14  *	return the next machine floating-point number of x in the
33 	ix = hx&0x7fffffff;		/* |x| */  in nextafter()
34 	iy = hy&0x7fffffff;		/* |y| */  in nextafter()
36 	if(((ix>=0x7ff00000)&&((ix-0x7ff00000)|lx)!=0) ||   /* x is nan */  in nextafter()
37 	   ((iy>=0x7ff00000)&&((iy-0x7ff00000)|ly)!=0))     /* y is nan */  in nextafter()
40 	if((ix|lx)==0) {			/* x == 0 */  in nextafter()
41 	    INSERT_WORDS(x,hy&0x80000000,1);	/* return +-minsubnormal */  in nextafter()
45 	if(hx>=0) {				/* x > 0 */  in nextafter()
46 	    if(hx>hy||((hx==hy)&&(lx>ly))) {	/* x > y, x -= ulp */  in nextafter()
47 		if(lx==0) hx -= 1;  in nextafter()
48 		lx -= 1;  in nextafter()
49 	    } else {				/* x < y, x += ulp */  in nextafter()
51 		if(lx==0) hx += 1;  in nextafter()
53 	} else {				/* x < 0 */  in nextafter()
54 	    if(hy>=0||hx>hy||((hx==hy)&&(lx>ly))){/* x < y, x -= ulp */  in nextafter()
55 		if(lx==0) hx -= 1;  in nextafter()
56 		lx -= 1;  in nextafter()
57 	    } else {				/* x > y, x += ulp */  in nextafter()
59 		if(lx==0) hx += 1;  in nextafter()
62 	hy = hx&0x7ff00000;  in nextafter()
63 	if(hy>=0x7ff00000) return x+x;	/* overflow  */  in nextafter()
64 	if(hy<0x00100000) {		/* underflow */  in nextafter()