| <!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/powf.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>powf.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_powf.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>::{fabsf, scalbnf, sqrtf}; |
| |
| <span class="kw">const </span>BP: [f32; <span class="number">2</span>] = [<span class="number">1.0</span>, <span class="number">1.5</span>]; |
| <span class="kw">const </span>DP_H: [f32; <span class="number">2</span>] = [<span class="number">0.0</span>, <span class="number">5.84960938e-01</span>]; <span class="comment">/* 0x3f15c000 */ |
| </span><span class="kw">const </span>DP_L: [f32; <span class="number">2</span>] = [<span class="number">0.0</span>, <span class="number">1.56322085e-06</span>]; <span class="comment">/* 0x35d1cfdc */ |
| </span><span class="kw">const </span>TWO24: f32 = <span class="number">16777216.0</span>; <span class="comment">/* 0x4b800000 */ |
| </span><span class="kw">const </span>HUGE: f32 = <span class="number">1.0e30</span>; |
| <span class="kw">const </span>TINY: f32 = <span class="number">1.0e-30</span>; |
| <span class="kw">const </span>L1: f32 = <span class="number">6.0000002384e-01</span>; <span class="comment">/* 0x3f19999a */ |
| </span><span class="kw">const </span>L2: f32 = <span class="number">4.2857143283e-01</span>; <span class="comment">/* 0x3edb6db7 */ |
| </span><span class="kw">const </span>L3: f32 = <span class="number">3.3333334327e-01</span>; <span class="comment">/* 0x3eaaaaab */ |
| </span><span class="kw">const </span>L4: f32 = <span class="number">2.7272811532e-01</span>; <span class="comment">/* 0x3e8ba305 */ |
| </span><span class="kw">const </span>L5: f32 = <span class="number">2.3066075146e-01</span>; <span class="comment">/* 0x3e6c3255 */ |
| </span><span class="kw">const </span>L6: f32 = <span class="number">2.0697501302e-01</span>; <span class="comment">/* 0x3e53f142 */ |
| </span><span class="kw">const </span>P1: f32 = <span class="number">1.6666667163e-01</span>; <span class="comment">/* 0x3e2aaaab */ |
| </span><span class="kw">const </span>P2: f32 = -<span class="number">2.7777778450e-03</span>; <span class="comment">/* 0xbb360b61 */ |
| </span><span class="kw">const </span>P3: f32 = <span class="number">6.6137559770e-05</span>; <span class="comment">/* 0x388ab355 */ |
| </span><span class="kw">const </span>P4: f32 = -<span class="number">1.6533901999e-06</span>; <span class="comment">/* 0xb5ddea0e */ |
| </span><span class="kw">const </span>P5: f32 = <span class="number">4.1381369442e-08</span>; <span class="comment">/* 0x3331bb4c */ |
| </span><span class="kw">const </span>LG2: f32 = <span class="number">6.9314718246e-01</span>; <span class="comment">/* 0x3f317218 */ |
| </span><span class="kw">const </span>LG2_H: f32 = <span class="number">6.93145752e-01</span>; <span class="comment">/* 0x3f317200 */ |
| </span><span class="kw">const </span>LG2_L: f32 = <span class="number">1.42860654e-06</span>; <span class="comment">/* 0x35bfbe8c */ |
| </span><span class="kw">const </span>OVT: f32 = <span class="number">4.2995665694e-08</span>; <span class="comment">/* -(128-log2(ovfl+.5ulp)) */ |
| </span><span class="kw">const </span>CP: f32 = <span class="number">9.6179670095e-01</span>; <span class="comment">/* 0x3f76384f =2/(3ln2) */ |
