blob: b219de0fca030ed45d827e08450ce82b151ad83e (
plain) (
blame)
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
|
/* Copyright (C) 1995-2015 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 "gmp.h"
#include "gmp-impl.h"
#include <ieee754.h>
#include <float.h>
#include <math.h>
/* Convert a multi-precision integer of the needed number of bits (64 for
long double) and an integral power of two to a `long double' in IEEE854
extended-precision format. */
long double
__mpn_construct_long_double (mp_srcptr frac_ptr, int expt, int sign)
{
union ieee854_long_double u;
u.ieee.negative = sign;
u.ieee.exponent = expt + IEEE854_LONG_DOUBLE_BIAS;
#if BITS_PER_MP_LIMB == 32
u.ieee.mantissa1 = frac_ptr[0];
u.ieee.mantissa0 = frac_ptr[1];
#elif BITS_PER_MP_LIMB == 64
u.ieee.mantissa1 = frac_ptr[0] & (((mp_limb_t) 1 << 32) - 1);
u.ieee.mantissa0 = frac_ptr[0] >> 32;
#else
#error "mp_limb size " BITS_PER_MP_LIMB "not accounted for"
#endif
return u.d;
}
|
