diff --git a/PWire.cc b/PWire.cc
index 13f41c9e7..7faa13207 100644
--- a/PWire.cc
+++ b/PWire.cc
@@ -17,14 +17,14 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: PWire.cc,v 1.3 2000/02/23 02:56:54 steve Exp $"
+#ident "$Id: PWire.cc,v 1.4 2000/12/11 00:31:43 steve Exp $"
 #endif
 
 # include  "PWire.h"
 # include  <assert.h>
 
 PWire::PWire(const string&n, NetNet::Type t, NetNet::PortType pt)
-: name_(n), type_(t), port_type_(pt), lidx_(0), ridx_(0)
+: name_(n), type_(t), port_type_(pt), signed_(false), lidx_(0), ridx_(0)
 {
 }
 
@@ -83,6 +83,16 @@ bool PWire::set_port_type(NetNet::PortType pt)
       }
 }
 
+void PWire::set_signed(bool flag)
+{
+      signed_ = flag;
+}
+
+bool PWire::get_signed() const
+{
+      return signed_;
+}
+
 void PWire::set_range(PExpr*m, PExpr*l)
 {
       msb_ = svector<PExpr*>(msb_,m);
@@ -100,6 +110,10 @@ void PWire::set_memory_idx(PExpr*ldx, PExpr*rdx)
 
 /*
  * $Log: PWire.cc,v $
+ * Revision 1.4  2000/12/11 00:31:43  steve
+ *  Add support for signed reg variables,
+ *  simulate in t-vvm signed comparisons.
+ *
  * Revision 1.3  2000/02/23 02:56:54  steve
  *  Macintosh compilers do not support ident.
  *
diff --git a/PWire.h b/PWire.h
index d268e397e..d307a66a7 100644
--- a/PWire.h
+++ b/PWire.h
@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: PWire.h,v 1.8 2000/05/02 16:27:38 steve Exp $"
+#ident "$Id: PWire.h,v 1.9 2000/12/11 00:31:43 steve Exp $"
 #endif
 
 # include  "netlist.h"
@@ -49,6 +49,9 @@ class PWire : public LineInfo {
       NetNet::PortType get_port_type() const;
       bool set_port_type(NetNet::PortType);
 
+      void set_signed(bool flag);
+      bool get_signed() const;
+
       void set_range(PExpr*msb, PExpr*lsb);
 
       void set_memory_idx(PExpr*ldx, PExpr*rdx);
@@ -64,6 +67,7 @@ class PWire : public LineInfo {
       string name_;
       NetNet::Type type_;
       NetNet::PortType port_type_;
+      bool signed_;
 
 	// These members hold expressions for the bit width of the
 	// wire. If they do not exist, the wire is 1 bit wide.
@@ -82,6 +86,10 @@ class PWire : public LineInfo {
 
 /*
  * $Log: PWire.h,v $
+ * Revision 1.9  2000/12/11 00:31:43  steve
+ *  Add support for signed reg variables,
+ *  simulate in t-vvm signed comparisons.
+ *
  * Revision 1.8  2000/05/02 16:27:38  steve
  *  Move signal elaboration to a seperate pass.
  *
diff --git a/design_dump.cc b/design_dump.cc
index 52c98f588..e6c908e17 100644
--- a/design_dump.cc
+++ b/design_dump.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: design_dump.cc,v 1.106 2000/12/10 06:41:59 steve Exp $"
+#ident "$Id: design_dump.cc,v 1.107 2000/12/11 00:31:43 steve Exp $"
 #endif
 
 /*
@@ -73,6 +73,8 @@ void NetNet::dump_net(ostream&o, unsigned ind) const
 	    pin_count() << "]";
       if (local_flag_)
 	    o << " (local)";
+      if (signed_)
+	    o << " signed";
       o << " (eref=" << get_eref() << ")";
       if (scope())
 	    o << " scope=" << scope()->name();
@@ -996,6 +998,10 @@ void Design::dump(ostream&o) const
 
 /*
  * $Log: design_dump.cc,v $
+ * Revision 1.107  2000/12/11 00:31:43  steve
+ *  Add support for signed reg variables,
+ *  simulate in t-vvm signed comparisons.
+ *
  * Revision 1.106  2000/12/10 06:41:59  steve
  *  Support delays on continuous assignment from idents. (PR#40)
  *
diff --git a/elab_sig.cc b/elab_sig.cc
index 98c118169..789748e3d 100644
--- a/elab_sig.cc
+++ b/elab_sig.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: elab_sig.cc,v 1.6 2000/12/04 17:37:04 steve Exp $"
+#ident "$Id: elab_sig.cc,v 1.7 2000/12/11 00:31:43 steve Exp $"
 #endif
 
