Handle signed magnitude compare all the

way through to the vvp code generator.

elab_net.cc

@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #ifdef HAVE_CVS_IDENT
-#ident "$Id: elab_net.cc,v 1.111 2003/03/29 05:51:25 steve Exp $"
+#ident "$Id: elab_net.cc,v 1.112 2003/04/11 05:18:08 steve Exp $"
 #endif
 
 # include "config.h"
@@ -421,14 +421,31 @@ NetNet* PEBinary::elaborate_net_cmp_(Design*des, NetScope*scope,
       unsigned dwidth = lsig->pin_count();
       if (rsig->pin_count() > dwidth) dwidth = rsig->pin_count();
 
-      NetNet*zero = 0;
+	/* Operands of binary compare need to be padded to equal
+	   size. Figure the pad bit needed to extend the narrowest
+	   vector. */
+      NetNet*padbit = 0;
       if (lsig->pin_count() != rsig->pin_count()) {
+	    unsigned lwid = lsig->pin_count();
+	    unsigned rwid = rsig->pin_count();
+
+	    padbit = new NetNet(scope, scope->local_symbol(), NetNet::WIRE);
+	    padbit->local_flag(true);
+
+	    if (lsig->get_signed() && (lwid < rwid)) {
+
+		  connect(padbit->pin(0), lsig->pin(lwid-1));
+
+	    } else if (rsig->get_signed() && (rwid < lwid)) {
+
+		  connect(padbit->pin(0), rsig->pin(rwid-1));
+
+	    } else {
 		  NetConst*tmp = new NetConst(scope, scope->local_symbol(),
 					      verinum::V0);
 		  des->add_node(tmp);
-	    zero = new NetNet(scope, scope->local_symbol(), NetNet::WIRE);
+		  connect(tmp->pin(0), padbit->pin(0));
-	    zero->local_flag(true);
+	    }
-	    connect(tmp->pin(0), zero->pin(0));
       }
 
       NetNet*osig = new NetNet(scope, scope->local_symbol(), NetNet::WIRE);
@@ -447,11 +464,11 @@ NetNet* PEBinary::elaborate_net_cmp_(Design*des, NetScope*scope,
 		for (unsigned idx = 0 ;  idx < lsig->pin_count() ; idx += 1)
 		      connect(cmp->pin_DataA(idx), lsig->pin(idx));
 		for (unsigned idx = lsig->pin_count(); idx < dwidth ; idx += 1)
-		      connect(cmp->pin_DataA(idx), zero->pin(0));
+		      connect(cmp->pin_DataA(idx), padbit->pin(0));
 		for (unsigned idx = 0 ;  idx < rsig->pin_count() ;  idx += 1)
 		      connect(cmp->pin_DataB(idx), rsig->pin(idx));
 		for (unsigned idx = rsig->pin_count(); idx < dwidth ; idx += 1)
-		      connect(cmp->pin_DataB(idx), zero->pin(0));
+		      connect(cmp->pin_DataB(idx), padbit->pin(0));
 
 		switch (op_) {
 		    case '<':
@@ -467,6 +484,11 @@ NetNet* PEBinary::elaborate_net_cmp_(Design*des, NetScope*scope,
 		      connect(cmp->pin_AGEB(), osig->pin(0));
 		      break;
 		}
+		  /* If both operands are signed, then do a signed
+		     compare. */
+		if (lsig->get_signed() && rsig->get_signed())
+		      cmp->set_signed(true);
+
 		gate = cmp;
 		break;
 	  }
@@ -487,12 +509,12 @@ NetNet* PEBinary::elaborate_net_cmp_(Design*des, NetScope*scope,
 		  if (idx < lsig->pin_count())
 			connect(cmp->pin(1), lsig->pin(idx));
 		  else
-			connect(cmp->pin(1), zero->pin(0));
+			connect(cmp->pin(1), padbit->pin(0));
 
 		  if (idx < rsig->pin_count())
 			connect(cmp->pin(2), rsig->pin(idx));
 		  else
-			connect(cmp->pin(2), zero->pin(0));
+			connect(cmp->pin(2), padbit->pin(0));
 