| </span><span class="kw">const </span>CP_H: f32 = <span class="number">9.6191406250e-01</span>; <span class="comment">/* 0x3f764000 =12b cp */ |
| </span><span class="kw">const </span>CP_L: f32 = -<span class="number">1.1736857402e-04</span>; <span class="comment">/* 0xb8f623c6 =tail of cp_h */ |
| </span><span class="kw">const </span>IVLN2: f32 = <span class="number">1.4426950216e+00</span>; |
| <span class="kw">const </span>IVLN2_H: f32 = <span class="number">1.4426879883e+00</span>; |
| <span class="kw">const </span>IVLN2_L: f32 = <span class="number">7.0526075433e-06</span>; |
| |
| <span class="attribute">#[cfg_attr(all(test, assert_no_panic), no_panic::no_panic)] |
| </span><span class="kw">pub fn </span>powf(x: f32, y: f32) -> f32 { |
| <span class="kw">let </span><span class="kw-2">mut </span>z: f32; |
| <span class="kw">let </span><span class="kw-2">mut </span>ax: f32; |
| <span class="kw">let </span>z_h: f32; |
| <span class="kw">let </span>z_l: f32; |
| <span class="kw">let </span><span class="kw-2">mut </span>p_h: f32; |
| <span class="kw">let </span><span class="kw-2">mut </span>p_l: f32; |
| <span class="kw">let </span>y1: f32; |
| <span class="kw">let </span><span class="kw-2">mut </span>t1: f32; |
| <span class="kw">let </span>t2: f32; |
| <span class="kw">let </span><span class="kw-2">mut </span>r: f32; |
| <span class="kw">let </span>s: f32; |
| <span class="kw">let </span><span class="kw-2">mut </span>sn: f32; |
| <span class="kw">let </span><span class="kw-2">mut </span>t: f32; |
| <span class="kw">let </span><span class="kw-2">mut </span>u: f32; |
| <span class="kw">let </span><span class="kw-2">mut </span>v: f32; |
| <span class="kw">let </span><span class="kw-2">mut </span>w: f32; |
| <span class="kw">let </span>i: i32; |
| <span class="kw">let </span><span class="kw-2">mut </span>j: i32; |
| <span class="kw">let </span><span class="kw-2">mut </span>k: i32; |
| <span class="kw">let </span><span class="kw-2">mut </span>yisint: i32; |
| <span class="kw">let </span><span class="kw-2">mut </span>n: i32; |
| <span class="kw">let </span>hx: i32; |
| <span class="kw">let </span>hy: i32; |
| <span class="kw">let </span><span class="kw-2">mut </span>ix: i32; |
| <span class="kw">let </span>iy: i32; |
| <span class="kw">let </span><span class="kw-2">mut </span>is: i32; |
| |
| hx = x.to_bits() <span class="kw">as </span>i32; |
| hy = y.to_bits() <span class="kw">as </span>i32; |
| |
| ix = hx & <span class="number">0x7fffffff</span>; |
| iy = hy & <span class="number">0x7fffffff</span>; |
| |
| <span class="comment">/* x**0 = 1, even if x is NaN */ |
| </span><span class="kw">if </span>iy == <span class="number">0 </span>{ |
| <span class="kw">return </span><span class="number">1.0</span>; |
| } |
| |
| <span class="comment">/* 1**y = 1, even if y is NaN */ |
| </span><span class="kw">if </span>hx == <span class="number">0x3f800000 </span>{ |
| <span class="kw">return </span><span class="number">1.0</span>; |
| } |
| |
| <span class="comment">/* NaN if either arg is NaN */ |
| </span><span class="kw">if </span>ix > <span class="number">0x7f800000 </span>|| iy > <span class="number">0x7f800000 </span>{ |
| <span class="kw">return </span>x + y; |
| } |
| |
