xref: /netbsd-src/external/lgpl3/gmp/dist/mpz/realloc.c (revision 72c7faa4dbb41dbb0238d6b4a109da0d4b236dd4)
1 /* _mpz_realloc -- make the mpz_t have NEW_ALLOC digits allocated.
2 
3 Copyright 1991, 1993-1995, 2000, 2001, 2008, 2015 Free Software
4 Foundation, Inc.
5 
6 This file is part of the GNU MP Library.
7 
8 The GNU MP Library is free software; you can redistribute it and/or modify
9 it under the terms of either:
10 
11   * the GNU Lesser General Public License as published by the Free
12     Software Foundation; either version 3 of the License, or (at your
13     option) any later version.
14 
15 or
16 
17   * the GNU General Public License as published by the Free Software
18     Foundation; either version 2 of the License, or (at your option) any
19     later version.
20 
21 or both in parallel, as here.
22 
23 The GNU MP Library is distributed in the hope that it will be useful, but
24 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
25 or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
26 for more details.
27 
28 You should have received copies of the GNU General Public License and the
29 GNU Lesser General Public License along with the GNU MP Library.  If not,
30 see https://www.gnu.org/licenses/.  */
31 
32 #include <stdlib.h>
33 #include <stdio.h>
34 #include "gmp-impl.h"
35 
36 void *
_mpz_realloc(mpz_ptr m,mp_size_t new_alloc)37 _mpz_realloc (mpz_ptr m, mp_size_t new_alloc)
38 {
39   mp_ptr mp;
40 
41   /* Never allocate zero space. */
42   new_alloc = MAX (new_alloc, 1);
43 
44   if (sizeof (mp_size_t) == sizeof (int))
45     {
46       if (UNLIKELY (new_alloc > ULONG_MAX / GMP_NUMB_BITS))
47 	{
48 	  fprintf (stderr, "gmp: overflow in mpz type\n");
49 	  abort ();
50 	}
51     }
52   else
53     {
54       if (UNLIKELY (new_alloc > INT_MAX))
55 	{
56 	  fprintf (stderr, "gmp: overflow in mpz type\n");
57 	  abort ();
58 	}
59     }
60 
61   if (ALLOC (m) == 0)
62     {
63       mp = __GMP_ALLOCATE_FUNC_LIMBS (new_alloc);
64     }
65   else
66     {
67       mp = __GMP_REALLOCATE_FUNC_LIMBS (PTR (m), ALLOC (m), new_alloc);
68 
69       /* Don't create an invalid number; if the current value doesn't fit after
70 	 reallocation, clear it to 0.  */
71       if (UNLIKELY (ABSIZ (m) > new_alloc))
72 	SIZ (m) = 0;
73     }
74 
75   PTR (m) = mp;
76   ALLOC(m) = new_alloc;
77   return (void *) mp;
78 }
79