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/* e_asinhl.c -- long double version of e_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
/* __ieee754_sinhl(x)
* Method :
* mathematically sinh(x) if defined to be (exp(x)-exp(-x))/2
* 1. Replace x by |x| (sinhl(-x) = -sinhl(x)).
* 2.
* E + E/(E+1)
* 0 <= x <= 25 : sinhl(x) := --------------, E=expm1l(x)
* 2
*
* 25 <= x <= lnovft : sinhl(x) := expl(x)/2
* lnovft <= x <= ln2ovft: sinhl(x) := expl(x/2)/2 * expl(x/2)
* ln2ovft < x : sinhl(x) := x*shuge (overflow)
*
* Special cases:
* sinhl(x) is |x| if x is +INF, -INF, or NaN.
* only sinhl(0)=0 is exact for finite x.
*/
#include "math.h"
#include "math_private.h"
#ifdef __STDC__
static const long double one = 1.0, shuge = 1.0e4931L;
#else
static long double one = 1.0, shuge = 1.0e4931L;
#endif
#ifdef __STDC__
long double __ieee754_sinhl(long double x)
#else
long double __ieee754_sinhl(x)
long double x;
#endif
{
long double t,w,h;
u_int32_t jx,ix,i0,i1;
/* Words of |x|. */
GET_LDOUBLE_WORDS(jx,i0,i1,x);
ix = jx&0x7fff;
/* x is INF or NaN */
if(ix==0x7fff) return x+x;
h = 0.5;
if (jx<0) h = -h;
/* |x| in [0,25], return sign(x)*0.5*(E+E/(E+1))) */
if (ix < 0x4003 || (ix == 0x4003 && i0 <= 0xc8000000)) { /* |x|<25 */
if (ix<0x3fe3) /* |x|<2**-28 */
if(shuge+x>one) return x;/* sinh(tiny) = tiny with inexact */
t = __expm1l(fabsl(x));
if(ix<0x3fff) return h*(2.0*t-t*t/(t+one));
return h*(t+t/(t+one));
}
/* |x| in [25, log(maxdouble)] return 0.5*exp(|x|) */
if (ix < 0x400c || (ix == 0x400c && i0 < 0xb17217f7))
return h*__ieee754_expl(fabsl(x));
/* |x| in [log(maxdouble), overflowthreshold] */
if (ix<0x400c || (ix == 0x400c && (i0 < 0xb174ddc0
|| (i0 == 0xb174ddc0
&& i1 <= 0x31aec0ea)))) {
w = __ieee754_expl(0.5*fabsl(x));
t = h*w;
return t*w;
}
/* |x| > overflowthreshold, sinhl(x) overflow */
return x*shuge;
}
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