X-Git-Url: https://git.distorted.org.uk/u/mdw/catacomb/blobdiff_plain/30cbe7a7d521a9c1806caba10fba69f7335a9757..298182ad446aaced14dea7ed0e7c968946787288:/mpbarrett.h

diff --git a/mpbarrett.h b/mpbarrett.h
index aa1971e..bb8b36a 100644
--- a/mpbarrett.h
+++ b/mpbarrett.h
@@ -1,6 +1,6 @@
 /* -*-c-*-
  *
- * $Id: mpbarrett.h,v 1.2 2000/10/08 12:03:44 mdw Exp $
+ * $Id$
  *
  * Barrett modular reduction
  *
@@ -27,17 +27,6 @@
  * MA 02111-1307, USA.
  */
 
-/*----- Revision history --------------------------------------------------* 
- *
- * $Log: mpbarrett.h,v $
- * Revision 1.2  2000/10/08 12:03:44  mdw
- * (mpbarrett_reduce): Cope with negative numbers.
- *
- * Revision 1.1  1999/12/10 23:22:00  mdw
- * Barrett reduction support: works with even moduli.
- *
- */
-
 /*----- Notes on Barrett reduction ----------------------------------------*
  *
  * Barrett reduction is a technique for computing modular residues.  Unlike
@@ -83,13 +72,12 @@ typedef struct mpbarrett {
  * Arguments:	@mpbarrett *mb@ = pointer to Barrett reduction context
  *		@mp *m@ = modulus to work to
  *
- *
- * Returns:	---
+ * Returns:	Zero on success, nonzero on error.
  *
  * Use:		Initializes a Barrett reduction context ready for use.
  */
 
-extern void mpbarrett_create(mpbarrett */*mb*/, mp */*m*/);
+extern int mpbarrett_create(mpbarrett */*mb*/, mp */*m*/);
 
 /* --- @mpbarrett_destroy@ --- *
  *
@@ -129,6 +117,23 @@ extern mp *mpbarrett_reduce(mpbarrett */*mb*/, mp */*d*/, mp */*m*/);
 
 extern mp *mpbarrett_exp(mpbarrett */*mb*/, mp */*d*/, mp */*a*/, mp */*e*/);
 
+/* --- @mpbarrett_mexp@ --- *
+ *
+ * Arguments:	@mpbarrett *mb@ = pointer to Barrett reduction context
+ *		@mp *d@ = fake destination
+ *		@const mp_expfactor *f@ = pointer to array of factors
+ *		@size_t n@ = number of factors supplied
+ *
+ * Returns:	If the bases are %$g_0, g_1, \ldots, g_{n-1}$% and the
+ *		exponents are %$e_0, e_1, \ldots, e_{n-1}$% then the result
+ *		is:
+ *
+ *		%$g_0^{e_0} g_1^{e_1} \ldots g_{n-1}^{e_{n-1}} \bmod m$%
+ */
+
+extern mp *mpbarrett_mexp(mpbarrett */*mb*/, mp */*d*/,
+			  const mp_expfactor */*f*/, size_t /*n*/);
+
 /*----- That's all, folks -------------------------------------------------*/
 
 #ifdef __cplusplus