comparison bn_mp_cmp_mag.c @ 1:22d5cf7d4b1a libtommath

Renaming branch
author Matt Johnston <matt@ucc.asn.au>
date Mon, 31 May 2004 18:23:46 +0000
parents
children d29b64170cf0
comparison
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-1:000000000000 1:22d5cf7d4b1a
1 /* LibTomMath, multiple-precision integer library -- Tom St Denis
2 *
3 * LibTomMath is a library that provides multiple-precision
4 * integer arithmetic as well as number theoretic functionality.
5 *
6 * The library was designed directly after the MPI library by
7 * Michael Fromberger but has been written from scratch with
8 * additional optimizations in place.
9 *
10 * The library is free for all purposes without any express
11 * guarantee it works.
12 *
13 * Tom St Denis, [email protected], http://math.libtomcrypt.org
14 */
15 #include <tommath.h>
16
17 /* compare maginitude of two ints (unsigned) */
18 int mp_cmp_mag (mp_int * a, mp_int * b)
19 {
20 int n;
21 mp_digit *tmpa, *tmpb;
22
23 /* compare based on # of non-zero digits */
24 if (a->used > b->used) {
25 return MP_GT;
26 }
27
28 if (a->used < b->used) {
29 return MP_LT;
30 }
31
32 /* alias for a */
33 tmpa = a->dp + (a->used - 1);
34
35 /* alias for b */
36 tmpb = b->dp + (a->used - 1);
37
38 /* compare based on digits */
39 for (n = 0; n < a->used; ++n, --tmpa, --tmpb) {
40 if (*tmpa > *tmpb) {
41 return MP_GT;
42 }
43
44 if (*tmpa < *tmpb) {
45 return MP_LT;
46 }
47 }
48 return MP_EQ;
49 }