| <!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/j0f.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>j0f.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> |
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| </pre><pre class="rust"><code><span class="comment">/* origin: FreeBSD /usr/src/lib/msun/src/e_j0f.c */ |
| /* |
| * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. |
| */ |
| /* |
| * ==================================================== |
| * 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>::{cosf, fabsf, logf, sinf, sqrtf}; |
| |
| <span class="kw">const </span>INVSQRTPI: f32 = <span class="number">5.6418961287e-01</span>; <span class="comment">/* 0x3f106ebb */ |
| </span><span class="kw">const </span>TPI: f32 = <span class="number">6.3661974669e-01</span>; <span class="comment">/* 0x3f22f983 */ |
| |
| </span><span class="kw">fn </span>common(ix: u32, x: f32, y0: bool) -> f32 { |
| <span class="kw">let </span>z: f32; |
| <span class="kw">let </span>s: f32; |
| <span class="kw">let </span><span class="kw-2">mut </span>c: f32; |
| <span class="kw">let </span><span class="kw-2">mut </span>ss: f32; |
| <span class="kw">let </span><span class="kw-2">mut </span>cc: f32; |
| <span class="comment">/* |
| * j0(x) = 1/sqrt(pi) * (P(0,x)*cc - Q(0,x)*ss) / sqrt(x) |
| * y0(x) = 1/sqrt(pi) * (P(0,x)*ss + Q(0,x)*cc) / sqrt(x) |
| */ |
| </span>s = sinf(x); |
| c = cosf(x); |
| <span class="kw">if </span>y0 { |
| c = -c; |
| } |
| cc = s + c; |
| <span class="kw">if </span>ix < <span class="number">0x7f000000 </span>{ |
| ss = s - c; |
| z = -cosf(<span class="number">2.0 </span>* x); |
| <span class="kw">if </span>s * c < <span class="number">0.0 </span>{ |
| cc = z / ss; |
| } <span class="kw">else </span>{ |
| ss = z / cc; |
| } |
| <span class="kw">if </span>ix < <span class="number">0x58800000 </span>{ |
| <span class="kw">if </span>y0 { |
| ss = -ss; |
| } |
| cc = pzerof(x) * cc - qzerof(x) * ss; |
| } |
| } |
| <span class="kw">return </span>INVSQRTPI * cc / sqrtf(x); |
| } |
| |
| <span class="comment">/* R0/S0 on [0, 2.00] */ |
| </span><span class="kw">const </span>R02: f32 = <span class="number">1.5625000000e-02</span>; <span class="comment">/* 0x3c800000 */ |
| </span><span class="kw">const </span>R03: f32 = -<span class="number">1.8997929874e-04</span>; <span class="comment">/* 0xb947352e */ |
| </span><span class="kw">const </span>R04: f32 = <span class="number">1.8295404516e-06</span>; <span class="comment">/* 0x35f58e88 */ |
| </span><span class="kw">const </span>R05: f32 = -<span class="number">4.6183270541e-09</span>; <span class="comment">/* 0xb19eaf3c */ |
| </span><span class="kw">const </span>S01: f32 = <span class="number">1.5619102865e-02</span>; <span class="comment">/* 0x3c7fe744 */ |
| </span><span class="kw">const </span>S02: f32 = <span class="number">1.1692678527e-04</span>; <span class="comment">/* 0x38f53697 */ |
| </span><span class="kw">const </span>S03: f32 = <span class="number">5.1354652442e-07</span>; <span class="comment">/* 0x3509daa6 */ |
| </span><span class="kw">const </span>S04: f32 = <span class="number">1.1661400734e-09</span>; <span class="comment">/* 0x30a045e8 */ |
| |
| </span><span class="kw">pub fn </span>j0f(<span class="kw-2">mut </span>x: f32) -> f32 { |
| <span class="kw">let </span>z: f32; |
