Release 2.1.2.

[u/mdw/catacomb] / mpbarrett-mexp.c

diff --git a/mpbarrett-mexp.c b/mpbarrett-mexp.c
index 68917aa..2cfda96 100644 (file)
--- a/mpbarrett-mexp.c
+++ b/mpbarrett-mexp.c
@@ -1,13 +1,13 @@
 /* -*-c-*-
  *
- * $Id: mpbarrett-mexp.c,v 1.2 2004/04/01 12:50:09 mdw Exp $
+ * $Id$
  *
  * Multiple simultaneous exponentiations
  *
  * (c) 1999 Straylight/Edgeware
  */
 
-/*----- Licensing notice --------------------------------------------------* 
+/*----- Licensing notice --------------------------------------------------*
  *
  * This file is part of Catacomb.
  *
@@ -15,33 +15,18 @@
  * it under the terms of the GNU Library General Public License as
  * published by the Free Software Foundation; either version 2 of the
  * License, or (at your option) any later version.
- * 
+ *
  * Catacomb is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU Library General Public License for more details.
- * 
+ *
  * You should have received a copy of the GNU Library General Public
  * License along with Catacomb; if not, write to the Free
  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
  * MA 02111-1307, USA.
  */
 
-/*----- Revision history --------------------------------------------------* 
- *
- * $Log: mpbarrett-mexp.c,v $
- * Revision 1.2  2004/04/01 12:50:09  mdw
- * Add cyclic group abstraction, with test code.  Separate off exponentation
- * functions for better static linking.  Fix a buttload of bugs on the way.
- * Generally ensure that negative exponents do inversion correctly.  Add
- * table of standard prime-field subgroups.  (Binary field subgroups are
- * currently unimplemented but easy to add if anyone ever finds a good one.)
- *
- * Revision 1.1  2001/06/16 12:58:34  mdw
- * Added simultaneous exponentiation with Barrett reduction.
- *
- */
-
 /*----- Header files ------------------------------------------------------*/
 
 #include "mp.h"
@@ -78,13 +63,10 @@ mp *mpbarrett_mexp(mpbarrett *mb, mp *d, const mp_expfactor *f, size_t n)
   for (i = 0; i < n; i++) {
     if (f[i].exp->f & MP_BURN)
       spare = MP_NEWSEC;
-    if (!(f[i].exp->f & MP_NEG))
+    if (MP_NEGP(f[i].exp))
+      ff[i].base = mp_modinv(MP_NEW, f[i].base, mb->m);
+    else
       ff[i].base = MP_COPY(f[i].base);
-    else {
-      ff[i].base = MP_NEW;
-      mp_gcd(&g, 0, &ff[i].base, mb->m, f[i].base);
-      assert(MP_EQ(g, MP_ONE));
-    }
     ff[i].exp = f[i].exp;
   }
   mp_drop(g);
@@ -188,7 +170,7 @@ int main(int argc, char *argv[])
   sub_init();
   test_run(argc, argv, tests, SRCDIR "/tests/mpbarrett");
   return (0);
-}   
+}
 
 #endif