| e_atanh.c (176451) | e_atanh.c (251599) |
|---|---|
| 1 2/* @(#)e_atanh.c 1.3 95/01/18 */ 3/* 4 * ==================================================== 5 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. 6 * 7 * Developed at SunSoft, a Sun Microsystems, Inc. business. 8 * Permission to use, copy, modify, and distribute this 9 * software is freely granted, provided that this notice 10 * is preserved. 11 * ==================================================== 12 * 13 */ 14 15#include <sys/cdefs.h> | 1 2/* @(#)e_atanh.c 1.3 95/01/18 */ 3/* 4 * ==================================================== 5 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. 6 * 7 * Developed at SunSoft, a Sun Microsystems, Inc. business. 8 * Permission to use, copy, modify, and distribute this 9 * software is freely granted, provided that this notice 10 * is preserved. 11 * ==================================================== 12 * 13 */ 14 15#include <sys/cdefs.h> |
| 16__FBSDID("$FreeBSD: head/lib/msun/src/e_atanh.c 176451 2008-02-22 02:30:36Z das $"); | 16__FBSDID("$FreeBSD: head/lib/msun/src/e_atanh.c 251599 2013-06-10 06:04:58Z das $"); |
| 17 18/* __ieee754_atanh(x) 19 * Method : 20 * 1.Reduced x to positive by atanh(-x) = -atanh(x) 21 * 2.For x>=0.5 22 * 1 2x x 23 * atanh(x) = --- * log(1 + -------) = 0.5 * log1p(2 * --------) 24 * 2 1 - x 1 - x 25 * 26 * For x<0.5 27 * atanh(x) = 0.5*log1p(2x+2x*x/(1-x)) 28 * 29 * Special cases: 30 * atanh(x) is NaN if |x| > 1 with signal; 31 * atanh(NaN) is that NaN with no signal; 32 * atanh(+-1) is +-INF with signal. 33 * 34 */ 35 | 17 18/* __ieee754_atanh(x) 19 * Method : 20 * 1.Reduced x to positive by atanh(-x) = -atanh(x) 21 * 2.For x>=0.5 22 * 1 2x x 23 * atanh(x) = --- * log(1 + -------) = 0.5 * log1p(2 * --------) 24 * 2 1 - x 1 - x 25 * 26 * For x<0.5 27 * atanh(x) = 0.5*log1p(2x+2x*x/(1-x)) 28 * 29 * Special cases: 30 * atanh(x) is NaN if |x| > 1 with signal; 31 * atanh(NaN) is that NaN with no signal; 32 * atanh(+-1) is +-INF with signal. 33 * 34 */ 35 |
| 36#include <float.h> 37 |
|
| 36#include "math.h" 37#include "math_private.h" 38 39static const double one = 1.0, huge = 1e300; 40static const double zero = 0.0; 41 42double 43__ieee754_atanh(double x) --- 11 unchanged lines hidden (view full) --- 55 SET_HIGH_WORD(x,ix); 56 if(ix<0x3fe00000) { /* x < 0.5 */ 57 t = x+x; 58 t = 0.5*log1p(t+t*x/(one-x)); 59 } else 60 t = 0.5*log1p((x+x)/(one-x)); 61 if(hx>=0) return t; else return -t; 62} | 38#include "math.h" 39#include "math_private.h" 40 41static const double one = 1.0, huge = 1e300; 42static const double zero = 0.0; 43 44double 45__ieee754_atanh(double x) --- 11 unchanged lines hidden (view full) --- 57 SET_HIGH_WORD(x,ix); 58 if(ix<0x3fe00000) { /* x < 0.5 */ 59 t = x+x; 60 t = 0.5*log1p(t+t*x/(one-x)); 61 } else 62 t = 0.5*log1p((x+x)/(one-x)); 63 if(hx>=0) return t; else return -t; 64} |
| 65 66#if LDBL_MANT_DIG == 53 67__weak_reference(atanh, atanhl); 68#endif |
|