span> |
| <span class="doccomment">///</span> |
| <span class="doccomment">/// use double precision for everything except passing x</span> |
| <span class="doccomment">/// use __rem_pio2_large() for large x</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::no_panic</span>)]</span> |
| <span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">fn</span> <span class="ident">rem_pio2f</span>(<span class="ident">x</span>: <span class="ident">f32</span>) -> (<span class="ident">i32</span>, <span class="ident">f64</span>) { |
| <span class="kw">let</span> <span class="ident">x64</span> <span class="op">=</span> <span class="ident">x</span> <span class="kw">as</span> <span class="ident">f64</span>; |
| |
| <span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">tx</span>: [<span class="ident">f64</span>; <span class="number">1</span>] <span class="op">=</span> [<span class="number">0.</span>]; |
| <span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">ty</span>: [<span class="ident">f64</span>; <span class="number">1</span>] <span class="op">=</span> [<span class="number">0.</span>]; |
| |
| <span class="kw">let</span> <span class="ident">ix</span> <span class="op">=</span> <span class="ident">x</span>.<span class="ident">to_bits</span>() <span class="op">&</span> <span class="number">0x7fffffff</span>; |
| <span class="comment">/* 25+53 bit pi is good enough for medium size */</span> |
| <span class="kw">if</span> <span class="ident">ix</span> <span class="op"><</span> <span class="number">0x4dc90fdb</span> { |
| <span class="comment">/* |x| ~< 2^28*(pi/2), medium size */</span> |
| <span class="comment">/* Use a specialized rint() to get fn. Assume round-to-nearest. */</span> |
| <span class="kw">let</span> <span class="ident">f_n</span> <span class="op">=</span> <span class="ident">x64</span> <span class="op">*</span> <span class="ident">INV_PIO2</span> <span class="op">+</span> <span class="ident">TOINT</span> <span class="op">-</span> <span class="ident">TOINT</span>; |
| <span class="kw">return</span> (<span class="ident">f_n</span> <span class="kw">as</span> <span class="ident">i32</span>, <span class="ident">x64</span> <span class="op">-</span> <span class="ident">f_n</span> <span class="op">*</span> <span class="ident">PIO2_1</span> <span class="op">-</span> <span class="ident">f_n</span> <span class="op">*</span> <span class="ident">PIO2_1T</span>); |
| } |
| <span class="kw">if</span> <span class="ident">ix</span> <span class="op">></span><span class="op">=</span> <span class="number">0x7f800000</span> { |
| <span class="comment">/* x is inf or NaN */</span> |
| <span class="kw">return</span> (<span class="number">0</span>, <span class="ident">x64</span> <span class="op">-</span> <span class="ident">x64</span>); |
| } |
| <span class="comment">/* scale x into [2^23, 2^24-1] */</span> |
| <span class="kw">let</span> <span class="ident">sign</span> <span class="op">=</span> (<span class="ident">x</span>.<span class="ident">to_bits</span>() <span class="op">></span><span class="op">></span> <span class="number">31</span>) <span class="op">!</span><span class="op">=</span> <span class="number">0</span>; |
| <span class="kw">let</span> <span class="ident">e0</span> <span class="op">=</span> ((<span class="ident">ix</span> <span class="op">></span><span class="op">></span> <span class="number">23</span>) <span class="op">-</span> (<span class="number">0x7f</span> <span class="op">+</span> <span class="number">23</span>)) <span class="kw">as</span> <span class="ident">i32</span>; <span class="comment">/* e0 = ilogb(|x|)-23, positive */</span> |
| <span class="ident">tx</span>[<span class="number">0</span>] <span class="op">=</span> <span class="ident">f32::from_bits</span>(<span class="ident">ix</span> <span class="op">-</span> (<span class="ident">e0</span> <span class="op"><</span><span class="op"><</span> <span class="number">23</span>) <span class="kw">as</span> <span class="ident">u32</span>) <span class="kw">as</span> <span class="ident">f64</span>; |
| <span class="kw">let</span> <span class="ident">n</span> <span class="op">=</span> <span class="ident">rem_pio2_large</span>(<span class="kw-2">&</span><span class="ident">tx</span>, <span class="kw-2">&mut</span> <span class="ident">ty</span>, <span class="ident">e0</span>, <span class="number">0</span>); |
| <span class="kw">if</span> <span class="ident">sign</span> { |
| <span class="kw">return</span> (<span class="op">-</span><span class="ident">n</span>, <span class="op">-</span><span class="ident">ty</span>[<span class="number">0</span>]); |
| } |
| (<span class="ident">n</span>, <span class="ident">ty</span>[<span class="number">0</span>]) |
| } |
| </code></pre></div> |
| </section><section id="search" class="content hidden"></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="1.60.0-nightly (1bd4fdc94 2022-01-12)" ></div> |
| </body></html> |
