1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
|
/* s_nexttowardf.c -- float version of s_nextafter.c.
* Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com
* and Jakub Jelinek, jj@ultra.linux.cz.
*/
/*
* ====================================================
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
*
* Developed at SunPro, a Sun Microsystems, Inc. business.
* Permission to use, copy, modify, and distribute this
* software is freely granted, provided that this notice
* is preserved.
* ====================================================
*/
#if defined(LIBM_SCCS) && !defined(lint)
static char rcsid[] = "$NetBSD: $";
#endif
#include <errno.h>
#include <math.h>
#include <math_private.h>
#include <math_ldbl_opt.h>
#include <float.h>
float __nexttowardf(float x, long double y)
{
int32_t hx,ix;
int64_t hy,iy;
double yhi;
GET_FLOAT_WORD(hx,x);
yhi = ldbl_high (y);
EXTRACT_WORDS64 (hy, yhi);
ix = hx&0x7fffffff; /* |x| */
iy = hy&0x7fffffffffffffffLL; /* |y| */
if((ix>0x7f800000) || /* x is nan */
(iy>0x7ff0000000000000LL))
/* y is nan */
return x+y;
if((long double) x==y) return y; /* x=y, return y */
if(ix==0) { /* x == 0 */
float u;
SET_FLOAT_WORD(x,(u_int32_t)((hy>>32)&0x80000000)|1);/* return +-minsub*/
u = math_opt_barrier (x);
u = u * u;
math_force_eval (u); /* raise underflow flag */
return x;
}
if(hx>=0) { /* x > 0 */
if(x > y) { /* x -= ulp */
hx -= 1;
} else { /* x < y, x += ulp */
hx += 1;
}
} else { /* x < 0 */
if(x < y) { /* x -= ulp */
hx -= 1;
} else { /* x > y, x += ulp */
hx += 1;
}
}
hy = hx&0x7f800000;
if(hy>=0x7f800000) {
float u = x+x; /* overflow */
math_force_eval (u);
__set_errno (ERANGE);
}
if(hy<0x00800000) { /* underflow */
float u = x*x;
math_force_eval (u); /* raise underflow flag */
__set_errno (ERANGE);
}
SET_FLOAT_WORD(x,hx);
return x;
}
long_double_symbol (libm, __nexttowardf, nexttowardf);
|
