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authorJakub Jelinek <jakub@redhat.com>2007-07-12 18:26:36 +0000
committerJakub Jelinek <jakub@redhat.com>2007-07-12 18:26:36 +0000
commit0ecb606cb6cf65de1d9fc8a919bceb4be476c602 (patch)
tree2ea1f8305970753e4a657acb2ccc15ca3eec8e2c /math/s_cacoshf.c
parent7d58530341304d403a6626d7f7a1913165fe2f32 (diff)
downloadglibc-0ecb606cb6cf65de1d9fc8a919bceb4be476c602.tar.gz
2.5-18.1
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1 files changed, 108 insertions, 0 deletions
diff --git a/math/s_cacoshf.c b/math/s_cacoshf.c
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+/* Return arc hyperbole cosine for float value.
+ Copyright (C) 1997, 2006 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 <complex.h>
+#include <math.h>
+
+#include "math_private.h"
+
+__complex__ float
+__cacoshf (__complex__ float x)
+{
+ __complex__ float res;
+ int rcls = fpclassify (__real__ x);
+ int icls = fpclassify (__imag__ x);
+
+ if (rcls <= FP_INFINITE || icls <= FP_INFINITE)
+ {
+ if (icls == FP_INFINITE)
+ {
+ __real__ res = HUGE_VALF;
+
+ if (rcls == FP_NAN)
+ __imag__ res = __nanf ("");
+ else
+ __imag__ res = __copysignf ((rcls == FP_INFINITE
+ ? (__real__ x < 0.0
+ ? M_PI - M_PI_4 : M_PI_4)
+ : M_PI_2), __imag__ x);
+ }
+ else if (rcls == FP_INFINITE)
+ {
+ __real__ res = HUGE_VALF;
+
+ if (icls >= FP_ZERO)
+ __imag__ res = __copysignf (signbit (__real__ x) ? M_PI : 0.0,
+ __imag__ x);
+ else
+ __imag__ res = __nanf ("");
+ }
+ else
+ {
+ __real__ res = __nanf ("");
+ __imag__ res = __nanf ("");
+ }
+ }
+ else if (rcls == FP_ZERO && icls == FP_ZERO)
+ {
+ __real__ res = 0.0;
+ __imag__ res = __copysignf (M_PI_2, __imag__ x);
+ }
+ else
+ {
+#if 1
+ __complex__ float y;
+
+ __real__ y = (__real__ x - __imag__ x) * (__real__ x + __imag__ x) - 1.0;
+ __imag__ y = 2.0 * __real__ x * __imag__ x;
+
+ y = __csqrtf (y);
+
+ if (__real__ x < 0.0)
+ y = -y;
+
+ __real__ y += __real__ x;
+ __imag__ y += __imag__ x;
+
+ res = __clogf (y);
+#else
+ float re2 = __real__ x * __real__ x;
+ float im2 = __imag__ x * __imag__ x;
+ float sq = re2 - im2 - 1.0;
+ float ro = __ieee754_sqrtf (sq * sq + 4 * re2 * im2);
+ float a = __ieee754_sqrtf ((sq + ro) / 2.0);
+ float b = __ieee754_sqrtf ((-sq + ro) / 2.0);
+
+ __real__ res = 0.5 * __ieee754_logf (re2 + __real__ x * 2 * a
+ + im2 + __imag__ x * 2 * b
+ + ro);
+ __imag__ res = __ieee754_atan2f (__imag__ x + b, __real__ x + a);
+#endif
+
+ /* We have to use the positive branch. */
+ if (__real__ res < 0.0)
+ res = -res;
+ }
+
+ return res;
+}
+#ifndef __cacoshf
+weak_alias (__cacoshf, cacoshf)
+#endif