xref: /linux/lib/crypto/mpi/mpi-cmp.c (revision 13150742b09e720fdf021de14cd2b98b37415a89)
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 
mpi_cmp_ui(MPI u,unsigned long v)25 int 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 }
48 EXPORT_SYMBOL_GPL(mpi_cmp_ui);
49 
mpi_cmp(MPI u,MPI v)50 int 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 }
74 EXPORT_SYMBOL_GPL(mpi_cmp);
75