1 /* e_atanhf.c -- float version of e_atanh.c.
2 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
6 * ====================================================
7 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
9 * Developed at SunPro, a Sun Microsystems, Inc. business.
10 * Permission to use, copy, modify, and distribute this
11 * software is freely granted, provided that this notice
13 * ====================================================
15 * $NetBSD: e_atanhf.c,v 1.7 2002/05/26 22:01:49 wiz Exp $
16 * $DragonFly: src/lib/libm/src/e_atanhf.c,v 1.1 2005/07/26 21:15:20 joerg Exp $
20 #include "math_private.h"
22 static const float one
= 1.0, huge
= 1e30
;
24 static const float zero
= 0.0;
33 if (ix
>0x3f800000) /* |x|>1 */
37 if(ix
<0x31800000&&(huge
+x
)>zero
) return x
; /* x<2**-28 */
39 if(ix
<0x3f000000) { /* x < 0.5 */
41 t
= (float)0.5*log1pf(t
+t
*x
/(one
-x
));
43 t
= (float)0.5*log1pf((x
+x
)/(one
-x
));
44 if(hx
>=0) return t
; else return -t
;