1*4882a593Smuzhiyun /* mpi-cmp.c - MPI functions
2*4882a593Smuzhiyun * Copyright (C) 1998, 1999 Free Software Foundation, Inc.
3*4882a593Smuzhiyun *
4*4882a593Smuzhiyun * This file is part of GnuPG.
5*4882a593Smuzhiyun *
6*4882a593Smuzhiyun * GnuPG is free software; you can redistribute it and/or modify
7*4882a593Smuzhiyun * it under the terms of the GNU General Public License as published by
8*4882a593Smuzhiyun * the Free Software Foundation; either version 2 of the License, or
9*4882a593Smuzhiyun * (at your option) any later version.
10*4882a593Smuzhiyun *
11*4882a593Smuzhiyun * GnuPG is distributed in the hope that it will be useful,
12*4882a593Smuzhiyun * but WITHOUT ANY WARRANTY; without even the implied warranty of
13*4882a593Smuzhiyun * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14*4882a593Smuzhiyun * GNU General Public License for more details.
15*4882a593Smuzhiyun *
16*4882a593Smuzhiyun * You should have received a copy of the GNU General Public License
17*4882a593Smuzhiyun * along with this program; if not, write to the Free Software
18*4882a593Smuzhiyun * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
19*4882a593Smuzhiyun */
20*4882a593Smuzhiyun
21*4882a593Smuzhiyun #include "mpi-internal.h"
22*4882a593Smuzhiyun
mpi_cmp_ui(MPI u,unsigned long v)23*4882a593Smuzhiyun int mpi_cmp_ui(MPI u, unsigned long v)
24*4882a593Smuzhiyun {
25*4882a593Smuzhiyun mpi_limb_t limb = v;
26*4882a593Smuzhiyun
27*4882a593Smuzhiyun mpi_normalize(u);
28*4882a593Smuzhiyun if (!u->nlimbs && !limb)
29*4882a593Smuzhiyun return 0;
30*4882a593Smuzhiyun if (u->sign)
31*4882a593Smuzhiyun return -1;
32*4882a593Smuzhiyun if (u->nlimbs > 1)
33*4882a593Smuzhiyun return 1;
34*4882a593Smuzhiyun
35*4882a593Smuzhiyun if (u->d[0] == limb)
36*4882a593Smuzhiyun return 0;
37*4882a593Smuzhiyun else if (u->d[0] > limb)
38*4882a593Smuzhiyun return 1;
39*4882a593Smuzhiyun else
40*4882a593Smuzhiyun return -1;
41*4882a593Smuzhiyun }
42*4882a593Smuzhiyun EXPORT_SYMBOL_GPL(mpi_cmp_ui);
43*4882a593Smuzhiyun
do_mpi_cmp(MPI u,MPI v,int absmode)44*4882a593Smuzhiyun static int do_mpi_cmp(MPI u, MPI v, int absmode)
45*4882a593Smuzhiyun {
46*4882a593Smuzhiyun mpi_size_t usize;
47*4882a593Smuzhiyun mpi_size_t vsize;
48*4882a593Smuzhiyun int usign;
49*4882a593Smuzhiyun int vsign;
50*4882a593Smuzhiyun int cmp;
51*4882a593Smuzhiyun
52*4882a593Smuzhiyun mpi_normalize(u);
53*4882a593Smuzhiyun mpi_normalize(v);
54*4882a593Smuzhiyun
55*4882a593Smuzhiyun usize = u->nlimbs;
56*4882a593Smuzhiyun vsize = v->nlimbs;
57*4882a593Smuzhiyun usign = absmode ? 0 : u->sign;
58*4882a593Smuzhiyun vsign = absmode ? 0 : v->sign;
59*4882a593Smuzhiyun
60*4882a593Smuzhiyun /* Compare sign bits. */
61*4882a593Smuzhiyun
62*4882a593Smuzhiyun if (!usign && vsign)
63*4882a593Smuzhiyun return 1;
64*4882a593Smuzhiyun if (usign && !vsign)
65*4882a593Smuzhiyun return -1;
66*4882a593Smuzhiyun
67*4882a593Smuzhiyun /* U and V are either both positive or both negative. */
68*4882a593Smuzhiyun
69*4882a593Smuzhiyun if (usize != vsize && !usign && !vsign)
70*4882a593Smuzhiyun return usize - vsize;
71*4882a593Smuzhiyun if (usize != vsize && usign && vsign)
72*4882a593Smuzhiyun return vsize + usize;
73*4882a593Smuzhiyun if (!usize)
74*4882a593Smuzhiyun return 0;
75*4882a593Smuzhiyun cmp = mpihelp_cmp(u->d, v->d, usize);
76*4882a593Smuzhiyun if (!cmp)
77*4882a593Smuzhiyun return 0;
78*4882a593Smuzhiyun if ((cmp < 0?1:0) == (usign?1:0))
79*4882a593Smuzhiyun return 1;
80*4882a593Smuzhiyun
81*4882a593Smuzhiyun return -1;
82*4882a593Smuzhiyun }
83*4882a593Smuzhiyun
mpi_cmp(MPI u,MPI v)84*4882a593Smuzhiyun int mpi_cmp(MPI u, MPI v)
85*4882a593Smuzhiyun {
86*4882a593Smuzhiyun return do_mpi_cmp(u, v, 0);
87*4882a593Smuzhiyun }
88*4882a593Smuzhiyun EXPORT_SYMBOL_GPL(mpi_cmp);
89*4882a593Smuzhiyun
mpi_cmpabs(MPI u,MPI v)90*4882a593Smuzhiyun int mpi_cmpabs(MPI u, MPI v)
91*4882a593Smuzhiyun {
92*4882a593Smuzhiyun return do_mpi_cmp(u, v, 1);
93*4882a593Smuzhiyun }
94*4882a593Smuzhiyun EXPORT_SYMBOL_GPL(mpi_cmpabs);
95