2.5-18.1

1 files changed, 114 insertions, 0 deletions

diff --git a/math/s_csqrt.c b/math/s_csqrt.c
new file mode 100644
index 0000000..04ed410
--- /dev/null
+++ b/math/s_csqrt.c
@@ -0,0 +1,114 @@
+/* Complex square root of double value.
+   Copyright (C) 1997, 1998, 2005 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Based on an algorithm by Stephen L. Moshier <moshier@world.std.com>.
+   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__ double
+__csqrt (__complex__ double x)
+{
+  __complex__ double 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_VAL;
+	  __imag__ res = __imag__ x;
+	}
+      else if (rcls == FP_INFINITE)
+	{
+	  if (__real__ x < 0.0)
+	    {
+	      __real__ res = icls == FP_NAN ? __nan ("") : 0;
+	      __imag__ res = __copysign (HUGE_VAL, __imag__ x);
+	    }
+	  else
+	    {
+	      __real__ res = __real__ x;
+	      __imag__ res = (icls == FP_NAN
+			      ? __nan ("") : __copysign (0.0, __imag__ x));
+	    }
+	}
+      else
+	{
+	  __real__ res = __nan ("");
+	  __imag__ res = __nan ("");
+	}
+    }
+  else
+    {
+      if (icls == FP_ZERO)
+	{
+	  if (__real__ x < 0.0)
+	    {
+	      __real__ res = 0.0;
+	      __imag__ res = __copysign (__ieee754_sqrt (-__real__ x),
+					 __imag__ x);
+	    }
+	  else
+	    {
+	      __real__ res = fabs (__ieee754_sqrt (__real__ x));
+	      __imag__ res = __copysign (0.0, __imag__ x);
+	    }
+	}
+      else if (rcls == FP_ZERO)
+	{
+	  double r = __ieee754_sqrt (0.5 * fabs (__imag__ x));
+
+	  __real__ res = r;
+	  __imag__ res = __copysign (r, __imag__ x);
+	}
+      else
+	{
+	  double d, r, s;
+
+	  d = __ieee754_hypot (__real__ x, __imag__ x);
+	  /* Use the identity   2  Re res  Im res = Im x
+	     to avoid cancellation error in  d +/- Re x.  */
+	  if (__real__ x > 0)
+	    {
+	      r = __ieee754_sqrt (0.5 * d + 0.5 * __real__ x);
+	      s = (0.5 * __imag__ x) / r;
+	    }
+	  else
+	    {
+	      s = __ieee754_sqrt (0.5 * d - 0.5 * __real__ x);
+	      r = fabs ((0.5 * __imag__ x) / s);
+	    }
+
+	  __real__ res = r;
+	  __imag__ res = __copysign (s, __imag__ x);
+	}
+    }
+
+  return res;
+}
+weak_alias (__csqrt, csqrt)
+#ifdef NO_LONG_DOUBLE
+strong_alias (__csqrt, __csqrtl)
+weak_alias (__csqrt, csqrtl)
+#endif