| <!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/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" 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> |
| </pre><pre class="rust"><code><span class="comment">/* origin: FreeBSD /usr/src/lib/msun/src/e_rem_pio2f.c */ |
| /* |
| * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. |
| * Debugged and optimized by Bruce D. Evans. |
| */ |
| /* |
| * ==================================================== |
| * 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="kw">super</span>::rem_pio2_large; |
| |
| <span class="kw">use </span>core::f64; |
| |
| <span class="kw">const </span>TOINT: f64 = <span class="number">1.5 </span>/ f64::EPSILON; |
| |
| <span class="doccomment">/// 53 bits of 2/pi |
| </span><span class="kw">const </span>INV_PIO2: f64 = <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>PIO2_1: f64 = <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>PIO2_1T: f64 = <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 |
| /// |
| /// use double precision for everything except passing x |
| /// use __rem_pio2_large() for large x |
| </span><span class="attribute">#[cfg_attr(all(test, assert_no_panic), no_panic::no_panic)] |
| </span><span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">fn </span>rem_pio2f(x: f32) -> (i32, f64) { |
| <span class="kw">let </span>x64 = x <span class="kw">as </span>f64; |
| |
| <span class="kw">let </span><span class="kw-2">mut </span>tx: [f64; <span class="number">1</span>] = [<span class="number">0.</span>]; |
| <span class="kw">let </span><span class="kw-2">mut </span>ty: [f64; <span class="number">1</span>] = [<span class="number">0.</span>]; |
| |
| <span class="kw">let </span>ix = x.to_bits() & <span class="number">0x7fffffff</span>; |
| <span class="comment">/* 25+53 bit pi is good enough for medium size */ |
| </span><span class="kw">if </span>ix < <span class="number">0x4dc90fdb </span>{ |
| <span class="comment">/* |x| ~< 2^28*(pi/2), medium size */ |
| /* Use a specialized rint() to get fn. Assume round-to-nearest. */ |
| </span><span class="kw">let </span>tmp = x64 * INV_PIO2 + TOINT; |
| <span class="comment">// force rounding of tmp to it's storage format on x87 to avoid |
| // excess precision issues. |
| </span><span class="attribute">#[cfg(all(target_arch = <span class="string">"x86"</span>, not(target_feature = <span class="string">"sse2"</span>)))] |
| </span><span class="kw">let </span>tmp = <span class="macro">force_eval!</span>(tmp); |
| <span class="kw">let </span>f_n = tmp - TOINT; |
| <span class="kw">return </span>(f_n <span class="kw">as </span>i32, x64 - f_n * PIO2_1 - f_n * PIO2_1T); |
| } |
| <span class="kw">if </span>ix >= <span class="number">0x7f800000 </span>{ |
| <span class="comment">/* x is inf or NaN */ |
| </span><span class="kw">return </span>(<span class="number">0</span>, x64 - x64); |
| } |
| <span class="comment">/* scale x into [2^23, 2^24-1] */ |
| </span><span class="kw">let </span>sign = (x.to_bits() >> <span class="number">31</span>) != <span class="number">0</span>; |
| <span class="kw">let </span>e0 = ((ix >> <span class="number">23</span>) - (<span class="number">0x7f </span>+ <span class="number">23</span>)) <span class="kw">as </span>i32; <span class="comment">/* e0 = ilogb(|x|)-23, positive */ |
| </span>tx[<span class="number">0</span>] = f32::from_bits(ix - (e0 << <span class="number">23</span>) <span class="kw">as </span>u32) <span class="kw">as </span>f64; |
| <span class="kw">let </span>n = rem_pio2_large(<span class="kw-2">&</span>tx, <span class="kw-2">&mut </span>ty, e0, <span class="number">0</span>); |
| <span class="kw">if </span>sign { |
| <span class="kw">return </span>(-n, -ty[<span class="number">0</span>]); |
| } |
| (n, ty[<span class="number">0</span>]) |
| } |
| </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> |