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* 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 */
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/*
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* ====================================================
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* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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*
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* Developed at SunPro, a Sun Microsystems, Inc. business.
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* Permission to use, copy, modify, and distribute this
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* software is freely granted, provided that this notice
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* is preserved.
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* ====================================================
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*/
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#if defined(LIBM_SCCS) && !defined(lint)
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static char rcsid[] = "$NetBSD: e_atanh.c,v 1.8 1995/05/10 20:44:55 jtc Exp $";
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#endif
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/* __ieee754_atanh(x)
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* Method :
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* 1.Reduced x to positive by atanh(-x) = -atanh(x)
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* 2.For x>=0.5
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* 1 2x x
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* atanh(x) = --- * log(1 + -------) = 0.5 * log1p(2 * --------)
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* 2 1 - x 1 - x
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*
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* For x<0.5
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* atanh(x) = 0.5*log1p(2x+2x*x/(1-x))
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*
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* Special cases:
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* atanh(x) is NaN if |x| > 1 with signal;
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* atanh(NaN) is that NaN with no signal;
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* atanh(+-1) is +-INF with signal.
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*
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*/
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#include "math.h"
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#include "math_private.h"
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#ifdef __STDC__
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static const double one = 1.0, huge = 1e300;
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#else
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static double one = 1.0, huge = 1e300;
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#endif
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#ifdef __STDC__
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static const double zero = 0.0;
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#else
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static double zero = 0.0;
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#endif
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#ifdef __STDC__
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double __ieee754_atanh(double x)
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#else
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double __ieee754_atanh(x)
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double x;
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#endif
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{
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double t;
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int32_t hx,ix;
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u_int32_t lx;
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EXTRACT_WORDS(hx,lx,x);
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ix = hx&0x7fffffff;
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if ((ix|((lx|(-lx))>>31))>0x3ff00000) /* |x|>1 */
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return (x-x)/(x-x);
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if(ix==0x3ff00000)
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return x/zero;
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if(ix<0x3e300000&&(huge+x)>zero) return x; /* x<2**-28 */
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SET_HIGH_WORD(x,ix);
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if(ix<0x3fe00000) { /* x < 0.5 */
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t = x+x;
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t = 0.5*__log1p(t+t*x/(one-x));
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} else
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t = 0.5*__log1p((x+x)/(one-x));
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if(hx>=0) return t; else return -t;
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}
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