diff options
Diffstat (limited to 'math/w_jn.c')
| -rw-r--r-- | math/w_jn.c | 127 |
1 files changed, 46 insertions, 81 deletions
diff --git a/math/w_jn.c b/math/w_jn.c index 41ec8b3..36fb448 100644 --- a/math/w_jn.c +++ b/math/w_jn.c @@ -1,98 +1,63 @@ -/* @(#)w_jn.c 5.1 93/09/24 */ -/* - * ==================================================== - * 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. - * ==================================================== - */ +/* Copyright (C) 2011 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Ulrich Drepper <drepper@gmail.com>, 2011. -#if defined(LIBM_SCCS) && !defined(lint) -static char rcsid[] = "$NetBSD: w_jn.c,v 1.6 1995/05/10 20:49:19 jtc Exp $"; -#endif + The GNU C 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. + + The GNU C 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. -/* - * wrapper jn(int n, double x), yn(int n, double x) - * floating point Bessel's function of the 1st and 2nd kind - * of order n - * - * Special cases: - * y0(0)=y1(0)=yn(n,0) = -inf with division by zero signal; - * y0(-ve)=y1(-ve)=yn(n,-ve) are NaN with invalid signal. - * Note 2. About jn(n,x), yn(n,x) - * For n=0, j0(x) is called, - * for n=1, j1(x) is called, - * for n<x, forward recursion us used starting - * from values of j0(x) and j1(x). - * for n>x, a continued fraction approximation to - * j(n,x)/j(n-1,x) is evaluated and then backward - * recursion is used starting from a supposed value - * for j(n,x). The resulting value of j(0,x) is - * compared with the actual value to correct the - * supposed value of j(n,x). - * - * yn(n,x) is similar in all respects, except - * that forward recursion is used for all - * values of n>1. - * - */ + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ +#include <fenv.h> #include <math.h> #include <math_private.h> -#ifdef __STDC__ - double jn(int n, double x) /* wrapper jn */ -#else - double jn(n,x) /* wrapper jn */ - double x; int n; -#endif + +/* wrapper jn */ +double +jn (int n, double x) { -#ifdef _IEEE_LIBM - return __ieee754_jn(n,x); -#else - double z; - z = __ieee754_jn(n,x); - if(_LIB_VERSION == _IEEE_ || __isnan(x) ) return z; - if(fabs(x)>X_TLOSS) { - return __kernel_standard((double)n,x,38); /* jn(|x|>X_TLOSS,n) */ - } else - return z; -#endif + if (__builtin_expect (fabs (x) > X_TLOSS, 0) && _LIB_VERSION != _IEEE_) + /* jn(n,|x|>X_TLOSS) */ + return __kernel_standard (n, x, 38); + + return __ieee754_jn (n, x); } #ifdef NO_LONG_DOUBLE strong_alias (jn, jnl) #endif -#ifdef __STDC__ - double yn(int n, double x) /* wrapper yn */ -#else - double yn(n,x) /* wrapper yn */ - double x; int n; -#endif +/* wrapper yn */ +double +yn (int n, double x) { -#ifdef _IEEE_LIBM - return __ieee754_yn(n,x); -#else - double z; - z = __ieee754_yn(n,x); - if(_LIB_VERSION == _IEEE_ || __isnan(x) ) return z; - if(x <= 0.0){ - if(x==0.0) - /* d= -one/(x-x); */ - return __kernel_standard((double)n,x,12); - else - /* d = zero/(x-x); */ - return __kernel_standard((double)n,x,13); - } - if(x>X_TLOSS) { - return __kernel_standard((double)n,x,39); /* yn(x>X_TLOSS,n) */ - } else - return z; -#endif + if (__builtin_expect (x <= 0.0 || x > X_TLOSS, 0) && _LIB_VERSION != _IEEE_) + { + if (x < 0.0) + { + /* d = zero/(x-x) */ + feraiseexcept (FE_INVALID); + return __kernel_standard (n, x, 13); + } + else if (x == 0.0) + /* d = -one/(x-x) */ + return __kernel_standard (n, x, 12); + else + /* yn(n,x>X_TLOSS) */ + return __kernel_standard (n, x, 39); + } + + return __ieee754_yn (n, x); } #ifdef NO_LONG_DOUBLE strong_alias (yn, ynl) |