| <span class="comment">/* determine if y is an odd int when x < 0 |
| * yisint = 0 ... y is not an integer |
| * yisint = 1 ... y is an odd int |
| * yisint = 2 ... y is an even int |
| */ |
| </span>yisint = <span class="number">0</span>; |
| <span class="kw">if </span>hx < <span class="number">0 </span>{ |
| <span class="kw">if </span>iy >= <span class="number">0x4b800000 </span>{ |
| yisint = <span class="number">2</span>; <span class="comment">/* even integer y */ |
| </span>} <span class="kw">else if </span>iy >= <span class="number">0x3f800000 </span>{ |
| k = (iy >> <span class="number">23</span>) - <span class="number">0x7f</span>; <span class="comment">/* exponent */ |
| </span>j = iy >> (<span class="number">23 </span>- k); |
| <span class="kw">if </span>(j << (<span class="number">23 </span>- k)) == iy { |
| yisint = <span class="number">2 </span>- (j & <span class="number">1</span>); |
| } |
| } |
| } |
| |
| <span class="comment">/* special value of y */ |
| </span><span class="kw">if </span>iy == <span class="number">0x7f800000 </span>{ |
| <span class="comment">/* y is +-inf */ |
| </span><span class="kw">if </span>ix == <span class="number">0x3f800000 </span>{ |
| <span class="comment">/* (-1)**+-inf is 1 */ |
| </span><span class="kw">return </span><span class="number">1.0</span>; |
| } <span class="kw">else if </span>ix > <span class="number">0x3f800000 </span>{ |
| <span class="comment">/* (|x|>1)**+-inf = inf,0 */ |
| </span><span class="kw">return if </span>hy >= <span class="number">0 </span>{ y } <span class="kw">else </span>{ <span class="number">0.0 </span>}; |
| } <span class="kw">else </span>{ |
| <span class="comment">/* (|x|<1)**+-inf = 0,inf */ |
| </span><span class="kw">return if </span>hy >= <span class="number">0 </span>{ <span class="number">0.0 </span>} <span class="kw">else </span>{ -y }; |
| } |
| } |
| <span class="kw">if </span>iy == <span class="number">0x3f800000 </span>{ |
| <span class="comment">/* y is +-1 */ |
| </span><span class="kw">return if </span>hy >= <span class="number">0 </span>{ x } <span class="kw">else </span>{ <span class="number">1.0 </span>/ x }; |
| } |
| |
| <span class="kw">if </span>hy == <span class="number">0x40000000 </span>{ |
| <span class="comment">/* y is 2 */ |
| </span><span class="kw">return </span>x * x; |
| } |
| |
| <span class="kw">if </span>hy == <span class="number">0x3f000000 |
| </span><span class="comment">/* y is 0.5 */ |
| </span>&& hx >= <span class="number">0 |
| </span>{ |
| <span class="comment">/* x >= +0 */ |
| </span><span class="kw">return </span>sqrtf(x); |
| } |
| |
| ax = fabsf(x); |
| <span class="comment">/* special value of x */ |
| </span><span class="kw">if </span>ix == <span class="number">0x7f800000 </span>|| ix == <span class="number">0 </span>|| ix == <span class="number">0x3f800000 </span>{ |
| <span class="comment">/* x is +-0,+-inf,+-1 */ |
| </span>z = ax; |
| <span class="kw">if </span>hy < <span class="number">0 </span>{ |
| <span class="comment">/* z = (1/|x|) */ |
| </span>z = <span class="number">1.0 </span>/ z; |
| } |
| |
| <span class="kw">if </span>hx < <span class="number">0 </span>{ |
| <span class="kw">if </span>((ix - <span class="number">0x3f800000</span>) | yisint) == <span class="number">0 </span>{ |
