Root/lib/mpi/mpi-cmp.c

1/* mpi-cmp.c - MPI functions
2 * Copyright (C) 1998, 1999 Free Software Foundation, Inc.
3 *
4 * This file is part of GnuPG.
5 *
6 * GnuPG is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * GnuPG is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
19 */
20
21#include "mpi-internal.h"
22
23int mpi_cmp_ui(MPI u, unsigned long v)
24{
25    mpi_limb_t limb = v;
26
27    mpi_normalize(u);
28    if (!u->nlimbs && !limb)
29        return 0;
30    if (u->sign)
31        return -1;
32    if (u->nlimbs > 1)
33        return 1;
34
35    if (u->d[0] == limb)
36        return 0;
37    else if (u->d[0] > limb)
38        return 1;
39    else
40        return -1;
41}
42EXPORT_SYMBOL_GPL(mpi_cmp_ui);
43
44int mpi_cmp(MPI u, MPI v)
45{
46    mpi_size_t usize, vsize;
47    int cmp;
48
49    mpi_normalize(u);
50    mpi_normalize(v);
51    usize = u->nlimbs;
52    vsize = v->nlimbs;
53    if (!u->sign && v->sign)
54        return 1;
55    if (u->sign && !v->sign)
56        return -1;
57    if (usize != vsize && !u->sign && !v->sign)
58        return usize - vsize;
59    if (usize != vsize && u->sign && v->sign)
60        return vsize + usize;
61    if (!usize)
62        return 0;
63    cmp = mpihelp_cmp(u->d, v->d, usize);
64    if (!cmp)
65        return 0;
66    if ((cmp < 0 ? 1 : 0) == (u->sign ? 1 : 0))
67        return 1;
68    return -1;
69}
70EXPORT_SYMBOL_GPL(mpi_cmp);
71

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