 		  connect(cmp->pin(0), gate->pin(idx+1));
 		  des->add_node(cmp);
@@ -527,12 +549,12 @@ NetNet* PEBinary::elaborate_net_cmp_(Design*des, NetScope*scope,
 		    if (idx < lsig->pin_count())
 			  connect(cmp->pin_DataA(idx), lsig->pin(idx));
 		    else
-			  connect(cmp->pin_DataA(idx), zero->pin(0));
+			  connect(cmp->pin_DataA(idx), padbit->pin(0));
 
 		    if (idx < rsig->pin_count())
 			  connect(cmp->pin_DataB(idx), rsig->pin(idx));
 		    else
-			  connect(cmp->pin_DataB(idx), zero->pin(0));
+			  connect(cmp->pin_DataB(idx), padbit->pin(0));
 
 	      }
 	      connect(cmp->pin_AEB(), osig->pin(0));
@@ -561,12 +583,12 @@ NetNet* PEBinary::elaborate_net_cmp_(Design*des, NetScope*scope,
 		    if (idx < lsig->pin_count())
 			  connect(cmp->pin_DataA(idx), lsig->pin(idx));
 		    else
-			  connect(cmp->pin_DataA(idx), zero->pin(0));
+			  connect(cmp->pin_DataA(idx), padbit->pin(0));
 
 		    if (idx < rsig->pin_count())
 			  connect(cmp->pin_DataB(idx), rsig->pin(idx));
 		    else
-			  connect(cmp->pin_DataB(idx), zero->pin(0));
+			  connect(cmp->pin_DataB(idx), padbit->pin(0));
 
 	      }
 	      connect(cmp->pin_ANEB(), osig->pin(0));
@@ -1014,16 +1036,36 @@ NetNet* PEBinary::elaborate_net_shift_(Design*des, NetScope*scope,
  * This method elaborates a call to a function in the context of a
  * continuous assignment.
  */
-NetNet* PECallFunction::elaborate_net(Design*des, NetScope*scope, unsigned,
+NetNet* PECallFunction::elaborate_net(Design*des, NetScope*scope,
-				      unsigned long,
+				      unsigned width,
-				      unsigned long,
+				      unsigned long rise,
-				      unsigned long,
+				      unsigned long fall,
-				      Link::strength_t,
+				      unsigned long decay,
-				      Link::strength_t) const
+				      Link::strength_t drive0,
+				      Link::strength_t drive1) const
 {
       unsigned errors = 0;
       unsigned func_pins = 0;
 
+	/* Handle the special case that the function call is to
+	   $signed. This takes a single expression argument, and
+	   forces it to be a signed result. Otherwise, it is as if the
+	   $signed did not exist. */
+      if (strcmp(path_.peek_name(0), "$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];
+	    NetNet*sub = expr->elaborate_net(des, scope, width, rise,
+					     fall, decay, drive0, drive1);
+	    sub->set_signed(true);
+	    return sub;
+      }
+
 	/* Look up the function definition. */
       NetFuncDef*def = des->find_function(scope, path_);
       if (def == 0) {
@@ -1276,6 +1318,7 @@ NetNet* PEIdent::elaborate_net(Design*des, NetScope*scope,
 		  const NetEConst*pc = dynamic_cast<const NetEConst*>(pe);
 		  assert(pc);
 		  verinum pvalue = pc->value();
+
 		  sig = new NetNet(scope, path_.peek_name(0),
 				   NetNet::IMPLICIT, pc->expr_width());
 		  NetConst*cp = new NetConst(scope, scope->local_symbol(),
@@ -2281,6 +2324,10 @@ NetNet* PEUnary::elaborate_net(Design*des, NetScope*scope,
 
 /*
  * $Log: elab_net.cc,v $
+ * Revision 1.112  2003/04/11 05:18:08  steve
+ *  Handle signed magnitude compare all the
+ *  way through to the vvp code generator.
+ *
  * Revision 1.111  2003/03/29 05:51:25  steve
  *  Sign extend NetMult inputs if result is signed.
  *

ivl.def

@@ -75,6 +75,7 @@ ivl_lpm_q
 ivl_lpm_scope
 ivl_lpm_select
 ivl_lpm_selects
+ivl_lpm_signed
 ivl_lpm_size
 ivl_lpm_type
 ivl_lpm_width

ivl_target.h

@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #ifdef HAVE_CVS_IDENT
-#ident "$Id: ivl_target.h,v 1.115 2003/03/10 23:40:53 steve Exp $"
+#ident "$Id: ivl_target.h,v 1.116 2003/04/11 05:18:08 steve Exp $"
 #endif
 
