42 lines
976 B
C
42 lines
976 B
C
#include "tommath_private.h"
|
|
#ifdef BN_MP_COUNT_BITS_C
|
|
/* LibTomMath, multiple-precision integer library -- Tom St Denis
|
|
*
|
|
* LibTomMath is a library that provides multiple-precision
|
|
* integer arithmetic as well as number theoretic functionality.
|
|
*
|
|
* The library was designed directly after the MPI library by
|
|
* Michael Fromberger but has been written from scratch with
|
|
* additional optimizations in place.
|
|
*
|
|
* SPDX-License-Identifier: Unlicense
|
|
*/
|
|
|
|
/* returns the number of bits in an int */
|
|
int mp_count_bits(const mp_int *a)
|
|
{
|
|
int r;
|
|
mp_digit q;
|
|
|
|
/* shortcut */
|
|
if (IS_ZERO(a)) {
|
|
return 0;
|
|
}
|
|
|
|
/* get number of digits and add that */
|
|
r = (a->used - 1) * DIGIT_BIT;
|
|
|
|
/* take the last digit and count the bits in it */
|
|
q = a->dp[a->used - 1];
|
|
while (q > (mp_digit)0) {
|
|
++r;
|
|
q >>= (mp_digit)1;
|
|
}
|
|
return r;
|
|
}
|
|
#endif
|
|
|
|
/* ref: $Format:%D$ */
|
|
/* git commit: $Format:%H$ */
|
|
/* commit time: $Format:%ai$ */
|