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

   1 #include <tommath.h>
   2 #ifdef BN_MP_CMP_MAG_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 /* compare maginitude of two ints (unsigned) */
  19 int mp_cmp_mag (mp_int * a, mp_int * b)
  20 {
  21   int     n;
  22   mp_digit *tmpa, *tmpb;
  23
  24   /* compare based on # of non-zero digits */
  25   if (a->used > b->used) {
  26     return MP_GT;
  27   }
  28
  29   if (a->used < b->used) {
  30     return MP_LT;
  31   }
  32
  33   /* alias for a */
  34   tmpa = a->dp + (a->used - 1);
  35
  36   /* alias for b */
  37   tmpb = b->dp + (a->used - 1);
  38
  39   /* compare based on digits  */
  40   for (n = 0; n < a->used; ++n, --tmpa, --tmpb) {
  41     if (*tmpa > *tmpb) {
  42       return MP_GT;
  43     }
  44
  45     if (*tmpa < *tmpb) {
  46       return MP_LT;
  47     }
  48   }
  49   return MP_EQ;
  50 }
  51 #endif
  52
  53 /* $Source: /cvs/libtom/libtommath/bn_mp_cmp_mag.c,v $ */
  54 /* $Revision: 1.3 $ */
  55 /* $Date: 2006/03/31 14:18:44 $ */