| <span class="kw">let </span>r: f32; |
| <span class="kw">let </span>s: f32; |
| <span class="kw">let </span><span class="kw-2">mut </span>ix: u32; |
| |
| ix = x.to_bits(); |
| ix &= <span class="number">0x7fffffff</span>; |
| <span class="kw">if </span>ix >= <span class="number">0x7f800000 </span>{ |
| <span class="kw">return </span><span class="number">1.0 </span>/ (x * x); |
| } |
| x = fabsf(x); |
| |
| <span class="kw">if </span>ix >= <span class="number">0x40000000 </span>{ |
| <span class="comment">/* |x| >= 2 */ |
| /* large ulp error near zeros */ |
| </span><span class="kw">return </span>common(ix, x, <span class="bool-val">false</span>); |
| } |
| <span class="kw">if </span>ix >= <span class="number">0x3a000000 </span>{ |
| <span class="comment">/* |x| >= 2**-11 */ |
| /* up to 4ulp error near 2 */ |
| </span>z = x * x; |
| r = z * (R02 + z * (R03 + z * (R04 + z * R05))); |
| s = <span class="number">1.0 </span>+ z * (S01 + z * (S02 + z * (S03 + z * S04))); |
| <span class="kw">return </span>(<span class="number">1.0 </span>+ x / <span class="number">2.0</span>) * (<span class="number">1.0 </span>- x / <span class="number">2.0</span>) + z * (r / s); |
| } |
| <span class="kw">if </span>ix >= <span class="number">0x21800000 </span>{ |
| <span class="comment">/* |x| >= 2**-60 */ |
| </span>x = <span class="number">0.25 </span>* x * x; |
| } |
| <span class="kw">return </span><span class="number">1.0 </span>- x; |
| } |
| |
| <span class="kw">const </span>U00: f32 = -<span class="number">7.3804296553e-02</span>; <span class="comment">/* 0xbd9726b5 */ |
| </span><span class="kw">const </span>U01: f32 = <span class="number">1.7666645348e-01</span>; <span class="comment">/* 0x3e34e80d */ |
| </span><span class="kw">const </span>U02: f32 = -<span class="number">1.3818567619e-02</span>; <span class="comment">/* 0xbc626746 */ |
| </span><span class="kw">const </span>U03: f32 = <span class="number">3.4745343146e-04</span>; <span class="comment">/* 0x39b62a69 */ |
| </span><span class="kw">const </span>U04: f32 = -<span class="number">3.8140706238e-06</span>; <span class="comment">/* 0xb67ff53c */ |
| </span><span class="kw">const </span>U05: f32 = <span class="number">1.9559013964e-08</span>; <span class="comment">/* 0x32a802ba */ |
| </span><span class="kw">const </span>U06: f32 = -<span class="number">3.9820518410e-11</span>; <span class="comment">/* 0xae2f21eb */ |
| </span><span class="kw">const </span>V01: f32 = <span class="number">1.2730483897e-02</span>; <span class="comment">/* 0x3c509385 */ |
| </span><span class="kw">const </span>V02: f32 = <span class="number">7.6006865129e-05</span>; <span class="comment">/* 0x389f65e0 */ |
| </span><span class="kw">const </span>V03: f32 = <span class="number">2.5915085189e-07</span>; <span class="comment">/* 0x348b216c */ |
| </span><span class="kw">const </span>V04: f32 = <span class="number">4.4111031494e-10</span>; <span class="comment">/* 0x2ff280c2 */ |
| |
| </span><span class="kw">pub fn </span>y0f(x: f32) -> f32 { |
| <span class="kw">let </span>z: f32; |
| <span class="kw">let </span>u: f32; |
| <span class="kw">let </span>v: f32; |
| <span class="kw">let </span>ix: u32; |
| |
| ix = x.to_bits(); |
| <span class="kw">if </span>(ix & <span class="number">0x7fffffff</span>) == <span class="number">0 </span>{ |
