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
80
81
82
83
|
/*
* Copyright © 2005-2014 Rich Felker, et al.
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#include "math_config.h"
// This is only necessary because the implementation of isnan only works
// properly when long double == double.
// See: https://sourceware.org/ml/newlib/2014/msg00684.html
#if !defined(_NEED_FLOAT_HUGE)
float
nexttowardf (float x, long double y)
{
uint32_t ux;
uint32_t e;
/*
* We can't do this if y isn't nan as that might raise INEXACT doing
* long double -> float conversion, and we don't want to do this
* in long double for machines without long double HW as we won't
* get any exceptions in that case.
*/
if (isnan(y))
return x + (issignaling(y) ? __builtin_nansf("") : (float) y);
if (isnan(x))
return x + x;
if ((long double) x == y)
return (float) y;
ux = asuint(x);
if (x == 0) {
ux = 1;
if (signbit(y))
ux |= 0x80000000;
x = asfloat(ux);
force_eval_float(x*x);
return x;
} else if ((long double) x < y) {
if (signbit(x))
ux--;
else
ux++;
} else {
if (signbit(x))
ux++;
else
ux--;
}
e = ux & 0x7f800000;
/* raise overflow if ux.value is infinite and x is finite */
if (e == 0x7f800000)
return check_oflowf(opt_barrier_float(x+x));
/* raise underflow if ux.value is subnormal or zero */
x = asfloat(ux);
if (e == 0)
return __math_denormf(x);
return x;
}
_MATH_ALIAS_f_fl(nexttoward)
#endif /* _NEED_FLOAT_HUGE */
|
