release/src/router/dropbear/libtommath/bn_mp_clamp.c

   1 #include <tommath.h>
   2 #ifdef BN_MP_CLAMP_C
   3 /* LibTomMath, multiple-precision integer library -- Tom St Denis
   4  *
   5  * LibTomMath is a library that provides multiple-precision
   6  * integer arithmetic as well as number theoretic functionality.
   7  *
   8  * The library was designed directly after the MPI library by
   9  * Michael Fromberger but has been written from scratch with
  10  * additional optimizations in place.
  11  *
  12  * The library is free for all purposes without any express
  13  * guarantee it works.
  14  *
  15  * Tom St Denis, tomstdenis@gmail.com, http://math.libtomcrypt.com
  16  */
  17
  18 /* trim unused digits
  19  *
  20  * This is used to ensure that leading zero digits are
  21  * trimed and the leading "used" digit will be non-zero
  22  * Typically very fast.  Also fixes the sign if there
  23  * are no more leading digits
  24  */
  25 void
  26 mp_clamp (mp_int * a)
  27 {
  28   /* decrease used while the most significant digit is
  29    * zero.
  30    */
  31   while (a->used > 0 && a->dp[a->used - 1] == 0) {
  32     --(a->used);
  33   }
  34
  35   /* reset the sign flag if used == 0 */
  36   if (a->used == 0) {
  37     a->sign = MP_ZPOS;
  38   }
  39 }
  40 #endif
  41
  42 /* $Source: /cvs/libtom/libtommath/bn_mp_clamp.c,v $ */
  43 /* $Revision: 1.3 $ */
  44 /* $Date: 2006/03/31 14:18:44 $ */