Mercurial > hg > Members > anatofuz > MoarVM

annotate 3rdparty/libtommath/bn_mp_mod_2d.c @ 0:2cf249471370

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
convert mercurial for git
author Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
date Tue, 08 May 2018 16:09:12 +0900
parents
children
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
0
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
1 #include <tommath_private.h>
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
2 #ifdef BN_MP_MOD_2D_C
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
3 /* LibTomMath, multiple-precision integer library -- Tom St Denis
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
4 *
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
5 * LibTomMath is a library that provides multiple-precision
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
6 * integer arithmetic as well as number theoretic functionality.
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
7 *
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
8 * The library was designed directly after the MPI library by
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
9 * Michael Fromberger but has been written from scratch with
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
10 * additional optimizations in place.
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
11 *
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
12 * The library is free for all purposes without any express
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
13 * guarantee it works.
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
14 *
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
15 * Tom St Denis, tstdenis82@gmail.com, http://libtom.org
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
16 */
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
17
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
18 /* calc a value mod 2**b */
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
19 int
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
20 mp_mod_2d (mp_int * a, int b, mp_int * c)
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
21 {
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
22 int x, res;
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
23
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
24 /* if b is <= 0 then zero the int */
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
25 if (b <= 0) {
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
26 mp_zero (c);
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
27 return MP_OKAY;
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
28 }
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
29
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
30 /* if the modulus is larger than the value than return */
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
31 if (b >= (int) (a->used * DIGIT_BIT)) {
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
32 res = mp_copy (a, c);
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
33 return res;
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
34 }
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
35
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
36 /* copy */
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
37 if ((res = mp_copy (a, c)) != MP_OKAY) {
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
38 return res;
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
39 }
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
40
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
41 /* zero digits above the last digit of the modulus */
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
42 for (x = (b / DIGIT_BIT) + (((b % DIGIT_BIT) == 0) ? 0 : 1); x < c->used; x++) {
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
43 c->dp[x] = 0;
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
44 }
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
45 /* clear the digit that is not completely outside/inside the modulus */
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
46 c->dp[b / DIGIT_BIT] &=
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
47 (mp_digit) ((((mp_digit) 1) << (((mp_digit) b) % DIGIT_BIT)) - ((mp_digit) 1));
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
48 mp_clamp (c);
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
49 return MP_OKAY;
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
50 }
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
51 #endif
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
52
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
53 /* $Source$ */
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
54 /* $Revision$ */
2cf249471370 convert mercurial for git
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
55 /* $Date$ */