 # include  "Module.h"
@@ -341,12 +341,17 @@ void PWire::elaborate_sig(Design*des, NetScope*scope) const
 	    NetNet*sig = new NetNet(scope, path + "." +basename, wtype, msb, lsb);
 	    sig->set_line(*this);
 	    sig->port_type(port_type_);
+	    sig->set_signed(get_signed());
 	    sig->set_attributes(attributes);
       }
 }
 
 /*
  * $Log: elab_sig.cc,v $
+ * Revision 1.7  2000/12/11 00:31:43  steve
+ *  Add support for signed reg variables,
+ *  simulate in t-vvm signed comparisons.
+ *
  * Revision 1.6  2000/12/04 17:37:04  steve
  *  Add Attrib class for holding NetObj attributes.
  *
diff --git a/netlist.cc b/netlist.cc
index 5daf62c45..454f248f2 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 1.150 2000/12/05 06:29:33 steve Exp $"
+#ident "$Id: netlist.cc,v 1.151 2000/12/11 00:31:43 steve Exp $"
 #endif
 
 # include  <cassert>
@@ -303,7 +303,7 @@ NetNode* NetNode::next_node()
 
 NetNet::NetNet(NetScope*s, const string&n, Type t, unsigned npins)
 : NetObj(s, n, npins), sig_next_(0), sig_prev_(0),
-    type_(t), port_type_(NOT_A_PORT), msb_(npins-1), lsb_(0),
+    type_(t), port_type_(NOT_A_PORT), signed_(false), msb_(npins-1), lsb_(0),
     local_flag_(false), eref_count_(0)
 {
       assert(s);
@@ -336,8 +336,8 @@ NetNet::NetNet(NetScope*s, const string&n, Type t, unsigned npins)
 NetNet::NetNet(NetScope*s, const string&n, Type t, long ms, long ls)
 : NetObj(s, n, ((ms>ls)?ms-ls:ls-ms) + 1), sig_next_(0),
     sig_prev_(0), type_(t),
-    port_type_(NOT_A_PORT), msb_(ms), lsb_(ls), local_flag_(false),
-    eref_count_(0)
+    port_type_(NOT_A_PORT), signed_(false), msb_(ms), lsb_(ls),
+    local_flag_(false), eref_count_(0)
 {
       assert(s);
 
@@ -394,6 +394,16 @@ void NetNet::port_type(NetNet::PortType t)
       port_type_ = t;
 }
 
+bool NetNet::get_signed() const
+{
+      return signed_;
+}
+
+void NetNet::set_signed(bool flag)
+{
+      signed_ = flag;
+}
+
 long NetNet::lsb() const
 {
       return lsb_;
@@ -2163,6 +2173,11 @@ string NetESignal::name() const
       return net_->name();
 }
 
+bool NetESignal::has_sign() const
+{
+      return net_->get_signed();
+}
+
 unsigned NetESignal::pin_count() const
 {
       return net_->pin_count();
@@ -2465,6 +2480,10 @@ bool NetUDP::sequ_glob_(string input, char output)
 
 /*
  * $Log: netlist.cc,v $
+ * Revision 1.151  2000/12/11 00:31:43  steve
+ *  Add support for signed reg variables,
+ *  simulate in t-vvm signed comparisons.
+ *
  * Revision 1.150  2000/12/05 06:29:33  steve
  *  Make signal attributes available to ivl_target API.
  *
diff --git a/netlist.h b/netlist.h
index 8d3fb5c2d..5f79fcc90 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 1.185 2000/12/05 06:29:33 steve Exp $"
+#ident "$Id: netlist.h,v 1.186 2000/12/11 00:31:43 steve Exp $"
 #endif
 
 /*
@@ -334,6 +334,11 @@ class NetNet  : public NetObj, public LineInfo {
       PortType port_type() const;
       void port_type(PortType t);
 
