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