libtommath/bn_mp_clamp.c
2019-04-07 17:26:31 +02:00

28 lines
673 B
C

#include "tommath_private.h"
#ifdef BN_MP_CLAMP_C
/* LibTomMath, multiple-precision integer library -- Tom St Denis */
/* SPDX-License-Identifier: Unlicense */
/* trim unused digits
*
* This is used to ensure that leading zero digits are
* trimed and the leading "used" digit will be non-zero
* Typically very fast. Also fixes the sign if there
* are no more leading digits
*/
void mp_clamp(mp_int *a)
{
/* decrease used while the most significant digit is
* zero.
*/
while ((a->used > 0) && (a->dp[a->used - 1] == 0u)) {
--(a->used);
}
/* reset the sign flag if used == 0 */
if (a->used == 0) {
a->sign = MP_ZPOS;
}
}
#endif