+	/* If a NetNet is signed, then its value is to be treated as
+	   signed. Otherwise, it is unsigned. */
+      bool get_signed() const;
+      void set_signed(bool);
+
 	/* These methods return the msb and lsb indices for the most
 	   significant and least significant bits. These are signed
 	   longs, and may be different from pin numbers. For example,
@@ -366,6 +371,7 @@ class NetNet  : public NetObj, public LineInfo {
     private:
       Type   type_;
       PortType port_type_;
+      bool signed_;
 
       long msb_, lsb_;
 
@@ -2477,6 +2483,10 @@ class NetESignal  : public NetExpr {
       NetESignal(NetNet*n);
       ~NetESignal();
 
+	// a NetESignal expression is signed if the NetNet that it
+	// refers to is signed.
+      bool has_sign() const;
+
       string name() const;
       virtual bool set_width(unsigned);
 
@@ -2825,6 +2835,10 @@ extern ostream& operator << (ostream&, NetNet::Type);
 
 /*
  * $Log: netlist.h,v $
+ * Revision 1.186  2000/12/11 00:31:43  steve
+ *  Add support for signed reg variables,
+ *  simulate in t-vvm signed comparisons.
+ *
  * Revision 1.185  2000/12/05 06:29:33  steve
  *  Make signal attributes available to ivl_target API.
  *
diff --git a/parse.y b/parse.y
index 972a3df9c..4da7d41e7 100644
--- a/parse.y
+++ b/parse.y
@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: parse.y,v 1.112 2000/12/10 22:01:36 steve Exp $"
+#ident "$Id: parse.y,v 1.113 2000/12/11 00:31:43 steve Exp $"
 #endif
 
 # include  "parse_misc.h"
@@ -195,13 +195,12 @@ source_file
      rule has presumably set up the scope. */
 block_item_decl
 	: K_reg range register_variable_list ';'
-		{ pform_set_net_range($3, $2);
+		{ pform_set_net_range($3, $2, false);
 		}
 	| K_reg register_variable_list ';'
 		{ delete $2; }
 	| K_reg K_signed range register_variable_list ';'
-		{ pform_set_net_range($4, $3);
-		  yyerror(@2, "sorry: signed reg not supported.");
+		{ pform_set_net_range($4, $3, true);
 		}
 	| K_reg K_signed register_variable_list ';'
 		{ delete $3;
diff --git a/pform.cc b/pform.cc
index 78b0e0940..6cf5953e0 100644
--- a/pform.cc
+++ b/pform.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: pform.cc,v 1.67 2000/11/30 17:31:42 steve Exp $"
+#ident "$Id: pform.cc,v 1.68 2000/12/11 00:31:43 steve Exp $"
 #endif
 
 # include  "compiler.h"
@@ -328,7 +328,9 @@ void pform_make_udp(const char*name, list<string>*parms,
  * only called by the parser within the scope of the net declaration,
  * and the name that I receive only has the tail component.
  */
-static void pform_set_net_range(const char*name, const svector<PExpr*>*range)
+static void pform_set_net_range(const char*name,
+				const svector<PExpr*>*range,
+				bool signed_flag)
 {
       assert(range);
       assert(range->count() == 2);
@@ -342,9 +344,12 @@ static void pform_set_net_range(const char*name, const svector<PExpr*>*range)
       assert((*range)[0]);
       assert((*range)[1]);
       cur->set_range((*range)[0], (*range)[1]);
+      cur->set_signed(signed_flag);
 }
 
-void pform_set_net_range(list<char*>*names, svector<PExpr*>*range)
+void pform_set_net_range(list<char*>*names,
+			 svector<PExpr*>*range,
+			 bool signed_flag)
 {
       assert(range->count() == 2);
 
@@ -352,7 +357,7 @@ void pform_set_net_range(list<char*>*names, svector<PExpr*>*range)
 		 ; cur != names->end()
 		 ; cur ++ ) {
 	    char*txt = *cur;
-	    pform_set_net_range(txt, range);
+	    pform_set_net_range(txt, range, signed_flag);
 	    free(txt);
       }
 
@@ -676,7 +681,7 @@ void pform_makewire(const vlltype&li,
 	    char*txt = *cur;
 	    pform_makewire(li, txt, type);
 	    if (range)
-		  pform_set_net_range(txt, range);
+		  pform_set_net_range(txt, range, false);
 	    free(txt);
       }
 
