{__HI(t)=0x43500000; 		 t*=x; __HI(t)=__HI(t)/3+B2;
{u.d = t; __HI(u)=0x43500000; t=u.d;		 t*=x; __HI(u)=__HI(u)/3+B2;
	double fd_cbrt(double x) #else	double fd_cbrt(x) 	double x;#endif{	int	hx;	double r,s,t=0.0,w;	unsigned sign;	hx = __HI(x);		/* high word of x */	sign=hx&0x80000000; 		/* sign= sign(x) */	hx  ^=sign;	if(hx>=0x7ff00000) return(x+x); /* cbrt(NaN,INF) is itself */	if((hx|__LO(x))==0) 	    return(x);		/* cbrt(0) is itself */	__HI(x) = hx;	/* x <- |x| */    /* rough cbrt to 5 bits */	if(hx<0x00100000) 		/* subnormal number */	  {__HI(t)=0x43500000; 		/* set t= 2**54 */	   t*=x; __HI(t)=__HI(t)/3+B2;	  }	else	  __HI(t)=hx/3+B1;	    /* new cbrt to 23 bits, may be implemented in single precision */	r=t*t/x;	s=C+r*t;	t*=G+F/(s+E+D/s);	    /* chopped to 20 bits and make it larger than cbrt(x) */ 	__LO(t)=0; __HI(t)+=0x00000001;    /* one step newton iteration to 53 bits with error less than 0.667 ulps */	s=t*t;		/* t*t is exact */	r=x/s;	w=t+t;	r=(r-t)/(w+r);	/* r-s is exact */	t=t+t*r;    /* retore the sign bit */	__HI(t) |= sign;	return(t);}