kc3-lang/libtommath/mp_reduce_is_2k.c

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• Hash : 3cdcec43
  Author :
  Date : 2019-10-29T18:41:25
  

  first batch of simplifications

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• mp_reduce_is_2k.c

• #include "tommath_private.h"
  #ifdef MP_REDUCE_IS_2K_C
  /* LibTomMath, multiple-precision integer library -- Tom St Denis */
  /* SPDX-License-Identifier: Unlicense */
  
  /* determines if mp_reduce_2k can be used */
  bool mp_reduce_is_2k(const mp_int *a)
  {
     if (a->used == 0) {
        return false;
     } else if (a->used == 1) {
        return true;
     } else if (a->used > 1) {
        int ix, iy = mp_count_bits(a), iw = 1;
        mp_digit iz = 1;
  
        /* Test every bit from the second digit up, must be 1 */
        for (ix = MP_DIGIT_BIT; ix < iy; ix++) {
           if ((a->dp[iw] & iz) == 0u) {
              return false;
           }
           iz <<= 1;
           if (iz > MP_DIGIT_MAX) {
              ++iw;
              iz = 1;
           }
        }
        return true;
     } else {
        return true;
     }
  }
  
  #endif
  

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