82 lines
2.2 KiB
C
82 lines
2.2 KiB
C
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/* Return arc tangent of complex __float128 value.
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Copyright (C) 1997, 1998 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C 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 GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, write to the Free
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Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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02111-1307 USA. */
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#include "quadmath-imp.h"
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__complex128
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catanq (__complex128 x)
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{
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__complex128 res;
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int rcls = fpclassifyq (__real__ x);
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int icls = fpclassifyq (__imag__ x);
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if (rcls <= QUADFP_INFINITE || icls <= QUADFP_INFINITE)
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{
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if (rcls == QUADFP_INFINITE)
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{
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__real__ res = copysignq (M_PI_2q, __real__ x);
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__imag__ res = copysignq (0.0, __imag__ x);
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}
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else if (icls == QUADFP_INFINITE)
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{
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if (rcls >= QUADFP_ZERO)
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__real__ res = copysignq (M_PI_2q, __real__ x);
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else
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__real__ res = nanq ("");
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__imag__ res = copysignq (0.0, __imag__ x);
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}
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else if (icls == QUADFP_ZERO || icls == QUADFP_INFINITE)
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{
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__real__ res = nanq ("");
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__imag__ res = copysignq (0.0, __imag__ x);
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}
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else
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{
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__real__ res = nanq ("");
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__imag__ res = nanq ("");
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}
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}
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else if (rcls == QUADFP_ZERO && icls == QUADFP_ZERO)
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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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__float128 r2, num, den;
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r2 = __real__ x * __real__ x;
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den = 1 - r2 - __imag__ x * __imag__ x;
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__real__ res = 0.5 * atan2q (2.0 * __real__ x, den);
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num = __imag__ x + 1.0;
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num = r2 + num * num;
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den = __imag__ x - 1.0;
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den = r2 + den * den;
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__imag__ res = 0.25 * logq (num / den);
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}
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return res;
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}
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