Remove the now obsolete NetNet list in NetScopes.

Now that NetNet objects in NetScopes are kept in a map, remove the
linked list for scanning them. This improves the lookup process from
an O(e**N) process to more like O(log(N)). This matters for very
large designs.

design_dump.cc

@@ -1148,12 +1148,9 @@ void NetScope::dump(ostream&o) const
       }
 
 	// Dump the signals,
-      if (signals_) {
+      for (signals_map_iter_t cur = signals_map_.begin()
-	    NetNet*cur = signals_->sig_next_;
+		 ; cur != signals_map_.end() ; cur ++) {
-	    do {
+	    cur->second->dump_net(o, 4);
-		  cur->dump_net(o, 4);
-		  cur = cur->sig_next_;
-	    } while (cur != signals_->sig_next_);
       }
 
 	// Dump specparams

emit.cc

@@ -373,23 +373,20 @@ void NetScope::emit_scope(struct target_t*tgt) const
       for (NetScope*cur = sub_ ;  cur ;  cur = cur->sib_)
 	    cur->emit_scope(tgt);
 
-      if (signals_) {
+      for (signals_map_iter_t cur = signals_map_.begin()
-	    NetNet*cur = signals_->sig_next_;
+		 ; cur != signals_map_.end() ; cur ++) {
-	    do {
+	    tgt->signal(cur->second);
-		  tgt->signal(cur);
+      }
-		  cur = cur->sig_next_;
-	    } while (cur != signals_->sig_next_);
 
-	      /* Run the signals again, but this time to connect the
+	// Run the signals again, but this time to connect the
-	         delay paths. This is done as a second pass because
+	// delay paths. This is done as a second pass because
-	         the paths reference other signals that may be later
+	// the paths reference other signals that may be later
-	         in the list. We can do it here because delay paths are
+	// in the list. We can do it here because delay paths are
-	         always connected within the scope. */
+	// always connected within the scope.
-	    cur = signals_->sig_next_;
+      for (signals_map_iter_t cur = signals_map_.begin()
-	    do {
+		 ; cur != signals_map_.end() ; cur ++) {
-		  tgt->signal_paths(cur);
+
-		  cur = cur->sig_next_;
+	    tgt->signal_paths(cur->second);
-	    } while (cur != signals_->sig_next_);
       }
 
 }

functor.cc

@@ -111,20 +111,12 @@ void NetScope::run_functor(Design*des, functor_t*fun)
 
 	// apply to signals. Each iteration, allow for the possibility
 	// that the current signal deletes itself.
-      if (signals_) {
-	    unsigned count = 0;
-	    NetNet*cur = signals_->sig_next_;
-	    do {
-		  count += 1;
-		  cur = cur->sig_next_;
-	    } while (cur != signals_->sig_next_);
 
-	    cur = signals_->sig_next_;
+      signals_map_iter_t cur = signals_map_.begin();
-	    for (unsigned idx = 0 ;  idx < count ;  idx += 1) {
+      while (cur != signals_map_.end()) {
-		  NetNet*tmp = cur->sig_next_;
+	    signals_map_iter_t tmp = cur;
-		  fun->signal(des, cur);
+	    cur ++;
-		  cur = tmp;
+	    fun->signal(des, tmp->second);
-	    }
       }
 }
 

net_scope.cc

@@ -38,7 +38,6 @@
 NetScope::NetScope(NetScope*up, const hname_t&n, NetScope::TYPE t)
 : type_(t), up_(up), sib_(0), sub_(0)
 {
-      signals_ = 0;
       events_ = 0;
       lcounter_ = 0;
       is_auto_ = false;
@@ -360,16 +359,6 @@ NetEvent* NetScope::find_event(perm_string name)
 
 void NetScope::add_signal(NetNet*net)
 {
-      if (signals_ == 0) {
-	    net->sig_next_ = net;
-	    net->sig_prev_ = net;
-      } else {
-	    net->sig_next_ = signals_->sig_next_;
-	    net->sig_prev_ = signals_;
-	    net->sig_next_->sig_prev_ = net;
-	    net->sig_prev_->sig_next_ = net;
-      }
-      signals_ = net;
       signals_map_[net->name()]=net;
 }
 
