kc3-lang/libtommath/s_mp_prime_is_divisible.c

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• Hash : 448f35e2
  Author :
  Date : 2019-10-29T20:07:29
  

  simplifications: prime functions

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• s_mp_prime_is_divisible.c

• #include "tommath_private.h"
  #ifdef S_MP_PRIME_IS_DIVISIBLE_C
  /* LibTomMath, multiple-precision integer library -- Tom St Denis */
  /* SPDX-License-Identifier: Unlicense */
  
  /* determines if an integers is divisible by one
   * of the first PRIME_SIZE primes or not
   *
   * sets result to 0 if not, 1 if yes
   */
  mp_err s_mp_prime_is_divisible(const mp_int *a, bool *result)
  {
     int i;
     for (i = 0; i < MP_PRIME_TAB_SIZE; i++) {
        /* what is a mod LBL_prime_tab[i] */
        mp_err err;
        mp_digit res;
        if ((err = mp_mod_d(a, s_mp_prime_tab[i], &res)) != MP_OKAY) {
           return err;
        }
  
        /* is the residue zero? */
        if (res == 0u) {
           *result = true;
           return MP_OKAY;
        }
     }
  
     /* default to not */
     *result = false;
     return MP_OKAY;
  }
  #endif
  

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