| z = (z - z) / (z - z); <span class="comment">/* (-1)**non-int is NaN */ |
| </span>} <span class="kw">else if </span>yisint == <span class="number">1 </span>{ |
| z = -z; <span class="comment">/* (x<0)**odd = -(|x|**odd) */ |
| </span>} |
| } |
| <span class="kw">return </span>z; |
| } |
| |
| sn = <span class="number">1.0</span>; <span class="comment">/* sign of result */ |
| </span><span class="kw">if </span>hx < <span class="number">0 </span>{ |
| <span class="kw">if </span>yisint == <span class="number">0 </span>{ |
| <span class="comment">/* (x<0)**(non-int) is NaN */ |
| </span><span class="kw">return </span>(x - x) / (x - x); |
| } |
| |
| <span class="kw">if </span>yisint == <span class="number">1 </span>{ |
| <span class="comment">/* (x<0)**(odd int) */ |
| </span>sn = -<span class="number">1.0</span>; |
| } |
| } |
| |
| <span class="comment">/* |y| is HUGE */ |
| </span><span class="kw">if </span>iy > <span class="number">0x4d000000 </span>{ |
| <span class="comment">/* if |y| > 2**27 */ |
| /* over/underflow if x is not close to one */ |
| </span><span class="kw">if </span>ix < <span class="number">0x3f7ffff8 </span>{ |
| <span class="kw">return if </span>hy < <span class="number">0 </span>{ |
| sn * HUGE * HUGE |
| } <span class="kw">else </span>{ |
| sn * TINY * TINY |
| }; |
| } |
| |
| <span class="kw">if </span>ix > <span class="number">0x3f800007 </span>{ |
| <span class="kw">return if </span>hy > <span class="number">0 </span>{ |
| sn * HUGE * HUGE |
| } <span class="kw">else </span>{ |
| sn * TINY * TINY |
| }; |
| } |
| |
| <span class="comment">/* now |1-x| is TINY <= 2**-20, suffice to compute |
| log(x) by x-x^2/2+x^3/3-x^4/4 */ |
| </span>t = ax - <span class="number">1.</span>; <span class="comment">/* t has 20 trailing zeros */ |
| </span>w = (t * t) * (<span class="number">0.5 </span>- t * (<span class="number">0.333333333333 </span>- t * <span class="number">0.25</span>)); |
| u = IVLN2_H * t; <span class="comment">/* IVLN2_H has 16 sig. bits */ |
| </span>v = t * IVLN2_L - w * IVLN2; |
| t1 = u + v; |
| is = t1.to_bits() <span class="kw">as </span>i32; |
| t1 = f32::from_bits(is <span class="kw">as </span>u32 & <span class="number">0xfffff000</span>); |
| t2 = v - (t1 - u); |
| } <span class="kw">else </span>{ |
| <span class="kw">let </span><span class="kw-2">mut </span>s2: f32; |
| <span class="kw">let </span><span class="kw-2">mut </span>s_h: f32; |
| <span class="kw">let </span>s_l: f32; |
| <span class="kw">let </span><span class="kw-2">mut </span>t_h: f32; |
| <span class="kw">let </span><span class="kw-2">mut </span>t_l: f32; |
| |
| n = <span class="number">0</span>; |
| <span class="comment">/* take care subnormal number */ |
| </span><span class="kw">if </span>ix < <span class="number">0x00800000 </span>{ |
| ax <span class="kw-2">*</span>= TWO24; |
| n -= <span class="number">24</span>; |
| ix = ax.to_bits() <span class="kw">as </span>i32; |
| } |
| n += ((ix) >> <span class="number">23</span>) - <span class="number">0x7f</span>; |
| j = ix & <span class="number">0x007fffff</span>; |
| <span class="comment">/* determine interval */ |
| </span>ix = j | <span class="number">0x3f800000</span>; <span class="comment">/* normalize ix */ |
| </span><span class="kw">if </span>j <= <span class="number">0x1cc471 </span>{ |
