diff options
Diffstat (limited to 'libm/src/e_atanhf.c')
-rw-r--r-- | libm/src/e_atanhf.c | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/libm/src/e_atanhf.c b/libm/src/e_atanhf.c new file mode 100644 index 0000000..64ebd3d --- /dev/null +++ b/libm/src/e_atanhf.c @@ -0,0 +1,46 @@ +/* e_atanhf.c -- float version of e_atanh.c. + * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. + */ + +/* + * ==================================================== + * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. + * + * Developed at SunPro, a Sun Microsystems, Inc. business. + * Permission to use, copy, modify, and distribute this + * software is freely granted, provided that this notice + * is preserved. + * ==================================================== + */ + +#ifndef lint +static char rcsid[] = "$FreeBSD: src/lib/msun/src/e_atanhf.c,v 1.6 2002/05/28 17:03:12 alfred Exp $"; +#endif + +#include "math.h" +#include "math_private.h" + +static const float one = 1.0, huge = 1e30; + +static const float zero = 0.0; + +float +__ieee754_atanhf(float x) +{ + float t; + int32_t hx,ix; + GET_FLOAT_WORD(hx,x); + ix = hx&0x7fffffff; + if (ix>0x3f800000) /* |x|>1 */ + return (x-x)/(x-x); + if(ix==0x3f800000) + return x/zero; + if(ix<0x31800000&&(huge+x)>zero) return x; /* x<2**-28 */ + SET_FLOAT_WORD(x,ix); + if(ix<0x3f000000) { /* x < 0.5 */ + t = x+x; + t = (float)0.5*log1pf(t+t*x/(one-x)); + } else + t = (float)0.5*log1pf((x+x)/(one-x)); + if(hx>=0) return t; else return -t; +} |