comparison bn_mp_clamp.c @ 2:86e0b50a9b58 libtommath-orig ltm-0.30-orig

ltm 0.30 orig import
author Matt Johnston <matt@ucc.asn.au>
date Mon, 31 May 2004 18:25:22 +0000
parents
children d29b64170cf0
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-1:000000000000 2:86e0b50a9b58
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 /* trim unused digits
18 *
19 * This is used to ensure that leading zero digits are
20 * trimed and the leading "used" digit will be non-zero
21 * Typically very fast. Also fixes the sign if there
22 * are no more leading digits
23 */
24 void
25 mp_clamp (mp_int * a)
26 {
27 /* decrease used while the most significant digit is
28 * zero.
29 */
30 while (a->used > 0 && a->dp[a->used - 1] == 0) {
31 --(a->used);
32 }
33
34 /* reset the sign flag if used == 0 */
35 if (a->used == 0) {
36 a->sign = MP_ZPOS;
37 }
38 }