From f40d006c26dce164927aa278bde5fd0a5737017f Mon Sep 17 00:00:00 2001
From: steve <steve>
Date: Mon, 2 Apr 2001 02:28:12 +0000
Subject: [PATCH]  Generate code for task calls.

---
 elaborate.cc          | 15 ++++++++++-----
 emit.cc               |  7 +++++--
 ivl_target.h          | 15 ++++++++++++++-
 net_design.cc         | 13 ++++++++-----
 netlist.cc            | 17 +++++++++++++++--
 netlist.h             | 17 +++++++++++------
 t-dll-api.cc          | 22 +++++++++++++++++++++-
 t-dll-proc.cc         | 30 +++++++++++++++++++++++++++++-
 t-dll.h               | 15 ++++++++++++++-
 t-vvm.cc              | 11 ++++++++---
 target.cc             |  7 +++++--
 target.h              |  7 +++++--
 tgt-stub/stub.c       |  9 ++++++++-
 tgt-vvp/vvp_priv.h    |  7 ++++++-
 tgt-vvp/vvp_process.c | 34 +++++++++++++++++++++++++++++++++-
 tgt-vvp/vvp_scope.c   |  9 ++++++++-
 vvp/README.txt        | 11 +++++++++--
 17 files changed, 209 insertions(+), 37 deletions(-)

diff --git a/elaborate.cc b/elaborate.cc
index 942439516..0e4b3abd3 100644
--- a/elaborate.cc
+++ b/elaborate.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: elaborate.cc,v 1.208 2001/02/15 06:59:36 steve Exp $"
+#ident "$Id: elaborate.cc,v 1.209 2001/04/02 02:28:12 steve Exp $"
 #endif
 
 /*
@@ -1366,7 +1366,8 @@ NetProc* PCallTask::elaborate_usr(Design*des, const string&path) const
       NetScope*scope = des->find_scope(path);
       assert(scope);
 
-      NetTaskDef*def = des->find_task(scope, name_);
+      NetScope*task = des->find_task(scope, name_);
+      NetTaskDef*def = task->task_def();
       if (def == 0) {
 	    cerr << get_line() << ": error: Enable of unknown task ``" <<
 		  scope->name() << "." << name_ << "''." << endl;
@@ -1386,7 +1387,7 @@ NetProc* PCallTask::elaborate_usr(Design*des, const string&path) const
 	/* Handle tasks with no parameters specially. There is no need
 	   to make a sequential block to hold the generated code. */
       if (nparms() == 0) {
-	    cur = new NetUTask(def);
+	    cur = new NetUTask(task);
 	    return cur;
       }
 
@@ -1425,7 +1426,7 @@ NetProc* PCallTask::elaborate_usr(Design*des, const string&path) const
       }
 
 	/* Generate the task call proper... */
-      cur = new NetUTask(def);
+      cur = new NetUTask(task);
       block->append(cur);
 
 
@@ -2171,7 +2172,8 @@ NetProc* PRepeat::elaborate(Design*des, const string&path) const
 
 void PTask::elaborate(Design*des, const string&path) const
 {
-      NetTaskDef*def = des->find_task(path);
+      NetScope*task = des->find_task(path);
+      NetTaskDef*def = task->task_def();
       assert(def);
 
       NetProc*st;
@@ -2367,6 +2369,9 @@ Design* elaborate(const map<string,Module*>&modules,
 
 /*
  * $Log: elaborate.cc,v $
+ * Revision 1.209  2001/04/02 02:28:12  steve
+ *  Generate code for task calls.
+ *
  * Revision 1.208  2001/02/15 06:59:36  steve
  *  FreeBSD port has a maintainer now.
  *
diff --git a/emit.cc b/emit.cc
index e85fa3c0b..f85a1751f 100644
--- a/emit.cc
+++ b/emit.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: emit.cc,v 1.56 2001/03/27 03:31:06 steve Exp $"
+#ident "$Id: emit.cc,v 1.57 2001/04/02 02:28:12 steve Exp $"
 #endif
 
 /*
@@ -357,7 +357,7 @@ void NetScope::emit_defs(struct target_t*tgt) const
 	    tgt->func_def(this->func_def());
 	    break;
 	  case TASK:
-	    tgt->task_def(this->task_def());
+	    tgt->task_def(this);
 	    break;
       }
 
