1/* s_nextafterl.c -- long double version of s_nextafter.c.
2 * Conversion to IEEE quad long double by Jakub Jelinek, jj@ultra.linux.cz.
3 */
4
5/*
6 * ====================================================
7 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
8 *
9 * Developed at SunPro, a Sun Microsystems, Inc. business.
10 * Permission to use, copy, modify, and distribute this
11 * software is freely granted, provided that this notice
12 * is preserved.
13 * ====================================================
14 */
15
16#if defined(LIBM_SCCS) && !defined(lint)
17static char rcsid[] = "$NetBSD: $";
18#endif
19
20/* IEEE functions
21 * nextafterl(x,y)
22 * return the next machine floating-point number of x in the
23 * direction toward y.
24 * Special cases:
25 */
26
27#include <errno.h>
28#include <math.h>
29#include <math-barriers.h>
30#include <math_private.h>
31#include <libm-alias-ldouble.h>
32
33_Float128 __nextafterl(_Float128 x, _Float128 y)
34{
35 int64_t hx,hy,ix,iy;
36 uint64_t lx,ly;
37
38 GET_LDOUBLE_WORDS64(hx,lx,x);
39 GET_LDOUBLE_WORDS64(hy,ly,y);
40 ix = hx&0x7fffffffffffffffLL; /* |x| */
41 iy = hy&0x7fffffffffffffffLL; /* |y| */
42
43 if(((ix>=0x7fff000000000000LL)&&((ix-0x7fff000000000000LL)|lx)!=0) || /* x is nan */
44 ((iy>=0x7fff000000000000LL)&&((iy-0x7fff000000000000LL)|ly)!=0)) /* y is nan */
45 return x+y;
46 if(x==y) return y; /* x=y, return y */
47 if((ix|lx)==0) { /* x == 0 */
48 _Float128 u;
49 SET_LDOUBLE_WORDS64(x,hy&0x8000000000000000ULL,1);/* return +-minsubnormal */
50 u = math_opt_barrier (x);
51 u = u * u;
52 math_force_eval (u); /* raise underflow flag */
53 return x;
54 }
55 if(hx>=0) { /* x > 0 */
56 if(hx>hy||((hx==hy)&&(lx>ly))) { /* x > y, x -= ulp */
57 if(lx==0) hx--;
58 lx--;
59 } else { /* x < y, x += ulp */
60 lx++;
61 if(lx==0) hx++;
62 }
63 } else { /* x < 0 */
64 if(hy>=0||hx>hy||((hx==hy)&&(lx>ly))){/* x < y, x -= ulp */
65 if(lx==0) hx--;
66 lx--;
67 } else { /* x > y, x += ulp */
68 lx++;
69 if(lx==0) hx++;
70 }
71 }
72 hy = hx&0x7fff000000000000LL;
73 if(hy==0x7fff000000000000LL) {
74 _Float128 u = x + x; /* overflow */
75 math_force_eval (u);
76 __set_errno (ERANGE);
77 }
78 if(hy==0) {
79 _Float128 u = x*x; /* underflow */
80 math_force_eval (u); /* raise underflow flag */
81 __set_errno (ERANGE);
82 }
83 SET_LDOUBLE_WORDS64(x,hx,lx);
84 return x;
85}
86libm_alias_ldouble (__nextafter, nextafter)
87strong_alias (__nextafterl, __nexttowardl)
88weak_alias (__nextafterl, nexttowardl)
89