tomsfastmath/src/exptmod/fp_2expt.c
Sebastian Andrzej Siewior f7e7f83718 provide tfm_private.h
tfm.h contains declarations for the public part of the library.
tfm_private.h contains the function which are private to tfm and should
not be exposed to the public.

Signed-off-by: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
2015-08-16 22:04:51 +02:00

40 lines
705 B
C

/* 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_private.h>
/* computes a = 2**b */
void fp_2expt(fp_int *a, int b)
{
int z;
/* zero a as per default */
fp_zero (a);
if (b < 0) {
return;
}
z = b / DIGIT_BIT;
if (z >= FP_SIZE) {
return;
}
/* set the used count of where the bit will go */
a->used = z + 1;
/* put the single bit in its place */
a->dp[z] = ((fp_digit)1) << (b % DIGIT_BIT);
}
/* $Source$ */
/* $Revision$ */
/* $Date$ */