| <span class="kw">return </span>-<span class="number">1.0 </span>/ <span class="number">0.0</span>; |
| } |
| <span class="kw">if </span>(ix >> <span class="number">31</span>) != <span class="number">0 </span>{ |
| <span class="kw">return </span><span class="number">0.0 </span>/ <span class="number">0.0</span>; |
| } |
| <span class="kw">if </span>ix >= <span class="number">0x7f800000 </span>{ |
| <span class="kw">return </span><span class="number">1.0 </span>/ x; |
| } |
| <span class="kw">if </span>ix >= <span class="number">0x40000000 </span>{ |
| <span class="comment">/* |x| >= 2.0 */ |
| /* large ulp error near zeros */ |
| </span><span class="kw">return </span>common(ix, x, <span class="bool-val">true</span>); |
| } |
| <span class="kw">if </span>ix >= <span class="number">0x39000000 </span>{ |
| <span class="comment">/* x >= 2**-13 */ |
| /* large ulp error at x ~= 0.89 */ |
| </span>z = x * x; |
| u = U00 + z * (U01 + z * (U02 + z * (U03 + z * (U04 + z * (U05 + z * U06))))); |
| v = <span class="number">1.0 </span>+ z * (V01 + z * (V02 + z * (V03 + z * V04))); |
| <span class="kw">return </span>u / v + TPI * (j0f(x) * logf(x)); |
| } |
| <span class="kw">return </span>U00 + TPI * logf(x); |
| } |
| |
| <span class="comment">/* The asymptotic expansions of pzero is |
| * 1 - 9/128 s^2 + 11025/98304 s^4 - ..., where s = 1/x. |
| * For x >= 2, We approximate pzero by |
| * pzero(x) = 1 + (R/S) |
| * where R = pR0 + pR1*s^2 + pR2*s^4 + ... + pR5*s^10 |
| * S = 1 + pS0*s^2 + ... + pS4*s^10 |
| * and |
| * | pzero(x)-1-R/S | <= 2 ** ( -60.26) |
| */ |
| </span><span class="kw">const </span>PR8: [f32; <span class="number">6</span>] = [ |
| <span class="comment">/* for x in [inf, 8]=1/[0,0.125] */ |
| </span><span class="number">0.0000000000e+00</span>, <span class="comment">/* 0x00000000 */ |
| </span>-<span class="number">7.0312500000e-02</span>, <span class="comment">/* 0xbd900000 */ |
| </span>-<span class="number">8.0816707611e+00</span>, <span class="comment">/* 0xc1014e86 */ |
| </span>-<span class="number">2.5706311035e+02</span>, <span class="comment">/* 0xc3808814 */ |
| </span>-<span class="number">2.4852163086e+03</span>, <span class="comment">/* 0xc51b5376 */ |
| </span>-<span class="number">5.2530439453e+03</span>, <span class="comment">/* 0xc5a4285a */ |
| </span>]; |
| <span class="kw">const </span>PS8: [f32; <span class="number">5</span>] = [ |
| <span class="number">1.1653436279e+02</span>, <span class="comment">/* 0x42e91198 */ |
| </span><span class="number">3.8337448730e+03</span>, <span class="comment">/* 0x456f9beb */ |
| </span><span class="number">4.0597855469e+04</span>, <span class="comment">/* 0x471e95db */ |
| </span><span class="number">1.1675296875e+05</span>, <span class="comment">/* 0x47e4087c */ |
| </span><span class="number">4.7627726562e+04</span>, <span class="comment">/* 0x473a0bba */ |
| </span>]; |
| <span class="kw">const </span>PR5: [f32; <span class="number">6</span>] = [ |
| <span class="comment">/* for x in [8,4.5454]=1/[0.125,0.22001] */ |
| </span>-<span class="number">1.1412546255e-11</span>, <span class="comment">/* 0xad48c58a */ |
| </span>-<span class="number">7.0312492549e-02</span>, <span class="comment">/* 0xbd8fffff */ |
| </span>-<span class="number">4.1596107483e+00</span>, <span class="comment">/* 0xc0851b88 */ |
