/* -*-c-*-
*
- * $Id: gf-arith.c,v 1.3 2004/03/27 17:54:11 mdw Exp $
+ * $Id$
*
* Basic arithmetic on binary polynomials
*
* MA 02111-1307, USA.
*/
-/*----- Revision history --------------------------------------------------*
- *
- * $Log: gf-arith.c,v $
- * Revision 1.3 2004/03/27 17:54:11 mdw
- * Standard curves and curve checking.
- *
- * Revision 1.2 2004/03/21 22:52:06 mdw
- * Merge and close elliptic curve branch.
- *
- * Revision 1.1.2.1 2004/03/21 22:39:46 mdw
- * Elliptic curves on binary fields work.
- *
- */
-
/*----- Header files ------------------------------------------------------*/
#include "gf.h"
int gf_irreduciblep(mp *f)
{
- unsigned long m = mp_bits(f) - 1;
+ unsigned long m;
mp *u = MP_TWO;
mp *v = MP_NEW;
- m /= 2;
+ if (MP_ZEROP(f))
+ return (0);
+ else if (MP_LEN(f) == 1) {
+ if (f->v[0] < 2) return (0);
+ if (f->v[0] < 4) return (1);
+ }
+ m = (mp_bits(f) - 1)/2;
while (m) {
u = gf_sqr(u, u);
gf_div(0, &u, u, f);
RIG(add, gf_add)
RIG(mul, gf_mul)
+RIG(exp, gf_exp)
#undef RIG
{ "mul", tmul, { &type_mp, &type_mp, &type_mp, 0 } },
{ "sqr", tsqr, { &type_mp, &type_mp, 0 } },
{ "div", tdiv, { &type_mp, &type_mp, &type_mp, &type_mp, 0 } },
+ { "exp", texp, { &type_mp, &type_mp, &type_mp, 0 } },
{ "irred", tirred, { &type_mp, &type_int, 0 } },
{ 0, 0, { 0 } },
};