kc3-lang/libtommath/bn_mp_get_long.c

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• Hash : 99c84acc
  Author :
  Date : 2015-11-13T10:28:23
  

  add parentheses for explicit operator precedence

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• bn_mp_get_long.c

• #include <tommath_private.h>
  #ifdef BN_MP_GET_LONG_C
  /* LibTomMath, multiple-precision integer library -- Tom St Denis
   *
   * LibTomMath is a library that provides multiple-precision
   * integer arithmetic as well as number theoretic functionality.
   *
   * The library was designed directly after the MPI library by
   * Michael Fromberger but has been written from scratch with
   * additional optimizations in place.
   *
   * The library is free for all purposes without any express
   * guarantee it works.
   *
   * Tom St Denis, tstdenis82@gmail.com, http://libtom.org
   */
  
  /* get the lower unsigned long of an mp_int, platform dependent */
  unsigned long mp_get_long(mp_int * a)
  {
    int i;
    unsigned long res;
  
    if (a->used == 0) {
       return 0;
    }
  
    /* get number of digits of the lsb we have to read */
    i = MIN(a->used,(int)(((sizeof(unsigned long) * CHAR_BIT) + DIGIT_BIT - 1) / DIGIT_BIT)) - 1;
  
    /* get most significant digit of result */
    res = DIGIT(a,i);
  
  #if (ULONG_MAX != 0xffffffffuL) || (DIGIT_BIT < 32)
    while (--i >= 0) {
      res = (res << DIGIT_BIT) | DIGIT(a,i);
    }
  #endif
    return res;
  }
  #endif
  

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