@@ -478,6 +478,9 @@ bool emit(const Design*des, const char*type)
 
 /*
  * $Log: emit.cc,v $
+ * Revision 1.57  2001/04/02 02:28:12  steve
+ *  Generate code for task calls.
+ *
  * Revision 1.56  2001/03/27 03:31:06  steve
  *  Support error code from target_t::end_design method.
  *
diff --git a/ivl_target.h b/ivl_target.h
index da7291cb9..cef02341d 100644
--- a/ivl_target.h
+++ b/ivl_target.h
@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: ivl_target.h,v 1.44 2001/04/02 00:28:35 steve Exp $"
+#ident "$Id: ivl_target.h,v 1.45 2001/04/02 02:28:12 steve Exp $"
 #endif
 
 #ifdef __cplusplus
@@ -249,6 +249,7 @@ typedef enum ivl_statement_type_e {
       IVL_ST_FORK,
       IVL_ST_STASK,
       IVL_ST_TRIGGER,
+      IVL_ST_UTASK,
       IVL_ST_WAIT,
       IVL_ST_WHILE
 } ivl_statement_type_t;
@@ -540,6 +541,10 @@ extern ivl_signal_t ivl_nexus_ptr_sig(ivl_nexus_ptr_t net);
  *    If the scope has no children, this method will return 0 and
  *    otherwise do nothing.
  *
+ * ivl_scope_def
+ *    Task definition scopes carry a task definition, in the form of
+ *    a statement. This method accesses that definition.
+ *
  * ivl_scope_event
  * ivl_scope_events
  *    Scopes have 0 or more event objects in them.
@@ -569,6 +574,9 @@ extern ivl_signal_t ivl_nexus_ptr_sig(ivl_nexus_ptr_t net);
 
 extern int          ivl_scope_children(ivl_scope_t net,
 				       ivl_scope_f func, void*cd);
+
+extern ivl_statement_t ivl_scope_def(ivl_scope_t net);
+
 extern unsigned     ivl_scope_events(ivl_scope_t net);
 extern ivl_event_t  ivl_scope_event(ivl_scope_t net, unsigned idx);
 extern unsigned     ivl_scope_logs(ivl_scope_t net);
@@ -674,6 +682,8 @@ extern ivl_statement_type_t ivl_statement_type(ivl_statement_t net);
 extern unsigned ivl_stmt_block_count(ivl_statement_t net);
   /* IVL_ST_BLOCK, IVL_ST_FORK */
 extern ivl_statement_t ivl_stmt_block_stmt(ivl_statement_t net, unsigned i);
+  /* IVL_ST_UTASK */
+extern ivl_scope_t ivl_stmt_call(ivl_statement_t net);
   /* IVL_ST_CASE */
 extern unsigned ivl_stmt_case_count(ivl_statement_t net);
   /* IVL_ST_CASE */
@@ -725,6 +735,9 @@ _END_DECL
 
 /*
  * $Log: ivl_target.h,v $
+ * Revision 1.45  2001/04/02 02:28:12  steve
+ *  Generate code for task calls.
+ *
  * Revision 1.44  2001/04/02 00:28:35  steve
  *  Support the scope expression node.
  *
diff --git a/net_design.cc b/net_design.cc
index ae0cc2c29..2805e3a32 100644
--- a/net_design.cc
+++ b/net_design.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: net_design.cc,v 1.18 2001/01/14 23:04:56 steve Exp $"
+#ident "$Id: net_design.cc,v 1.19 2001/04/02 02:28:12 steve Exp $"
 #endif
 
 /*
@@ -393,20 +393,20 @@ NetFuncDef* Design::find_function(const string&key)
       return 0;
 }
 
-NetTaskDef* Design::find_task(NetScope*scope, const string&name)
+NetScope* Design::find_task(NetScope*scope, const string&name)
 {
       NetScope*task = find_scope(scope, name);
       if (task && (task->type() == NetScope::TASK))
-	    return task->task_def();
+	    return task;
 
       return 0;
 }
 
-NetTaskDef* Design::find_task(const string&key)
+NetScope* Design::find_task(const string&key)
 {
       NetScope*task = find_scope(key);
       if (task && (task->type() == NetScope::TASK))
-	    return task->task_def();
+	    return task;
 
       return 0;
 }
@@ -473,6 +473,9 @@ void Design::delete_process(NetProcTop*top)
 
