#include "tommath_private.h"
#ifdef BN_MP_REDUCE_2K_SETUP_C
/* LibTomMath, multiple-precision integer library -- Tom St Denis */
/* SPDX-License-Identifier: Unlicense */
/* determines the setup value */
int mp_reduce_2k_setup(const mp_int *a, mp_digit *d)
{
int res, p;
mp_int tmp;
if ((res = mp_init(&tmp)) != MP_OKAY) {
return res;
}
p = mp_count_bits(a);
if ((res = mp_2expt(&tmp, p)) != MP_OKAY) {
mp_clear(&tmp);
return res;
}
if ((res = s_mp_sub(&tmp, a, &tmp)) != MP_OKAY) {
mp_clear(&tmp);
return res;
}
*d = tmp.dp[0];
mp_clear(&tmp);
return MP_OKAY;
}
#endif
