From 004ecd08ddd08f3cd6da6438847a8c89827bfeb8 Mon Sep 17 00:00:00 2001
From: steve <steve>
Date: Wed, 2 Jul 2003 04:19:16 +0000
Subject: [PATCH]  Elide empty begin-end in conditionals.

---
 elaborate.cc | 22 +++++++++++++++++++++-
 netlist.h    | 12 +++++++++---
 2 files changed, 30 insertions(+), 4 deletions(-)

diff --git a/elaborate.cc b/elaborate.cc
index 59c244461..9d1aa1f2c 100644
--- a/elaborate.cc
+++ b/elaborate.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #ifdef HAVE_CVS_IDENT
-#ident "$Id: elaborate.cc,v 1.283 2003/06/21 01:21:43 steve Exp $"
+#ident "$Id: elaborate.cc,v 1.284 2003/07/02 04:19:16 steve Exp $"
 #endif
 
 # include "config.h"
@@ -1387,6 +1387,23 @@ NetProc* PCondit::elaborate(Design*des, NetScope*scope) const
       NetProc*i = if_? if_->elaborate(des, scope) : 0;
       NetProc*e = else_? else_->elaborate(des, scope) : 0;
 
+	// Detect the special cases that the if or else statements are
+	// empty blocks. If this is the case, remove the blocks as
+	// null statements.
+      if (NetBlock*tmp = dynamic_cast<NetBlock*>(i)) {
+	    if (tmp->proc_first() == 0) {
+		  delete i;
+		  i = 0;
+	    }
+      }
+
+      if (NetBlock*tmp = dynamic_cast<NetBlock*>(e)) {
+	    if (tmp->proc_first() == 0) {
+		  delete e;
+		  e = 0;
+	    }
+      }
+
       NetCondit*res = new NetCondit(expr, i, e);
       res->set_line(*this);
       return res;
@@ -2560,6 +2577,9 @@ Design* elaborate(list<const char*>roots)
 
 /*
  * $Log: elaborate.cc,v $
+ * Revision 1.284  2003/07/02 04:19:16  steve
+ *  Elide empty begin-end in conditionals.
+ *
  * Revision 1.283  2003/06/21 01:21:43  steve
  *  Harmless fixup of warnings.
  *
diff --git a/netlist.h b/netlist.h
index fbfeca4a2..c3249680e 100644
--- a/netlist.h
+++ b/netlist.h
@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #ifdef HAVE_CVS_IDENT
-#ident "$Id: netlist.h,v 1.292 2003/06/21 01:21:43 steve Exp $"
+#ident "$Id: netlist.h,v 1.293 2003/07/02 04:19:16 steve Exp $"
 #endif
 
 /*
@@ -1628,8 +1628,11 @@ class NetCAssign  : public NetProc, public NetNode {
 };
 
 
-/* A condit represents a conditional. It has an expression to test,
-   and a pair of statements to select from. */
+/*
+ * A condit represents a conditional. It has an expression to test,
+ * and a pair of statements to select from. If the original statement
+ * has empty clauses, then the NetProc for it will be a nul pointer.
+ */
 class NetCondit  : public NetProc {
 
     public:
@@ -3306,6 +3309,9 @@ extern ostream& operator << (ostream&, NetNet::Type);
 
 /*
  * $Log: netlist.h,v $
+ * Revision 1.293  2003/07/02 04:19:16  steve
+ *  Elide empty begin-end in conditionals.
+ *
  * Revision 1.292  2003/06/21 01:21:43  steve
  *  Harmless fixup of warnings.
  *