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Giac_maj/libtommath-0.39/bn_mp_clamp.c 1.15 KB
6663b6c9   adorian   projet complet av...
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  #include <tommath.h>
  #ifdef BN_MP_CLAMP_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
   */
  
  /* trim unused digits 
   *
   * This is used to ensure that leading zero digits are
   * trimed and the leading "used" digit will be non-zero
   * Typically very fast.  Also fixes the sign if there
   * are no more leading digits
   */
  void
  mp_clamp (mp_int * a)
  {
    /* decrease used while the most significant digit is
     * zero.
     */
    while (a->used > 0 && a->dp[a->used - 1] == 0) {
      --(a->used);
    }
  
    /* reset the sign flag if used == 0 */
    if (a->used == 0) {
      a->sign = MP_ZPOS;
    }
  }
  #endif
  
  /* $Source: /cvs/libtom/libtommath/bn_mp_clamp.c,v $ */
  /* $Revision: 1.3 $ */
  /* $Date: 2006/03/31 14:18:44 $ */