iset_si.c revision 1.1.1.1 
1/* mpf_init_set_si() -- Initialize a float and assign it from a signed int.
2
3Copyright 1993, 1994, 1995, 2000, 2001, 2003, 2004 Free Software Foundation,
4Inc.
5
6This file is part of the GNU MP Library.
7
8The GNU MP Library is free software; you can redistribute it and/or modify
9it under the terms of the GNU Lesser General Public License as published by
10the Free Software Foundation; either version 3 of the License, or (at your
11option) any later version.
12
13The GNU MP Library is distributed in the hope that it will be useful, but
14WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
15or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
16License for more details.
17
18You should have received a copy of the GNU Lesser General Public License
19along with the GNU MP Library.  If not, see http://www.gnu.org/licenses/.  */
20
21#include "gmp.h"
22#include "gmp-impl.h"
23
24void
25mpf_init_set_si (mpf_ptr r, long int val)
26{
27  mp_size_t prec = __gmp_default_fp_limb_precision;
28  mp_size_t size;
29  mp_limb_t vl;
30
31  r->_mp_prec = prec;
32  r->_mp_d = (mp_ptr) (*__gmp_allocate_func) ((prec + 1) * BYTES_PER_MP_LIMB);
33
34  vl = (mp_limb_t) (unsigned long int) (val >= 0 ? val : -val);
35
36  r->_mp_d[0] = vl & GMP_NUMB_MASK;
37  size = vl != 0;
38
39#if BITS_PER_ULONG > GMP_NUMB_BITS
40  vl >>= GMP_NUMB_BITS;
41  r->_mp_d[1] = vl;
42  size += (vl != 0);
43#endif
44
45  r->_mp_exp = size;
46  r->_mp_size = val >= 0 ? size : -size;
47}
48