 /*
  * $Log: net_design.cc,v $
+ * Revision 1.19  2001/04/02 02:28:12  steve
+ *  Generate code for task calls.
+ *
  * Revision 1.18  2001/01/14 23:04:56  steve
  *  Generalize the evaluation of floating point delays, and
  *  get it working with delay assignment statements.
diff --git a/netlist.cc b/netlist.cc
index 8710ed0c3..e84e497c4 100644
--- a/netlist.cc
+++ b/netlist.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: netlist.cc,v 1.157 2001/02/10 21:20:38 steve Exp $"
+#ident "$Id: netlist.cc,v 1.158 2001/04/02 02:28:12 steve Exp $"
 #endif
 
 # include  <cassert>
@@ -1752,7 +1752,7 @@ NetEUFunc* NetEUFunc::dup_expr() const
       return 0;
 }
 
-NetUTask::NetUTask(NetTaskDef*def)
+NetUTask::NetUTask(NetScope*def)
 : task_(def)
 {
 }
@@ -1761,6 +1761,16 @@ NetUTask::~NetUTask()
 {
 }
 
+const string& NetUTask::name() const
+{
+      return task_->name();
+}
+
+const NetScope* NetUTask::task() const
+{
+      return task_;
+}
+
 NetExpr::NetExpr(unsigned w)
 : width_(w)
 {
@@ -2460,6 +2470,9 @@ bool NetUDP::sequ_glob_(string input, char output)
 
 /*
  * $Log: netlist.cc,v $
+ * Revision 1.158  2001/04/02 02:28:12  steve
+ *  Generate code for task calls.
+ *
  * Revision 1.157  2001/02/10 21:20:38  steve
  *  Binary operators with operands of indefinite width
  *  has itself an indefinite width.
diff --git a/netlist.h b/netlist.h
index 1d6ef2965..11b04ec94 100644
--- a/netlist.h
+++ b/netlist.h
@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: netlist.h,v 1.200 2001/03/29 02:52:01 steve Exp $"
+#ident "$Id: netlist.h,v 1.201 2001/04/02 02:28:12 steve Exp $"
 #endif
 
 /*
@@ -1979,16 +1979,18 @@ class NetEUFunc  : public NetExpr {
 class NetUTask  : public NetProc {
 
     public:
-      NetUTask(NetTaskDef*);
+      NetUTask(NetScope*);
       ~NetUTask();
 
-      const string& name() const { return task_->name(); }
+      const string& name() const;
+
+      const NetScope* task() const;
 
       virtual bool emit_proc(struct target_t*) const;
       virtual void dump(ostream&, unsigned ind) const;
 
     private:
-      NetTaskDef*task_;
+      NetScope*task_;
 };
 
 /*
@@ -2784,8 +2786,8 @@ class Design {
       NetFuncDef* find_function(const string&path);
 
 	// Tasks
-      NetTaskDef* find_task(NetScope*scope, const string&name);
-      NetTaskDef* find_task(const string&key);
+      NetScope* find_task(NetScope*scope, const string&name);
+      NetScope* find_task(const string&key);
 
 	// NODES
       void add_node(NetNode*);
@@ -2870,6 +2872,9 @@ extern ostream& operator << (ostream&, NetNet::Type);
 
 /*
  * $Log: netlist.h,v $
+ * Revision 1.201  2001/04/02 02:28:12  steve
+ *  Generate code for task calls.
+ *
  * Revision 1.200  2001/03/29 02:52:01  steve
  *  Add const probe method to NetEvent.
  *
diff --git a/t-dll-api.cc b/t-dll-api.cc
index ce7fb32a1..f4baf01a4 100644
--- a/t-dll-api.cc
+++ b/t-dll-api.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: t-dll-api.cc,v 1.31 2001/04/02 00:28:35 steve Exp $"
+#ident "$Id: t-dll-api.cc,v 1.32 2001/04/02 02:28:12 steve Exp $"
 #endif
 
