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
|
/* mpfr_set -- copy of a floating-point number
Copyright 1999, 2001, 2002, 2003, 2004, 2005, 2006 Free Software Foundation.
This file is part of the MPFR Library.
The MPFR 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 MPFR 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 MPFR Library; see the file COPYING.LIB. If not, write to
the Free Software Foundation, Inc., 51 Franklin Place, Fifth Floor, Boston,
MA 02110-1301, USA. */
#include "mpfr-impl.h"
/* set a to abs(b) * signb: a=b when signb = SIGN(b), a=abs(b) when signb=1 */
int
mpfr_set4 (mpfr_ptr a, mpfr_srcptr b, mp_rnd_t rnd_mode, int signb)
{
/* Sign is ALWAYS copied */
MPFR_SET_SIGN (a, signb);
/* Exponent is also always copied since if the number is singular,
the exponent field determined the number.
Can't use MPFR_SET_EXP since the exponent may be singular */
MPFR_EXP (a) = MPFR_EXP (b);
if (MPFR_UNLIKELY (MPFR_IS_SINGULAR (b)))
{
/* MPFR_SET_NAN, MPFR_SET_ZERO and MPFR_SET_INF are useless
since MPFR_EXP (a) = MPFR_EXP (b) does the job */
if (MPFR_IS_NAN (b))
MPFR_RET_NAN;
else
MPFR_RET (0);
}
else if (MPFR_LIKELY (MPFR_PREC (b) == MPFR_PREC (a)))
{
/* Same precision and b is not singular:
* just copy the mantissa, and set the exponent and the sign
* The result is exact. */
MPN_COPY (MPFR_MANT (a), MPFR_MANT (b),
(MPFR_PREC (b) + BITS_PER_MP_LIMB-1)/BITS_PER_MP_LIMB);
MPFR_RET (0);
}
else
{
int inex;
/* Else Round B inside a */
MPFR_RNDRAW (inex, a, MPFR_MANT (b), MPFR_PREC (b), rnd_mode, signb,
if (MPFR_UNLIKELY ( ++MPFR_EXP (a) > __gmpfr_emax))
return mpfr_overflow (a, rnd_mode, signb) );
MPFR_RET (inex);
}
}
/* Set a to b */
#undef mpfr_set
int
mpfr_set (mpfr_ptr a, mpfr_srcptr b, mp_rnd_t rnd_mode)
{
return mpfr_set4 (a, b, rnd_mode, MPFR_SIGN (b));
}
/* Set a to |b| */
#undef mpfr_abs
int
mpfr_abs (mpfr_ptr a, mpfr_srcptr b, mp_rnd_t rnd_mode)
{
return mpfr_set4 (a, b, rnd_mode, MPFR_SIGN_POS);
}
|
