mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-22 19:00:07 +00:00
f7eac6eb50
* Makeconfig ($(common-objpfx)config.make): Depend on config.h.in. Mon Mar 4 17:35:09 1996 Roland McGrath <roland@charlie-brown.gnu.ai.mit.edu> * hurd/catch-signal.c (hurd_safe_memmove): New function. (hurd_safe_copyin, hurd_safe_copyout): New functions. * hurd/hurd/sigpreempt.h: Declare them. Sun Mar 3 08:43:44 1996 Roland McGrath <roland@charlie-brown.gnu.ai.mit.edu> Replace math code with fdlibm from Sun as modified for netbsd by JT Conklin and Ian Taylor, including x86 FPU support. * sysdeps/libm-ieee754, sysdeps/libm-i387: New directories. * math/math_private.h: New file. * sysdeps/i386/fpu/Implies: New file. * sysdeps/ieee754/Implies: New file. * math/machine/asm.h, math/machine/endian.h: New files. * math/Makefile, math/math.h: Rewritten. * mathcalls.h, math/mathcalls.h: New file, broken out of math.h. * math/finite.c: File removed. * sysdeps/generic/Makefile [$(subdir)=math]: Frobnication removed. * math/test-math.c: Include errno.h and string.h. * sysdeps/unix/bsd/dirstream.h: File removed. * sysdeps/unix/bsd/readdir.c: File removed.
75 lines
1.8 KiB
C
75 lines
1.8 KiB
C
/* @(#)e_atanh.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: e_atanh.c,v 1.8 1995/05/10 20:44:55 jtc Exp $";
|
|
#endif
|
|
|
|
/* __ieee754_atanh(x)
|
|
* Method :
|
|
* 1.Reduced x to positive by atanh(-x) = -atanh(x)
|
|
* 2.For x>=0.5
|
|
* 1 2x x
|
|
* atanh(x) = --- * log(1 + -------) = 0.5 * log1p(2 * --------)
|
|
* 2 1 - x 1 - x
|
|
*
|
|
* For x<0.5
|
|
* atanh(x) = 0.5*log1p(2x+2x*x/(1-x))
|
|
*
|
|
* Special cases:
|
|
* atanh(x) is NaN if |x| > 1 with signal;
|
|
* atanh(NaN) is that NaN with no signal;
|
|
* atanh(+-1) is +-INF with signal.
|
|
*
|
|
*/
|
|
|
|
#include "math.h"
|
|
#include "math_private.h"
|
|
|
|
#ifdef __STDC__
|
|
static const double one = 1.0, huge = 1e300;
|
|
#else
|
|
static double one = 1.0, huge = 1e300;
|
|
#endif
|
|
|
|
#ifdef __STDC__
|
|
static const double zero = 0.0;
|
|
#else
|
|
static double zero = 0.0;
|
|
#endif
|
|
|
|
#ifdef __STDC__
|
|
double __ieee754_atanh(double x)
|
|
#else
|
|
double __ieee754_atanh(x)
|
|
double x;
|
|
#endif
|
|
{
|
|
double t;
|
|
int32_t hx,ix;
|
|
u_int32_t lx;
|
|
EXTRACT_WORDS(hx,lx,x);
|
|
ix = hx&0x7fffffff;
|
|
if ((ix|((lx|(-lx))>>31))>0x3ff00000) /* |x|>1 */
|
|
return (x-x)/(x-x);
|
|
if(ix==0x3ff00000)
|
|
return x/zero;
|
|
if(ix<0x3e300000&&(huge+x)>zero) return x; /* x<2**-28 */
|
|
SET_HIGH_WORD(x,ix);
|
|
if(ix<0x3fe00000) { /* x < 0.5 */
|
|
t = x+x;
|
|
t = 0.5*__log1p(t+t*x/(one-x));
|
|
} else
|
|
t = 0.5*__log1p((x+x)/(one-x));
|
|
if(hx>=0) return t; else return -t;
|
|
}
|