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

00001 #include <tommath.h>
00002 #ifdef BN_MP_NEG_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 /* b = -a */
00019 int mp_neg (mp_int * a, mp_int * b)
00020 {
00021   int     res;
00022   if (a != b) {
00023      if ((res = mp_copy (a, b)) != MP_OKAY) {
00024         return res;
00025      }
00026   }
00027 
00028   if (mp_iszero(b) != MP_YES) {
00029      b->sign = (a->sign == MP_ZPOS) ? MP_NEG : MP_ZPOS;
00030   } else {
00031      b->sign = MP_ZPOS;
00032   }
00033 
00034   return MP_OKAY;
00035 }
00036 #endif
00037 
00038 /* $Source: /cvsroot/tcl/libtommath/bn_mp_neg.c,v $ */
00039 /* $Revision: 1.1.1.4 $ */
00040 /* $Date: 2006/12/01 00:08:11 $ */