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comparison libtommath/bn_s_mp_mul_high_digs.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
comparison
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1435:f849a5ca2efc 1436:60fc6476e044
1 #include <tommath.h> 1 #include <tommath_private.h>
2 #ifdef BN_S_MP_MUL_HIGH_DIGS_C 2 #ifdef BN_S_MP_MUL_HIGH_DIGS_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 /* multiplies |a| * |b| and does not compute the lower digs digits 18 /* multiplies |a| * |b| and does not compute the lower digs digits
19 * [meant to get the higher part of the product] 19 * [meant to get the higher part of the product]
20 */ 20 */
28 mp_digit tmpx, *tmpt, *tmpy; 28 mp_digit tmpx, *tmpt, *tmpy;
29 29
30 /* can we use the fast multiplier? */ 30 /* can we use the fast multiplier? */
31 #ifdef BN_FAST_S_MP_MUL_HIGH_DIGS_C 31 #ifdef BN_FAST_S_MP_MUL_HIGH_DIGS_C
32 if (((a->used + b->used + 1) < MP_WARRAY) 32 if (((a->used + b->used + 1) < MP_WARRAY)
33 && MIN (a->used, b->used) < (1 << ((CHAR_BIT * sizeof (mp_word)) - (2 * DIGIT_BIT)))) { 33 && (MIN (a->used, b->used) < (1 << ((CHAR_BIT * sizeof(mp_word)) - (2 * DIGIT_BIT))))) {
34 return fast_s_mp_mul_high_digs (a, b, c, digs); 34 return fast_s_mp_mul_high_digs (a, b, c, digs);
35 } 35 }
36 #endif 36 #endif
37 37
38 if ((res = mp_init_size (&t, a->used + b->used + 1)) != MP_OKAY) { 38 if ((res = mp_init_size (&t, a->used + b->used + 1)) != MP_OKAY) {
55 /* alias for where to read the right hand side from */ 55 /* alias for where to read the right hand side from */
56 tmpy = b->dp + (digs - ix); 56 tmpy = b->dp + (digs - ix);
57 57
58 for (iy = digs - ix; iy < pb; iy++) { 58 for (iy = digs - ix; iy < pb; iy++) {
59 /* calculate the double precision result */ 59 /* calculate the double precision result */
60 r = ((mp_word)*tmpt) + 60 r = (mp_word)*tmpt +
61 ((mp_word)tmpx) * ((mp_word)*tmpy++) + 61 ((mp_word)tmpx * (mp_word)*tmpy++) +
62 ((mp_word) u); 62 (mp_word)u;
63 63
64 /* get the lower part */ 64 /* get the lower part */
65 *tmpt++ = (mp_digit) (r & ((mp_word) MP_MASK)); 65 *tmpt++ = (mp_digit) (r & ((mp_word) MP_MASK));
66 66
67 /* carry the carry */ 67 /* carry the carry */
74 mp_clear (&t); 74 mp_clear (&t);
75 return MP_OKAY; 75 return MP_OKAY;
76 } 76 }
77 #endif 77 #endif
78 78
79 /* $Source: /cvs/libtom/libtommath/bn_s_mp_mul_high_digs.c,v $ */ 79 /* $Source$ */
80 /* $Revision: 1.3 $ */ 80 /* $Revision$ */
81 /* $Date: 2006/03/31 14:18:44 $ */ 81 /* $Date$ */