@@ -878,7 +883,7 @@ void pform_set_port_type(list<char*>*names,
 	    char*txt = *cur;
 	    pform_set_port_type(txt, pt);
 	    if (range)
-		  pform_set_net_range(txt, range);
+		  pform_set_net_range(txt, range, false);
 	    free(txt);
       }
 
@@ -902,6 +907,7 @@ static void pform_set_reg_integer(const char*nm)
 
       cur->set_range(new PENumber(new verinum(INTEGER_WIDTH-1, INTEGER_WIDTH)),
 		     new PENumber(new verinum(0UL, INTEGER_WIDTH)));
+      cur->set_signed(true);
 }
 
 void pform_set_reg_integer(list<char*>*names)
@@ -1002,6 +1008,10 @@ int pform_parse(const char*path, map<string,Module*>&modules,
 
 /*
  * $Log: pform.cc,v $
+ * Revision 1.68  2000/12/11 00:31:43  steve
+ *  Add support for signed reg variables,
+ *  simulate in t-vvm signed comparisons.
+ *
  * Revision 1.67  2000/11/30 17:31:42  steve
  *  Change LineInfo to store const C strings.
  *
diff --git a/pform.h b/pform.h
index 2e5f248de..4df816619 100644
--- a/pform.h
+++ b/pform.h
@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: pform.h,v 1.44 2000/11/30 17:31:42 steve Exp $"
+#ident "$Id: pform.h,v 1.45 2000/12/11 00:31:43 steve Exp $"
 #endif
 
 # include  "netlist.h"
@@ -137,7 +137,7 @@ extern void pform_make_reginit(const struct vlltype&li,
 			       const string&name, PExpr*expr);
 extern void pform_set_port_type(list<char*>*names, svector<PExpr*>*,
 				NetNet::PortType);
-extern void pform_set_net_range(list<char*>*names, svector<PExpr*>*);
+extern void pform_set_net_range(list<char*>*names, svector<PExpr*>*, bool);
 extern void pform_set_reg_idx(const string&name, PExpr*l, PExpr*r);
 extern void pform_set_reg_integer(list<char*>*names);
 extern void pform_set_reg_time(list<char*>*names);
@@ -202,6 +202,10 @@ extern void pform_dump(ostream&out, Module*mod);
 
 /*
  * $Log: pform.h,v $
+ * Revision 1.45  2000/12/11 00:31:43  steve
+ *  Add support for signed reg variables,
+ *  simulate in t-vvm signed comparisons.
+ *
  * Revision 1.44  2000/11/30 17:31:42  steve
  *  Change LineInfo to store const C strings.
  *
diff --git a/pform_dump.cc b/pform_dump.cc
index 821313308..00d2bd9ea 100644
--- a/pform_dump.cc
+++ b/pform_dump.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: pform_dump.cc,v 1.64 2000/12/10 22:01:36 steve Exp $"
+#ident "$Id: pform_dump.cc,v 1.65 2000/12/11 00:31:43 steve Exp $"
 #endif
 
 /*
@@ -219,6 +219,10 @@ void PWire::dump(ostream&out) const
 	    break;
       }
 
+      if (signed_) {
+	    out << " signed";
+      }
+
       assert(msb_.count() == lsb_.count());
       for (unsigned idx = 0 ;  idx < msb_.count() ;  idx += 1) {
 	    assert(msb_[idx]);
@@ -806,6 +810,10 @@ void PUdp::dump(ostream&out) const
 
 /*
  * $Log: pform_dump.cc,v $
+ * Revision 1.65  2000/12/11 00:31:43  steve
+ *  Add support for signed reg variables,
+ *  simulate in t-vvm signed comparisons.
+ *
  * Revision 1.64  2000/12/10 22:01:36  steve
  *  Support decimal constants in behavioral delays.
  *
diff --git a/t-vvm.cc b/t-vvm.cc
index 0ca2809a7..68953639b 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 1.188 2000/12/10 06:41:59 steve Exp $"
+#ident "$Id: t-vvm.cc,v 1.189 2000/12/11 00:31:43 steve Exp $"
 #endif
 