| <span class="comment">/* |x|<sqrt(3/2) */ |
| </span>k = <span class="number">0</span>; |
| } <span class="kw">else if </span>j < <span class="number">0x5db3d7 </span>{ |
| <span class="comment">/* |x|<sqrt(3) */ |
| </span>k = <span class="number">1</span>; |
| } <span class="kw">else </span>{ |
| k = <span class="number">0</span>; |
| n += <span class="number">1</span>; |
| ix -= <span class="number">0x00800000</span>; |
| } |
| ax = f32::from_bits(ix <span class="kw">as </span>u32); |
| |
| <span class="comment">/* compute s = s_h+s_l = (x-1)/(x+1) or (x-1.5)/(x+1.5) */ |
| </span>u = ax - <span class="macro">i!</span>(BP, k <span class="kw">as </span>usize); <span class="comment">/* bp[0]=1.0, bp[1]=1.5 */ |
| </span>v = <span class="number">1.0 </span>/ (ax + <span class="macro">i!</span>(BP, k <span class="kw">as </span>usize)); |
| s = u * v; |
| s_h = s; |
| is = s_h.to_bits() <span class="kw">as </span>i32; |
| s_h = f32::from_bits(is <span class="kw">as </span>u32 & <span class="number">0xfffff000</span>); |
| <span class="comment">/* t_h=ax+bp[k] High */ |
| </span>is = (((ix <span class="kw">as </span>u32 >> <span class="number">1</span>) & <span class="number">0xfffff000</span>) | <span class="number">0x20000000</span>) <span class="kw">as </span>i32; |
| t_h = f32::from_bits(is <span class="kw">as </span>u32 + <span class="number">0x00400000 </span>+ ((k <span class="kw">as </span>u32) << <span class="number">21</span>)); |
| t_l = ax - (t_h - <span class="macro">i!</span>(BP, k <span class="kw">as </span>usize)); |
| s_l = v * ((u - s_h * t_h) - s_h * t_l); |
| <span class="comment">/* compute log(ax) */ |
| </span>s2 = s * s; |
| r = s2 * s2 * (L1 + s2 * (L2 + s2 * (L3 + s2 * (L4 + s2 * (L5 + s2 * L6))))); |
| r += s_l * (s_h + s); |
| s2 = s_h * s_h; |
| t_h = <span class="number">3.0 </span>+ s2 + r; |
| is = t_h.to_bits() <span class="kw">as </span>i32; |
| t_h = f32::from_bits(is <span class="kw">as </span>u32 & <span class="number">0xfffff000</span>); |
| t_l = r - ((t_h - <span class="number">3.0</span>) - s2); |
| <span class="comment">/* u+v = s*(1+...) */ |
| </span>u = s_h * t_h; |
| v = s_l * t_h + t_l * s; |
| <span class="comment">/* 2/(3log2)*(s+...) */ |
| </span>p_h = u + v; |
| is = p_h.to_bits() <span class="kw">as </span>i32; |
| p_h = f32::from_bits(is <span class="kw">as </span>u32 & <span class="number">0xfffff000</span>); |
| p_l = v - (p_h - u); |
| z_h = CP_H * p_h; <span class="comment">/* cp_h+cp_l = 2/(3*log2) */ |
| </span>z_l = CP_L * p_h + p_l * CP + <span class="macro">i!</span>(DP_L, k <span class="kw">as </span>usize); |
| <span class="comment">/* log2(ax) = (s+..)*2/(3*log2) = n + dp_h + z_h + z_l */ |
| </span>t = n <span class="kw">as </span>f32; |
| t1 = ((z_h + z_l) + <span class="macro">i!</span>(DP_H, k <span class="kw">as </span>usize)) + t; |
| is = t1.to_bits() <span class="kw">as </span>i32; |
| t1 = f32::from_bits(is <span class="kw">as </span>u32 & <span class="number">0xfffff000</span>); |
| t2 = z_l - (((t1 - t) - <span class="macro">i!</span>(DP_H, k <span class="kw">as </span>usize)) - z_h); |
| }; |
| |
| <span class="comment">/* split up y into y1+y2 and compute (y1+y2)*(t1+t2) */ |
| </span>is = y.to_bits() <span class="kw">as </span>i32; |