| </span>-<span class="number">6.7674766541e+01</span>, <span class="comment">/* 0xc287597b */ |
| </span>-<span class="number">3.3123129272e+02</span>, <span class="comment">/* 0xc3a59d9b */ |
| </span>-<span class="number">3.4643338013e+02</span>, <span class="comment">/* 0xc3ad3779 */ |
| </span>]; |
| <span class="kw">const </span>PS5: [f32; <span class="number">5</span>] = [ |
| <span class="number">6.0753936768e+01</span>, <span class="comment">/* 0x42730408 */ |
| </span><span class="number">1.0512523193e+03</span>, <span class="comment">/* 0x44836813 */ |
| </span><span class="number">5.9789707031e+03</span>, <span class="comment">/* 0x45bad7c4 */ |
| </span><span class="number">9.6254453125e+03</span>, <span class="comment">/* 0x461665c8 */ |
| </span><span class="number">2.4060581055e+03</span>, <span class="comment">/* 0x451660ee */ |
| </span>]; |
| |
| <span class="kw">const </span>PR3: [f32; <span class="number">6</span>] = [ |
| <span class="comment">/* for x in [4.547,2.8571]=1/[0.2199,0.35001] */ |
| </span>-<span class="number">2.5470459075e-09</span>, <span class="comment">/* 0xb12f081b */ |
| </span>-<span class="number">7.0311963558e-02</span>, <span class="comment">/* 0xbd8fffb8 */ |
| </span>-<span class="number">2.4090321064e+00</span>, <span class="comment">/* 0xc01a2d95 */ |
| </span>-<span class="number">2.1965976715e+01</span>, <span class="comment">/* 0xc1afba52 */ |
| </span>-<span class="number">5.8079170227e+01</span>, <span class="comment">/* 0xc2685112 */ |
| </span>-<span class="number">3.1447946548e+01</span>, <span class="comment">/* 0xc1fb9565 */ |
| </span>]; |
| <span class="kw">const </span>PS3: [f32; <span class="number">5</span>] = [ |
| <span class="number">3.5856033325e+01</span>, <span class="comment">/* 0x420f6c94 */ |
| </span><span class="number">3.6151397705e+02</span>, <span class="comment">/* 0x43b4c1ca */ |
| </span><span class="number">1.1936077881e+03</span>, <span class="comment">/* 0x44953373 */ |
| </span><span class="number">1.1279968262e+03</span>, <span class="comment">/* 0x448cffe6 */ |
| </span><span class="number">1.7358093262e+02</span>, <span class="comment">/* 0x432d94b8 */ |
| </span>]; |
| |
| <span class="kw">const </span>PR2: [f32; <span class="number">6</span>] = [ |
| <span class="comment">/* for x in [2.8570,2]=1/[0.3499,0.5] */ |
| </span>-<span class="number">8.8753431271e-08</span>, <span class="comment">/* 0xb3be98b7 */ |
| </span>-<span class="number">7.0303097367e-02</span>, <span class="comment">/* 0xbd8ffb12 */ |
| </span>-<span class="number">1.4507384300e+00</span>, <span class="comment">/* 0xbfb9b1cc */ |
| </span>-<span class="number">7.6356959343e+00</span>, <span class="comment">/* 0xc0f4579f */ |
| </span>-<span class="number">1.1193166733e+01</span>, <span class="comment">/* 0xc1331736 */ |
| </span>-<span class="number">3.2336456776e+00</span>, <span class="comment">/* 0xc04ef40d */ |
| </span>]; |
| <span class="kw">const </span>PS2: [f32; <span class="number">5</span>] = [ |
| <span class="number">2.2220300674e+01</span>, <span class="comment">/* 0x41b1c32d */ |
| </span><span class="number">1.3620678711e+02</span>, <span class="comment">/* 0x430834f0 */ |
| </span><span class="number">2.7047027588e+02</span>, <span class="comment">/* 0x43873c32 */ |
