/home/ntakagi/work/tcl8.5.1/libtommath/bn_mp_cmp_mag.c Source File

00001 #include <tommath.h>
00002 #ifdef BN_MP_CMP_MAG_C
00003 /* LibTomMath, multiple-precision integer library -- Tom St Denis
00004  *
00005  * LibTomMath is a library that provides multiple-precision
00006  * integer arithmetic as well as number theoretic functionality.
00007  *
00008  * The library was designed directly after the MPI library by
00009  * Michael Fromberger but has been written from scratch with
00010  * additional optimizations in place.
00011  *
00012  * The library is free for all purposes without any express
00013  * guarantee it works.
00014  *
00015  * Tom St Denis, tomstdenis@gmail.com, http://math.libtomcrypt.com
00016  */
00017 
00018 /* compare maginitude of two ints (unsigned) */
00019 int mp_cmp_mag (mp_int * a, mp_int * b)
00020 {
00021   int     n;
00022   mp_digit *tmpa, *tmpb;
00023 
00024   /* compare based on # of non-zero digits */
00025   if (a->used > b->used) {
00026     return MP_GT;
00027   }
00028   
00029   if (a->used < b->used) {
00030     return MP_LT;
00031   }
00032 
00033   /* alias for a */
00034   tmpa = a->dp + (a->used - 1);
00035 
00036   /* alias for b */
00037   tmpb = b->dp + (a->used - 1);
00038 
00039   /* compare based on digits  */
00040   for (n = 0; n < a->used; ++n, --tmpa, --tmpb) {
00041     if (*tmpa > *tmpb) {
00042       return MP_GT;
00043     }
00044 
00045     if (*tmpa < *tmpb) {
00046       return MP_LT;
00047     }
00048   }
00049   return MP_EQ;
00050 }
00051 #endif
00052 
00053 /* $Source: /cvsroot/tcl/libtommath/bn_mp_cmp_mag.c,v $ */
00054 /* $Revision: 1.1.1.3 $ */
00055 /* $Date: 2006/12/01 00:08:11 $ */