2 * Conversion from s_nextafter.c by Ulrich Drepper, Cygnus Support,
7 * ====================================================
8 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
10 * Developed at SunPro, a Sun Microsystems, Inc. business.
11 * Permission to use, copy, modify, and distribute this
12 * software is freely granted, provided that this notice
14 * ====================================================
17 #if defined(LIBM_SCCS) && !defined(lint)
18 static char rcsid[] = "$NetBSD: $";
23 * return the next machine floating-point number of x in the
29 #include <math_private.h>
32 double __nexttoward(double x, long double y)
35 u_int32_t lx,hy,ly,esy;
37 EXTRACT_WORDS(hx,lx,x);
38 GET_LDOUBLE_WORDS(esy,hy,ly,y);
39 ix = hx&0x7fffffff; /* |x| */
40 iy = esy&0x7fff; /* |y| */
42 if(((ix>=0x7ff00000)&&((ix-0x7ff00000)|lx)!=0) || /* x is nan */
43 ((iy>=0x7fff)&&(hy|ly)!=0)) /* y is nan */
45 if((long double) x==y) return y; /* x=y, return y */
46 if((ix|lx)==0) { /* x == 0 */
48 INSERT_WORDS(x,(esy&0x8000)<<16,1); /* return +-minsub */
49 u = math_opt_barrier (x);
51 math_force_eval (u); /* raise underflow flag */
54 if(hx>=0) { /* x > 0 */
55 if (x > y) { /* x -= ulp */
58 } else { /* x < y, x += ulp */
63 if (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)
75 /* Force conversion to double. */
80 double u = x*x; /* underflow */
81 math_force_eval (u); /* raise underflow flag */
83 INSERT_WORDS(x,hx,lx);
86 weak_alias (__nexttoward, nexttoward)