--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libquadmath/math/coshq.c	Sun Aug 21 07:07:55 2011 +0900
@@ -0,0 +1,108 @@
+/*
+ * ====================================================
+ * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
+ *
+ * Developed at SunPro, a Sun Microsystems, Inc. business.
+ * Permission to use, copy, modify, and distribute this
+ * software is freely granted, provided that this notice
+ * is preserved.
+ * ====================================================
+ */
+
+/* Changes for 128-bit __float128 are
+   Copyright (C) 2001 Stephen L. Moshier <moshier@na-net.ornl.gov>
+   and are incorporated herein by permission of the author.  The author 
+   reserves the right to distribute this material elsewhere under different
+   copying permissions.  These modifications are distributed here under 
+   the following terms:
+
+    This 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.
+
+    This 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 this library; if not, write to the Free Software
+    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307  USA */
+
+/* __ieee754_coshl(x)
+ * Method :
+ * mathematically coshl(x) if defined to be (exp(x)+exp(-x))/2
+ *      1. Replace x by |x| (coshl(x) = coshl(-x)).
+ *      2.
+ *                                                      [ exp(x) - 1 ]^2
+ *          0        <= x <= ln2/2  :  coshl(x) := 1 + -------------------
+ *                                                         2*exp(x)
+ *
+ *                                                 exp(x) +  1/exp(x)
+ *          ln2/2    <= x <= 22     :  coshl(x) := -------------------
+ *                                                         2
+ *          22       <= x <= lnovft :  coshl(x) := expl(x)/2
+ *          lnovft   <= x <= ln2ovft:  coshl(x) := expl(x/2)/2 * expl(x/2)
+ *          ln2ovft  <  x           :  coshl(x) := huge*huge (overflow)
+ *
+ * Special cases:
+ *      coshl(x) is |x| if x is +INF, -INF, or NaN.
+ *      only coshl(0)=1 is exact for finite x.
+ */
+
+#include "quadmath-imp.h"
+
+static const __float128 one = 1.0Q, half = 0.5Q, huge = 1.0e4900Q,
+  ovf_thresh = 1.1357216553474703894801348310092223067821E4Q;
+
+__float128
+coshq (__float128 x)
+{
+  __float128 t, w;
+  int32_t ex;
+  ieee854_float128 u;
+
+  u.value = x;
+  ex = u.words32.w0 & 0x7fffffff;
+
+  /* Absolute value of x.  */
+  u.words32.w0 = ex;
+
+  /* x is INF or NaN */
+  if (ex >= 0x7fff0000)
+    return x * x;
+
+  /* |x| in [0,0.5*ln2], return 1+expm1l(|x|)^2/(2*expl(|x|)) */
+  if (ex < 0x3ffd62e4) /* 0.3465728759765625 */
+    {
+      t = expm1q (u.value);
+      w = one + t;
+      if (ex < 0x3fb80000) /* |x| < 2^-116 */
+	return w;		/* cosh(tiny) = 1 */
+
+      return one + (t * t) / (w + w);
+    }
+
+  /* |x| in [0.5*ln2,40], return (exp(|x|)+1/exp(|x|)/2; */
+  if (ex < 0x40044000)
+    {
+      t = expq (u.value);
+      return half * t + half / t;
+    }
+
+  /* |x| in [22, ln(maxdouble)] return half*exp(|x|) */
+  if (ex <= 0x400c62e3) /* 11356.375 */
+    return half * expq (u.value);
+
+  /* |x| in [log(maxdouble), overflowthresold] */
+  if (u.value <= ovf_thresh)
+    {
+      w = expq (half * u.value);
+      t = half * w;
+      return t * w;
+    }
+
+  /* |x| > overflowthresold, cosh(x) overflow */
+  return huge * huge;
+}