/*
 * $Id: math_cosh.c,v 1.3 2005-02-25 10:14:21 obarthel Exp $
 *
 * :ts=4
 *
 * Portable ISO 'C' (1994) runtime library for the Amiga computer
 * Copyright (c) 2002-2005 by Olaf Barthel <olsen@sourcery.han.de>
 * 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.
 */

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

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

#if defined(FLOATING_POINT_SUPPORT)

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

#if defined(IEEE_FLOATING_POINT_SUPPORT)

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

#if defined(__GNUC__)

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

#if defined(SMALL_DATA)
#define A4(x) "a4@(" #x ":W)"
#elif defined(SMALL_DATA32)
#define A4(x) "a4@(" #x ":L)"
#else
#define A4(x) #x
#endif /* SMALL_DATA */

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

extern double __cosh(double x);

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

asm("

	.text
	.even

	.globl	_MathIeeeDoubTransBase
	.globl	___cosh

___cosh:

	movel	a6,sp@-
	movel	"A4(_MathIeeeDoubTransBase)",a6
	moveml	sp@(8),d0/d1
	jsr		a6@(-66:W)
	movel	sp@+,a6
	rts

");

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

#else

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

INLINE STATIC const double
__cosh(double x)
{
	double result;

	result = IEEEDPCosh(x);

	return(result);
}

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

#endif /* __GNUC__ */

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

#endif /* IEEE_FLOATING_POINT_SUPPORT */

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

#if defined(M68881_FLOATING_POINT_SUPPORT)

INLINE STATIC const double
__cosh(double x)
{
	double result;

	__asm ("fcosh%.x %1,%0"
	       : "=f" (result)
	       : "f" (x));

	return(result);
}

#endif /* M68881_FLOATING_POINT_SUPPORT */

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

#if defined(PPC_FLOATING_POINT_SUPPORT)

static const double one = 1.0, half=0.5, huge = 1.0e300;

INLINE STATIC const double
__cosh(double x)
{	
	double t,w;
	int ix;
	unsigned int lx;

    /* High word of |x|. */
	GET_HIGH_WORD(ix,x);
	ix &= 0x7fffffff;

    /* x is INF or NaN */
	if(ix>=0x7ff00000) 
		return x*x;	

    /* |x| in [0,0.5*ln2], return 1+__expm1(|x|)^2/(2*exp(|x|)) */
	if(ix<0x3fd62e43) 
	{
	    t = __expm1(fabs(x));
	    w = one+t;
	    if (ix<0x3c800000)
			return w;	/* cosh(tiny) = 1 */
	    return one+(t*t)/(w+w);
	}

    /* |x| in [0.5*ln2,22], return (exp(|x|)+1/exp(|x|)/2; */
	if (ix < 0x40360000) 
	{
		t = exp(fabs(x));
		return half*t+half/t;
	}

    /* |x| in [22, log(maxdouble)] return half*exp(|x|) */
	if (ix < 0x40862E42)  
		return half*exp(fabs(x));

    /* |x| in [log(maxdouble), overflowthresold] */
	GET_LOW_WORD(lx,x);
	if (ix<0x408633CE || (ix==0x408633ce && lx<=(unsigned int)0x8fb9f87d)) 
	{
	    w = exp(half*fabs(x));
	    t = half*w;
	    return t*w;
	}

    /* |x| > overflowthresold, cosh(x) overflow */
	return huge*huge;
}

#endif /* PPC_FLOATING_POINT_SUPPORT */

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

double
cosh(double x)
{
	double result;

	result = __cosh(x);

	return(result);
}

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

#endif /* FLOATING_POINT_SUPPORT */
