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2fc507c98f
* modelines: tw -> sw shiftwidth, not textwidth. * space-surround modelines * fix irregular modelines * Fix modeline in titlegen.c
112 lines
4.7 KiB
C
112 lines
4.7 KiB
C
/*-*- mode:c;indent-tabs-mode:t;c-basic-offset:8;tab-width:8;coding:utf-8 -*-│
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│ vi: set noet ft=c ts=8 sw=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/internal.h"
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#include "libc/tinymath/invtrigl.internal.h"
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#include "libc/tinymath/ldshape.internal.h"
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#if !(LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024)
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asm(".ident\t\"\\n\\n\
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fdlibm (fdlibm license)\\n\
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Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.\"");
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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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/* origin: FreeBSD /usr/src/lib/msun/src/e_asinl.c */
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/*
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* ====================================================
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* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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*
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* Developed at SunSoft, a Sun Microsystems, Inc. business.
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* Permission to use, copy, modify, and distribute this
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* software is freely granted, provided that this notice
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* is preserved.
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* ====================================================
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*/
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/*
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* See comments in asin.c.
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* Converted to long double by David Schultz <das@FreeBSD.ORG>.
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*/
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#if LDBL_MANT_DIG == 64
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#define CLOSETO1(u) (u.i.m>>56 >= 0xf7)
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#define CLEARBOTTOM(u) (u.i.m &= -1ULL << 32)
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#elif LDBL_MANT_DIG == 113
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#define CLOSETO1(u) (u.i.top >= 0xee00)
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#define CLEARBOTTOM(u) (u.i.lo = 0)
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#endif
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/**
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* Returns arc sine of 𝑥.
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*
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* @define atan2(𝑥,sqrt((1-𝑥)*(1+𝑥)))
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* @domain -1 ≤ 𝑥 ≤ 1
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*/
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long double asinl(long double x)
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{
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union ldshape u = {x};
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long double z, r, s;
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uint16_t e = u.i.se & 0x7fff;
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int sign = u.i.se >> 15;
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if (e >= 0x3fff) { /* |x| >= 1 or nan */
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/* asin(+-1)=+-pi/2 with inexact */
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if (x == 1 || x == -1)
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return x*pio2_hi + 0x1p-120f;
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return 0/(x-x);
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}
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if (e < 0x3fff - 1) { /* |x| < 0.5 */
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if (e < 0x3fff - (LDBL_MANT_DIG+1)/2) {
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/* return x with inexact if x!=0 */
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FORCE_EVAL(x + 0x1p120f);
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return x;
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}
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return x + x*__invtrigl_R(x*x);
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}
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/* 1 > |x| >= 0.5 */
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z = (1.0 - fabsl(x))*0.5;
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s = sqrtl(z);
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r = __invtrigl_R(z);
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if (CLOSETO1(u)) {
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x = pio2_hi - (2*(s+s*r)-pio2_lo);
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} else {
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long double f, c;
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u.f = s;
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CLEARBOTTOM(u);
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f = u.f;
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c = (z - f*f)/(s + f);
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x = 0.5*pio2_hi-(2*s*r - (pio2_lo-2*c) - (0.5*pio2_hi-2*f));
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}
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return sign ? -x : x;
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}
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#endif /* long double is long */
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