Donatien Garnier / MiniTLS-GPL

A super trimmed down TLS stack, GPL licensed

Dependents:   MiniTLS-HTTPS-Example

MiniTLS - A super trimmed down TLS/SSL Library for embedded devices Author: Donatien Garnier Copyright (C) 2013-2014 AppNearMe Ltd

This program 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 2 of the License, or (at your option) any later version.

This program 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 02110-1301, USA.

math/mul/fp_mul.c

Committer:
MiniTLS
Date:
2014-06-10
Revision:
4:cbaf466d717d
Parent:
0:35aa5be3b78d

File content as of revision 4:cbaf466d717d:

/* TomsFastMath, a fast ISO C bignum library.
 * 
 * This project is meant to fill in where LibTomMath
 * falls short.  That is speed ;-)
 *
 * This project is public domain and free for all purposes.
 * 
 * Tom St Denis, tomstdenis@gmail.com
 */
#include <tfm.h>

/* c = a * b */
void fp_mul(fp_int *A, fp_int *B, fp_int *C)
{
    int   y, yy;

    /* call generic if we're out of range */
    if (A->used + B->used > FP_SIZE) {
       fp_mul_comba(A, B, C);
       return ;
    }

     y  = MAX(A->used, B->used);
     yy = MIN(A->used, B->used);
    /* pick a comba (unrolled 4/8/16/32 x or rolled) based on the size
       of the largest input.  We also want to avoid doing excess mults if the 
       inputs are not close to the next power of two.  That is, for example,
       if say y=17 then we would do (32-17)^2 = 225 unneeded multiplications 
    */

#ifdef TFM_MUL3
        if (y <= 3) {
           fp_mul_comba3(A,B,C);
           return;
        }
#endif
#ifdef TFM_MUL4
        if (y == 4) {
           fp_mul_comba4(A,B,C);
           return;
        }
#endif
#ifdef TFM_MUL6
        if (y <= 6) {
           fp_mul_comba6(A,B,C);
           return;
        }
#endif
#ifdef TFM_MUL7
        if (y == 7) {
           fp_mul_comba7(A,B,C);
           return;
        }
#endif
#ifdef TFM_MUL8
        if (y == 8) {
           fp_mul_comba8(A,B,C);
           return;
        }
#endif
#ifdef TFM_MUL9
        if (y == 9) {
           fp_mul_comba9(A,B,C);
           return;
        }
#endif
#ifdef TFM_MUL12
        if (y <= 12) {
           fp_mul_comba12(A,B,C);
           return;
        }
#endif
#ifdef TFM_MUL17
        if (y <= 17) {
           fp_mul_comba17(A,B,C);
           return;
        }
#endif

#ifdef TFM_SMALL_SET
        if (y <= 16) {
           fp_mul_comba_small(A,B,C);
           return;
        }
#endif        
#if defined(TFM_MUL20)
        if (y <= 20) {
           fp_mul_comba20(A,B,C);
           return;
        }
#endif
#if defined(TFM_MUL24)
        if (yy >= 16 && y <= 24) {
           fp_mul_comba24(A,B,C);
           return;
        }
#endif
#if defined(TFM_MUL28)
        if (yy >= 20 && y <= 28) {
           fp_mul_comba28(A,B,C);
           return;
        }
#endif
#if defined(TFM_MUL32)
        if (yy >= 24 && y <= 32) {
           fp_mul_comba32(A,B,C);
           return;
        }
#endif
#if defined(TFM_MUL48)
        if (yy >= 40 && y <= 48) {
           fp_mul_comba48(A,B,C);
           return;
        }
#endif        
#if defined(TFM_MUL64)
        if (yy >= 56 && y <= 64) {
           fp_mul_comba64(A,B,C);
           return;
        }
#endif
        fp_mul_comba(A,B,C);
}


/* $Source: /cvs/libtom/tomsfastmath/src/mul/fp_mul.c,v $ */
/* $Revision: 1.1 $ */
/* $Date: 2006/12/31 21:25:53 $ */