| y1 = f32::from_bits(is <span class="kw">as </span>u32 & <span class="number">0xfffff000</span>); |
| p_l = (y - y1) * t1 + y * t2; |
| p_h = y1 * t1; |
| z = p_l + p_h; |
| j = z.to_bits() <span class="kw">as </span>i32; |
| <span class="kw">if </span>j > <span class="number">0x43000000 </span>{ |
| <span class="comment">/* if z > 128 */ |
| </span><span class="kw">return </span>sn * HUGE * HUGE; <span class="comment">/* overflow */ |
| </span>} <span class="kw">else if </span>j == <span class="number">0x43000000 </span>{ |
| <span class="comment">/* if z == 128 */ |
| </span><span class="kw">if </span>p_l + OVT > z - p_h { |
| <span class="kw">return </span>sn * HUGE * HUGE; <span class="comment">/* overflow */ |
| </span>} |
| } <span class="kw">else if </span>(j & <span class="number">0x7fffffff</span>) > <span class="number">0x43160000 </span>{ |
| <span class="comment">/* z < -150 */ |
| // FIXME: check should be (uint32_t)j > 0xc3160000 |
| </span><span class="kw">return </span>sn * TINY * TINY; <span class="comment">/* underflow */ |
| </span>} <span class="kw">else if </span>j <span class="kw">as </span>u32 == <span class="number">0xc3160000 |
| </span><span class="comment">/* z == -150 */ |
| </span>&& p_l <= z - p_h |
| { |
| <span class="kw">return </span>sn * TINY * TINY; <span class="comment">/* underflow */ |
| </span>} |
| |
| <span class="comment">/* |
| * compute 2**(p_h+p_l) |
| */ |
| </span>i = j & <span class="number">0x7fffffff</span>; |
| k = (i >> <span class="number">23</span>) - <span class="number">0x7f</span>; |
| n = <span class="number">0</span>; |
| <span class="kw">if </span>i > <span class="number">0x3f000000 </span>{ |
| <span class="comment">/* if |z| > 0.5, set n = [z+0.5] */ |
| </span>n = j + (<span class="number">0x00800000 </span>>> (k + <span class="number">1</span>)); |
| k = ((n & <span class="number">0x7fffffff</span>) >> <span class="number">23</span>) - <span class="number">0x7f</span>; <span class="comment">/* new k for n */ |
| </span>t = f32::from_bits(n <span class="kw">as </span>u32 & !(<span class="number">0x007fffff </span>>> k)); |
| n = ((n & <span class="number">0x007fffff</span>) | <span class="number">0x00800000</span>) >> (<span class="number">23 </span>- k); |
| <span class="kw">if </span>j < <span class="number">0 </span>{ |
| n = -n; |
| } |
| p_h -= t; |
| } |
| t = p_l + p_h; |
| is = t.to_bits() <span class="kw">as </span>i32; |
| t = f32::from_bits(is <span class="kw">as </span>u32 & <span class="number">0xffff8000</span>); |
| u = t * LG2_H; |
| v = (p_l - (t - p_h)) * LG2 + t * LG2_L; |
| z = u + v; |
| w = v - (z - u); |
| t = z * z; |
| t1 = z - t * (P1 + t * (P2 + t * (P3 + t * (P4 + t * P5)))); |
| r = (z * t1) / (t1 - <span class="number">2.0</span>) - (w + z * w); |
| z = <span class="number">1.0 </span>- (r - z); |
| j = z.to_bits() <span class="kw">as </span>i32; |
| j += n << <span class="number">23</span>; |
| <span class="kw">if </span>(j >> <span class="number">23</span>) <= <span class="number">0 </span>{ |
| <span class="comment">/* subnormal output */ |
| </span>z = scalbnf(z, n); |
| } <span class="kw">else </span>{ |
| z = f32::from_bits(j <span class="kw">as </span>u32); |
| } |
| sn * z |
| } |
| </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> |