| </span><span class="number">1.5387539673e+02</span>, <span class="comment">/* 0x4319e01a */ |
| </span><span class="number">1.4657617569e+01</span>, <span class="comment">/* 0x416a859a */ |
| </span>]; |
| |
| <span class="kw">fn </span>pzerof(x: f32) -> f32 { |
| <span class="kw">let </span>p: <span class="kw-2">&</span>[f32; <span class="number">6</span>]; |
| <span class="kw">let </span>q: <span class="kw-2">&</span>[f32; <span class="number">5</span>]; |
| <span class="kw">let </span>z: f32; |
| <span class="kw">let </span>r: f32; |
| <span class="kw">let </span>s: f32; |
| <span class="kw">let </span><span class="kw-2">mut </span>ix: u32; |
| |
| ix = x.to_bits(); |
| ix &= <span class="number">0x7fffffff</span>; |
| <span class="kw">if </span>ix >= <span class="number">0x41000000 </span>{ |
| p = <span class="kw-2">&</span>PR8; |
| q = <span class="kw-2">&</span>PS8; |
| } <span class="kw">else if </span>ix >= <span class="number">0x409173eb </span>{ |
| p = <span class="kw-2">&</span>PR5; |
| q = <span class="kw-2">&</span>PS5; |
| } <span class="kw">else if </span>ix >= <span class="number">0x4036d917 </span>{ |
| p = <span class="kw-2">&</span>PR3; |
| q = <span class="kw-2">&</span>PS3; |
| } <span class="kw">else |
| </span><span class="comment">/*ix >= 0x40000000*/ |
| </span>{ |
| p = <span class="kw-2">&</span>PR2; |
| q = <span class="kw-2">&</span>PS2; |
| } |
| z = <span class="number">1.0 </span>/ (x * x); |
| r = p[<span class="number">0</span>] + z * (p[<span class="number">1</span>] + z * (p[<span class="number">2</span>] + z * (p[<span class="number">3</span>] + z * (p[<span class="number">4</span>] + z * p[<span class="number">5</span>])))); |
| s = <span class="number">1.0 </span>+ z * (q[<span class="number">0</span>] + z * (q[<span class="number">1</span>] + z * (q[<span class="number">2</span>] + z * (q[<span class="number">3</span>] + z * q[<span class="number">4</span>])))); |
| <span class="kw">return </span><span class="number">1.0 </span>+ r / s; |
| } |
| |
| <span class="comment">/* For x >= 8, the asymptotic expansions of qzero is |
| * -1/8 s + 75/1024 s^3 - ..., where s = 1/x. |
| * We approximate pzero by |
| * qzero(x) = s*(-1.25 + (R/S)) |
| * where R = qR0 + qR1*s^2 + qR2*s^4 + ... + qR5*s^10 |
| * S = 1 + qS0*s^2 + ... + qS5*s^12 |
| * and |
| * | qzero(x)/s +1.25-R/S | <= 2 ** ( -61.22) |
| */ |
| </span><span class="kw">const </span>QR8: [f32; <span class="number">6</span>] = [ |
| <span class="comment">/* for x in [inf, 8]=1/[0,0.125] */ |
| </span><span class="number">0.0000000000e+00</span>, <span class="comment">/* 0x00000000 */ |
| </span><span class="number">7.3242187500e-02</span>, <span class="comment">/* 0x3d960000 */ |
| </span><span class="number">1.1768206596e+01</span>, <span class="comment">/* 0x413c4a93 */ |
| </span><span class="number">5.5767340088e+02</span>, <span class="comment">/* 0x440b6b19 */ |
| </span><span class="number">8.8591972656e+03</span>, <span class="comment">/* 0x460a6cca */ |
| </span><span class="number">3.7014625000e+04</span>, <span class="comment">/* 0x471096a0 */ |
| </span>]; |
| <span class="kw">const </span>QS8: [f32; <span class="number">6</span>] = [ |
| <span class="number">1.6377603149e+02</span>, <span class="comment">/* 0x4323c6aa */ |
