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comparison bn_mp_sqr.c @ 1:22d5cf7d4b1a libtommath

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Renaming branch
author Matt Johnston <matt@ucc.asn.au>
date Mon, 31 May 2004 18:23:46 +0000
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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 /* computes b = a*a */
18 int
19 mp_sqr (mp_int * a, mp_int * b)
20 {
21 int res;
22 #ifndef NO_LTM_TOOM
23 /* use Toom-Cook? */
24 if (a->used >= TOOM_SQR_CUTOFF) {
25 res = mp_toom_sqr(a, b);
26 } else
27 #endif
28 #ifndef NO_LTM_KARATSUBA
29 /* Karatsuba? */
30 if (a->used >= KARATSUBA_SQR_CUTOFF) {
31 res = mp_karatsuba_sqr (a, b);
32 } else
33 #endif
34 {
35 /* can we use the fast comba multiplier? */
36 if ((a->used * 2 + 1) < MP_WARRAY &&
37 a->used <
38 (1 << (sizeof(mp_word) * CHAR_BIT - 2*DIGIT_BIT - 1))) {
39 res = fast_s_mp_sqr (a, b);
40 } else {
41 res = s_mp_sqr (a, b);
42 }
43 }
44 b->sign = MP_ZPOS;
45 return res;
46 }