1 /* fp_mul_comba_3.i
2 *
3 * Copyright (C) 2006-2021 wolfSSL Inc.
4 *
5 * This file is part of wolfSSL.
6 *
7 * wolfSSL is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * wolfSSL is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335, USA
20 */
21
22
23
24 #ifdef TFM_MUL3
fp_mul_comba3(fp_int * A,fp_int * B,fp_int * C)25 int fp_mul_comba3(fp_int *A, fp_int *B, fp_int *C)
26 {
27 fp_digit c0, c1, c2, at[6];
28
29 XMEMCPY(at, A->dp, 3 * sizeof(fp_digit));
30 XMEMCPY(at+3, B->dp, 3 * sizeof(fp_digit));
31 COMBA_START;
32
33 COMBA_CLEAR;
34 /* 0 */
35 MULADD(at[0], at[3]);
36 COMBA_STORE(C->dp[0]);
37 /* 1 */
38 COMBA_FORWARD;
39 MULADD(at[0], at[4]); MULADD(at[1], at[3]);
40 COMBA_STORE(C->dp[1]);
41 /* 2 */
42 COMBA_FORWARD;
43 MULADD(at[0], at[5]); MULADD(at[1], at[4]); MULADD(at[2], at[3]);
44 COMBA_STORE(C->dp[2]);
45 /* 3 */
46 COMBA_FORWARD;
47 MULADD(at[1], at[5]); MULADD(at[2], at[4]);
48 COMBA_STORE(C->dp[3]);
49 /* 4 */
50 COMBA_FORWARD;
51 MULADD(at[2], at[5]);
52 COMBA_STORE(C->dp[4]);
53 COMBA_STORE2(C->dp[5]);
54 C->used = 6;
55 C->sign = A->sign ^ B->sign;
56 fp_clamp(C);
57 COMBA_FINI;
58
59 return FP_OKAY;
60 }
61 #endif
62