From d958a4a5af384e048fba2da279282611631e6340 Mon Sep 17 00:00:00 2001
From: steve <steve>
Date: Mon, 5 Feb 2007 01:08:10 +0000
Subject: [PATCH]  Handle relink of continuous assignment.

---
 vvp/vthread.cc | 26 +++++++++++++++++++++-----
 vvp/vvp_net.cc |  6 +++++-
 vvp/vvp_net.h  |  6 +++++-
 3 files changed, 31 insertions(+), 7 deletions(-)

diff --git a/vvp/vthread.cc b/vvp/vthread.cc
index 5be8eaef8..49b7dec10 100644
--- a/vvp/vthread.cc
+++ b/vvp/vthread.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #ifdef HAVE_CVS_IDENT
-#ident "$Id: vthread.cc,v 1.159 2007/01/31 22:28:55 steve Exp $"
+#ident "$Id: vthread.cc,v 1.160 2007/02/05 01:08:10 steve Exp $"
 #endif
 
 # include  "config.h"
@@ -759,10 +759,23 @@ bool of_CASSIGN_LINK(vthread_t thr, vvp_code_t cp)
       vvp_net_t*dst = cp->net;
       vvp_net_t*src = cp->net2;
 
-	/* For now, assert that the destination continuous assign
-	   input is empty. That should be so as you can have only one
-	   continuous assignment active for the destination. */
-      assert(dst->port[1].nil());
+      vvp_fun_signal_base*sig
+	    = reinterpret_cast<vvp_fun_signal_base*>(dst->fun);
+      assert(sig);
+
+	/* Detect the special case that we are already continuous
+	   assigning the source onto the destination. */
+      if (sig->cassign_link == src)
+	    return true;
+
+	/* If there is an existing cassign driving this node, then
+	   unlink it. We can have only 1 cassign at a time. */
+      if (sig->cassign_link != 0) {
+	    vvp_net_ptr_t tmp (dst,1);
+	    unlink_from_driver(sig->cassign_link, tmp);
+      }
+
+      sig->cassign_link = src;
 
 	/* Link the output of the src to the port[1] (the cassign
 	   port) of the destination. */
@@ -3378,6 +3391,9 @@ bool of_JOIN_UFUNC(vthread_t thr, vvp_code_t cp)
 
 /*
  * $Log: vthread.cc,v $
+ * Revision 1.160  2007/02/05 01:08:10  steve
+ *  Handle relink of continuous assignment.
+ *
  * Revision 1.159  2007/01/31 22:28:55  steve
  *  Fix missing check for thread bits width in ADDI
  *
diff --git a/vvp/vvp_net.cc b/vvp/vvp_net.cc
index 2a927503c..4b4d045d7 100644
--- a/vvp/vvp_net.cc
+++ b/vvp/vvp_net.cc
@@ -16,7 +16,7 @@
  *    along with this program; if not, write to the Free Software
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
-#ident "$Id: vvp_net.cc,v 1.57 2006/12/10 17:15:48 steve Exp $"
+#ident "$Id: vvp_net.cc,v 1.58 2007/02/05 01:08:10 steve Exp $"
 
 # include  "config.h"
 # include  "vvp_net.h"
@@ -1386,6 +1386,7 @@ vvp_fun_signal_base::vvp_fun_signal_base()
       needs_init_ = true;
       continuous_assign_active_ = false;
       force_link = 0;
+      cassign_link = 0;
 }
 
 void vvp_fun_signal_base::deassign()
@@ -2256,6 +2257,9 @@ vvp_bit4_t compare_gtge_signed(const vvp_vector4_t&a,
 
 /*
  * $Log: vvp_net.cc,v $
+ * Revision 1.58  2007/02/05 01:08:10  steve
+ *  Handle relink of continuous assignment.
+ *
  * Revision 1.57  2006/12/10 17:15:48  steve
  *  Fix build error overloading pow function.
  *
diff --git a/vvp/vvp_net.h b/vvp/vvp_net.h
index b4f789da8..a56af8196 100644
--- a/vvp/vvp_net.h
+++ b/vvp/vvp_net.h
@@ -18,7 +18,7 @@
  *    along with this program; if not, write to the Free Software
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
-#ident "$Id: vvp_net.h,v 1.54 2007/01/16 05:44:17 steve Exp $"
+#ident "$Id: vvp_net.h,v 1.55 2007/02/05 01:08:10 steve Exp $"
 
 # include  "config.h"
 # include  <stddef.h>
@@ -800,6 +800,7 @@ class vvp_fun_signal_base : public vvp_net_fun_t, public vvp_vpi_callback {
 	   source node of the force, so that subsequent %force and
 	   %release instructions can undo the link as needed. */
       struct vvp_net_t*force_link;
+      struct vvp_net_t*cassign_link;
 
     protected:
 
@@ -1035,6 +1036,9 @@ inline void vvp_send_vec4_pv(vvp_net_ptr_t ptr, const vvp_vector4_t&val,
 
 /*
  * $Log: vvp_net.h,v $
+ * Revision 1.55  2007/02/05 01:08:10  steve
+ *  Handle relink of continuous assignment.
+ *
  * Revision 1.54  2007/01/16 05:44:17  steve
  *  Major rework of array handling. Memories are replaced with the
  *  more general concept of arrays. The NetMemory and NetEMemory