adtools/clib2

/*
 * $Id: math_asinhf.c,v 1.3 2006-01-08 12:04:23 obarthel Exp $
 *
 * :ts=4
 *
 * Portable ISO 'C' (1994) runtime library for the Amiga computer
 * Copyright (c) 2002-2015 by Olaf Barthel <obarthel (at) gmx.net>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   - Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *
 *   - Neither the name of Olaf Barthel nor the names of contributors
 *     may be used to endorse or promote products derived from this
 *     software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 *
 * PowerPC math library based in part on work by Sun Microsystems
 * 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.
 *
 *
 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
 */

#ifndef _MATH_HEADERS_H
#include "math_headers.h"
#endif /* _MATH_HEADERS_H */

/****************************************************************************/

#if defined(FLOATING_POINT_SUPPORT)

/****************************************************************************/

static const float 
one =  1.0000000000e+00, /* 0x3F800000 */
ln2 =  6.9314718246e-01, /* 0x3f317218 */
huge=  1.0000000000e+30; 

float
asinhf(float x)
{    
    float t,w;
    LONG hx,ix;
    GET_FLOAT_WORD(hx,x);
    ix = hx&0x7fffffff;
    if(ix>=0x7f800000) return x+x;    /* x is inf or NaN */
    if(ix< 0x31800000) {    /* |x|<2**-28 */
        if(huge+x>one) return x;    /* return x inexact except 0 */
    } 
    if(ix>0x4d800000) {    /* |x| > 2**28 */
        w = logf(fabsf(x))+ln2;
    } else if (ix>0x40000000) {    /* 2**28 > |x| > 2.0 */
        t = fabsf(x);
        w = logf((float)2.0*t+one/(sqrtf(x*x+one)+t));
    } else {        /* 2.0 > |x| > 2**-28 */
        t = x*x;
        w =log1pf(fabsf(x)+t/(one+sqrtf(one+t)));
    }
    if(hx>0) return w; else return -w;
}

/****************************************************************************/

#endif /* FLOATING_POINT_SUPPORT */