From 98c39cfa24c4cbb8cc7464d4af6663f97868e28e Mon Sep 17 00:00:00 2001
From: Cary R <cygcary@yahoo.com>
Date: Fri, 18 Sep 2009 17:32:39 -0700
Subject: [PATCH] Add support for .part/v.s

This patch adds support for .part/v.s. A variable part select with
a signed select expression in a continuous assign.
---
 tgt-vvp/vvp_scope.c | 13 +++----------
 vvp/README.txt      |  8 +++++---
 vvp/compile.h       |  2 +-
 vvp/lexor.lex       |  1 +
 vvp/parse.y         |  6 ++++--
 vvp/part.cc         | 22 ++++++++++------------
 vvp/part.h          |  7 ++++---
 7 files changed, 28 insertions(+), 31 deletions(-)

diff --git a/tgt-vvp/vvp_scope.c b/tgt-vvp/vvp_scope.c
index bb8cb76e2..a7d8591cb 100644
--- a/tgt-vvp/vvp_scope.c
+++ b/tgt-vvp/vvp_scope.c
@@ -1654,16 +1654,9 @@ static void draw_lpm_part(ivl_lpm_t net)
 	    fprintf(vvp_out, ", %u, %u;\n", base, width);
       } else {
 	    const char*sel_symbol = draw_net_input(sel);
-	      /* We need to enhance .part/v to support a signed index. */
-	    if (ivl_lpm_signed(net) && width_of_nexus(sel) < 8*sizeof(int)) {
-		  fprintf(stderr, "%s:%u: tgt-vvp warning: V0.9 may give "
-		                  "incorrect results for a select with a "
-		                  "signed index less than %zu bits.\n",
-		                  ivl_lpm_file(net), ivl_lpm_lineno(net),
-		                  8*sizeof(int));
-	    }
-	    fprintf(vvp_out, "L_%p%s .part/v %s",
-		    net, dly, draw_net_input(ivl_lpm_data(net,0)));
+	    fprintf(vvp_out, "L_%p%s .part/v%s %s", net, dly,
+	                     (ivl_lpm_signed(net) ? ".s" : ""),
+	                     draw_net_input(ivl_lpm_data(net,0)));
 	    fprintf(vvp_out, ", %s", sel_symbol);
 	    fprintf(vvp_out, ", %u;\n", width);
       }
diff --git a/vvp/README.txt b/vvp/README.txt
index 6e9ad1876..abb57e775 100644
--- a/vvp/README.txt
+++ b/vvp/README.txt
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2001 Stephen Williams (steve@icarus.com)
+ * Copyright (c) 2001-2009 Stephen Williams (steve@icarus.com)
  *
  */
 
@@ -473,6 +473,7 @@ bit number, and a width. Normally, those bits are constant values.
 	<label> .part <symbol>, <base>, <wid>;
 	<label> .part/pv <symbol>, <base>, <wid>, <vector_wid>;
 	<label> .part/v <symbol>, <symbol>, <wid>;
+	<label> .part/v.s <symbol>, <symbol>, <wid>;
 
 The input is typically a .reg or .net, but can be any vector node in
 the netlist.
@@ -485,7 +486,8 @@ that part is written to. Destination nodes use this value to check
 further output widths.
 
 The .part/v variation takes a vector (or long) input on port-1 as the
-base of the part select. Thus, the part select can move around.
+base of the part select. Thus, the part select can move around. The
+.part/v.s variation treats the vector as a signed value.
 
 PART CONCATENATION STATEMENTS:
 
@@ -1111,7 +1113,7 @@ current read or write context of the running thread, using its
 stored context index.
 
 /*
- * Copyright (c) 2001 Stephen Williams (steve@icarus.com)
+ * Copyright (c) 2001-2009 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
diff --git a/vvp/compile.h b/vvp/compile.h
index f63732246..26a0c277a 100644
--- a/vvp/compile.h
+++ b/vvp/compile.h
@@ -141,7 +141,7 @@ extern void compile_part_select_pv(char*label, char*src,
 				   unsigned base, unsigned wid,
 				   unsigned vec_wid);
 extern void compile_part_select_var(char*label, char*src,
-				     char*var, unsigned wid);
+                                    char*var, unsigned wid, bool is_signed);
 
 /*
  * This is called by the parser to make the various arithmetic and
diff --git a/vvp/lexor.lex b/vvp/lexor.lex
index 94d454115..3fa7ecc7c 100644
--- a/vvp/lexor.lex
+++ b/vvp/lexor.lex
@@ -160,6 +160,7 @@ static char* strdupnew(char const *str)
 ".part"     { return K_PART; }
 ".part/pv"  { return K_PART_PV; }
 ".part/v"   { return K_PART_V; }
+".part/v.s" { return K_PART_V_S; }
 ".port"     { return K_PORT; }
 ".reduce/and" { return K_REDUCE_AND; }
 ".reduce/or"  { return K_REDUCE_OR; }
diff --git a/vvp/parse.y b/vvp/parse.y
index 92e7d34c3..7efba3f31 100644
--- a/vvp/parse.y
+++ b/vvp/parse.y
@@ -79,7 +79,7 @@ static struct __vpiModPath*modpath_dst = 0;
 %token K_MODPATH K_NET K_NET_S K_NET_R
 %token K_NET8 K_NET8_S
 %token K_PARAM_STR K_PARAM_L K_PARAM_REAL K_PART K_PART_PV
-%token K_PART_V K_PORT K_PV K_REDUCE_AND K_REDUCE_OR K_REDUCE_XOR
+%token K_PART_V K_PART_V_S K_PORT K_PV K_REDUCE_AND K_REDUCE_OR K_REDUCE_XOR
 %token K_REDUCE_NAND K_REDUCE_NOR K_REDUCE_XNOR K_REPEAT
 %token K_RESOLV K_SCOPE K_SFUNC K_SFUNC_E K_SHIFTL K_SHIFTR K_SHIFTRS
 %token K_THREAD K_TIMESCALE K_TRAN K_TRANIF0 K_TRANIF1 K_TRANVP
@@ -250,7 +250,9 @@ statement
 		{ compile_part_select_pv($1, $3, $5, $7, $9); }
 