 # include  "t-dll.h"
@@ -452,6 +452,12 @@ extern "C" int ivl_scope_children(ivl_scope_t net,
       return 0;
 }
 
+extern "C" ivl_statement_t ivl_scope_def(ivl_scope_t net)
+{
+      assert(net);
+      return net->def;
+}
+
 extern "C" unsigned ivl_scope_events(ivl_scope_t net)
 {
       assert(net);
@@ -608,6 +614,17 @@ extern "C" ivl_statement_t ivl_stmt_block_stmt(ivl_statement_t net,
       }
 }
 
+extern "C" ivl_scope_t ivl_stmt_call(ivl_statement_t net)
+{
+      switch (net->type_) {
+	  case IVL_ST_UTASK:
+	    return net->u_.utask_.def;
+	  default:
+	    assert(0);
+	    return 0;
+      }
+}
+
 extern "C" unsigned ivl_stmt_case_count(ivl_statement_t net)
 {
       switch (net->type_) {
@@ -812,6 +829,9 @@ extern "C" ivl_statement_t ivl_stmt_sub_stmt(ivl_statement_t net)
 
 /*
  * $Log: t-dll-api.cc,v $
+ * Revision 1.32  2001/04/02 02:28:12  steve
+ *  Generate code for task calls.
+ *
  * Revision 1.31  2001/04/02 00:28:35  steve
  *  Support the scope expression node.
  *
diff --git a/t-dll-proc.cc b/t-dll-proc.cc
index b399f96dc..032db16b7 100644
--- a/t-dll-proc.cc
+++ b/t-dll-proc.cc
@@ -18,7 +18,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: t-dll-proc.cc,v 1.19 2001/04/01 06:52:28 steve Exp $"
+#ident "$Id: t-dll-proc.cc,v 1.20 2001/04/02 02:28:12 steve Exp $"
 #endif
 
 # include  "target.h"
@@ -74,6 +74,22 @@ bool dll_target::process(const NetProcTop*net)
       return true;
 }
 
+void dll_target::task_def(const NetScope*net)
+{
+      ivl_scope_t scope = lookup_scope_(net);
+      const NetTaskDef*def = net->task_def();
+
+      assert(stmt_cur_ == 0);
+      stmt_cur_ = (struct ivl_statement_s*)calloc(1, sizeof*stmt_cur_);
+      assert(stmt_cur_);
+      def->proc()->emit_proc(this);
+
+      assert(stmt_cur_);
+      scope->def = stmt_cur_;
+      stmt_cur_ = 0;
+
+}
+
 /*
  */
 void dll_target::proc_assign(const NetAssign*net)
@@ -330,6 +346,15 @@ bool dll_target::proc_trigger(const NetEvTrig*net)
       return true;
 }
 
+void dll_target::proc_utask(const NetUTask*net)
+{
+      assert(stmt_cur_);
+      assert(stmt_cur_->type_ == IVL_ST_NONE);
+
+      stmt_cur_->type_ = IVL_ST_UTASK;
+      stmt_cur_->u_.utask_.def = lookup_scope_(net->task());
+}
+
 bool dll_target::proc_wait(const NetEvWait*net)
 {
       assert(stmt_cur_);
@@ -438,6 +463,9 @@ void dll_target::proc_while(const NetWhile*net)
 
 /*
  * $Log: t-dll-proc.cc,v $
+ * Revision 1.20  2001/04/02 02:28:12  steve
+ *  Generate code for task calls.
+ *
  * Revision 1.19  2001/04/01 06:52:28  steve
  *  support the NetWhile statement.
  *
diff --git a/t-dll.h b/t-dll.h
index 3a28b0d68..041e8c36e 100644
--- a/t-dll.h
+++ b/t-dll.h
@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: t-dll.h,v 1.31 2001/04/02 00:28:35 steve Exp $"
+#ident "$Id: t-dll.h,v 1.32 2001/04/02 02:28:12 steve Exp $"
 #endif
 
 # include  "target.h"
@@ -84,9 +84,12 @@ struct dll_target  : public target_t, public expr_scan_t {
       bool proc_delay(const NetPDelay*);
       void proc_stask(const NetSTask*);
       bool proc_trigger(const NetEvTrig*);
+      void proc_utask(const NetUTask*);
       bool proc_wait(const NetEvWait*);
       void proc_while(const NetWhile*);
 
