1/* s_nextafterl.c -- long double version of s_nextafter.c.
2 * Special version for i387.
3 * Conversion to long double by Ulrich Drepper,
4 * Cygnus Support, drepper@cygnus.com.
5 */
6
7/*
8 * ====================================================
9 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
10 *
11 * Developed at SunPro, a Sun Microsystems, Inc. business.
12 * Permission to use, copy, modify, and distribute this
13 * software is freely granted, provided that this notice
14 * is preserved.
15 * ====================================================
16 */
17
18#if defined(LIBM_SCCS) && !defined(lint)
19static char rcsid[] = "$NetBSD: $";
20#endif
21
22/* IEEE functions
23 * nextafterl(x,y)
24 * return the next machine floating-point number of x in the
25 * direction toward y.
26 * Special cases:
27 */
28
29#include <errno.h>
30#include <math.h>
31#include <math_private.h>
32#include <libm-alias-ldouble.h>
33
34long double __nextafterl(long double x, long double y)
35{
36 uint32_t hx,hy,ix,iy;
37 uint32_t lx,ly;
38 int32_t esx,esy;
39
40 GET_LDOUBLE_WORDS(esx,hx,lx,x);
41 GET_LDOUBLE_WORDS(esy,hy,ly,y);
42 ix = esx&0x7fff; /* |x| */
43 iy = esy&0x7fff; /* |y| */
44
45 /* Intel's extended format has the normally implicit 1 explicit
46 present. Sigh! */
47 if(((ix==0x7fff)&&(((hx&0x7fffffff)|lx)!=0)) || /* x is nan */
48 ((iy==0x7fff)&&(((hy&0x7fffffff)|ly)!=0))) /* y is nan */
49 return x+y;
50 if(x==y) return y; /* x=y, return y */
51 if((ix|hx|lx)==0) { /* x == 0 */
52 long double u;
53 SET_LDOUBLE_WORDS(x,esy&0x8000,0,1);/* return +-minsubnormal */
54 u = math_opt_barrier (x);
55 u = u * u;
56 math_force_eval (u); /* raise underflow flag */
57 return x;
58 }
59 if(esx>=0) { /* x > 0 */
60 if(esx>esy||((esx==esy) && (hx>hy||((hx==hy)&&(lx>ly))))) {
61 /* x > y, x -= ulp */
62 if(lx==0) {
63 if (hx <= 0x80000000) {
64 if (esx == 0) {
65 --hx;
66 } else {
67 esx -= 1;
68 hx = hx - 1;
69 if (esx > 0)
70 hx |= 0x80000000;
71 }
72 } else
73 hx -= 1;
74 }
75 lx -= 1;
76 } else { /* x < y, x += ulp */
77 lx += 1;
78 if(lx==0) {
79 hx += 1;
80 if (hx==0 || (esx == 0 && hx == 0x80000000)) {
81 esx += 1;
82 hx |= 0x80000000;
83 }
84 }
85 }
86 } else { /* x < 0 */
87 if(esy>=0||(esx>esy||((esx==esy)&&(hx>hy||((hx==hy)&&(lx>ly)))))){
88 /* x < y, x -= ulp */
89 if(lx==0) {
90 if (hx <= 0x80000000 && esx != 0xffff8000) {
91 esx -= 1;
92 hx = hx - 1;
93 if ((esx&0x7fff) > 0)
94 hx |= 0x80000000;
95 } else
96 hx -= 1;
97 }
98 lx -= 1;
99 } else { /* x > y, x += ulp */
100 lx += 1;
101 if(lx==0) {
102 hx += 1;
103 if (hx==0 || (esx == 0xffff8000 && hx == 0x80000000)) {
104 esx += 1;
105 hx |= 0x80000000;
106 }
107 }
108 }
109 }
110 esy = esx&0x7fff;
111 if(esy==0x7fff) {
112 long double u = x + x; /* overflow */
113 math_force_eval (u);
114 __set_errno (ERANGE);
115 }
116 if(esy==0) {
117 long double u = x*x; /* underflow */
118 math_force_eval (u); /* raise underflow flag */
119 __set_errno (ERANGE);
120 }
121 SET_LDOUBLE_WORDS(x,esx,hx,lx);
122 return x;
123}
124libm_alias_ldouble (__nextafter, nextafter)
125strong_alias (__nextafterl, __nexttowardl)
126weak_alias (__nextafterl, nexttowardl)
127