Support $signed cast of expressions.

elab_expr.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_expr.cc,v 1.47 2001/12/29 20:41:30 steve Exp $"
+#ident "$Id: elab_expr.cc,v 1.48 2001/12/31 00:08:14 steve Exp $"
 #endif
 
 # include "config.h"
@@ -162,6 +162,26 @@ NetEBinary* PEBinary::elaborate_expr_base_(Design*des,
  */
 NetExpr* PECallFunction::elaborate_sfunc_(Design*des, NetScope*scope) const
 {
+
+	/* Catch the special case that the system function is the
+	   $signed function. This function is special, in that it does
+	   not lead to executable code but takes the single parameter
+	   and makes it into a signed expression. No bits are changed,
+	   it just changes the interpretation. */
+      if (strcmp(path_.peek_name(0), "$signed") == 0) {
+	    if ((parms_.count() != 1) || (parms_[0] == 0)) {
+		  cerr << get_line() << ": error: The $signed() function "
+		       << "takes exactly one(1) argument." << endl;
+		  des->errors += 1;
+		  return 0;
+	    }
+
+	    PExpr*expr = parms_[0];
+	    NetExpr*sub = expr->elaborate_expr(des, scope);
+	    sub->cast_signed(true);
+	    return sub;
+      }
+
       unsigned wid = 32;
 
       if (strcmp(path_.peek_name(0), "$time") == 0)
@@ -651,6 +671,9 @@ NetEUnary* PEUnary::elaborate_expr(Design*des, NetScope*scope) const
 
 /*
  * $Log: elab_expr.cc,v $
+ * Revision 1.48  2001/12/31 00:08:14  steve
+ *  Support $signed cast of expressions.
+ *
  * Revision 1.47  2001/12/29 20:41:30  steve
  *  Allow escaped $ in identifiers.
  *

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 1.178 2001/12/03 04:47:15 steve Exp $"
+#ident "$Id: netlist.cc,v 1.179 2001/12/31 00:08:14 steve Exp $"
 #endif
 
 # include "config.h"
@@ -1789,7 +1789,7 @@ const NetScope* NetUTask::task() const
 }
 
 NetExpr::NetExpr(unsigned w)
-: width_(w)
+: width_(w), signed_flag_(false)
 {
 }
 
@@ -1799,7 +1799,12 @@ NetExpr::~NetExpr()
 
 bool NetExpr::has_sign() const
 {
-      return false;
+      return signed_flag_;
+}
+
+void NetExpr::cast_signed(bool flag)
+{
+      signed_flag_ = flag;
 }
 
 bool NetExpr::has_width() const
@@ -2046,6 +2051,7 @@ NetEConcat* NetEConcat::dup_expr() const
 NetEConst::NetEConst(const verinum&val)
 : NetExpr(val.len()), value_(val)
 {
+      cast_signed(value_.has_sign());
 }
 
 NetEConst::~NetEConst()
@@ -2057,11 +2063,6 @@ const verinum& NetEConst::value() const
       return value_;
 }
 
-bool NetEConst::has_sign() const
-{
-      return value_.has_sign();
-}
-
 bool NetEConst::has_width() const
 {
       return value_.has_len();
@@ -2214,6 +2215,7 @@ NetESignal::NetESignal(NetNet*n)
       lsi_ = 0;
       net_->incr_eref();
       set_line(*n);
+      cast_signed(net_->get_signed());
 }
 
 NetESignal::NetESignal(NetNet*n, unsigned m, unsigned l)
@@ -2224,6 +2226,7 @@ NetESignal::NetESignal(NetNet*n, unsigned m, unsigned l)
       lsi_ = l;
       net_->incr_eref();
       set_line(*n);
+      cast_signed(net_->get_signed());
 }
 
 NetESignal::~NetESignal()
@@ -2236,11 +2239,6 @@ string NetESignal::name() const
       return net_->name();
 }
 
-bool NetESignal::has_sign() const
-{
-      return net_->get_signed();
-}
-
 unsigned NetESignal::bit_count() const
 {
       return msi_ - lsi_ + 1;
@@ -2407,6 +2405,9 @@ const NetProc*NetTaskDef::proc() const
 
 /*
  * $Log: netlist.cc,v $
+ * Revision 1.179  2001/12/31 00:08:14  steve
+ *  Support $signed cast of expressions.
+ *
  * Revision 1.178  2001/12/03 04:47:15  steve
  *  Parser and pform use hierarchical names as hname_t
  *  objects instead of encoded strings.

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 1.227 2001/12/03 04:47:15 steve Exp $"
+#ident "$Id: netlist.h,v 1.228 2001/12/31 00:08:14 steve Exp $"
 #endif
 
 /*
@@ -847,7 +847,8 @@ class NetExpr  : public LineInfo {
 
 	// This method returns true if the expression is
 	// signed. Unsigned expressions return false.
-      virtual bool has_sign() const;
+      bool has_sign() const;
+      void cast_signed(bool flag);
 
 	// This returns true if the expression has a definite
 	// width. This is generally true, but in some cases the
@@ -880,6 +881,7 @@ class NetExpr  : public LineInfo {
 
     private:
       unsigned width_;
+      bool signed_flag_;
 
     private: // not implemented
       NetExpr(const NetExpr&);
@@ -901,7 +903,6 @@ class NetEConst  : public NetExpr {
 
       virtual bool set_width(unsigned w);
 
-      virtual bool has_sign() const;
       virtual bool has_width() const;
 
       virtual void expr_scan(struct expr_scan_t*) const;
@@ -2501,10 +2502,6 @@ class NetESignal  : public NetExpr {
       NetESignal(NetNet*n, unsigned msi, unsigned lsi);
       ~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);
 
@@ -2867,6 +2864,9 @@ extern ostream& operator << (ostream&, NetNet::Type);
 
 /*
  * $Log: netlist.h,v $
+ * Revision 1.228  2001/12/31 00:08:14  steve
+ *  Support $signed cast of expressions.
+ *
  * Revision 1.227  2001/12/03 04:47:15  steve
  *  Parser and pform use hierarchical names as hname_t
  *  objects instead of encoded strings.

t-dll-expr.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-expr.cc,v 1.20 2001/10/23 04:22:41 steve Exp $"
+#ident "$Id: t-dll-expr.cc,v 1.21 2001/12/31 00:08:14 steve Exp $"
 #endif
 
 # include "config.h"
@@ -127,7 +127,7 @@ void dll_target::expr_const(const NetEConst*net)
 	    char*bits;
 	    expr_->type_ = IVL_EX_NUMBER;
 	    expr_->width_= net->expr_width();
-	    expr_->signed_ = val.has_sign()? 1 : 0;
+	    expr_->signed_ = net->has_sign()? 1 : 0;
 	    expr_->u_.number_.bits_ = bits = (char*)malloc(expr_->width_);
 	    for (idx = 0 ;  idx < expr_->width_ ;  idx += 1)
 		  switch (val.get(idx)) {
@@ -347,6 +347,9 @@ void dll_target::expr_unary(const NetEUnary*net)
 
 /*
  * $Log: t-dll-expr.cc,v $
+ * Revision 1.21  2001/12/31 00:08:14  steve
+ *  Support $signed cast of expressions.
+ *
  * Revision 1.20  2001/10/23 04:22:41  steve
  *  Support bit selects of non-0 lsb for vectors.
  *