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comparison libtommath/bn_mp_mul_2d.c @ 1436:60fc6476e044

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Update to libtommath v1.0
author Matt Johnston <matt@ucc.asn.au>
date Sat, 24 Jun 2017 22:37:14 +0800
parents 5ff8218bcee9
children 8bba51a55704
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1435:f849a5ca2efc 1436:60fc6476e044
1 #include <tommath.h> 1 #include <tommath_private.h>
2 #ifdef BN_MP_MUL_2D_C 2 #ifdef BN_MP_MUL_2D_C
3 /* LibTomMath, multiple-precision integer library -- Tom St Denis 3 /* LibTomMath, multiple-precision integer library -- Tom St Denis
4 * 4 *
5 * LibTomMath is a library that provides multiple-precision 5 * LibTomMath is a library that provides multiple-precision
6 * integer arithmetic as well as number theoretic functionality. 6 * integer arithmetic as well as number theoretic functionality.
10 * additional optimizations in place. 10 * additional optimizations in place.
11 * 11 *
12 * The library is free for all purposes without any express 12 * The library is free for all purposes without any express
13 * guarantee it works. 13 * guarantee it works.
14 * 14 *
15 * Tom St Denis, [email protected], http://math.libtomcrypt.com 15 * Tom St Denis, [email protected], http://libtom.org
16 */ 16 */
17 17
18 /* shift left by a certain bit count */ 18 /* shift left by a certain bit count */
19 int mp_mul_2d (mp_int * a, int b, mp_int * c) 19 int mp_mul_2d (mp_int * a, int b, mp_int * c)
20 { 20 {
26 if ((res = mp_copy (a, c)) != MP_OKAY) { 26 if ((res = mp_copy (a, c)) != MP_OKAY) {
27 return res; 27 return res;
28 } 28 }
29 } 29 }
30 30
31 if (c->alloc < (int)(c->used + b/DIGIT_BIT + 1)) { 31 if (c->alloc < (int)(c->used + (b / DIGIT_BIT) + 1)) {
32 if ((res = mp_grow (c, c->used + b / DIGIT_BIT + 1)) != MP_OKAY) { 32 if ((res = mp_grow (c, c->used + (b / DIGIT_BIT) + 1)) != MP_OKAY) {
33 return res; 33 return res;
34 } 34 }
35 } 35 }
36 36
37 /* shift by as many digits in the bit count */ 37 /* shift by as many digits in the bit count */
42 } 42 }
43 43
44 /* shift any bit count < DIGIT_BIT */ 44 /* shift any bit count < DIGIT_BIT */
45 d = (mp_digit) (b % DIGIT_BIT); 45 d = (mp_digit) (b % DIGIT_BIT);
46 if (d != 0) { 46 if (d != 0) {
47 register mp_digit *tmpc, shift, mask, r, rr; 47 mp_digit *tmpc, shift, mask, r, rr;
48 register int x; 48 int x;
49 49
50 /* bitmask for carries */ 50 /* bitmask for carries */
51 mask = (((mp_digit)1) << d) - 1; 51 mask = (((mp_digit)1) << d) - 1;
52 52
53 /* shift for msbs */ 53 /* shift for msbs */
78 mp_clamp (c); 78 mp_clamp (c);
79 return MP_OKAY; 79 return MP_OKAY;
80 } 80 }
81 #endif 81 #endif
82 82
83 /* $Source: /cvs/libtom/libtommath/bn_mp_mul_2d.c,v $ */ 83 /* $Source$ */
84 /* $Revision: 1.3 $ */ 84 /* $Revision$ */
85 /* $Date: 2006/03/31 14:18:44 $ */ 85 /* $Date$ */