A variety of small tweaks and fixes. Make mpmont etc. return errors

[u/mdw/catacomb] / mpbarrett.h

diff --git a/mpbarrett.h b/mpbarrett.h
index d9c02ad..bb8b36a 100644 (file)
--- a/mpbarrett.h
+++ b/mpbarrett.h
@@ -1,6 +1,6 @@
 /* -*-c-*-
  *
- * $Id: mpbarrett.h,v 1.1 1999/12/10 23:22:00 mdw Exp $
+ * $Id$
  *
  * Barrett modular reduction
  *
@@ -27,14 +27,6 @@
  * MA 02111-1307, USA.
  */
 
-/*----- Revision history --------------------------------------------------* 
- *
- * $Log: mpbarrett.h,v $
- * 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
@@ -80,13 +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@ --- *
  *
@@ -109,8 +100,7 @@ extern void mpbarrett_destroy(mpbarrett */*mb*/);
  * Returns:    The residue of @m@ modulo the number in the reduction
  *             context.
  *
- * Use:                Performs an efficient modular reduction.  The argument is
- *             assumed to be positive.
+ * Use:                Performs an efficient modular reduction.
  */
 
 extern mp *mpbarrett_reduce(mpbarrett */*mb*/, mp */*d*/, mp */*m*/);
@@ -127,6 +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