RTAI API: base/math/w_atanh.c Source File

00001 /* @(#)w_atanh.c 5.1 93/09/24 */
00002 /*
00003  * ====================================================
00004  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
00005  *
00006  * Developed at SunPro, a Sun Microsystems, Inc. business.
00007  * Permission to use, copy, modify, and distribute this
00008  * software is freely granted, provided that this notice 
00009  * is preserved.
00010  * ====================================================
00011  */
00012 
00013 #if defined(LIBM_SCCS) && !defined(lint)
00014 static char rcsid[] = "$NetBSD: w_atanh.c,v 1.6 1995/05/10 20:48:43 jtc Exp $";
00015 #endif
00016 
00017 /* 
00018  * wrapper atanh(x)
00019  */
00020 
00021 #include "math.h"
00022 #include "mathP.h"
00023 
00024 
00025 #ifdef __STDC__
00026     double atanh(double x)      /* wrapper atanh */
00027 #else
00028     double atanh(x)         /* wrapper atanh */
00029     double x;
00030 #endif
00031 {
00032 #ifdef _IEEE_LIBM
00033     return __ieee754_atanh(x);
00034 #else
00035     double z,y;
00036     z = __ieee754_atanh(x);
00037     if(_LIB_VERSION == _IEEE_ || isnan(x)) return z;
00038     y = fabs(x);
00039     if(y>=1.0) {
00040         if(y>1.0)
00041             return __kernel_standard(x,x,30); /* atanh(|x|>1) */
00042         else 
00043             return __kernel_standard(x,x,31); /* atanh(|x|==1) */
00044     } else
00045         return z;
00046 #endif
00047 }