| </span><span class="number">8.0983447266e+03</span>, <span class="comment">/* 0x45fd12c2 */ |
| </span><span class="number">1.4253829688e+05</span>, <span class="comment">/* 0x480b3293 */ |
| </span><span class="number">8.0330925000e+05</span>, <span class="comment">/* 0x49441ed4 */ |
| </span><span class="number">8.4050156250e+05</span>, <span class="comment">/* 0x494d3359 */ |
| </span>-<span class="number">3.4389928125e+05</span>, <span class="comment">/* 0xc8a7eb69 */ |
| </span>]; |
| |
| <span class="kw">const </span>QR5: [f32; <span class="number">6</span>] = [ |
| <span class="comment">/* for x in [8,4.5454]=1/[0.125,0.22001] */ |
| </span><span class="number">1.8408595828e-11</span>, <span class="comment">/* 0x2da1ec79 */ |
| </span><span class="number">7.3242180049e-02</span>, <span class="comment">/* 0x3d95ffff */ |
| </span><span class="number">5.8356351852e+00</span>, <span class="comment">/* 0x40babd86 */ |
| </span><span class="number">1.3511157227e+02</span>, <span class="comment">/* 0x43071c90 */ |
| </span><span class="number">1.0272437744e+03</span>, <span class="comment">/* 0x448067cd */ |
| </span><span class="number">1.9899779053e+03</span>, <span class="comment">/* 0x44f8bf4b */ |
| </span>]; |
| <span class="kw">const </span>QS5: [f32; <span class="number">6</span>] = [ |
| <span class="number">8.2776611328e+01</span>, <span class="comment">/* 0x42a58da0 */ |
| </span><span class="number">2.0778142090e+03</span>, <span class="comment">/* 0x4501dd07 */ |
| </span><span class="number">1.8847289062e+04</span>, <span class="comment">/* 0x46933e94 */ |
| </span><span class="number">5.6751113281e+04</span>, <span class="comment">/* 0x475daf1d */ |
| </span><span class="number">3.5976753906e+04</span>, <span class="comment">/* 0x470c88c1 */ |
| </span>-<span class="number">5.3543427734e+03</span>, <span class="comment">/* 0xc5a752be */ |
| </span>]; |
| |
| <span class="kw">const </span>QR3: [f32; <span class="number">6</span>] = [ |
| <span class="comment">/* for x in [4.547,2.8571]=1/[0.2199,0.35001] */ |
| </span><span class="number">4.3774099900e-09</span>, <span class="comment">/* 0x3196681b */ |
| </span><span class="number">7.3241114616e-02</span>, <span class="comment">/* 0x3d95ff70 */ |
| </span><span class="number">3.3442313671e+00</span>, <span class="comment">/* 0x405607e3 */ |
| </span><span class="number">4.2621845245e+01</span>, <span class="comment">/* 0x422a7cc5 */ |
| </span><span class="number">1.7080809021e+02</span>, <span class="comment">/* 0x432acedf */ |
| </span><span class="number">1.6673394775e+02</span>, <span class="comment">/* 0x4326bbe4 */ |
| </span>]; |
| <span class="kw">const </span>QS3: [f32; <span class="number">6</span>] = [ |
| <span class="number">4.8758872986e+01</span>, <span class="comment">/* 0x42430916 */ |
| </span><span class="number">7.0968920898e+02</span>, <span class="comment">/* 0x44316c1c */ |
| </span><span class="number">3.7041481934e+03</span>, <span class="comment">/* 0x4567825f */ |
| </span><span class="number">6.4604252930e+03</span>, <span class="comment">/* 0x45c9e367 */ |
| </span><span class="number">2.5163337402e+03</span>, <span class="comment">/* 0x451d4557 */ |
| </span>-<span class="number">1.4924745178e+02</span>, <span class="comment">/* 0xc3153f59 */ |
| </span>]; |
| |
