/* fp_mul_comba_4.i

 *

 * Copyright (C) 2006-2025 wolfSSL Inc.

 *

 * This file is part of wolfSSL.

 *

 * wolfSSL is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 3 of the License, or

 * (at your option) any later version.

 *

 * wolfSSL is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335, USA

 */

#ifdef TFM_MUL4

int fp_mul_comba4(fp_int *A, fp_int *B, fp_int *C)

{

   fp_digit c0, c1, c2;

#ifndef WOLFSSL_SMALL_STACK

   fp_digit at[8];

#else

   fp_digit *at;

#endif

#ifdef WOLFSSL_SMALL_STACK

   at = (fp_digit*)XMALLOC(sizeof(fp_digit) * 8, NULL, DYNAMIC_TYPE_TMP_BUFFER);

   if (at == NULL)

       return FP_MEM;

#endif

   XMEMCPY(at, A->dp, 4 * sizeof(fp_digit));

   XMEMCPY(at+4, B->dp, 4 * sizeof(fp_digit));

   COMBA_START;

   COMBA_CLEAR;

   /* 0 */

   MULADD(at[0], at[4]); 

   COMBA_STORE(C->dp[0]);

   /* 1 */

   COMBA_FORWARD;

   MULADD(at[0], at[5]);    MULADD(at[1], at[4]); 

   COMBA_STORE(C->dp[1]);

   /* 2 */

   COMBA_FORWARD;

   MULADD(at[0], at[6]);    MULADD(at[1], at[5]);    MULADD(at[2], at[4]); 

   COMBA_STORE(C->dp[2]);

   /* 3 */

   COMBA_FORWARD;

   MULADD(at[0], at[7]);    MULADD(at[1], at[6]);    MULADD(at[2], at[5]);    MULADD(at[3], at[4]); 

   COMBA_STORE(C->dp[3]);

   /* 4 */

   COMBA_FORWARD;

   MULADD(at[1], at[7]);    MULADD(at[2], at[6]);    MULADD(at[3], at[5]); 

   COMBA_STORE(C->dp[4]);

   /* 5 */

   COMBA_FORWARD;

   MULADD(at[2], at[7]);    MULADD(at[3], at[6]); 

   COMBA_STORE(C->dp[5]);

   /* 6 */

   COMBA_FORWARD;

   MULADD(at[3], at[7]); 

   COMBA_STORE(C->dp[6]);

   COMBA_STORE2(C->dp[7]);

   C->used = 8;

   C->sign = A->sign ^ B->sign;

   fp_clamp(C);

   COMBA_FINI;

#ifdef WOLFSSL_SMALL_STACK

   XFREE(at, NULL, DYNAMIC_TYPE_TMP_BUFFER);

#endif

   return FP_OKAY;

}

#endif