+      void task_def(const NetScope*);
+
       struct ivl_expr_s*expr_;
       void expr_binary(const NetEBinary*);
       void expr_concat(const NetEConcat*);
@@ -304,6 +307,9 @@ struct ivl_scope_s {
 
       unsigned nlpm_;
       ivl_lpm_t* lpm_;
+
+	/* Scopes that are tasks have a definition. */
+      ivl_statement_t def;
 };
 
 /*
@@ -385,6 +391,10 @@ struct ivl_statement_s {
 		  ivl_event_t event_;
 	    } trig_;
 
+	    struct { /* IVL_ST_UTASK */
+		  ivl_scope_t def;
+	    } utask_;
+
 	    struct { /* IVL_ST_WAIT */
 		  ivl_event_t event_;
 		  ivl_statement_t stmt_;
@@ -399,6 +409,9 @@ struct ivl_statement_s {
 
 /*
  * $Log: t-dll.h,v $
+ * Revision 1.32  2001/04/02 02:28:12  steve
+ *  Generate code for task calls.
+ *
  * Revision 1.31  2001/04/02 00:28:35  steve
  *  Support the scope expression node.
  *
diff --git a/t-vvm.cc b/t-vvm.cc
index ed0092911..fd021e835 100644
--- a/t-vvm.cc
+++ b/t-vvm.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: t-vvm.cc,v 1.203 2001/03/27 03:31:06 steve Exp $"
+#ident "$Id: t-vvm.cc,v 1.204 2001/04/02 02:28:12 steve Exp $"
 #endif
 
 # include  <iostream>
@@ -150,7 +150,7 @@ class target_vvm : public target_t {
       virtual void event(const NetEvent*);
       virtual void signal(const NetNet*);
       virtual void memory(const NetMemory*);
-      virtual void task_def(const NetTaskDef*);
+      virtual void task_def(const NetScope*);
       virtual void func_def(const NetFuncDef*);
 
       virtual void lpm_add_sub(const NetAddSub*);
@@ -1357,8 +1357,10 @@ void target_vvm::memory(const NetMemory*mem)
 	    mem->count() << ");" << endl;
 }
 
-void target_vvm::task_def(const NetTaskDef*def)
+void target_vvm::task_def(const NetScope*scope)
 {
+      const NetTaskDef*def = scope->task_def();
+
       thread_step_ = 0;
       const string name = mangle(def->name());
       const string save_thread_class = thread_class_;
@@ -3636,6 +3638,9 @@ extern const struct target tgt_vvm = {
 };
 /*
  * $Log: t-vvm.cc,v $
+ * Revision 1.204  2001/04/02 02:28:12  steve
+ *  Generate code for task calls.
+ *
  * Revision 1.203  2001/03/27 03:31:06  steve
  *  Support error code from target_t::end_design method.
  *
diff --git a/target.cc b/target.cc
index ae67b189f..f5b45e3b6 100644
--- a/target.cc
+++ b/target.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: target.cc,v 1.50 2001/03/27 03:31:06 steve Exp $"
+#ident "$Id: target.cc,v 1.51 2001/04/02 02:28:13 steve Exp $"
 #endif
 
 # include  "target.h"
@@ -49,7 +49,7 @@ void target_t::func_def(const NetFuncDef*)
 	    "Unhandled function definition." << endl;
 }
 
-void target_t::task_def(const NetTaskDef*)
+void target_t::task_def(const NetScope*)
 {
       cerr << "target (" << typeid(*this).name() <<  "): "
 	    "Unhandled task definition." << endl;
@@ -389,6 +389,9 @@ void expr_scan_t::expr_binary(const NetEBinary*ex)
 
 /*
  * $Log: target.cc,v $
+ * Revision 1.51  2001/04/02 02:28:13  steve
+ *  Generate code for task calls.
+ *
  * Revision 1.50  2001/03/27 03:31:06  steve
  *  Support error code from target_t::end_design method.
  *
diff --git a/target.h b/target.h
index e66074e91..3574dd051 100644
--- a/target.h
+++ b/target.h
@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: target.h,v 1.49 2001/03/27 03:31:06 steve Exp $"
+#ident "$Id: target.h,v 1.50 2001/04/02 02:28:13 steve Exp $"
 #endif
 
