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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/libm-ieee754/s_tanh.c | |
parent | 86421aa57ecfd70963ae66848bd6a6dd3b8e0fe6 (diff) | |
download | glibc-abfbdde177c3a7155070dda1b2cdc8292054cc26.zip glibc-abfbdde177c3a7155070dda1b2cdc8292054cc26.tar.gz glibc-abfbdde177c3a7155070dda1b2cdc8292054cc26.tar.bz2 |
Update.
Diffstat (limited to 'sysdeps/libm-ieee754/s_tanh.c')
-rw-r--r-- | sysdeps/libm-ieee754/s_tanh.c | 93 |
1 files changed, 0 insertions, 93 deletions
diff --git a/sysdeps/libm-ieee754/s_tanh.c b/sysdeps/libm-ieee754/s_tanh.c deleted file mode 100644 index 944f963..0000000 --- a/sysdeps/libm-ieee754/s_tanh.c +++ /dev/null @@ -1,93 +0,0 @@ -/* @(#)s_tanh.c 5.1 93/09/24 */ -/* - * ==================================================== - * 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: s_tanh.c,v 1.7 1995/05/10 20:48:22 jtc Exp $"; -#endif - -/* Tanh(x) - * Return the Hyperbolic Tangent of x - * - * Method : - * x -x - * e - e - * 0. tanh(x) is defined to be ----------- - * x -x - * e + e - * 1. reduce x to non-negative by tanh(-x) = -tanh(x). - * 2. 0 <= x <= 2**-55 : tanh(x) := x*(one+x) - * -t - * 2**-55 < x <= 1 : tanh(x) := -----; t = expm1(-2x) - * t + 2 - * 2 - * 1 <= x <= 22.0 : tanh(x) := 1- ----- ; t=expm1(2x) - * t + 2 - * 22.0 < x <= INF : tanh(x) := 1. - * - * Special cases: - * tanh(NaN) is NaN; - * only tanh(0)=0 is exact for finite argument. - */ - -#include "math.h" -#include "math_private.h" - -#ifdef __STDC__ -static const double one=1.0, two=2.0, tiny = 1.0e-300; -#else -static double one=1.0, two=2.0, tiny = 1.0e-300; -#endif - -#ifdef __STDC__ - double __tanh(double x) -#else - double __tanh(x) - double x; -#endif -{ - double t,z; - int32_t jx,ix,lx; - - /* High word of |x|. */ - EXTRACT_WORDS(jx,lx,x); - ix = jx&0x7fffffff; - - /* x is INF or NaN */ - if(ix>=0x7ff00000) { - if (jx>=0) return one/x+one; /* tanh(+-inf)=+-1 */ - else return one/x-one; /* tanh(NaN) = NaN */ - } - - /* |x| < 22 */ - if (ix < 0x40360000) { /* |x|<22 */ - if ((ix | lx) == 0) - return x; /* x == +-0 */ - if (ix<0x3c800000) /* |x|<2**-55 */ - return x*(one+x); /* tanh(small) = small */ - if (ix>=0x3ff00000) { /* |x|>=1 */ - t = __expm1(two*fabs(x)); - z = one - two/(t+two); - } else { - t = __expm1(-two*fabs(x)); - z= -t/(t+two); - } - /* |x| > 22, return +-1 */ - } else { - z = one - tiny; /* raised inexact flag */ - } - return (jx>=0)? z: -z; -} -weak_alias (__tanh, tanh) -#ifdef NO_LONG_DOUBLE -strong_alias (__tanh, __tanhl) -weak_alias (__tanh, tanhl) -#endif |