 #ifdef __cplusplus
@@ -643,6 +643,10 @@ extern const char* ivl_udp_name(ivl_udp_t net);
  *    This is the size of the select input for a LPM_MUX device, or the 
  *    address bus width of an LPM_RAM.
  *
+ * ivl_lpm_signed
+ *    Arithmetic LPM devices may be signed or unsigned if there is a
+ *    distinction.
+ *
  * ivl_lpm_size
  *    In addition to a width, some devices have a size. The size is
  *    often the number of inputs per out, i.e., the number of inputs
@@ -652,6 +656,7 @@ extern const char* ivl_udp_name(ivl_udp_t net);
 extern const char*    ivl_lpm_name(ivl_lpm_t net); /* (Obsolete) */
 extern const char*    ivl_lpm_basename(ivl_lpm_t net);
 extern ivl_scope_t    ivl_lpm_scope(ivl_lpm_t net);
+extern int            ivl_lpm_signed(ivl_lpm_t net);
 extern ivl_lpm_type_t ivl_lpm_type(ivl_lpm_t net);
 extern unsigned       ivl_lpm_width(ivl_lpm_t net);
 
@@ -1204,6 +1209,10 @@ _END_DECL
 
 /*
  * $Log: ivl_target.h,v $
+ * Revision 1.116  2003/04/11 05:18:08  steve
+ *  Handle signed magnitude compare all the
+ *  way through to the vvp code generator.
+ *
  * Revision 1.115  2003/03/10 23:40:53  steve
  *  Keep parameter constants for the ivl_target API.
  *

netlist.cc

@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #ifdef HAVE_CVS_IDENT
-#ident "$Id: netlist.cc,v 1.210 2003/03/29 05:51:25 steve Exp $"
+#ident "$Id: netlist.cc,v 1.211 2003/04/11 05:18:08 steve Exp $"
 #endif
 
 # include "config.h"
@@ -849,6 +849,7 @@ const Link& NetCLShift::pin_Distance(unsigned idx) const
 NetCompare::NetCompare(NetScope*s, const string&n, unsigned wi)
 : NetNode(s, lex_strings.add(n.c_str()), 8+2*wi), width_(wi)
 {
+      signed_flag_ = false;
       pin(0).set_dir(Link::INPUT); pin(0).set_name("Aclr");
       pin(1).set_dir(Link::INPUT); pin(1).set_name("Clock");
       pin(2).set_dir(Link::OUTPUT); pin(2).set_name("AGB");
@@ -874,6 +875,16 @@ unsigned NetCompare::width() const
       return width_;
 }
 
+bool NetCompare::get_signed() const
+{
+      return signed_flag_;
+}
+
+void NetCompare::set_signed(bool flag)
+{
+      signed_flag_ = flag;
+}
+
 Link& NetCompare::pin_Aclr()
 {
       return pin(0);
@@ -2151,6 +2162,10 @@ const NetProc*NetTaskDef::proc() const
 
 /*
  * $Log: netlist.cc,v $
+ * Revision 1.211  2003/04/11 05:18:08  steve
+ *  Handle signed magnitude compare all the
+ *  way through to the vvp code generator.
+ *
  * Revision 1.210  2003/03/29 05:51:25  steve
  *  Sign extend NetMult inputs if result is signed.
  *

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 1.284 2003/04/08 04:33:55 steve Exp $"
+#ident "$Id: netlist.h,v 1.285 2003/04/11 05:18:08 steve Exp $"
 #endif
 
 /*
@@ -533,6 +533,9 @@ class NetCompare  : public NetNode {
 
       unsigned width() const;
 
+      bool get_signed() const;
+      void set_signed(bool);
+
       Link& pin_Aclr();
       Link& pin_Clock();
       Link& pin_AGB();
@@ -563,6 +566,7 @@ class NetCompare  : public NetNode {
 
     private:
       unsigned width_;
+      bool signed_flag_;
 };
 
