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-rw-r--r--libquadmath/math/ctanhq.c120
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diff --git a/libquadmath/math/ctanhq.c b/libquadmath/math/ctanhq.c
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+/* Complex hyperbole tangent for __float128.
+ Copyright (C) 1997-2012 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, see
+ <http://www.gnu.org/licenses/>. */
+
+#include "quadmath-imp.h"
+
+#ifdef HAVE_FENV_H
+# include <fenv.h>
+#endif
+
+
+__complex128
+ctanhq (__complex128 x)
+{
+ __complex128 res;
+
+ if (__builtin_expect (!finiteq (__real__ x) || !finiteq (__imag__ x), 0))
+ {
+ if (__quadmath_isinf_nsq (__real__ x))
+ {
+ __real__ res = copysignq (1.0Q, __real__ x);
+ __imag__ res = copysignq (0.0Q, __imag__ x);
+ }
+ else if (__imag__ x == 0.0Q)
+ {
+ res = x;
+ }
+ else
+ {
+ __real__ res = nanq ("");
+ __imag__ res = nanq ("");
+
+#ifdef HAVE_FENV_H
+ if (__quadmath_isinf_nsq (__imag__ x))
+ feraiseexcept (FE_INVALID);
+#endif
+ }
+ }
+ else
+ {
+ __float128 sinix, cosix;
+ __float128 den;
+ const int t = (int) ((FLT128_MAX_EXP - 1) * M_LN2q / 2);
+ int icls = fpclassifyq (__imag__ x);
+
+ /* tanh(x+iy) = (sinh(2x) + i*sin(2y))/(cosh(2x) + cos(2y))
+ = (sinh(x)*cosh(x) + i*sin(y)*cos(y))/(sinh(x)^2 + cos(y)^2). */
+
+ if (__builtin_expect (icls != QUADFP_SUBNORMAL, 1))
+ {
+ sincosq (__imag__ x, &sinix, &cosix);
+ }
+ else
+ {
+ sinix = __imag__ x;
+ cosix = 1.0Q;
+ }
+
+ if (fabsq (__real__ x) > t)
+ {
+ /* Avoid intermediate overflow when the imaginary part of
+ the result may be subnormal. Ignoring negligible terms,
+ the real part is +/- 1, the imaginary part is
+ sin(y)*cos(y)/sinh(x)^2 = 4*sin(y)*cos(y)/exp(2x). */
+ __float128 exp_2t = expq (2 * t);
+
+ __real__ res = copysignq (1.0, __real__ x);
+ __imag__ res = 4 * sinix * cosix;
+ __real__ x = fabsq (__real__ x);
+ __real__ x -= t;
+ __imag__ res /= exp_2t;
+ if (__real__ x > t)
+ {
+ /* Underflow (original real part of x has absolute value
+ > 2t). */
+ __imag__ res /= exp_2t;
+ }
+ else
+ __imag__ res /= expq (2 * __real__ x);
+ }
+ else
+ {
+ __float128 sinhrx, coshrx;
+ if (fabsq (__real__ x) > FLT128_MIN)
+ {
+ sinhrx = sinhq (__real__ x);
+ coshrx = coshq (__real__ x);
+ }
+ else
+ {
+ sinhrx = __real__ x;
+ coshrx = 1.0Q;
+ }
+
+ if (fabsq (sinhrx) > fabsq (cosix) * FLT128_EPSILON)
+ den = sinhrx * sinhrx + cosix * cosix;
+ else
+ den = cosix * cosix;
+ __real__ res = sinhrx * coshrx / den;
+ __imag__ res = sinix * cosix / den;
+ }
+ }
+
+ return res;
+}