X-Git-Url: https://git.distorted.org.uk/u/mdw/catacomb/blobdiff_plain/fcdaa1806c38c703a6e72b87e189396a05d165e4..2685767a6125c1620719c7de6234aedf41857b7e:/prim.c

diff --git a/prim.c b/prim.c
index bdad98b..752da9f 100644
--- 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;