Google Git
Sign in
apache / incubator-teaclave-website / refs/heads/asf-site / . / api-docs / crates-app / src / libm / math / sincosf.rs.html
blob: 2a0c7891e36fd95ac5ce56fe17c7649ce4fd3786 [file] [log] [blame]
<!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/sincosf.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>sincosf.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>
</pre><pre class="rust"><code><span class="comment">/* origin: FreeBSD /usr/src/lib/msun/src/s_sinf.c */
/*
* Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
* 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 super</span>::{k_cosf, k_sinf, rem_pio2f};
<span class="comment">/* Small multiples of pi/2 rounded to double precision. */
</span><span class="kw">const </span>PI_2: f32 = <span class="number">0.5 </span>* <span class="number">3.1415926535897931160E+00</span>;
<span class="kw">const </span>S1PIO2: f32 = <span class="number">1.0 </span>* PI_2; <span class="comment">/* 0x3FF921FB, 0x54442D18 */
</span><span class="kw">const </span>S2PIO2: f32 = <span class="number">2.0 </span>* PI_2; <span class="comment">/* 0x400921FB, 0x54442D18 */
</span><span class="kw">const </span>S3PIO2: f32 = <span class="number">3.0 </span>* PI_2; <span class="comment">/* 0x4012D97C, 0x7F3321D2 */
</span><span class="kw">const </span>S4PIO2: f32 = <span class="number">4.0 </span>* PI_2; <span class="comment">/* 0x401921FB, 0x54442D18 */
</span><span class="attribute">#[cfg_attr(all(test, assert_no_panic), no_panic::no_panic)]
</span><span class="kw">pub fn </span>sincosf(x: f32) -&gt; (f32, f32) {
<span class="kw">let </span>s: f32;
<span class="kw">let </span>c: f32;
<span class="kw">let </span><span class="kw-2">mut </span>ix: u32;
<span class="kw">let </span>sign: bool;
ix = x.to_bits();
sign = (ix &gt;&gt; <span class="number">31</span>) != <span class="number">0</span>;
ix &amp;= <span class="number">0x7fffffff</span>;
<span class="comment">/* |x| ~&lt;= pi/4 */
</span><span class="kw">if </span>ix &lt;= <span class="number">0x3f490fda </span>{
<span class="comment">/* |x| &lt; 2**-12 */
</span><span class="kw">if </span>ix &lt; <span class="number">0x39800000 </span>{
<span class="comment">/* raise inexact if x!=0 and underflow if subnormal */
</span><span class="kw">let </span>x1p120 = f32::from_bits(<span class="number">0x7b800000</span>); <span class="comment">// 0x1p120 == 2^120
</span><span class="kw">if </span>ix &lt; <span class="number">0x00100000 </span>{
<span class="macro">force_eval!</span>(x / x1p120);
} <span class="kw">else </span>{
<span class="macro">force_eval!</span>(x + x1p120);
}
<span class="kw">return </span>(x, <span class="number">1.0</span>);
}
<span class="kw">return </span>(k_sinf(x <span class="kw">as </span>f64), k_cosf(x <span class="kw">as </span>f64));
}
<span class="comment">/* |x| ~&lt;= 5*pi/4 */
</span><span class="kw">if </span>ix &lt;= <span class="number">0x407b53d1 </span>{
<span class="kw">if </span>ix &lt;= <span class="number">0x4016cbe3 </span>{
<span class="comment">/* |x| ~&lt;= 3pi/4 */
</span><span class="kw">if </span>sign {
s = -k_cosf((x + S1PIO2) <span class="kw">as </span>f64);
c = k_sinf((x + S1PIO2) <span class="kw">as </span>f64);
} <span class="kw">else </span>{
s = k_cosf((S1PIO2 - x) <span class="kw">as </span>f64);
c = k_sinf((S1PIO2 - x) <span class="kw">as </span>f64);
}
}
<span class="comment">/* -sin(x+c) is not correct if x+c could be 0: -0 vs +0 */
</span><span class="kw">else </span>{
<span class="kw">if </span>sign {
s = -k_sinf((x + S2PIO2) <span class="kw">as </span>f64);
c = -k_cosf((x + S2PIO2) <span class="kw">as </span>f64);
} <span class="kw">else </span>{
s = -k_sinf((x - S2PIO2) <span class="kw">as </span>f64);
c = -k_cosf((x - S2PIO2) <span class="kw">as </span>f64);
}
}
<span class="kw">return </span>(s, c);
}
<span class="comment">/* |x| ~&lt;= 9*pi/4 */
</span><span class="kw">if </span>ix &lt;= <span class="number">0x40e231d5 </span>{
