Collect analog branches into islands.

Discipline islands all along were intended to carry collections of
analog branches, as well as the current switch modeling support.

design_dump.cc

@@ -678,7 +678,7 @@ void NetTaskDef::dump(ostream&o, unsigned ind) const
 void NetTran::dump_node(ostream&o, unsigned ind) const
 {
       o << setw(ind) << "" << type_ << " " << name()
-	<< " island " << island;
+	<< " island " << get_island();
       if (type_ == IVL_SW_TRAN_VP) {
 	    o << " width=" << vector_width()
 	      << " part=" << part_width()

elab_expr.cc

@@ -1254,6 +1254,7 @@ NetExpr* PECallFunction::elaborate_access_func_(Design*des, NetScope*scope,
 	    branch = new NetBranch(dis);
 	    branch->set_line(*this);
 	    connect(branch->pin(0), sig->pin(0));
+	    join_island(branch);
 
       } else {
 	    ivl_assert(*this, 0);

ivl_target_priv.h

@@ -1,5 +1,5 @@
 #ifndef __ivl_target_priv_H
-#define __ivl_target_H
+#define __ivl_target_priv_H
 /*
  * Copyright (c) 2008 Stephen Williams (steve@icarus.com)
  *
@@ -33,10 +33,10 @@
 * have disciplines and do not belong to islands.
 */
 
-class discipline_t;
+class ivl_discipline_s;
 
 struct ivl_island_s {
-      discipline_t*discipline;
+      ivl_discipline_s*discipline;
 	// user accessible flags. They are initially false, always.
       vector<bool> flags;
 };

net_tran.cc

@@ -78,7 +78,7 @@ unsigned NetTran::part_offset() const
       return off_;
 }
 
-void join_island(NetObj*obj)
+void join_island(NetPins*obj)
 {
       IslandBranch*branch = dynamic_cast<IslandBranch*> (obj);
 
@@ -88,7 +88,7 @@ void join_island(NetObj*obj)
 
 	// If this is a branch, but already given to an island, then
 	// stop.
-      if (branch->island)
+      if (branch->island_)
 	    return;
 
       list<NetObj*> uncommitted_neighbors;
@@ -110,31 +110,32 @@ void join_island(NetObj*obj)
 		  if (tmp == obj)
 			continue;
 
-		    // If tmb is not a branch, then skip it.
+		    // If tmp is not a branch, then skip it.
 		  IslandBranch*tmp_branch = dynamic_cast<IslandBranch*> (tmp);
 		  if (tmp_branch == 0)
 			continue;
 
-		    // If that is an uncommitted branch, then save
+		    // If tmp is an uncommitted branch, then save
 		    // it. When I finally choose an island for self,
 		    // these branches will be scanned so that they join
 		    // this island as well.
-		  if (tmp_branch->island == 0) {
+		  if (tmp_branch->island_ == 0) {
 			uncommitted_neighbors.push_back(tmp);
 			continue;
 		  }
 
-		  ivl_assert(*obj, branch->island==0 || branch->island==tmp_branch->island);
+		  ivl_assert(*obj, branch->island_==0 || branch->island_==tmp_branch->island_);
 
 		    // We found an existing island to join. Join it
 		    // now. Keep scanning in order to find more neighbors.
-		  if (branch->island == 0) {
+		  if (branch->island_ == 0) {
 			if (debug_elaborate)
 			      cerr << obj->get_fileline() << ": debug: "
 				   << "Join branch to existing island." << endl;
-			branch->island = tmp_branch->island;
+			branch->island_ = tmp_branch->island_;
+			ivl_assert(*obj, branch->island_->discipline == tmp_branch->island_->discipline);
 
-		  } else if (branch->island != tmp_branch->island) {
+		  } else if (branch->island_ != tmp_branch->island_) {
 			cerr << obj->get_fileline() << ": internal error: "
 			     << "Oops, Found 2 neighboring islands." << endl;
 			ivl_assert(*obj, 0);
@@ -144,9 +145,9 @@ void join_island(NetObj*obj)
 
 	// If after all that we did not find an island to join, then
 	// start the island not and join it.
-      if (branch->island == 0) {
+      if (branch->island_ == 0) {
-	    branch->island = new ivl_island_s;
+	    branch->island_ = new ivl_island_s;
-	    branch->island->discipline = 0;
+	    branch->island_->discipline = branch->discipline_;
 	    if (debug_elaborate)
 		  cerr << obj->get_fileline() << ": debug: "
 		       << "Create new island for this branch" << endl;

netlist.cc

@@ -243,7 +243,7 @@ NetNode::~NetNode()
 }
 
 NetBranch::NetBranch(ivl_discipline_t dis)
-: NetPins(2), discipline_(dis)
+: NetPins(2), IslandBranch(dis)
 {
       pin(0).set_dir(Link::PASSIVE);
       pin(1).set_dir(Link::PASSIVE);

netlist.h

@@ -55,6 +55,7 @@ class NetEvent;
 class NetNet;
 class NetNode;
 class NetObj;
+class NetPins;
 class NetProc;
 class NetProcTop;
 class NetRelease;
@@ -74,7 +75,7 @@ struct functor_t;
 
 ostream& operator << (ostream&o, ivl_variable_type_t val);
 
-extern void join_island(NetObj*obj);
+extern void join_island(NetPins*obj);
 
 class NetPins : public LineInfo {
 
@@ -154,10 +155,15 @@ class NetObj  : public NetPins, public Attrib {
 
 class IslandBranch {
     public:
-      IslandBranch() : island(0) { }
+      IslandBranch(ivl_discipline_t dis =0) : island_(0), discipline_(dis) { }
 
-    public:
+      ivl_island_t get_island() const { return island_; }
-      struct ivl_island_s* island;
+
+      friend void join_island(NetPins*);
+
+    private:
+      ivl_island_t island_;
+      ivl_discipline_t discipline_;
 };
 
 /*
@@ -168,7 +174,7 @@ class IslandBranch {
  * potential. Pin(1) is the sink of flow and the minus (or ground) of
  * potential.
  */
-class NetBranch  : public NetPins {
+class NetBranch  : public NetPins, public IslandBranch {
 
     public:
       explicit NetBranch(ivl_discipline_t dis);
@@ -176,7 +182,6 @@ class NetBranch  : public NetPins {
       ~NetBranch();
 
     private:
-      ivl_discipline_t discipline_;
       perm_string name_;
 };
 

t-dll.cc

@@ -1051,7 +1051,7 @@ bool dll_target::tran(const NetTran*net)
       obj->offset = 0;
       obj->name = net->name();
       obj->scope = find_scope(des_, net->scope());
-      obj->island = net->island;
+      obj->island = net->get_island();
       assert(obj->scope);
       assert(obj->island);