POK
atanh.c
1 /*
2  * POK header
3  *
4  * The following file is a part of the POK project. Any modification should
5  * made according to the POK licence. You CANNOT use this file or a part of
6  * this file is this part of a file for your own project
7  *
8  * For more information on the POK licence, please see our LICENCE FILE
9  *
10  * Please follow the coding guidelines described in doc/CODING_GUIDELINES
11  *
12  * Copyright (c) 2007-2009 POK team
13  *
14  * Created by julien on Fri Jan 30 14:41:34 2009
15  */
16 
17 /* @(#)w_atanh.c 5.1 93/09/24 */
18 /*
19  * ====================================================
20  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
21  *
22  * Developed at SunPro, a Sun Microsystems, Inc. business.
23  * Permission to use, copy, modify, and distribute this
24  * software is freely granted, provided that this notice
25  * is preserved.
26  * ====================================================
27  */
28 
29 #ifdef POK_NEEDS_LIBMATH
30 
31 /*
32  * wrapper atanh(x)
33  */
34 
35 #include <libm.h>
36 #include "math_private.h"
37 
38 
39 double
40 atanh(double x) /* wrapper atanh */
41 {
42 #ifdef _IEEE_LIBM
43  return __ieee754_atanh(x);
44 #else
45  double z,y;
46  z = __ieee754_atanh(x);
47  if(_LIB_VERSION == _IEEE_ || isnan(x)) return z;
48  y = fabs(x);
49  if(y>=1.0) {
50  if(y>1.0)
51  return __kernel_standard(x,x,30); /* atanh(|x|>1) */
52  else
53  return __kernel_standard(x,x,31); /* atanh(|x|==1) */
54  } else
55  return z;
56 #endif
57 }
58 
59 #endif