示例#1
0
double
__ieee754_sinh(double x)
{
	double t,h;
	int32_t ix,jx;

    /* High word of |x|. */
	GET_HIGH_WORD(jx,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] */
	if (ix<=0x408633CE)
	    return h*2.0*__ldexp_exp(fabs(x), -1);

    /* |x| > overflowthresold, sinh(x) overflow */
	return x*shuge;
}
示例#2
0
double
__ieee754_cosh(double x)
{
	double t,w;
	int32_t ix;

    /* 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 = __ieee754_exp(fabs(x));
		return half*t+half/t;
	}

    /* |x| in [22, log(maxdouble)] return half*exp(|x|) */
	if (ix < 0x40862E42)  return half*__ieee754_exp(fabs(x));

    /* |x| in [log(maxdouble), overflowthresold] */
	if (ix<=0x408633CE)
	    return __ldexp_exp(fabs(x), -1);

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