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+/*
+ * ====================================================
+ * 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.
+ * ====================================================
+ */
+
+/*
+  Long double expansions 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, see
+    <http://www.gnu.org/licenses/>.  */
+
+/* __ieee754_asin(x)
+ * Method :
+ *	Since  asin(x) = x + x^3/6 + x^5*3/40 + x^7*15/336 + ...
+ *	we approximate asin(x) on [0,0.5] by
+ *		asin(x) = x + x*x^2*R(x^2)
+ *
+ *	For x in [0.5,1]
+ *		asin(x) = pi/2-2*asin(sqrt((1-x)/2))
+ *	Let y = (1-x), z = y/2, s := sqrt(z), and pio2_hi+pio2_lo=pi/2;
+ *	then for x>0.98
+ *		asin(x) = pi/2 - 2*(s+s*z*R(z))
+ *			= pio2_hi - (2*(s+s*z*R(z)) - pio2_lo)
+ *	For x<=0.98, let pio4_hi = pio2_hi/2, then
+ *		f = hi part of s;
+ *		c = sqrt(z) - f = (z-f*f)/(s+f)		...f+c=sqrt(z)
+ *	and
+ *		asin(x) = pi/2 - 2*(s+s*z*R(z))
+ *			= pio4_hi+(pio4-2s)-(2s*z*R(z)-pio2_lo)
+ *			= pio4_hi+(pio4-2f)-(2s*z*R(z)-(pio2_lo+2c))
+ *
+ * Special cases:
+ *	if x is NaN, return x itself;
+ *	if |x|>1, return NaN with invalid signal.
+ *
+ */
+
+
+#include <float.h>
+#include <math.h>
+#include <math_private.h>
+
+static const long double
+  one = 1.0L,
+  huge = 1.0e+4932L,
+  pio2_hi = 0x1.921fb54442d1846ap+0L, /* pi/2 rounded to nearest to 64
+					 bits.  */
+  pio2_lo = -0x7.6733ae8fe47c65d8p-68L, /* pi/2 - pio2_hi rounded to
+					   nearest to 64 bits.  */
+  pio4_hi = 0xc.90fdaa22168c235p-4L, /* pi/4 rounded to nearest to 64
+					bits.  */
+
+	/* coefficient for R(x^2) */
+
+  /* asin(x) = x + x^3 pS(x^2) / qS(x^2)
+     0 <= x <= 0.5
+     peak relative error 1.9e-21  */
+  pS0 =  -1.008714657938491626019651170502036851607E1L,
+  pS1 =   2.331460313214179572063441834101394865259E1L,
+  pS2 =  -1.863169762159016144159202387315381830227E1L,
+  pS3 =   5.930399351579141771077475766877674661747E0L,
+  pS4 =  -6.121291917696920296944056882932695185001E-1L,
+  pS5 =   3.776934006243367487161248678019350338383E-3L,
+
+  qS0 =  -6.052287947630949712886794360635592886517E1L,
+  qS1 =   1.671229145571899593737596543114258558503E2L,
+  qS2 =  -1.707840117062586426144397688315411324388E2L,
+  qS3 =   7.870295154902110425886636075950077640623E1L,
+  qS4 =  -1.568433562487314651121702982333303458814E1L;
+    /* 1.000000000000000000000000000000000000000E0 */
+
+long double
+__ieee754_asinl (long double x)
+{
+  long double t, w, p, q, c, r, s;
+  int32_t ix;
+  u_int32_t se, i0, i1, k;
+
+  GET_LDOUBLE_WORDS (se, i0, i1, x);
+  ix = se & 0x7fff;
+  ix = (ix << 16) | (i0 >> 16);
+  if (ix >= 0x3fff8000)
+    {				/* |x|>= 1 */
+      if (ix == 0x3fff8000 && ((i0 - 0x80000000) | i1) == 0)
+	/* asin(1)=+-pi/2 with inexact */
+	return x * pio2_hi + x * pio2_lo;
+      return (x - x) / (x - x);	/* asin(|x|>1) is NaN */
+    }
+  else if (ix < 0x3ffe8000)
+    {				/* |x|<0.5 */
+      if (ix < 0x3fde8000)
+	{			/* if |x| < 2**-33 */
+	  math_check_force_underflow (x);
+	  if (huge + x > one)
+	    return x;		/* return x with inexact if x!=0 */
+	}
+      else
+	{
+	  t = x * x;
+	  p =
+	    t * (pS0 +
+		 t * (pS1 + t * (pS2 + t * (pS3 + t * (pS4 + t * pS5)))));
+	  q = qS0 + t * (qS1 + t * (qS2 + t * (qS3 + t * (qS4 + t))));
+	  w = p / q;
+	  return x + x * w;
+	}
+    }
+  /* 1> |x|>= 0.5 */
+  w = one - fabsl (x);
+  t = w * 0.5;
+  p = t * (pS0 + t * (pS1 + t * (pS2 + t * (pS3 + t * (pS4 + t * pS5)))));
+  q = qS0 + t * (qS1 + t * (qS2 + t * (qS3 + t * (qS4 + t))));
+  s = __ieee754_sqrtl (t);
+  if (ix >= 0x3ffef999)
+    {				/* if |x| > 0.975 */
+      w = p / q;
+      t = pio2_hi - (2.0 * (s + s * w) - pio2_lo);
+    }
+  else
+    {
+      GET_LDOUBLE_WORDS (k, i0, i1, s);
+      i1 = 0;
+      SET_LDOUBLE_WORDS (w,k,i0,i1);
+      c = (t - w * w) / (s + w);
+      r = p / q;
+      p = 2.0 * s * r - (pio2_lo - 2.0 * c);
+      q = pio4_hi - 2.0 * w;
+      t = pio4_hi - (p - q);
+    }
+  if ((se & 0x8000) == 0)
+    return t;
+  else
+    return -t;
+}
+strong_alias (__ieee754_asinl, __asinl_finite)