/* -*-c-*-
*
- * $Id: gfreduce.c,v 1.4 2004/03/27 00:04:46 mdw Exp $
+ * $Id$
*
* Efficient reduction modulo sparse binary polynomials
*
* MA 02111-1307, USA.
*/
-/*----- Revision history --------------------------------------------------*
- *
- * $Log: gfreduce.c,v $
- * Revision 1.4 2004/03/27 00:04:46 mdw
- * Implement efficient reduction for pleasant-looking primes.
- *
- * Revision 1.3 2004/03/23 15:19:32 mdw
- * Test elliptic curves more thoroughly.
- *
- * 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 <mLib/alloc.h>
y = gfreduce_do(r, t, t);
y = gf_add(y, y, x);
}
- rc = !MP_ISZERO(y);
+ rc = !MP_ZEROP(y);
mp_drop(spare);
mp_drop(y);
return (rc);
z = gf_add(z, z, t);
w = gf_add(w, w, rho);
}
- if (!MP_ISZERO(w))
+ if (!MP_ZEROP(w))
break;
MP_DROP(z);
MP_DROP(w);
mp *spare = (e->f & MP_BURN) ? MP_NEWSEC : MP_NEW;
MP_SHRINK(e);
- if (!MP_LEN(e))
+ MP_COPY(a);
+ if (MP_ZEROP(e))
;
- else if (MP_LEN(e) < EXP_THRESH)
- EXP_SIMPLE(x, a, e);
- else
- EXP_WINDOW(x, a, e);
+ else {
+ if (MP_NEGP(e))
+ a = gf_modinv(a, a, gr->p);
+ if (MP_LEN(e) < EXP_THRESH)
+ EXP_SIMPLE(x, a, e);
+ else
+ EXP_WINDOW(x, a, e);
+ }
mp_drop(d);
+ mp_drop(a);
mp_drop(spare);
return (x);
}