 # include  <iostream>
@@ -706,16 +706,26 @@ void vvm_proc_rval::expr_binary(const NetEBinary*expr)
 		<< lres << "," << rres << ");" << endl;
 	    break;
 	  case 'G': // >=
-	    tgt_->defn << "      " << result << "[0] = vvm_binop_ge("
-		<< lres << "," << rres << ");" << endl;
+	    if (expr->left()->has_sign() && expr->right()->has_sign()) {
+		  tgt_->defn << "      " << result << "[0] = vvm_binop_ge_s("
+			     << lres << "," << rres << ");" << endl;
+	    } else {
+		  tgt_->defn << "      " << result << "[0] = vvm_binop_ge("
+			     << lres << "," << rres << ");" << endl;
+	    }
 	    break;
 	  case 'l': // left shift(<<)
 	    tgt_->defn << "      " << "vvm_binop_shiftl(" << result
 		<< ", " << lres << "," << rres << ");" << endl;
 	    break;
 	  case 'L': // <=
-	    tgt_->defn << "      " << result << "[0] = vvm_binop_le("
-		<< lres << "," << rres << ");" << endl;
+	    if (expr->left()->has_sign() && expr->right()->has_sign()) {
+		  tgt_->defn << "      " << result << "[0] = vvm_binop_le_s("
+			     << lres << "," << rres << ");" << endl;
+	    } else {
+		  tgt_->defn << "      " << result << "[0] = vvm_binop_le("
+			     << lres << "," << rres << ");" << endl;
+	    }
 	    break;
 	  case 'N': // !==
 	    tgt_->defn << "      " << result << "[0] = vvm_binop_nee("
@@ -726,12 +736,22 @@ void vvm_proc_rval::expr_binary(const NetEBinary*expr)
 		<< lres << "," << rres << ");" << endl;
 	    break;
 	  case '<':
-	    tgt_->defn << "      " << result << "[0] = vvm_binop_lt("
-		<< lres << "," << rres << ");" << endl;
+	    if (expr->left()->has_sign() && expr->right()->has_sign()) {
+		  tgt_->defn << "      " << result << "[0] = vvm_binop_lt_s("
+			     << lres << "," << rres << ");" << endl;
+	    } else {
+		  tgt_->defn << "      " << result << "[0] = vvm_binop_lt("
+			     << lres << "," << rres << ");" << endl;
+	    }
 	    break;
 	  case '>':
-	    tgt_->defn << "      " << result << "[0] = vvm_binop_gt("
-		<< lres << "," << rres << ");" << endl;
+	    if (expr->left()->has_sign() && expr->right()->has_sign()) {
+		  tgt_->defn << "      " << result << "[0] = vvm_binop_gt_s("
+			     << lres << "," << rres << ");" << endl;
+	    } else {
+		  tgt_->defn << "      " << result << "[0] = vvm_binop_gt("
+			     << lres << "," << rres << ");" << endl;
+	    }
 	    break;
 	  case 'o': // logical or (||)
 	    tgt_->defn << "      " << result << "[0] = vvm_binop_lor("
@@ -3370,6 +3390,10 @@ extern const struct target tgt_vvm = {
 };
 /*
  * $Log: t-vvm.cc,v $
+ * Revision 1.189  2000/12/11 00:31:43  steve
+ *  Add support for signed reg variables,
+ *  simulate in t-vvm signed comparisons.
+ *
  * Revision 1.188  2000/12/10 06:41:59  steve
  *  Support delays on continuous assignment from idents. (PR#40)
  *
diff --git a/vvm/vvm_func.cc b/vvm/vvm_func.cc
index 721f5bdac..7bd46d146 100644
--- a/vvm/vvm_func.cc
+++ b/vvm/vvm_func.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: vvm_func.cc,v 1.12 2000/07/06 18:12:28 steve Exp $"
+#ident "$Id: vvm_func.cc,v 1.13 2000/12/11 00:31:44 steve Exp $"
 #endif
 
 # include  "vvm_func.h"
@@ -385,6 +385,34 @@ vpip_bit_t vvm_binop_lt(const vvm_bitset_t&l, const vvm_bitset_t&r)
       return result;
 }
 
