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https://github.com/jart/cosmopolitan.git
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66 lines
3.5 KiB
C
66 lines
3.5 KiB
C
/*-*- mode:c;indent-tabs-mode:t;c-basic-offset:8;tab-width:8;coding:utf-8 -*-│
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│vi: set et ft=c ts=8 tw=8 fenc=utf-8 :vi│
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╚──────────────────────────────────────────────────────────────────────────────╝
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│ │
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│ Musl Libc │
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│ Copyright © 2005-2014 Rich Felker, et al. │
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│ │
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│ Permission is hereby granted, free of charge, to any person obtaining │
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│ a copy of this software and associated documentation files (the │
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│ "Software"), to deal in the Software without restriction, including │
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│ without limitation the rights to use, copy, modify, merge, publish, │
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│ distribute, sublicense, and/or sell copies of the Software, and to │
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│ permit persons to whom the Software is furnished to do so, subject to │
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│ the following conditions: │
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│ │
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│ The above copyright notice and this permission notice shall be │
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│ included in all copies or substantial portions of the Software. │
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│ │
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│ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, │
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│ EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF │
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│ MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. │
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│ IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY │
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│ CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, │
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│ TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE │
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│ SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. │
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│ │
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╚─────────────────────────────────────────────────────────────────────────────*/
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#include "libc/math.h"
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#include "libc/tinymath/feval.internal.h"
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#include "libc/tinymath/ldshape.internal.h"
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asm(".ident\t\"\\n\\n\
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Musl libc (MIT License)\\n\
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Copyright 2005-2014 Rich Felker, et. al.\"");
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asm(".include \"libc/disclaimer.inc\"");
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/* clang-format off */
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/**
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* Returns inverse hyperbolic sine of 𝑥.
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* @define asinh(x) = sign(x)*log(|x|+sqrt(x*x+1)) ~= x - x^3/6 + o(x^5)
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*/
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long double asinhl(long double x)
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{
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union ldshape u = {x};
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unsigned e = u.i.se & 0x7fff;
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unsigned s = u.i.se >> 15;
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/* |x| */
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u.i.se = e;
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x = u.f;
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if (e >= 0x3fff + 32) {
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/* |x| >= 0x1p32 or inf or nan */
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x = logl(x) + 0.693147180559945309417232121458176568L;
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} else if (e >= 0x3fff + 1) {
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/* |x| >= 2 */
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x = logl(2*x + 1/(sqrtl(x*x+1)+x));
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} else if (e >= 0x3fff - 32) {
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/* |x| >= 0x1p-32 */
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x = log1pl(x + x*x/(sqrtl(x*x+1)+1));
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} else {
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/* |x| < 0x1p-32, raise inexact if x!=0 */
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fevall(x + 0x1p120f);
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}
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return s ? -x : x;
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}
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