From 9fb317a4e1772c26700ea6d5a9fbd6657ea68681 Mon Sep 17 00:00:00 2001
From: Cary R <cygcary@yahoo.com>
Date: Mon, 5 Sep 2011 16:10:08 -0700
Subject: [PATCH] A vpiBitVar can have a non-zero LSB and can be unsigned.

The general bit variable can be either signed or unsigned and can
have a non-zero LSB.
---
 vvp/parse.y       |  4 ++--
 vvp/vpi_priv.h    |  2 +-
 vvp/vpi_signal.cc | 52 +++++++++++++++++++++++++++--------------------
 vvp/words.cc      |  4 ++--
 4 files changed, 35 insertions(+), 27 deletions(-)

diff --git a/vvp/parse.y b/vvp/parse.y
index 23bab0337..5b7a310f1 100644
--- a/vvp/parse.y
+++ b/vvp/parse.y
@@ -682,10 +682,10 @@ statement
   | T_LABEL K_VAR_I local_flag T_STRING ',' T_NUMBER T_NUMBER ';'
       { compile_variable($1, $4, $6, $7, vpiIntegerVar, true, $3); }
 
-  | T_LABEL K_VAR_2S local_flag T_STRING ',' T_NUMBER T_NUMBER ';'
+  | T_LABEL K_VAR_2S local_flag T_STRING ',' signed_t_number signed_t_number ';'
       { compile_variable($1, $4, $6, $7, vpiIntVar, true, $3); }
 
-  | T_LABEL K_VAR_2U local_flag T_STRING ',' T_NUMBER T_NUMBER ';'
+  | T_LABEL K_VAR_2U local_flag T_STRING ',' signed_t_number signed_t_number ';'
       { compile_variable($1, $4, $6, $7, vpiIntVar, false, $3); }
 
   | T_LABEL K_VAR_R T_STRING ',' signed_t_number signed_t_number ';'
diff --git a/vvp/vpi_priv.h b/vvp/vpi_priv.h
index 71c859fbc..68272c41c 100644
--- a/vvp/vpi_priv.h
+++ b/vvp/vpi_priv.h
@@ -263,7 +263,7 @@ extern unsigned vpip_size(__vpiSignal *sig);
 extern struct __vpiScope* vpip_scope(__vpiSignal*sig);
 
 extern vpiHandle vpip_make_int2(const char*name, int msb, int lsb,
-			       vvp_net_t*vec);
+			       bool signed_flag, vvp_net_t*vec);
 extern vpiHandle vpip_make_int4(const char*name, int msb, int lsb,
 			       vvp_net_t*vec);
 extern vpiHandle vpip_make_var4(const char*name, int msb, int lsb,
diff --git a/vvp/vpi_signal.cc b/vvp/vpi_signal.cc
index f51ccee52..08df4e1ce 100644
--- a/vvp/vpi_signal.cc
+++ b/vvp/vpi_signal.cc
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2001-2010 Stephen Williams (steve@icarus.com)
+ * Copyright (c) 2001-2011 Stephen Williams (steve@icarus.com)
  *
  *    This source code is free software; you can redistribute it
  *    and/or modify it in source code form under the terms of the GNU
@@ -996,31 +996,39 @@ vpiHandle vpip_make_int4(const char*name, int msb, int lsb, vvp_net_t*vec)
 }
 
 /*
- * Construct a vpi
+ * Construct the two-state SystemVerilog variables.
  */
-vpiHandle vpip_make_int2(const char*name, int msb, int lsb, vvp_net_t*vec)
+vpiHandle vpip_make_int2(const char*name, int msb, int lsb, bool signed_flag,
+                         vvp_net_t*vec)
 {
-      vpiHandle obj = vpip_make_net4(name, msb,lsb, true, vec);
+      vpiHandle obj = vpip_make_net4(name, msb, lsb, signed_flag, vec);
 
-      assert(lsb == 0);
-      switch (msb) {
-	  case 7:
-	    obj->vpi_type = &vpip_byte_rt;
-	    break;
-	  case 15:
-	    obj->vpi_type = &vpip_shortint_rt;
-	    break;
-	  case 31:
-	    obj->vpi_type = &vpip_int_rt;
-	    break;
-	  case 63:
-	    obj->vpi_type = &vpip_longint_rt;
-	    break;
-	  default:
-	      // Every other type of bit vector is a vpiBitVar with
-	      // array dimensions.
+	// All unsigned 2-state variables are a vpiBitVar. All 2-state
+	// variables with a non-zero lsb are also a vpiBitVar.
+      if ((! signed_flag) || (lsb != 0) ) {
 	    obj->vpi_type = &vpip_bitvar_rt;
-	    break;
+      } else {
+	      // These could also be bit declarations with matching
+	      // information, but for now they get the apparent type.
+	    switch (msb) {
+		case 7:
+		  obj->vpi_type = &vpip_byte_rt;
+		  break;
+		case 15:
+		  obj->vpi_type = &vpip_shortint_rt;
+		  break;
+		case 31:
+		  obj->vpi_type = &vpip_int_rt;
+		  break;
+		case 63:
+		  obj->vpi_type = &vpip_longint_rt;
+		  break;
+		default:
+		    // Every other type of bit vector is a vpiBitVar with
+		    // array dimensions.
+		  obj->vpi_type = &vpip_bitvar_rt;
+		  break;
+	    }
       }
 
       return obj;
diff --git a/vvp/words.cc b/vvp/words.cc
index 9485cc257..a1168223f 100644
--- a/vvp/words.cc
+++ b/vvp/words.cc
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2003-2010 Stephen Williams (steve@icarus.com)
+ * Copyright (c) 2003-2011 Stephen Williams (steve@icarus.com)
  *
  *    This source code is free software; you can redistribute it
  *    and/or modify it in source code form under the terms of the GNU
@@ -117,7 +117,7 @@ void compile_variable(char*label, char*name,
 		  obj = vpip_make_int4(name, msb, lsb, net);
 		  break;
 		case vpiIntVar: // This handles all the atom2 int types
-		  obj = vpip_make_int2(name, msb, lsb, net);
+		  obj = vpip_make_int2(name, msb, lsb, signed_flag, net);
 		  break;
 		default:
 		  fprintf(stderr, "internal error: %s: vpi_type_code=%d\n", name, vpi_type_code);