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120 lines
5.6 KiB
C
120 lines
5.6 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/complex.h"
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#include "libc/math.h"
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#include "libc/tinymath/complex.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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/* origin: FreeBSD /usr/src/lib/msun/src/s_cexp.c */
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/*-
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* Copyright (c) 2011 David Schultz <das@FreeBSD.ORG>
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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static const uint32_t
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exp_ovfl = 0x40862e42, /* high bits of MAX_EXP * ln2 ~= 710 */
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cexp_ovfl = 0x4096b8e4; /* (MAX_EXP - MIN_DENORM_EXP) * ln2 */
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double complex cexp(double complex z)
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{
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double x, y, exp_x;
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uint32_t hx, hy, lx, ly;
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x = creal(z);
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y = cimag(z);
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EXTRACT_WORDS(hy, ly, y);
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hy &= 0x7fffffff;
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/* cexp(x + I 0) = exp(x) + I 0 */
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if ((hy | ly) == 0)
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return CMPLX(exp(x), y);
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EXTRACT_WORDS(hx, lx, x);
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/* cexp(0 + I y) = cos(y) + I sin(y) */
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if (((hx & 0x7fffffff) | lx) == 0)
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return CMPLX(cos(y), sin(y));
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if (hy >= 0x7ff00000) {
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if (lx != 0 || (hx & 0x7fffffff) != 0x7ff00000) {
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/* cexp(finite|NaN +- I Inf|NaN) = NaN + I NaN */
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return CMPLX(y - y, y - y);
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} else if (hx & 0x80000000) {
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/* cexp(-Inf +- I Inf|NaN) = 0 + I 0 */
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return CMPLX(0.0, 0.0);
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} else {
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/* cexp(+Inf +- I Inf|NaN) = Inf + I NaN */
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return CMPLX(x, y - y);
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}
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}
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if (hx >= exp_ovfl && hx <= cexp_ovfl) {
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/*
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* x is between 709.7 and 1454.3, so we must scale to avoid
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* overflow in exp(x).
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*/
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return __ldexp_cexp(z, 0);
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} else {
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/*
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* Cases covered here:
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* - x < exp_ovfl and exp(x) won't overflow (common case)
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* - x > cexp_ovfl, so exp(x) * s overflows for all s > 0
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* - x = +-Inf (generated by exp())
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* - x = NaN (spurious inexact exception from y)
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*/
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exp_x = exp(x);
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return CMPLX(exp_x * cos(y), exp_x * sin(y));
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}
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}
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