 	| T_LABEL K_PART_V T_SYMBOL ',' T_SYMBOL ',' T_NUMBER ';'
-		{ compile_part_select_var($1, $3, $5, $7); }
+		{ compile_part_select_var($1, $3, $5, $7, false); }
+	| T_LABEL K_PART_V_S T_SYMBOL ',' T_SYMBOL ',' T_NUMBER ';'
+		{ compile_part_select_var($1, $3, $5, $7, true); }
 
         | T_LABEL K_CONCAT '[' T_NUMBER T_NUMBER T_NUMBER T_NUMBER ']' ','
 	  symbols ';'
diff --git a/vvp/part.cc b/vvp/part.cc
index 3f5e96caa..f96623fc1 100644
--- a/vvp/part.cc
+++ b/vvp/part.cc
@@ -229,8 +229,8 @@ void vvp_fun_part_pv::recv_vec8(vvp_net_ptr_t port, const vvp_vector8_t&bit)
       vvp_send_vec8_pv(port.ptr()->out, bit, base_, wid_, vwid_);
 }
 
-vvp_fun_part_var::vvp_fun_part_var(unsigned w)
-: wid_(w)
+vvp_fun_part_var::vvp_fun_part_var(unsigned w, bool is_signed)
+: wid_(w), is_signed_(is_signed)
 {
 }
 
@@ -251,9 +251,7 @@ bool vvp_fun_part_var::recv_vec4_(vvp_net_ptr_t port, const vvp_vector4_t&bit,
 	      // INT_MIN is before the vector and is used to
 	      // represent a 'bx value on the select input.
 	    tmp = INT_MIN;
-	      // We need a new .part/v that knows if the index is signed.
-	      // For now this will work for a normal integer value.
-	    vector4_to_value(bit, tmp, false);
+	    vector4_to_value(bit, tmp, is_signed_);
 	    if ((int)tmp == base) return false;
 	    base = tmp;
 	    break;
@@ -280,8 +278,8 @@ bool vvp_fun_part_var::recv_vec4_(vvp_net_ptr_t port, const vvp_vector4_t&bit,
       return false;
 }
 
-vvp_fun_part_var_sa::vvp_fun_part_var_sa(unsigned w)
-: vvp_fun_part_var(w), base_(0)
+vvp_fun_part_var_sa::vvp_fun_part_var_sa(unsigned w, bool is_signed)
+: vvp_fun_part_var(w, is_signed), base_(0)
 {
 }
 
@@ -320,8 +318,8 @@ struct vvp_fun_part_var_state_s {
       vvp_vector4_t ref;
 };
 
-vvp_fun_part_var_aa::vvp_fun_part_var_aa(unsigned w)
-: vvp_fun_part_var(w)
+vvp_fun_part_var_aa::vvp_fun_part_var_aa(unsigned w, bool is_signed)
+: vvp_fun_part_var(w, is_signed)
 {
       context_scope_ = vpip_peek_context_scope();
       context_idx_ = vpip_add_item_to_context(this, context_scope_);
@@ -436,13 +434,13 @@ void compile_part_select_pv(char*label, char*source,
 }
 
 void compile_part_select_var(char*label, char*source, char*var,
-			     unsigned wid)
+			     unsigned wid, bool is_signed)
 {
       vvp_fun_part_var*fun = 0;
       if (vpip_peek_current_scope()->is_automatic) {
-            fun = new vvp_fun_part_var_aa(wid);
+            fun = new vvp_fun_part_var_aa(wid, is_signed);
       } else {
-            fun = new vvp_fun_part_var_sa(wid);
+            fun = new vvp_fun_part_var_sa(wid, is_signed);
       }
       vvp_net_t*net = new vvp_net_t;
       net->fun = fun;
diff --git a/vvp/part.h b/vvp/part.h
index 09f32093c..bfc8a7783 100644
--- a/vvp/part.h
+++ b/vvp/part.h
@@ -125,7 +125,7 @@ class vvp_fun_part_pv  : public vvp_net_fun_t {
 class vvp_fun_part_var  : public vvp_net_fun_t {
 
     public:
-      explicit vvp_fun_part_var(unsigned wid);
+      explicit vvp_fun_part_var(unsigned wid, bool is_signed);
       ~vvp_fun_part_var();
 
     protected:
@@ -134,6 +134,7 @@ class vvp_fun_part_var  : public vvp_net_fun_t {
                       vvp_vector4_t&ref);
 
       unsigned wid_;
+      bool is_signed_;
 };
 
 /*
@@ -142,7 +143,7 @@ class vvp_fun_part_var  : public vvp_net_fun_t {
 class vvp_fun_part_var_sa  : public vvp_fun_part_var {
 
     public:
-      explicit vvp_fun_part_var_sa(unsigned wid);
+      explicit vvp_fun_part_var_sa(unsigned wid, bool is_signed);
       ~vvp_fun_part_var_sa();
 
     public:
@@ -166,7 +167,7 @@ class vvp_fun_part_var_sa  : public vvp_fun_part_var {
 class vvp_fun_part_var_aa  : public vvp_fun_part_var, public automatic_hooks_s {
 
     public:
-      explicit vvp_fun_part_var_aa(unsigned wid);
+      explicit vvp_fun_part_var_aa(unsigned wid, bool is_signed);
       ~vvp_fun_part_var_aa();
 
     public: