/* derived from /netlib/fdlibm */ /* @(#)e_sinh.c 1.3 95/01/18 *//* * ==================================================== * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. * * Developed at SunSoft, a Sun Microsystems, Inc. business. * Permission to use, copy, modify, and distribute this * software is freely granted, provided that this notice  * is preserved. * ==================================================== */ /* __ieee754_sinh(x) * Method :  * mathematically sinh(x) if defined to be (exp(x)-exp(-x))/2 *	1. Replace x by |x| (sinh(-x) = -sinh(x)).  *	2.  *		                                    E + E/(E+1) *	    0        <= x <= 22     :  sinh(x) := --------------, E=expm1(x) *			       			        2 * *	    22       <= x <= lnovft :  sinh(x) := exp(x)/2  *	    lnovft   <= x <= ln2ovft:  sinh(x) := exp(x/2)/2 * exp(x/2) *	    ln2ovft  <  x	    :  sinh(x) := x*sHuge (overflow) * * Special cases: *	sinh(x) is |x| if x is +INF, -INF, or NaN. *	only sinh(0)=0 is exact for finite x. */ #include "fdlibm.h" static const double one = 1.0, sHuge = 1.0e307; 	double __ieee754_sinh(double x){		double t,w,h;	int ix,jx;	unsigned lx;     /* High word of |x|. */	jx = __HI(x);	ix = jx&0x7fffffff;     /* x is INF or NaN */	if(ix>=0x7ff00000) return x+x;	 	h = 0.5;	if (jx<0) h = -h;    /* |x| in [0,22], return sign(x)*0.5*(E+E/(E+1))) */	if (ix < 0x40360000) {		/* |x|<22 */	    if (ix<0x3e300000) 		/* |x|<2**-28 */		if(sHuge+x>one) return x;/* sinh(tiny) = tiny with inexact */	    t = expm1(fabs(x));	    if(ix<0x3ff00000) return h*(2.0*t-t*t/(t+one));	    return h*(t+t/(t+one));	}     /* |x| in [22, log(maxdouble)] return 0.5*exp(|x|) */	if (ix < 0x40862E42)  return h*__ieee754_exp(fabs(x));     /* |x| in [log(maxdouble), overflowthresold] */	lx = *( (((*(unsigned*)&one)>>29)) + (unsigned*)&x);	if (ix<0x408633CE || (ix==0x408633ce)&&(lx<=(unsigned)0x8fb9f87d)) {	    w = __ieee754_exp(0.5*fabs(x));	    t = h*w;	    return t*w;	}     /* |x| > overflowthresold, sinh(x) overflow */	return x*sHuge;}