b2dad0e372
2000-04-21 Benjamin Kosnik <bkoz@redhat.com> * libstdc++-v3: New directory. From-SVN: r33317
71 lines
2.1 KiB
C
71 lines
2.1 KiB
C
/* Complex tangent function for double. */
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/* Copyright (C) 1997-1999 Free Software Foundation, Inc.
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This file is part of the GNU ISO C++ Library. This library is free
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software; you can redistribute it and/or modify it under the
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terms of the GNU General Public License as published by the
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Free Software Foundation; either version 2, or (at your option)
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any later version.
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This library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License along
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with this library; see the file COPYING. If not, write to the Free
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Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
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USA.
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As a special exception, you may use this file as part of a free software
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library without restriction. Specifically, if other files instantiate
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templates or use macros or inline functions from this file, or you compile
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this file and link it with other files to produce an executable, this
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file does not by itself cause the resulting executable to be covered by
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the GNU General Public License. This exception does not however
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invalidate any other reasons why the executable file might be covered by
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the GNU General Public License. */
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#include <math.h>
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#include "mathconf.h"
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__complex__ double
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ctan (__complex__ double x)
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{
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__complex__ double res;
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if (!FINITE_P (__real__ x) || !FINITE_P (__imag__ x))
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{
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if (INFINITE_P (__imag__ x))
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{
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__real__ res = copysign (0.0, __real__ x);
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__imag__ res = copysign (1.0, __imag__ x);
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}
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else if (__real__ x == 0.0)
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{
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res = x;
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}
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else
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{
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__real__ res = NAN;
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__imag__ res = NAN;
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}
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}
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else
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{
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double sin2rx = sin (2.0 * __real__ x);
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double cos2rx = cos (2.0 * __real__ x);
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double den;
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den = cos2rx + cosh (2.0 * __imag__ x);
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__real__ res = sin2rx / den;
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__imag__ res = sinh (2.0 * __imag__ x) / den;
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}
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return res;
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}
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