14  *	nexttoward(x,y)
16  *	direction toward y.
23 nexttoward64(__float64 x, long double y)  in nexttoward64()  argument
31 	GET_LDOUBLE_WORDS64(hy,ly,y);  in nexttoward64()
33 	iy = hy&0x7fffffffffffffffLL;	/* |y| */  in nexttoward64()
36             force_eval_long_double(opt_barrier_long_double(y)+y);  in nexttoward64()
39 	if((iy>=0x7fff000000000000LL)&&((iy-0x7fff000000000000LL)|ly)!=0) { /* y is nan */  in nexttoward64()
40             return (__float64) (y + y);  in nexttoward64()
42 	if((long double) x==y) return y;	/* x=y, return y */  in nexttoward64()
49 	    if ((long double) x > y) {	        /* x > y, x -= ulp */  in nexttoward64()
52 	    } else {				/* x < y, x += ulp */  in nexttoward64()
57             if ((long double) x < y) {	        /* x < y, x -= ulp */  in nexttoward64()
60 	    } else {				/* x > y, x += ulp */  in nexttoward64()