1/* mpf_fits_u*_p -- test whether an mpf fits a C unsigned type.
2
3Copyright 2001, 2002 Free Software Foundation, Inc.
4
5This file is part of the GNU MP Library.
6
7The GNU MP Library is free software; you can redistribute it and/or modify
8it under the terms of the GNU Lesser General Public License as published by
9the Free Software Foundation; either version 3 of the License, or (at your
10option) any later version.
11
12The GNU MP Library is distributed in the hope that it will be useful, but
13WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
14or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
15License for more details.
16
17You should have received a copy of the GNU Lesser General Public License
18along with the GNU MP Library.  If not, see http://www.gnu.org/licenses/.  */
19
20#include "gmp.h"
21#include "gmp-impl.h"
22
23
24/* Notice this is equivalent to mpz_set_f + mpz_fits_u*_p.  */
25
26int
27FUNCTION (mpf_srcptr f) __GMP_NOTHROW
28{
29  mp_size_t  fn;
30  mp_srcptr  fp;
31  mp_exp_t   exp;
32  mp_limb_t  fl;
33
34  fn = SIZ(f);
35  if (fn <= 0)
36    return fn == 0;  /* zero fits, negatives don't */
37
38  exp = EXP(f);
39  if (exp < 1)
40    return 1;  /* 0 < f < 1 truncates to zero, so fits */
41
42  fp = PTR(f);
43
44  if (exp == 1)
45    {
46      fl = fp[fn-1];
47    }
48#if GMP_NAIL_BITS != 0
49  else if (exp == 2 && MAXIMUM > GMP_NUMB_MAX)
50    {
51      fl = fp[fn-1];
52      if ((fl >> GMP_NAIL_BITS) != 0)
53	return 0;
54      fl = (fl << GMP_NUMB_BITS);
55      if (fn >= 2)
56        fl |= fp[fn-2];
57    }
58#endif
59  else
60    return 0;
61
62  return fl <= MAXIMUM;
63}
64