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 <linux/export.h>
22
23#include "mpi-internal.h"
24
25int mpi_cmp_ui(MPI u, unsigned long v)
26{
27	mpi_limb_t limb = v;
28
29	mpi_normalize(u);
30	if (u->nlimbs == 0) {
31		if (v == 0)
32			return 0;
33		else
34			return -1;
35	}
36	if (u->sign)
37		return -1;
38	if (u->nlimbs > 1)
39		return 1;
40
41	if (u->d[0] == limb)
42		return 0;
43	else if (u->d[0] > limb)
44		return 1;
45	else
46		return -1;
47}
48EXPORT_SYMBOL_GPL(mpi_cmp_ui);
49
50int mpi_cmp(MPI u, MPI v)
51{
52	mpi_size_t usize, vsize;
53	int cmp;
54
55	mpi_normalize(u);
56	mpi_normalize(v);
57	usize = u->nlimbs;
58	vsize = v->nlimbs;
59	if (!u->sign && v->sign)
60		return 1;
61	if (u->sign && !v->sign)
62		return -1;
63	if (usize != vsize && !u->sign && !v->sign)
64		return usize - vsize;
65	if (usize != vsize && u->sign && v->sign)
66		return vsize - usize;
67	if (!usize)
68		return 0;
69	cmp = mpihelp_cmp(u->d, v->d, usize);
70	if (u->sign)
71		return -cmp;
72	return cmp;
73}
74EXPORT_SYMBOL_GPL(mpi_cmp);