4d77c1151c
* reworked amd64/_fpmath.h and arm64/_fpmath.h to support 128-bit long doubles. * improved tests to cover long double cases * made modfl an alias for LP32 Tests pass on x86, x86_64, arm, arm64 and mips. Bug: 12921273 Change-Id: Ibe39acde57972447a8950fa45b1e702acc68ebeb
75 lines
1.8 KiB
C
75 lines
1.8 KiB
C
/* from: FreeBSD: head/lib/msun/src/e_atanh.c 176451 2008-02-22 02:30:36Z das */
|
|
|
|
/* @(#)e_atanh.c 1.3 95/01/18 */
|
|
/*
|
|
* ====================================================
|
|
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
|
|
*
|
|
* Developed at SunSoft, a Sun Microsystems, Inc. business.
|
|
* Permission to use, copy, modify, and distribute this
|
|
* software is freely granted, provided that this notice
|
|
* is preserved.
|
|
* ====================================================
|
|
*
|
|
*/
|
|
|
|
#include <sys/cdefs.h>
|
|
__FBSDID("$FreeBSD$");
|
|
|
|
/*
|
|
* See e_atanh.c for complete comments.
|
|
*
|
|
* Converted to long double by David Schultz <das@FreeBSD.ORG> and
|
|
* Bruce D. Evans.
|
|
*/
|
|
|
|
#include <float.h>
|
|
#ifdef __i386__
|
|
#include <ieeefp.h>
|
|
#endif
|
|
|
|
#include "fpmath.h"
|
|
#include "math.h"
|
|
#include "math_private.h"
|
|
|
|
/* EXP_TINY is the threshold below which we use atanh(x) ~= x. */
|
|
#if LDBL_MANT_DIG == 64
|
|
#define EXP_TINY -34
|
|
#elif LDBL_MANT_DIG == 113
|
|
#define EXP_TINY -58
|
|
#else
|
|
#error "Unsupported long double format"
|
|
#endif
|
|
|
|
#if LDBL_MAX_EXP != 0x4000
|
|
/* We also require the usual expsign encoding. */
|
|
#error "Unsupported long double format"
|
|
#endif
|
|
|
|
#define BIAS (LDBL_MAX_EXP - 1)
|
|
|
|
static const double one = 1.0, huge = 1e300;
|
|
static const double zero = 0.0;
|
|
|
|
long double
|
|
atanhl(long double x)
|
|
{
|
|
long double t;
|
|
uint16_t hx, ix;
|
|
|
|
ENTERI();
|
|
GET_LDBL_EXPSIGN(hx, x);
|
|
ix = hx & 0x7fff;
|
|
if (ix >= 0x3fff) /* |x| >= 1, or NaN or misnormal */
|
|
RETURNI(fabsl(x) == 1 ? x / zero : (x - x) / (x - x));
|
|
if (ix < BIAS + EXP_TINY && (huge + x) > zero)
|
|
RETURNI(x); /* x is tiny */
|
|
SET_LDBL_EXPSIGN(x, ix);
|
|
if (ix < 0x3ffe) { /* |x| < 0.5, or misnormal */
|
|
t = x+x;
|
|
t = 0.5*log1pl(t+t*x/(one-x));
|
|
} else
|
|
t = 0.5*log1pl((x+x)/(one-x));
|
|
RETURNI((hx & 0x8000) == 0 ? t : -t);
|
|
}
|