Tcl Source Code

   if (b < 0) {
      return MP_VAL;
   }

   limb = b / DIGIT_BIT;

   /*
    * Zero is a special value with the member "used" set to zero.
    * Needs to be tested before the check for the upper boundary
    * otherwise (limb >= a->used) would be true for a = 0
    */

   if (mp_iszero(a) != MP_NO) {
      return MP_NO;
   }

   if (limb >= a->used) {
      return MP_VAL;
   }

   bit = (mp_digit)(1) << (b % DIGIT_BIT);

   isset = a->dp[limb] & bit;
   return (isset != 0u) ? MP_YES : MP_NO;
}