1 /* @(#)w_atanh.c 5.1 93/09/24 */ 2 /* 3 * ==================================================== 4 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. 5 * 6 * Developed at SunPro, a Sun Microsystems, Inc. business. 7 * Permission to use, copy, modify, and distribute this 8 * software is freely granted, provided that this notice 9 * is preserved. 10 * ==================================================== 11 */ 12 13 #if defined(LIBM_SCCS) && !defined(lint) 14 static char rcsid[] = "$Id: w_atanh.c,v 1.5 1994/09/22 16:45:27 jtc Exp $"; 15 #endif 16 17 /* 18 * wrapper atanh(x) 19 */ 20 21 #include "math.h" 22 #include "math_private.h" 23 24 25 #ifdef __STDC__ 26 double atanh(double x) /* wrapper atanh */ 27 #else 28 double atanh(x) /* wrapper atanh */ 29 double x; 30 #endif 31 { 32 #ifdef _IEEE_LIBM 33 return __ieee754_atanh(x); 34 #else 35 double z,y; 36 z = __ieee754_atanh(x); 37 if(_LIB_VERSION == _IEEE_ || isnan(x)) return z; 38 y = fabs(x); 39 if(y>=1.0) { 40 if(y>1.0) 41 return __kernel_standard(x,x,30); /* atanh(|x|>1) */ 42 else 43 return __kernel_standard(x,x,31); /* atanh(|x|==1) */ 44 } else 45 return z; 46 #endif 47 } 48