 # include  "netlist.h"
@@ -69,7 +69,7 @@ struct target_t {
       virtual void memory(const NetMemory*);
 
 	/* Output a defined task. */
-      virtual void task_def(const NetTaskDef*);
+      virtual void task_def(const NetScope*);
       virtual void func_def(const NetFuncDef*);
 
 	/* LPM style components are handled here. */
@@ -160,6 +160,9 @@ extern const struct target *target_table[];
 
 /*
  * $Log: target.h,v $
+ * Revision 1.50  2001/04/02 02:28:13  steve
+ *  Generate code for task calls.
+ *
  * Revision 1.49  2001/03/27 03:31:06  steve
  *  Support error code from target_t::end_design method.
  *
diff --git a/tgt-stub/stub.c b/tgt-stub/stub.c
index 773153a99..51b665144 100644
--- a/tgt-stub/stub.c
+++ b/tgt-stub/stub.c
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: stub.c,v 1.34 2001/04/01 01:48:21 steve Exp $"
+#ident "$Id: stub.c,v 1.35 2001/04/02 02:28:13 steve Exp $"
 #endif
 
 /*
@@ -238,6 +238,10 @@ static void show_statement(ivl_statement_t net, unsigned ind)
 	    fprintf(out, "%*s-> ...\n", ind, "");
 	    break;
 
+	  case IVL_ST_UTASK:
+	    fprintf(out, "%*scall task ...\n", ind, "");
+	    break;
+
 	  case IVL_ST_WAIT: {
 		ivl_event_t evnt = ivl_stmt_event(net);
 		fprintf(out, "%*s@(%s)\n", ind, "", ivl_event_name(evnt));
@@ -480,6 +484,9 @@ DECLARE_CYGWIN_DLL(DllMain);
 
 /*
  * $Log: stub.c,v $
+ * Revision 1.35  2001/04/02 02:28:13  steve
+ *  Generate code for task calls.
+ *
  * Revision 1.34  2001/04/01 01:48:21  steve
  *  Redesign event information to support arbitrary edge combining.
  *
diff --git a/tgt-vvp/vvp_priv.h b/tgt-vvp/vvp_priv.h
index cfbf50cbb..e519b9b98 100644
--- a/tgt-vvp/vvp_priv.h
+++ b/tgt-vvp/vvp_priv.h
@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT)
-#ident "$Id: vvp_priv.h,v 1.6 2001/03/31 17:36:39 steve Exp $"
+#ident "$Id: vvp_priv.h,v 1.7 2001/04/02 02:28:13 steve Exp $"
 #endif
 
 # include  "ivl_target.h"
@@ -38,6 +38,8 @@ extern FILE* vvp_out;
  */
 extern int draw_process(ivl_process_t net, void*x);
 
+extern int draw_task_definition(ivl_scope_t scope);
+
 extern int draw_scope(ivl_scope_t scope, ivl_scope_t parent);
 
 /*
@@ -71,6 +73,9 @@ extern void clr_vector(struct vector_info vec);
 
 /*
  * $Log: vvp_priv.h,v $
+ * Revision 1.7  2001/04/02 02:28:13  steve
+ *  Generate code for task calls.
+ *
  * Revision 1.6  2001/03/31 17:36:39  steve
  *  Generate vvp code for case statements.
  *
diff --git a/tgt-vvp/vvp_process.c b/tgt-vvp/vvp_process.c
index aec2acddf..d61a3cd48 100644
--- a/tgt-vvp/vvp_process.c
+++ b/tgt-vvp/vvp_process.c
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT)
-#ident "$Id: vvp_process.c,v 1.18 2001/04/02 00:27:53 steve Exp $"
+#ident "$Id: vvp_process.c,v 1.19 2001/04/02 02:28:13 steve Exp $"
 #endif
 
