lx = __LO(x);
lx = __LO(u);
	int fd_ilogb(double x)#else	int fd_ilogb(x)	double x;#endif{	int hx,lx,ix;	hx  = (__HI(x))&0x7fffffff;	/* high word of x */	if(hx<0x00100000) {	    lx = __LO(x);	    if((hx|lx)==0) 		return 0x80000001;	/* ilogb(0) = 0x80000001 */	    else			/* subnormal x */		if(hx==0) {		    for (ix = -1043; lx>0; lx<<=1) ix -=1;		} else {		    for (ix = -1022,hx<<=11; hx>0; hx<<=1) ix -=1;		}	    return ix;	}	else if (hx<0x7ff00000) return (hx>>20)-1023;	else return 0x7fffffff;}