+/*
+ * This is the < operator that applies to signed operands.
+ */
+vpip_bit_t vvm_binop_lt_s(const vvm_bitset_t&l, const vvm_bitset_t&r)
+{
+      vpip_bit_t l_pad = l.get_bit(l.get_width()-1);
+      vpip_bit_t r_pad = r.get_bit(r.get_width()-1);
+
+	/* If l>=0 and r>=0, return $unsigned(l) < $unsigned(r) */
+      if (B_IS0(l_pad) && B_IS0(r_pad))
+	    return vvm_binop_lt(l, r);
+
+	/* If l < 0 and r < 0, return $unsigned(r) < $unsigned(l) */
+      if (B_IS1(l_pad) && B_IS1(r_pad))
+	    return vvm_binop_lt(r, l);
+
+	/* If l >= 0 and r < 0, return false; */
+      if (B_IS0(l_pad) && B_IS1(r_pad))
+	    return St0;
+
+	/* if l < 0 and r >= 0, return true; */
+      if (B_IS1(l_pad) && B_IS0(r_pad))
+	    return St1;
+
+	/* Otherwise, one or the other side is unknown. Return X. */
+      return StX;
+}
+
 vpip_bit_t vvm_binop_le(const vvm_bitset_t&l, const vvm_bitset_t&r)
 {
       vpip_bit_t result = St1;
@@ -406,6 +434,34 @@ vpip_bit_t vvm_binop_le(const vvm_bitset_t&l, const vvm_bitset_t&r)
       return result;
 }
 
+/*
+ * This is the <= operator that applies to signed operands.
+ */
+vpip_bit_t vvm_binop_le_s(const vvm_bitset_t&l, const vvm_bitset_t&r)
+{
+      vpip_bit_t l_pad = l.get_bit(l.get_width()-1);
+      vpip_bit_t r_pad = r.get_bit(r.get_width()-1);
+
+	/* If l>=0 and r>=0, return $unsigned(l) <= $unsigned(r) */
+      if (B_IS0(l_pad) && B_IS0(r_pad))
+	    return vvm_binop_le(l, r);
+
+	/* If l < 0 and r < 0, return $unsigned(r) <= $unsigned(l) */
+      if (B_IS1(l_pad) && B_IS1(r_pad))
+	    return vvm_binop_le(r, l);
+
+	/* If l >= 0 and r < 0, return false; */
+      if (B_IS0(l_pad) && B_IS1(r_pad))
+	    return St0;
+
+	/* if l < 0 and r >= 0, return true; */
+      if (B_IS1(l_pad) && B_IS0(r_pad))
+	    return St1;
+
+	/* Otherwise, one or the other side is unknown. Return X. */
+      return StX;
+}
+
 vpip_bit_t vvm_binop_gt(const vvm_bitset_t&l, const vvm_bitset_t&r)
 {
       vpip_bit_t result = St0;
@@ -430,6 +486,34 @@ vpip_bit_t vvm_binop_gt(const vvm_bitset_t&l, const vvm_bitset_t&r)
       return result;
 }
 
+/*
+ * This is the > operator that applies to signed operands.
+ */
+vpip_bit_t vvm_binop_gt_s(const vvm_bitset_t&l, const vvm_bitset_t&r)
+{
+      vpip_bit_t l_pad = l.get_bit(l.get_width()-1);
+      vpip_bit_t r_pad = r.get_bit(r.get_width()-1);
+
+	/* If l>=0 and r>=0, return $unsigned(l) > $unsigned(r) */
+      if (B_IS0(l_pad) && B_IS0(r_pad))
+	    return vvm_binop_gt(l, r);
+
+	/* If l < 0 and r < 0, return $unsigned(r) > $unsigned(l) */
+      if (B_IS1(l_pad) && B_IS1(r_pad))
+	    return vvm_binop_gt(r, l);
+
+	/* If l >= 0 and r < 0, return true; */
+      if (B_IS0(l_pad) && B_IS1(r_pad))
+	    return St1;
+
+	/* if l < 0 and r >= 0, return false; */
+      if (B_IS1(l_pad) && B_IS0(r_pad))
+	    return St0;
+
+	/* Otherwise, one or the other side is unknown. Return X. */
+      return StX;
+}
+
 vpip_bit_t vvm_binop_ge(const vvm_bitset_t&l, const vvm_bitset_t&r)
 {
       vpip_bit_t result = St1;
@@ -453,6 +537,34 @@ vpip_bit_t vvm_binop_ge(const vvm_bitset_t&l, const vvm_bitset_t&r)
       return result;
 }
 
