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
30 #include <math-barriers.h>
31 #include <math_private.h>
33 #include <libm-alias-double.h>
35 double __nextafter(double x, double y)
40 EXTRACT_WORDS(hx,lx,x);
41 EXTRACT_WORDS(hy,ly,y);
42 ix = hx&0x7fffffff; /* |x| */
43 iy = hy&0x7fffffff; /* |y| */
45 if(((ix>=0x7ff00000)&&((ix-0x7ff00000)|lx)!=0) || /* x is nan */
46 ((iy>=0x7ff00000)&&((iy-0x7ff00000)|ly)!=0)) /* y is nan */
48 if(x==y) return y; /* x=y, return y */
49 if((ix|lx)==0) { /* x == 0 */
51 INSERT_WORDS(x,hy&0x80000000,1); /* return +-minsubnormal */
52 u = math_opt_barrier (x);
54 math_force_eval (u); /* raise underflow flag */
57 if(hx>=0) { /* x > 0 */
58 if(hx>hy||((hx==hy)&&(lx>ly))) { /* x > y, x -= ulp */
61 } else { /* x < y, x += ulp */
66 if(hy>=0||hx>hy||((hx==hy)&&(lx>ly))){/* x < y, x -= ulp */
69 } else { /* x > y, x += ulp */
76 double u = x+x; /* overflow */
81 double u = x*x; /* underflow */
82 math_force_eval (u); /* raise underflow flag */
85 INSERT_WORDS(x,hx,lx);
88 libm_alias_double (__nextafter, nextafter)
90 strong_alias (__nextafter, __nexttowardl)
91 weak_alias (__nexttowardl, nexttowardl)
93 strong_alias (__nextafter, __nexttoward)
95 weak_alias (__nextafter, nexttoward)