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-rw-r--r--libquadmath/math/catanq.c81
1 files changed, 81 insertions, 0 deletions
diff --git a/libquadmath/math/catanq.c b/libquadmath/math/catanq.c
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+++ b/libquadmath/math/catanq.c
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+/* Return arc tangent of complex __float128 value.
+ Copyright (C) 1997, 1998 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+
+#include "quadmath-imp.h"
+
+
+__complex128
+catanq (__complex128 x)
+{
+ __complex128 res;
+ int rcls = fpclassifyq (__real__ x);
+ int icls = fpclassifyq (__imag__ x);
+
+ if (rcls <= QUADFP_INFINITE || icls <= QUADFP_INFINITE)
+ {
+ if (rcls == QUADFP_INFINITE)
+ {
+ __real__ res = copysignq (M_PI_2q, __real__ x);
+ __imag__ res = copysignq (0.0, __imag__ x);
+ }
+ else if (icls == QUADFP_INFINITE)
+ {
+ if (rcls >= QUADFP_ZERO)
+ __real__ res = copysignq (M_PI_2q, __real__ x);
+ else
+ __real__ res = nanq ("");
+ __imag__ res = copysignq (0.0, __imag__ x);
+ }
+ else if (icls == QUADFP_ZERO || icls == QUADFP_INFINITE)
+ {
+ __real__ res = nanq ("");
+ __imag__ res = copysignq (0.0, __imag__ x);
+ }
+ else
+ {
+ __real__ res = nanq ("");
+ __imag__ res = nanq ("");
+ }
+ }
+ else if (rcls == QUADFP_ZERO && icls == QUADFP_ZERO)
+ {
+ res = x;
+ }
+ else
+ {
+ __float128 r2, num, den;
+
+ r2 = __real__ x * __real__ x;
+
+ den = 1 - r2 - __imag__ x * __imag__ x;
+
+ __real__ res = 0.5 * atan2q (2.0 * __real__ x, den);
+
+ num = __imag__ x + 1.0;
+ num = r2 + num * num;
+
+ den = __imag__ x - 1.0;
+ den = r2 + den * den;
+
+ __imag__ res = 0.25 * logq (num / den);
+ }
+
+ return res;
+}