 /*
@@ -3246,6 +3250,10 @@ extern ostream& operator << (ostream&, NetNet::Type);
 
 /*
  * $Log: netlist.h,v $
+ * Revision 1.285  2003/04/11 05:18:08  steve
+ *  Handle signed magnitude compare all the
+ *  way through to the vvp code generator.
+ *
  * Revision 1.284  2003/04/08 04:33:55  steve
  *  Synthesize shift expressions.
  *

t-dll-api.cc

@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #ifdef HAVE_CVS_IDENT
-#ident "$Id: t-dll-api.cc,v 1.96 2003/03/10 23:40:53 steve Exp $"
+#ident "$Id: t-dll-api.cc,v 1.97 2003/04/11 05:18:08 steve Exp $"
 #endif
 
 # include "config.h"
@@ -902,6 +902,35 @@ extern "C" unsigned ivl_lpm_selects(ivl_lpm_t net)
       }
 }
 
+extern "C" int ivl_lpm_signed(ivl_lpm_t net)
+{
+      assert(net);
+      switch (net->type) {
+	  case IVL_LPM_FF:
+	  case IVL_LPM_RAM:
+	  case IVL_LPM_MUX:
+	    return 0;
+	  case IVL_LPM_ADD:
+	  case IVL_LPM_CMP_EQ:
+	  case IVL_LPM_CMP_GE:
+	  case IVL_LPM_CMP_GT:
+	  case IVL_LPM_CMP_NE:
+	  case IVL_LPM_DIVIDE:
+	  case IVL_LPM_MOD:
+	  case IVL_LPM_MULT:
+	  case IVL_LPM_SUB:
+	    return net->u_.arith.signed_flag;
+	  case IVL_LPM_SHIFTL:
+	  case IVL_LPM_SHIFTR:
+	    return 0;
+	  case IVL_LPM_UFUNC:
+	    return 0;
+	  default:
+	    assert(0);
+	    return 0;
+      }
+}
+
 extern "C" unsigned ivl_lpm_size(ivl_lpm_t net)
 {
       switch (net->type) {
@@ -1797,6 +1826,10 @@ extern "C" ivl_variable_type_t ivl_variable_type(ivl_variable_t net)
 
 /*
  * $Log: t-dll-api.cc,v $
+ * Revision 1.97  2003/04/11 05:18:08  steve
+ *  Handle signed magnitude compare all the
+ *  way through to the vvp code generator.
+ *
  * Revision 1.96  2003/03/10 23:40:53  steve
  *  Keep parameter constants for the ivl_target API.
  *

t-dll.cc

@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #ifdef HAVE_CVS_IDENT
-#ident "$Id: t-dll.cc,v 1.109 2003/03/29 05:51:25 steve Exp $"
+#ident "$Id: t-dll.cc,v 1.110 2003/04/11 05:18:08 steve Exp $"
 #endif
 
 # include "config.h"
@@ -1071,6 +1071,8 @@ void dll_target::lpm_add_sub(const NetAddSub*net)
       obj->scope = find_scope(des_, net->scope());
       assert(obj->scope);
 
+      obj->u_.arith.signed_flag = 0;
+
 	/* Choose the width of the adder. If the carry bit is
 	   connected, then widen the adder by one and plan on leaving
 	   the fake inputs unconnected. */
@@ -1219,6 +1221,7 @@ void dll_target::lpm_compare(const NetCompare*net)
       bool swap_operands = false;
 
       obj->u_.arith.width = net->width();
+      obj->u_.arith.signed_flag = net->get_signed()? 1 : 0;
 
       obj->u_.arith.q = new ivl_nexus_t[1 + 2 * obj->u_.arith.width];
       obj->u_.arith.a = obj->u_.arith.q + 1;
@@ -2117,6 +2120,10 @@ extern const struct target tgt_dll = { "dll", &dll_target_obj };
 
 /*
  * $Log: t-dll.cc,v $
+ * Revision 1.110  2003/04/11 05:18:08  steve
+ *  Handle signed magnitude compare all the
+ *  way through to the vvp code generator.
+ *
  * Revision 1.109  2003/03/29 05:51:25  steve
  *  Sign extend NetMult inputs if result is signed.
  *

t-dll.h

@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #ifdef HAVE_CVS_IDENT
-#ident "$Id: t-dll.h,v 1.100 2003/03/10 23:40:54 steve Exp $"
+#ident "$Id: t-dll.h,v 1.101 2003/04/11 05:18:08 steve Exp $"
 #endif
 
 # include  "target.h"
@@ -334,7 +334,8 @@ struct ivl_lpm_s {
 	    } shift;
 
 	    struct ivl_lpm_arith_s {
-		  unsigned short width;
+		  unsigned width :16;
+		  unsigned signed_flag :1;
 		  ivl_nexus_t*q, *a, *b;
 	    } arith;
 
@@ -672,6 +673,10 @@ struct ivl_variable_s {
 
 /*
  * $Log: t-dll.h,v $
+ * Revision 1.101  2003/04/11 05:18:08  steve
+ *  Handle signed magnitude compare all the
+ *  way through to the vvp code generator.
+ *
  * Revision 1.100  2003/03/10 23:40:54  steve
  *  Keep parameter constants for the ivl_target API.
  *

tgt-stub/stub.c

@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #ifdef HAVE_CVS_IDENT
-#ident "$Id: stub.c,v 1.76 2003/03/29 05:51:26 steve Exp $"
+#ident "$Id: stub.c,v 1.77 2003/04/11 05:18:08 steve Exp $"
 #endif
 
 # include "config.h"
@@ -304,8 +304,11 @@ static void show_lpm(ivl_lpm_t net)
 	  }
 
 	  default:
-	    fprintf(out, "  %s: <width=%u>\n", ivl_lpm_basename(net),
+	    fprintf(out, "  LPM(%d) %s: <width=%u, signed=%d>\n",
-		    ivl_lpm_width(net));
+		    ivl_lpm_type(net),
+		    ivl_lpm_basename(net),
+		    ivl_lpm_width(net),
+		    ivl_lpm_signed(net));
       }
 }
 
@@ -837,6 +840,10 @@ int target_design(ivl_design_t des)
 
 /*
  * $Log: stub.c,v $
+ * Revision 1.77  2003/04/11 05:18:08  steve
+ *  Handle signed magnitude compare all the
+ *  way through to the vvp code generator.
+ *
  * Revision 1.76  2003/03/29 05:51:26  steve
  *  Sign extend NetMult inputs if result is signed.
  *

tgt-vvp/vvp_scope.c

@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #ifdef HAVE_CVS_IDENT
-#ident "$Id: vvp_scope.c,v 1.91 2003/03/25 02:15:48 steve Exp $"
+#ident "$Id: vvp_scope.c,v 1.92 2003/04/11 05:18:08 steve Exp $"
 #endif
 
 # include  "vvp_priv.h"
@@ -1133,6 +1133,7 @@ static void draw_lpm_cmp(ivl_lpm_t net)
 {
       unsigned width;
       const char*type = "";
+      const char*signed_string = ivl_lpm_signed(net)? ".s" : "";
 
       width = ivl_lpm_width(net);
 
@@ -1147,9 +1148,10 @@ static void draw_lpm_cmp(ivl_lpm_t net)
 	    assert(0);
       }
 
-      fprintf(vvp_out, "L_%s.%s .cmp/%s %u", 
+      fprintf(vvp_out, "L_%s.%s .cmp/%s%s %u", 
 	      vvp_mangle_id(ivl_scope_name(ivl_lpm_scope(net))),
-	      vvp_mangle_id(ivl_lpm_basename(net)), type, width);
+	      vvp_mangle_id(ivl_lpm_basename(net)), type,
+	      signed_string, width);
 
       draw_lpm_arith_a_b_inputs(net);
 
@@ -1627,6 +1629,10 @@ int draw_scope(ivl_scope_t net, ivl_scope_t parent)
 
 /*
  * $Log: vvp_scope.c,v $
+ * Revision 1.92  2003/04/11 05:18:08  steve
+ *  Handle signed magnitude compare all the
+ *  way through to the vvp code generator.
+ *
  * Revision 1.91  2003/03/25 02:15:48  steve
  *  Use hash code for scope labels.
  *