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 #ifndef lint 14 static char rcsid[] = "$Id: w_atanh.c,v 1.3 1994/02/18 02:27:16 jtc Exp $"; 15 #endif 16 17 /* 18 * wrapper atanh(x) 19 */ 20 21 #include <math.h> 22 23 24 #ifdef __STDC__ 25 double atanh(double x) /* wrapper atanh */ 26 #else 27 double atanh(x) /* wrapper atanh */ 28 double x; 29 #endif 30 { 31 #ifdef _IEEE_LIBM 32 return __ieee754_atanh(x); 33 #else 34 double z,y; 35 z = __ieee754_atanh(x); 36 if(_LIB_VERSION == _IEEE_ || isnan(x)) return z; 37 y = fabs(x); 38 if(y>=1.0) { 39 if(y>1.0) 40 return __kernel_standard(x,x,30); /* atanh(|x|>1) */ 41 else 42 return __kernel_standard(x,x,31); /* atanh(|x|==1) */ 43 } else 44 return z; 45 #endif 46 } 47