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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_cexp.c
parent7d58530341304d403a6626d7f7a1913165fe2f32 (diff)
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2.5-18.1
Diffstat (limited to 'math/s_cexp.c')
-rw-r--r--math/s_cexp.c127
1 files changed, 127 insertions, 0 deletions
diff --git a/math/s_cexp.c b/math/s_cexp.c
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+++ b/math/s_cexp.c
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+/* Return value of complex exponential function for double complex value.
+   Copyright (C) 1997 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 <fenv.h>
+#include <math.h>
+
+#include "math_private.h"
+
+
+__complex__ double
+__cexp (__complex__ double x)
+{
+  __complex__ double retval;
+  int rcls = fpclassify (__real__ x);
+  int icls = fpclassify (__imag__ x);
+
+  if (rcls >= FP_ZERO)
+    {
+      /* Real part is finite.  */
+      if (icls >= FP_ZERO)
+	{
+	  /* Imaginary part is finite.  */
+	  double exp_val = __ieee754_exp (__real__ x);
+	  double sinix, cosix;
+
+	  __sincos (__imag__ x, &sinix, &cosix);
+
+	  if (isfinite (exp_val))
+	    {
+	      __real__ retval = exp_val * cosix;
+	      __imag__ retval = exp_val * sinix;
+	    }
+	  else
+	    {
+	      __real__ retval = __copysign (exp_val, cosix);
+	      __imag__ retval = __copysign (exp_val, sinix);
+	    }
+	}
+      else
+	{
+	  /* If the imaginary part is +-inf or NaN and the real part
+	     is not +-inf the result is NaN + iNaN.  */
+	  __real__ retval = __nan ("");
+	  __imag__ retval = __nan ("");
+
+#ifdef FE_INVALID
+	  feraiseexcept (FE_INVALID);
+#endif
+	}
+    }
+  else if (rcls == FP_INFINITE)
+    {
+      /* Real part is infinite.  */
+      if (icls >= FP_ZERO)
+	{
+	  /* Imaginary part is finite.  */
+	  double value = signbit (__real__ x) ? 0.0 : HUGE_VAL;
+
+	  if (icls == FP_ZERO)
+	    {
+	      /* Imaginary part is 0.0.  */
+	      __real__ retval = value;
+	      __imag__ retval = __imag__ x;
+	    }
+	  else
+	    {
+	      double sinix, cosix;
+
+	      __sincos (__imag__ x, &sinix, &cosix);
+
+	      __real__ retval = __copysign (value, cosix);
+	      __imag__ retval = __copysign (value, sinix);
+	    }
+	}
+      else if (signbit (__real__ x) == 0)
+	{
+	  __real__ retval = HUGE_VAL;
+	  __imag__ retval = __nan ("");
+
+#ifdef FE_INVALID
+	  if (icls == FP_INFINITE)
+	    feraiseexcept (FE_INVALID);
+#endif
+	}
+      else
+	{
+	  __real__ retval = 0.0;
+	  __imag__ retval = __copysign (0.0, __imag__ x);
+	}
+    }
+  else
+    {
+      /* If the real part is NaN the result is NaN + iNaN.  */
+      __real__ retval = __nan ("");
+      __imag__ retval = __nan ("");
+
+#ifdef FE_INVALID
+      if (rcls != FP_NAN || icls != FP_NAN)
+	feraiseexcept (FE_INVALID);
+#endif
+    }
+
+  return retval;
+}
+weak_alias (__cexp, cexp)
+#ifdef NO_LONG_DOUBLE
+strong_alias (__cexp, __cexpl)
+weak_alias (__cexp, cexpl)
+#endif