| <span class="kw">const </span>QR2: [f32; <span class="number">6</span>] = [ |
| <span class="comment">/* for x in [2.8570,2]=1/[0.3499,0.5] */ |
| </span><span class="number">1.5044444979e-07</span>, <span class="comment">/* 0x342189db */ |
| </span><span class="number">7.3223426938e-02</span>, <span class="comment">/* 0x3d95f62a */ |
| </span><span class="number">1.9981917143e+00</span>, <span class="comment">/* 0x3fffc4bf */ |
| </span><span class="number">1.4495602608e+01</span>, <span class="comment">/* 0x4167edfd */ |
| </span><span class="number">3.1666231155e+01</span>, <span class="comment">/* 0x41fd5471 */ |
| </span><span class="number">1.6252708435e+01</span>, <span class="comment">/* 0x4182058c */ |
| </span>]; |
| <span class="kw">const </span>QS2: [f32; <span class="number">6</span>] = [ |
| <span class="number">3.0365585327e+01</span>, <span class="comment">/* 0x41f2ecb8 */ |
| </span><span class="number">2.6934811401e+02</span>, <span class="comment">/* 0x4386ac8f */ |
| </span><span class="number">8.4478375244e+02</span>, <span class="comment">/* 0x44533229 */ |
| </span><span class="number">8.8293585205e+02</span>, <span class="comment">/* 0x445cbbe5 */ |
| </span><span class="number">2.1266638184e+02</span>, <span class="comment">/* 0x4354aa98 */ |
| </span>-<span class="number">5.3109550476e+00</span>, <span class="comment">/* 0xc0a9f358 */ |
| </span>]; |
| |
| <span class="kw">fn </span>qzerof(x: f32) -> f32 { |
| <span class="kw">let </span>p: <span class="kw-2">&</span>[f32; <span class="number">6</span>]; |
| <span class="kw">let </span>q: <span class="kw-2">&</span>[f32; <span class="number">6</span>]; |
| <span class="kw">let </span>s: f32; |
| <span class="kw">let </span>r: f32; |
| <span class="kw">let </span>z: f32; |
| <span class="kw">let </span><span class="kw-2">mut </span>ix: u32; |
| |
| ix = x.to_bits(); |
| ix &= <span class="number">0x7fffffff</span>; |
| <span class="kw">if </span>ix >= <span class="number">0x41000000 </span>{ |
| p = <span class="kw-2">&</span>QR8; |
| q = <span class="kw-2">&</span>QS8; |
| } <span class="kw">else if </span>ix >= <span class="number">0x409173eb </span>{ |
| p = <span class="kw-2">&</span>QR5; |
| q = <span class="kw-2">&</span>QS5; |
| } <span class="kw">else if </span>ix >= <span class="number">0x4036d917 </span>{ |
| p = <span class="kw-2">&</span>QR3; |
| q = <span class="kw-2">&</span>QS3; |
| } <span class="kw">else |
| </span><span class="comment">/*ix >= 0x40000000*/ |
| </span>{ |
| p = <span class="kw-2">&</span>QR2; |
| q = <span class="kw-2">&</span>QS2; |
| } |
| z = <span class="number">1.0 </span>/ (x * x); |
| r = p[<span class="number">0</span>] + z * (p[<span class="number">1</span>] + z * (p[<span class="number">2</span>] + z * (p[<span class="number">3</span>] + z * (p[<span class="number">4</span>] + z * p[<span class="number">5</span>])))); |
| s = <span class="number">1.0 </span>+ z * (q[<span class="number">0</span>] + z * (q[<span class="number">1</span>] + z * (q[<span class="number">2</span>] + z * (q[<span class="number">3</span>] + z * (q[<span class="number">4</span>] + z * q[<span class="number">5</span>]))))); |
| <span class="kw">return </span>(-<span class="number">0.125 </span>+ r / s) / x; |
| } |
| </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> |
