Add an internal-representation no-op function.

[u/mdw/catacomb] / prim.c

diff --git a/prim.c b/prim.c
index bdad98b..752da9f 100644 (file)
--- a/prim.c
+++ b/prim.c
@@ -1,6 +1,6 @@
 /* -*-c-*-
  *
- * $Id: prim.c,v 1.1 1999/12/22 15:58:59 mdw Exp $
+ * $Id: prim.c,v 1.3 2000/10/08 12:11:22 mdw Exp $
  *
  * Finding primitive elements
  *
@@ -30,6 +30,14 @@
 /*----- Revision history --------------------------------------------------* 
  *
  * $Log: prim.c,v $
+ * Revision 1.3  2000/10/08 12:11:22  mdw
+ * Use @MP_EQ@ instead of @MP_CMP@.
+ *
+ * Revision 1.2  2000/07/29 09:57:42  mdw
+ * Improve primitive-element testing a lot.  Now much more sensible and
+ * orthogonal: you can find a generator for any given subgroup order by
+ * putting in the appropriate parameters.
+ *
  * Revision 1.1  1999/12/22 15:58:59  mdw
  * Search for primitive elements using prime-search equipment.
  *
@@ -57,27 +65,37 @@ int prim_test(int rq, pgen_event *ev, void *p)
     case PGEN_BEGIN:
       return (PGEN_TRY);
     case PGEN_TRY: {
-      mp *x = MP_NEW;
-      mp *f = c->f;
+      mp *x;
       rc = PGEN_FAIL;
 
-      x = mpmont_exp(&c->mm, x, ev->m, f);
-      if (MP_CMP(x, ==, MP_ONE))
-       goto done;
-      if (c->n == 0) {
-       mp_drop(ev->m);
-       ev->m = MP_COPY(x);
-      } else {
-       size_t n = c->n - 1;
-       f++;
+      if (!c->exp)
+        x = mp_copy(ev->m);
+      else {
+       x = mpmont_exp(&c->mm, MP_NEW, ev->m, c->exp);
+       if (MP_EQ(x, MP_ONE))
+         goto done;
+      }
+      if (c->n == 0)
+        goto ok;
+      else {
+       size_t n = c->n;
+       mp **f = c->f;
+       mp *y = MP_NEW;
        while (n) {
-         x = mpmont_exp(&c->mm, x, ev->m, f);
-         if (MP_CMP(x, ==, MP_ONE))
+         y = mpmont_exp(&c->mm, y, x, *f);
+         if (MP_EQ(y, MP_ONE)) {
+           mp_drop(y);
            goto done;
+         }
          n--; f++;
        }
+       mp_drop(y);
       }
+    ok:
       rc = PGEN_DONE;
+      mp_drop(ev->m);
+      ev->m = x;
+      break;
     done:
       mp_drop(x);
     } break;