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Giac_maj/libtommath-0.39/bn_mp_cmp_mag.c 1.25 KB
6663b6c9   adorian   projet complet av...
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  #include <tommath.h>
  #ifdef BN_MP_CMP_MAG_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, tomstdenis@gmail.com, http://math.libtomcrypt.com
   */
  
  /* compare maginitude of two ints (unsigned) */
  int mp_cmp_mag (mp_int * a, mp_int * b)
  {
    int     n;
    mp_digit *tmpa, *tmpb;
  
    /* compare based on # of non-zero digits */
    if (a->used > b->used) {
      return MP_GT;
    }
    
    if (a->used < b->used) {
      return MP_LT;
    }
  
    /* alias for a */
    tmpa = a->dp + (a->used - 1);
  
    /* alias for b */
    tmpb = b->dp + (a->used - 1);
  
    /* compare based on digits  */
    for (n = 0; n < a->used; ++n, --tmpa, --tmpb) {
      if (*tmpa > *tmpb) {
        return MP_GT;
      }
  
      if (*tmpa < *tmpb) {
        return MP_LT;
      }
    }
    return MP_EQ;
  }
  #endif
  
  /* $Source: /cvs/libtom/libtommath/bn_mp_cmp_mag.c,v $ */
  /* $Revision: 1.3 $ */
  /* $Date: 2006/03/31 14:18:44 $ */