1/* w_jnl.c -- long double version of w_jn.c.
2 * Conversion to long double by Ulrich Drepper,
3 * Cygnus Support, drepper@cygnus.com.
4 */
5
6/*
7 * ====================================================
8 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
9 *
10 * Developed at SunPro, a Sun Microsystems, Inc. business.
11 * Permission to use, copy, modify, and distribute this
12 * software is freely granted, provided that this notice
13 * is preserved.
14 * ====================================================
15 */
16
17#if defined(LIBM_SCCS) && !defined(lint)
18static char rcsid[] = "$NetBSD: $";
19#endif
20
21/*
22 * wrapper jn(int n, double x), yn(int n, double x)
23 * floating point Bessel's function of the 1st and 2nd kind
24 * of order n
25 *
26 * Special cases:
27 * y0(0)=y1(0)=yn(n,0) = -inf with division by zero signal;
28 * y0(-ve)=y1(-ve)=yn(n,-ve) are NaN with invalid signal.
29 * Note 2. About jn(n,x), yn(n,x)
30 * For n=0, j0(x) is called,
31 * for n=1, j1(x) is called,
32 * for n<x, forward recursion us used starting
33 * from values of j0(x) and j1(x).
34 * for n>x, a continued fraction approximation to
35 * j(n,x)/j(n-1,x) is evaluated and then backward
36 * recursion is used starting from a supposed value
37 * for j(n,x). The resulting value of j(0,x) is
38 * compared with the actual value to correct the
39 * supposed value of j(n,x).
40 *
41 * yn(n,x) is similar in all respects, except
42 * that forward recursion is used for all
43 * values of n>1.
44 *
45 */
46
47#include <math.h>
48#include <math_private.h>
49#include <math-svid-compat.h>
50#include <libm-alias-ldouble.h>
51
52#if LIBM_SVID_COMPAT
53long double __jnl(int n, long double x) /* wrapper jnl */
54{
55# ifdef _IEEE_LIBM
56 return __ieee754_jnl(n,x);
57# else
58 long double z;
59 z = __ieee754_jnl(n,x);
60 if (_LIB_VERSION == _IEEE_
61 || _LIB_VERSION == _POSIX_
62 || isnan(x))
63 return z;
64 if(fabsl(x)>X_TLOSS) {
65 return __kernel_standard_l((double)n,x,238); /* jn(|x|>X_TLOSS,n) */
66 } else
67 return z;
68# endif
69}
70libm_alias_ldouble (__jn, jn)
71
72long double __ynl(int n, long double x) /* wrapper ynl */
73{
74# ifdef _IEEE_LIBM
75 return __ieee754_ynl(n,x);
76# else
77 long double z;
78 z = __ieee754_ynl(n,x);
79 if(_LIB_VERSION == _IEEE_ || isnan(x) ) return z;
80 if(x <= 0.0){
81 if(x==0.0)
82 /* d= -one/(x-x); */
83 return __kernel_standard_l((double)n,x,212);
84 else
85 /* d = zero/(x-x); */
86 return __kernel_standard_l((double)n,x,213);
87 }
88 if(x>X_TLOSS && _LIB_VERSION != _POSIX_) {
89 return __kernel_standard_l((double)n,x,239); /* yn(x>X_TLOSS,n) */
90 } else
91 return z;
92# endif
93}
94libm_alias_ldouble (__yn, yn)
95#endif
96