mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-25 22:40:05 +00:00
88 lines
2.1 KiB
C
88 lines
2.1 KiB
C
/* s_asinhl.c -- long double version of s_asinh.c.
|
|
* Conversion to long double by Ulrich Drepper,
|
|
* Cygnus Support, drepper@cygnus.com.
|
|
*/
|
|
|
|
/*
|
|
* ====================================================
|
|
* 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: $";
|
|
#endif
|
|
|
|
/* asinhl(x)
|
|
* Method :
|
|
* Based on
|
|
* asinhl(x) = signl(x) * logl [ |x| + sqrtl(x*x+1) ]
|
|
* we have
|
|
* asinhl(x) := x if 1+x*x=1,
|
|
* := signl(x)*(logl(x)+ln2)) for large |x|, else
|
|
* := signl(x)*logl(2|x|+1/(|x|+sqrtl(x*x+1))) if|x|>2, else
|
|
* := signl(x)*log1pl(|x| + x^2/(1 + sqrtl(1+x^2)))
|
|
*/
|
|
|
|
#include "math.h"
|
|
#include "math_private.h"
|
|
|
|
#ifdef __STDC__
|
|
static const long double
|
|
#else
|
|
static long double
|
|
#endif
|
|
one = 1.0L,
|
|
ln2 = 6.931471805599453094172321214581765681e-1L,
|
|
huge = 1.0e+4900L;
|
|
|
|
#ifdef __STDC__
|
|
long double
|
|
__asinhl (long double x)
|
|
#else
|
|
long double
|
|
__asinhl (x)
|
|
long double x;
|
|
#endif
|
|
{
|
|
long double t, w;
|
|
int32_t ix, sign;
|
|
ieee854_long_double_shape_type u;
|
|
|
|
u.value = x;
|
|
sign = u.parts32.w0;
|
|
ix = sign & 0x7fffffff;
|
|
if (ix == 0x7fff0000)
|
|
return x + x; /* x is inf or NaN */
|
|
if (ix < 0x3fc70000)
|
|
{ /* |x| < 2^ -56 */
|
|
if (huge + x > one)
|
|
return x; /* return x inexact except 0 */
|
|
}
|
|
u.parts32.w0 = ix;
|
|
if (ix > 0x40350000)
|
|
{ /* |x| > 2 ^ 54 */
|
|
w = __ieee754_logl (u.value) + ln2;
|
|
}
|
|
else if (ix >0x40000000)
|
|
{ /* 2^ 54 > |x| > 2.0 */
|
|
t = u.value;
|
|
w = __ieee754_logl (2.0 * t + one / (__ieee754_sqrtl (x * x + one) + t));
|
|
}
|
|
else
|
|
{ /* 2.0 > |x| > 2 ^ -56 */
|
|
t = x * x;
|
|
w = __log1pl (u.value + t / (one + __ieee754_sqrtl (one + t)));
|
|
}
|
|
if (sign & 0x80000000)
|
|
return -w;
|
|
else
|
|
return w;
|
|
}
|
|
weak_alias (__asinhl, asinhl)
|