1 /* e_atanhf.c -- float version of e_atanh.c.
2 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
4 * $FreeBSD: src/lib/msun/src/e_atanhf.c,v 1.5 1999/08/28 00:06:29 peter Exp $
5 * $DragonFly: src/lib/msun/src/Attic/e_atanhf.c,v 1.2 2003/06/17 04:26:52 dillon Exp $
9 * ====================================================
10 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
12 * Developed at SunPro, a Sun Microsystems, Inc. business.
13 * Permission to use, copy, modify, and distribute this
14 * software is freely granted, provided that this notice
16 * ====================================================
20 #include "math_private.h"
23 static const float one = 1.0, huge = 1e30;
25 static float one = 1.0, huge = 1e30;
29 static const float zero = 0.0;
31 static float zero = 0.0;
35 float __ieee754_atanhf(float x)
37 float __ieee754_atanhf(x)
45 if (ix>0x3f800000) /* |x|>1 */
49 if(ix<0x31800000&&(huge+x)>zero) return x; /* x<2**-28 */
51 if(ix<0x3f000000) { /* x < 0.5 */
53 t = (float)0.5*log1pf(t+t*x/(one-x));
55 t = (float)0.5*log1pf((x+x)/(one-x));
56 if(hx>=0) return t; else return -t;