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author | Ulrich Drepper <drepper@redhat.com> | 1999-07-14 00:54:57 +0000 |
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committer | Ulrich Drepper <drepper@redhat.com> | 1999-07-14 00:54:57 +0000 |
commit | abfbdde177c3a7155070dda1b2cdc8292054cc26 (patch) | |
tree | e021306b596381fbf8311d2b7eb294e918ff17c8 /sysdeps/ieee754/ldbl-96/e_atanhl.c | |
parent | 86421aa57ecfd70963ae66848bd6a6dd3b8e0fe6 (diff) | |
download | glibc-abfbdde177c3a7155070dda1b2cdc8292054cc26.tar.gz glibc-abfbdde177c3a7155070dda1b2cdc8292054cc26.tar.xz glibc-abfbdde177c3a7155070dda1b2cdc8292054cc26.zip |
Update.
Diffstat (limited to 'sysdeps/ieee754/ldbl-96/e_atanhl.c')
-rw-r--r-- | sysdeps/ieee754/ldbl-96/e_atanhl.c | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/sysdeps/ieee754/ldbl-96/e_atanhl.c b/sysdeps/ieee754/ldbl-96/e_atanhl.c new file mode 100644 index 0000000000..fdcd1e9fe8 --- /dev/null +++ b/sysdeps/ieee754/ldbl-96/e_atanhl.c @@ -0,0 +1,79 @@ +/* s_atanhl.c -- long double version of s_atan.c. + * Conversion to long double by Ulrich Drepper, + * Cygnus Support, drepper@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. + * ==================================================== + */ + +#if defined(LIBM_SCCS) && !defined(lint) +static char rcsid[] = "$NetBSD: $"; +#endif + +/* __ieee754_atanhl(x) + * Method : + * 1.Reduced x to positive by atanh(-x) = -atanh(x) + * 2.For x>=0.5 + * 1 2x x + * atanhl(x) = --- * log(1 + -------) = 0.5 * log1p(2 * --------) + * 2 1 - x 1 - x + * + * For x<0.5 + * atanhl(x) = 0.5*log1pl(2x+2x*x/(1-x)) + * + * Special cases: + * atanhl(x) is NaN if |x| > 1 with signal; + * atanhl(NaN) is that NaN with no signal; + * atanhl(+-1) is +-INF with signal. + * + */ + +#include "math.h" +#include "math_private.h" + +#ifdef __STDC__ +static const long double one = 1.0, huge = 1e4900L; +#else +static long double one = 1.0, huge = 1e4900L; +#endif + +#ifdef __STDC__ +static const long double zero = 0.0; +#else +static double long zero = 0.0; +#endif + +#ifdef __STDC__ + long double __ieee754_atanhl(long double x) +#else + long double __ieee754_atanhl(x) + long double x; +#endif +{ + long double t; + int32_t ix; + u_int32_t se,i0,i1; + GET_LDOUBLE_WORDS(se,i0,i1,x); + ix = se&0x7fff; + if ((ix+((((i0&0x7fffffff)|i1)|(-((i0&0x7fffffff)|i1)))>>31))>0x3fff) + /* |x|>1 */ + return (x-x)/(x-x); + if(ix==0x3fff) + return x/zero; + if(ix<0x3fe3&&(huge+x)>zero) return x; /* x<2**-28 */ + SET_LDOUBLE_EXP(x,ix); + if(ix<0x3ffe) { /* x < 0.5 */ + t = x+x; + t = 0.5*__log1pl(t+t*x/(one-x)); + } else + t = 0.5*__log1pl((x+x)/(one-x)); + if(se<=0x7fff) return t; else return -t; +} |