 # include  "vvp_priv.h"
@@ -335,6 +335,15 @@ static int show_stmt_trigger(ivl_statement_t net)
       return 0;
 }
 
+static int show_stmt_utask(ivl_statement_t net)
+{
+      ivl_scope_t task = ivl_stmt_call(net);
+
+      fprintf(vvp_out, "    %%fork TD_%s;\n", ivl_scope_name(task));
+      fprintf(vvp_out, "    %%join;\n");
+      return 0;
+}
+
 static int show_stmt_wait(ivl_statement_t net)
 {
       ivl_event_t ev = ivl_stmt_event(net);
@@ -496,6 +505,10 @@ static int show_statement(ivl_statement_t net)
 	    rc += show_stmt_trigger(net);
 	    break;
 
+	  case IVL_ST_UTASK:
+	    rc += show_stmt_utask(net);
+	    break;
+
 	  case IVL_ST_WAIT:
 	    rc += show_stmt_wait(net);
 	    break;
@@ -561,8 +574,27 @@ int draw_process(ivl_process_t net, void*x)
       return rc;
 }
 
+int draw_task_definition(ivl_scope_t scope)
+{
+      int rc = 0;
+      ivl_statement_t def = ivl_scope_def(scope);
+
+      fprintf(vvp_out, "TD_%s ;\n", ivl_scope_name(scope));
+
+      assert(def);
+      rc += show_statement(def);
+
+      fprintf(vvp_out, "    %%end;\n");
+
+      thread_count += 1;
+      return rc;
+}
+
 /*
  * $Log: vvp_process.c,v $
+ * Revision 1.19  2001/04/02 02:28:13  steve
+ *  Generate code for task calls.
+ *
  * Revision 1.18  2001/04/02 00:27:53  steve
  *  Scopes and numbers as vpi_call parameters.
  *
diff --git a/tgt-vvp/vvp_scope.c b/tgt-vvp/vvp_scope.c
index 59d115f3b..1e52ad161 100644
--- a/tgt-vvp/vvp_scope.c
+++ b/tgt-vvp/vvp_scope.c
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT)
-#ident "$Id: vvp_scope.c,v 1.11 2001/04/01 21:34:48 steve Exp $"
+#ident "$Id: vvp_scope.c,v 1.12 2001/04/02 02:28:13 steve Exp $"
 #endif
 
 # include  "vvp_priv.h"
@@ -257,12 +257,19 @@ int draw_scope(ivl_scope_t net, ivl_scope_t parent)
 	    draw_event_in_scope(event);
       }
 
+      if (ivl_scope_type(net) == IVL_SCT_TASK)
+	    draw_task_definition(net);
+
+
       ivl_scope_children(net, (ivl_scope_f*) draw_scope, net);
       return 0;
 }
 
 /*
  * $Log: vvp_scope.c,v $
+ * Revision 1.12  2001/04/02 02:28:13  steve
+ *  Generate code for task calls.
+ *
  * Revision 1.11  2001/04/01 21:34:48  steve
  *  Recognize the BUF device.
  *
diff --git a/vvp/README.txt b/vvp/README.txt
index c8f91fdda..65e8a33ab 100644
--- a/vvp/README.txt
+++ b/vvp/README.txt
@@ -1,7 +1,7 @@
 /*
  * Copyright (c) 2001 Stephen Williams (steve@icarus.com)
  *
- *  $Id: README.txt,v 1.11 2001/03/30 04:55:22 steve Exp $
+ *  $Id: README.txt,v 1.12 2001/04/02 02:28:13 steve Exp $
  */
 
 VVP SIMULATION ENGINE
@@ -242,12 +242,19 @@ A transient thread is created with a %fork instruction. When a
 transient thread is created this way, the operand to the %fork gives
 the starting address, and the new thread is said to be a child of the
 forking thread. The children of a thread are pushed onto a stack of
-children.
+children. A thread can have only one direct child.
 
 A transient thread is reaped with a %join instruction. %join waits for
 the top thread in the stack of children to complete, then
 continues. It is an error to %join when there are no children.
 
+As you can see, the transient thread in VVP is a cross between a
+conventional thread and a function call. In fact, there is no %call
+instruction in vvp, the job is accomplished with %fork/%join in the
+caller and %end in the callee. The %fork, then is simply a
+generalization of a function call, where the caller does not
+necessarily wait for the callee.
+
 TRUTH TABLES
 
 The logic that a functor represents is expressed as a truth table. The