@@ -377,15 +366,6 @@ void NetScope::rem_signal(NetNet*net)
 {
       assert(net->scope() == this);
       signals_map_.erase(net->name());
-      if (signals_ == net)
-	    signals_ = net->sig_prev_;
-
-      if (signals_ == net) {
-	    signals_ = 0;
-      } else {
-	    net->sig_prev_->sig_next_ = net->sig_next_;
-	    net->sig_next_->sig_prev_ = net->sig_prev_;
-      }
 }
 
 /*
@@ -395,21 +375,10 @@ void NetScope::rem_signal(NetNet*net)
  */
 NetNet* NetScope::find_signal(perm_string key)
 {
-      if (signals_ == 0)
-	    return 0;
-
       if (signals_map_.find(key)!=signals_map_.end())
-        return signals_map_[key];
+	    return signals_map_[key];
       else
-        return 0;
+	    return 0;
-
-      NetNet*cur = signals_;
-      do {
-	    if (cur->name() == key)
-		  return cur;
-	    cur = cur->sig_prev_;
-      } while (cur != signals_);
-      return 0;
 }
 
 /*

netlist.cc

@@ -427,7 +427,7 @@ const Link& NetDelaySrc::condit_pin() const
 }
 
 NetNet::NetNet(NetScope*s, perm_string n, Type t, unsigned npins)
-: NetObj(s, n, 1), sig_next_(0), sig_prev_(0),
+: NetObj(s, n, 1),
     type_(t), port_type_(NOT_A_PORT), data_type_(IVL_VT_NO_TYPE),
     signed_(false), isint_(false), discipline_(0), msb_(npins-1), lsb_(0),
     dimensions_(0),
@@ -466,8 +466,7 @@ NetNet::NetNet(NetScope*s, perm_string n, Type t, unsigned npins)
 
 NetNet::NetNet(NetScope*s, perm_string n, Type t,
 	       long ms, long ls)
-: NetObj(s, n, 1),
+: NetObj(s, n, 1), type_(t),
-    sig_next_(0), sig_prev_(0), type_(t),
     port_type_(NOT_A_PORT), data_type_(IVL_VT_NO_TYPE), signed_(false),
     isint_(false), discipline_(0), msb_(ms), lsb_(ls), dimensions_(0), s0_(0), e0_(0),
     local_flag_(false), eref_count_(0), lref_count_(0)
@@ -514,7 +513,7 @@ static unsigned calculate_count(long s, long e)
 NetNet::NetNet(NetScope*s, perm_string n, Type t,
 	       long ms, long ls, long array_s, long array_e)
 : NetObj(s, n, calculate_count(array_s, array_e)),
-    sig_next_(0), sig_prev_(0), type_(t), port_type_(NOT_A_PORT),
+    type_(t), port_type_(NOT_A_PORT),
     data_type_(IVL_VT_NO_TYPE), signed_(false), isint_(false),
     discipline_(0), msb_(ms), lsb_(ls), dimensions_(1), s0_(array_s), e0_(array_e),
     local_flag_(false), eref_count_(0), lref_count_(0)

netlist.h

@@ -614,11 +614,6 @@ class NetNet  : public NetObj {
 
       virtual void dump_net(ostream&, unsigned) const;
 
-    private:
-	// The NetScope class uses this for listing signals.
-      friend class NetScope;
-      NetNet*sig_next_, *sig_prev_;
-
     private:
       Type   type_;
       PortType port_type_;
@@ -861,8 +856,8 @@ class NetScope : public Attrib {
       NetNet::Type default_nettype_;
 
       NetEvent *events_;
+      typedef std::map<perm_string,NetNet*>::const_iterator signals_map_iter_t;
       std::map <perm_string,NetNet*> signals_map_;
-      NetNet   *signals_;
       perm_string module_name_;
       union {
 	    NetTaskDef*task_;