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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)
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2.5-18.1
Diffstat (limited to 'math/s_cacoshf.c')
-rw-r--r--math/s_cacoshf.c108
1 files changed, 108 insertions, 0 deletions
diff --git a/math/s_cacoshf.c b/math/s_cacoshf.c
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+++ 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