KGC_TEST/miracl/source/mrpi.c

99 lines
4.0 KiB
C

/***************************************************************************
*
Copyright 2013 CertiVox UK Ltd. *
*
This file is part of CertiVox MIRACL Crypto SDK. *
*
The CertiVox MIRACL Crypto SDK provides developers with an *
extensive and efficient set of cryptographic functions. *
For further information about its features and functionalities please *
refer to http://www.certivox.com *
*
* The CertiVox MIRACL Crypto SDK is free software: you can *
redistribute it and/or modify it under the terms of the *
GNU Affero General Public License as published by the *
Free Software Foundation, either version 3 of the License, *
or (at your option) any later version. *
*
* The CertiVox MIRACL Crypto SDK 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 Affero General Public License for more details. *
*
* You should have received a copy of the GNU Affero General Public *
License along with CertiVox MIRACL Crypto SDK. *
If not, see <http://www.gnu.org/licenses/>. *
*
You can be released from the requirements of the license by purchasing *
a commercial license. Buying such a license is mandatory as soon as you *
develop commercial activities involving the CertiVox MIRACL Crypto SDK *
without disclosing the source code of your own applications, or shipping *
the CertiVox MIRACL Crypto SDK with a closed source product. *
*
***************************************************************************/
/*
* MIRACL calculate pi - by Gauss-Legendre method
* mrpi.c
*/
#include <stdlib.h>
#include "miracl.h"
#ifdef MR_FLASH
void fpi(_MIPD_ flash pi)
{ /* Calculate pi using Guass-Legendre method */
int x,nits,op[5];
#ifdef MR_OS_THREADS
miracl *mr_mip=get_mip();
#endif
if (mr_mip->ERNUM) return;
MR_IN(53)
if (size(mr_mip->pi)!=0)
{
copy(mr_mip->pi,pi);
mr_mip->EXACT=FALSE;
MR_OUT
return;
}
fconv(_MIPP_ 1,2,mr_mip->pi);
froot(_MIPP_ mr_mip->pi,2,mr_mip->pi);
fconv(_MIPP_ 1,1,mr_mip->w11);
fconv(_MIPP_ 1,4,mr_mip->w12);
x=1;
op[0]=0x6C;
op[1]=1;
op[4]=0;
nits=mr_mip->lg2b*mr_mip->nib/4;
while (x<nits)
{
copy(mr_mip->w11,mr_mip->w13);
op[2]=1;
op[3]=2;
flop(_MIPP_ mr_mip->w11,mr_mip->pi,op,mr_mip->w11);
fmul(_MIPP_ mr_mip->pi,mr_mip->w13,mr_mip->pi);
froot(_MIPP_ mr_mip->pi,2,mr_mip->pi);
fsub(_MIPP_ mr_mip->w11,mr_mip->w13,mr_mip->w13);
fmul(_MIPP_ mr_mip->w13,mr_mip->w13,mr_mip->w13);
op[3]=1;
op[2]=(-x);
flop(_MIPP_ mr_mip->w12,mr_mip->w13,op,mr_mip->w12); /* w12 = w12 - x.w13 */
x*=2;
}
fadd(_MIPP_ mr_mip->w11,mr_mip->pi,mr_mip->pi);
fmul(_MIPP_ mr_mip->pi,mr_mip->pi,mr_mip->pi);
op[0]=0x48;
op[2]=0;
op[3]=4;
flop(_MIPP_ mr_mip->pi,mr_mip->w12,op,mr_mip->pi); /* pi = pi/(4.w12) */
if (pi!=NULL) copy(mr_mip->pi,pi);
MR_OUT
}
#endif