/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2011 Nexenta Systems, Inc. All rights reserved.
*/
/*
* Copyright 2006 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma weak __sinhl = sinhl
#include "libm.h"
#include "longdouble.h"
/*
* sinhl(X)
* RETURN THE HYPERBOLIC SINE OF X
*
* Method :
* 1. reduce x to non-negative by sinhl(-x) = - sinhl(x).
* 2.
*
* expm1l(x) + expm1l(x)/(expm1l(x)+1)
* 0 <= x <= lnovft : sinhl(x) := --------------------------------
* 2
*
* lnovft <= x < INF : sinhl(x) := expl(x-MEP1*ln2)*2**ME
*
* here
* lnovft: logrithm of the overflow threshold
* = MEP1*ln2 chopped to machine precision.
* ME maximum exponent
* MEP1 maximum exponent plus 1
*
* Special cases:
* sinhl(x) is x if x is +INF, -INF, or NaN.
* only sinhl(0)=0 is exact for finite argument.
*
*/
#define ME 16383
#define MEP1 16384
#define LNOVFT 1.135652340629414394949193107797076342845e+4L
/* last 32 bits of LN2HI is zero */
#define LN2HI 6.931471805599453094172319547495844850203e-0001L
#define LN2LO 1.667085920830552208890449330400379754169e-0025L
static const long double
half = 0.5L,
one = 1.0L,
ln2hi = LN2HI,
ln2lo = LN2LO,
lnovftL = LNOVFT;
long double
sinhl(long double x) {
long double r, t;
if (!finitel(x))
return (x + x); /* sinh of NaN or +-INF is itself */
r = fabsl(x);
if (r < lnovftL) {
t = expm1l(r);
r = copysignl((t + t / (one + t)) * half, x);
} else {
r = copysignl(expl((r - MEP1 * ln2hi) - MEP1 * ln2lo), x);
r = scalbnl(r, ME);
}
return (r);
}