+/*
+ * This is the >= operator that applies to signed operands.
+ */
+vpip_bit_t vvm_binop_ge_s(const vvm_bitset_t&l, const vvm_bitset_t&r)
+{
+      vpip_bit_t l_pad = l.get_bit(l.get_width()-1);
+      vpip_bit_t r_pad = r.get_bit(r.get_width()-1);
+
+	/* If l>=0 and r>=0, return $unsigned(l) >= $unsigned(r) */
+      if (B_IS0(l_pad) && B_IS0(r_pad))
+	    return vvm_binop_ge(l, r);
+
+	/* If l < 0 and r < 0, return $unsigned(r) >= $unsigned(l) */
+      if (B_IS1(l_pad) && B_IS1(r_pad))
+	    return vvm_binop_ge(r, l);
+
+	/* If l >= 0 and r < 0, return true; */
+      if (B_IS0(l_pad) && B_IS1(r_pad))
+	    return St1;
+
+	/* if l < 0 and r >= 0, return false; */
+      if (B_IS1(l_pad) && B_IS0(r_pad))
+	    return St0;
+
+	/* Otherwise, one or the other side is unknown. Return X. */
+      return StX;
+}
+
 vpip_bit_t vvm_binop_land(const vvm_bitset_t&l, const vvm_bitset_t&r)
 {
       vpip_bit_t res1 = vvm_unop_or(l);
@@ -495,6 +607,10 @@ void vvm_ternary(vvm_bitset_t&v, vpip_bit_t c,
 
 /*
  * $Log: vvm_func.cc,v $
+ * Revision 1.13  2000/12/11 00:31:44  steve
+ *  Add support for signed reg variables,
+ *  simulate in t-vvm signed comparisons.
+ *
  * Revision 1.12  2000/07/06 18:12:28  steve
  *  unop_not can take out width same as in width.
  *
diff --git a/vvm/vvm_func.h b/vvm/vvm_func.h
index 50cba3d20..9689ed774 100644
--- a/vvm/vvm_func.h
+++ b/vvm/vvm_func.h
@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: vvm_func.h,v 1.29 2000/05/19 04:22:56 steve Exp $"
+#ident "$Id: vvm_func.h,v 1.30 2000/12/11 00:31:44 steve Exp $"
 #endif
 
 # include  "vvm.h"
@@ -184,17 +184,21 @@ extern vpip_bit_t vvm_binop_xeq(const vvm_bitset_t&l, const vvm_bitset_t&r);
 extern vpip_bit_t vvm_binop_zeq(const vvm_bitset_t&l, const vvm_bitset_t&r);
 
 
-extern vpip_bit_t vvm_binop_lt(const vvm_bitset_t&l, const vvm_bitset_t&r);
-
 /*
- * The <= operator takes operands of natural width and returns a
- * single bit. The result is V1 if l <= r, otherwise V0;
+ * The _s variants are signed versions. That is, it assumes the
+ * operands are signed values and does the comparison on that basis.
  */
+extern vpip_bit_t vvm_binop_lt(const vvm_bitset_t&l, const vvm_bitset_t&r);
+extern vpip_bit_t vvm_binop_lt_s(const vvm_bitset_t&l, const vvm_bitset_t&r);
+
 extern vpip_bit_t vvm_binop_le(const vvm_bitset_t&l, const vvm_bitset_t&r);
+extern vpip_bit_t vvm_binop_le_s(const vvm_bitset_t&l, const vvm_bitset_t&r);
 
 extern vpip_bit_t vvm_binop_gt(const vvm_bitset_t&l, const vvm_bitset_t&r);
+extern vpip_bit_t vvm_binop_gt_s(const vvm_bitset_t&l, const vvm_bitset_t&r);
 
 extern vpip_bit_t vvm_binop_ge(const vvm_bitset_t&l, const vvm_bitset_t&r);
+extern vpip_bit_t vvm_binop_ge_s(const vvm_bitset_t&l, const vvm_bitset_t&r);
 
 extern vpip_bit_t vvm_binop_land(const vvm_bitset_t&l, const vvm_bitset_t&r);
 
@@ -206,6 +210,10 @@ extern void vvm_ternary(vvm_bitset_t&v, vpip_bit_t c,
 
 /*
  * $Log: vvm_func.h,v $
+ * Revision 1.30  2000/12/11 00:31:44  steve
+ *  Add support for signed reg variables,
+ *  simulate in t-vvm signed comparisons.
+ *
  * Revision 1.29  2000/05/19 04:22:56  steve
  *  Add the integer modulus function.
  *