<span class="kw">if </span>ix &lt;= <span class="number">0x40afeddf </span>{
<span class="comment">/* |x| ~&lt;= 7*pi/4 */
</span><span class="kw">if </span>sign {
s = k_cosf((x + S3PIO2) <span class="kw">as </span>f64);
c = -k_sinf((x + S3PIO2) <span class="kw">as </span>f64);
} <span class="kw">else </span>{
s = -k_cosf((x - S3PIO2) <span class="kw">as </span>f64);
c = k_sinf((x - S3PIO2) <span class="kw">as </span>f64);
}
} <span class="kw">else </span>{
<span class="kw">if </span>sign {
s = k_sinf((x + S4PIO2) <span class="kw">as </span>f64);
c = k_cosf((x + S4PIO2) <span class="kw">as </span>f64);
} <span class="kw">else </span>{
s = k_sinf((x - S4PIO2) <span class="kw">as </span>f64);
c = k_cosf((x - S4PIO2) <span class="kw">as </span>f64);
}
}
<span class="kw">return </span>(s, c);
}
<span class="comment">/* sin(Inf or NaN) is NaN */
</span><span class="kw">if </span>ix &gt;= <span class="number">0x7f800000 </span>{
<span class="kw">let </span>rv = x - x;
<span class="kw">return </span>(rv, rv);
}
<span class="comment">/* general argument reduction needed */
</span><span class="kw">let </span>(n, y) = rem_pio2f(x);
s = k_sinf(y);
c = k_cosf(y);
<span class="kw">match </span>n &amp; <span class="number">3 </span>{
<span class="number">0 </span>=&gt; (s, c),
<span class="number">1 </span>=&gt; (c, -s),
<span class="number">2 </span>=&gt; (-s, -c),
<span class="number">3 </span>=&gt; (-c, s),
<span class="attribute">#[cfg(debug_assertions)]
</span><span class="kw">_ </span>=&gt; <span class="macro">unreachable!</span>(),
<span class="attribute">#[cfg(not(debug_assertions))]
</span><span class="kw">_ </span>=&gt; (<span class="number">0.0</span>, <span class="number">1.0</span>),
}
}
<span class="comment">// PowerPC tests are failing on LLVM 13: https://github.com/rust-lang/rust/issues/88520
</span><span class="attribute">#[cfg(not(target_arch = <span class="string">&quot;powerpc64&quot;</span>))]
#[cfg(test)]
</span><span class="kw">mod </span>tests {
<span class="kw">use </span><span class="kw">super</span>::sincosf;
<span class="kw">use </span><span class="kw">crate</span>::_eqf;
<span class="attribute">#[test]
</span><span class="kw">fn </span>with_pi() {
<span class="kw">let </span>(s, c) = sincosf(core::f32::consts::PI);
_eqf(s.abs(), <span class="number">0.0</span>).unwrap();
_eqf(c, -<span class="number">1.0</span>).unwrap();
}
<span class="attribute">#[test]
</span><span class="kw">fn </span>rotational_symmetry() {
<span class="kw">use </span>core::f32::consts::PI;
<span class="kw">const </span>N: usize = <span class="number">24</span>;
<span class="kw">for </span>n <span class="kw">in </span><span class="number">0</span>..N {
<span class="kw">let </span>theta = <span class="number">2. </span>* PI * (n <span class="kw">as </span>f32) / (N <span class="kw">as </span>f32);
<span class="kw">let </span>(s, c) = sincosf(theta);
<span class="kw">let </span>(s_plus, c_plus) = sincosf(theta + <span class="number">2. </span>* PI);
<span class="kw">let </span>(s_minus, c_minus) = sincosf(theta - <span class="number">2. </span>* PI);
<span class="kw">const </span>TOLERANCE: f32 = <span class="number">1e-6</span>;
<span class="macro">assert!</span>(
(s - s_plus).abs() &lt; TOLERANCE,
<span class="string">&quot;|{} - {}| = {} &gt;= {}&quot;</span>,
s,
s_plus,
(s - s_plus).abs(),
TOLERANCE
);
<span class="macro">assert!</span>(
(s - s_minus).abs() &lt; TOLERANCE,
<span class="string">&quot;|{} - {}| = {} &gt;= {}&quot;</span>,
s,
s_minus,
(s - s_minus).abs(),
TOLERANCE
);
<span class="macro">assert!</span>(
(c - c_plus).abs() &lt; TOLERANCE,
<span class="string">&quot;|{} - {}| = {} &gt;= {}&quot;</span>,
c,
c_plus,
(c - c_plus).abs(),
TOLERANCE
);
<span class="macro">assert!</span>(
(c - c_minus).abs() &lt; TOLERANCE,
<span class="string">&quot;|{} - {}| = {} &gt;= {}&quot;</span>,
c,
c_minus,
(c - c_minus).abs(),
TOLERANCE
);
}
}
}
</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>