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
|
/* Set NaN payload. ldbl-128ibm version.
Copyright (C) 2016-2019 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <math.h>
#include <math_private.h>
#include <nan-high-order-bit.h>
#include <stdint.h>
#define SET_HIGH_BIT (HIGH_ORDER_BIT_IS_SET_FOR_SNAN ? SIG : !SIG)
#define BIAS 0x3ff
#define PAYLOAD_DIG 51
#define EXPLICIT_MANT_DIG 52
int
FUNC (long double *x, long double payload)
{
double hi, lo;
uint64_t hx, lx;
ldbl_unpack (payload, &hi, &lo);
EXTRACT_WORDS64 (hx, hi);
EXTRACT_WORDS64 (lx, lo);
int exponent = hx >> EXPLICIT_MANT_DIG;
/* Test if argument is (a) negative or too large; (b) too small,
except for 0 when allowed; (c) not an integer. All valid
arguments have the low part zero. */
if ((lx & 0x7fffffffffffffffULL) != 0
|| exponent >= BIAS + PAYLOAD_DIG
|| (exponent < BIAS && !(SET_HIGH_BIT && hx == 0))
|| (hx & ((1ULL << (BIAS + EXPLICIT_MANT_DIG - exponent)) - 1)) != 0)
{
*x = 0.0L;
return 1;
}
if (hx != 0)
{
hx &= (1ULL << EXPLICIT_MANT_DIG) - 1;
hx |= 1ULL << EXPLICIT_MANT_DIG;
hx >>= BIAS + EXPLICIT_MANT_DIG - exponent;
}
hx |= 0x7ff0000000000000ULL | (SET_HIGH_BIT ? 0x8000000000000ULL : 0);
INSERT_WORDS64 (hi, hx);
*x = ldbl_pack (hi, 0.0);
return 0;
}
|
