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)
18 static 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
50 #if !defined __NO_LONG_DOUBLE_MATH
51 # ifndef __DO_XSI_MATH__
52 long double
jnl(int n,long double x)53 jnl(int n, long double x) /* wrapper jnl */
54 {
55 # if defined(__UCLIBC_HAS_FENV__)
56 long double z;
57 z = (long double) __ieee754_jn(n, (double) x);
58 if (_LIB_VERSION == _IEEE_
59 || _LIB_VERSION == _POSIX_
60 || isnan(x))
61 return z;
62 if(fabsl(x)>X_TLOSS) {
63 return __kernel_standard_l((double)n,x,238); /* jn(|x|>X_TLOSS,n) */
64 } else
65 return z;
66 # else
67 return (long double) __ieee754_jn(n, (double) x);
68 # endif /* __UCLIBC_HAS_FENV__ */
69 }
70
71 long double
ynl(int n,long double x)72 ynl(int n, long double x) /* wrapper ynl */
73 {
74 # if defined(__UCLIBC_HAS_FENV__)
75 long double z;
76 z = (long double) __ieee754_yn(n,(double) x);
77 if(_LIB_VERSION == _IEEE_ || isnan(x) ) return z;
78 if(x <= 0.0){
79 if(x==0.0)
80 /* d= -one/(x-x); */
81 return __kernel_standard_l((double)n,x,212);
82 else
83 /* d = zero/(x-x); */
84 return __kernel_standard_l((double)n,x,213);
85 }
86 if(x>X_TLOSS && _LIB_VERSION != _POSIX_) {
87 return __kernel_standard_l((double)n,x,239); /* yn(x>X_TLOSS,n) */
88 } else
89 return z;
90 # else
91 return (long double) __ieee754_yn(n,(double) x);
92 # endif /* __UCLIBC_HAS_FENV__ */
93 }
94 # endif /* __DO_XSI_MATH__ */
95 #endif /* __NO_LONG_DOUBLE_MATH */
96