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

00001 #include <tommath.h>
00002 #ifdef BN_MP_CLAMP_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 /* trim unused digits 
00019  *
00020  * This is used to ensure that leading zero digits are
00021  * trimed and the leading "used" digit will be non-zero
00022  * Typically very fast.  Also fixes the sign if there
00023  * are no more leading digits
00024  */
00025 void
00026 mp_clamp (mp_int * a)
00027 {
00028   /* decrease used while the most significant digit is
00029    * zero.
00030    */
00031   while (a->used > 0 && a->dp[a->used - 1] == 0) {
00032     --(a->used);
00033   }
00034 
00035   /* reset the sign flag if used == 0 */
00036   if (a->used == 0) {
00037     a->sign = MP_ZPOS;
00038   }
00039 }
00040 #endif
00041 
00042 /* $Source: /cvsroot/tcl/libtommath/bn_mp_clamp.c,v $ */
00043 /* $Revision: 1.1.1.3 $ */
00044 /* $Date: 2006/12/01 00:08:11 $ */