1 /* @(#)s_nextafter.c 5.1 93/09/24 */
3 * ====================================================
4 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
6 * Developed at SunPro, a Sun Microsystems, Inc. business.
7 * Permission to use, copy, modify, and distribute this
8 * software is freely granted, provided that this notice
10 * ====================================================
13 #if defined(LIBM_SCCS) && !defined(lint)
14 static char rcsid[] = "$NetBSD: s_nextafter.c,v 1.8 1995/05/10 20:47:58 jtc Exp $";
19 * return the next machine floating-point number of x in the
24 /* Ugly hack so that the aliasing works. */
25 #define __nexttoward __internal___nexttoward
26 #define nexttoward __internal_nexttoward
29 #include <math_private.h>
32 double __nextafter(double x, double y)
37 EXTRACT_WORDS(hx,lx,x);
38 EXTRACT_WORDS(hy,ly,y);
39 ix = hx&0x7fffffff; /* |x| */
40 iy = hy&0x7fffffff; /* |y| */
42 if(((ix>=0x7ff00000)&&((ix-0x7ff00000)|lx)!=0) || /* x is nan */
43 ((iy>=0x7ff00000)&&((iy-0x7ff00000)|ly)!=0)) /* y is nan */
45 if(x==y) return y; /* x=y, return y */
46 if((ix|lx)==0) { /* x == 0 */
48 INSERT_WORDS(x,hy&0x80000000,1); /* return +-minsubnormal */
49 u = math_opt_barrier (x);
51 math_force_eval (u); /* raise underflow flag */
54 if(hx>=0) { /* x > 0 */
55 if(hx>hy||((hx==hy)&&(lx>ly))) { /* x > y, x -= ulp */
58 } else { /* x < y, x += ulp */
63 if(hy>=0||hx>hy||((hx==hy)&&(lx>ly))){/* x < y, x -= ulp */
66 } else { /* x > y, x += ulp */
73 x = x+x; /* overflow */
74 if (FLT_EVAL_METHOD != 0 && FLT_EVAL_METHOD != 1)
76 return x; /* overflow */
79 double u = x*x; /* underflow */
80 math_force_eval (u); /* raise underflow flag */
82 INSERT_WORDS(x,hx,lx);
85 weak_alias (__nextafter, nextafter)
87 strong_alias (__nextafter, __nextafterl)
88 weak_alias (__nextafter, nextafterl)
89 strong_alias (__nextafter, __nexttowardl)
90 weak_alias (__nexttowardl, nexttowardl)
92 strong_alias (__nextafter, __nexttoward)
94 weak_alias (__nextafter, nexttoward)