From 62d7c081dcead2bf7312eb9127ceb2e6b77fd388 Mon Sep 17 00:00:00 2001
From: Stephen Williams <steve@icarus.com>
Date: Fri, 13 Jun 2008 19:47:48 -0700
Subject: [PATCH] Sign extend signed vectors when getting vpiIntVal.

When getting values using vpi_get_value, the vpiIntVal is the integer
value and should be sign-extended if the source value is signed.
---
 vvp/vpi_signal.cc | 24 ++++++++----------------
 vvp/vvp_net.cc    | 28 ++++++++++++++++++++++++++++
 vvp/vvp_net.h     |  1 +
 3 files changed, 37 insertions(+), 16 deletions(-)

diff --git a/vvp/vpi_signal.cc b/vvp/vpi_signal.cc
index 8388aa420..8d53076d6 100644
--- a/vvp/vpi_signal.cc
+++ b/vvp/vpi_signal.cc
@@ -294,21 +294,13 @@ static void format_vpiDecStrVal(vvp_fun_signal_vec*sig, int base, unsigned wid,
 }
 
 static void format_vpiIntVal(vvp_fun_signal_vec*sig, int base, unsigned wid,
-                             s_vpi_value*vp)
+                             int signed_flag, s_vpi_value*vp)
 {
-      unsigned iwid = 8 * sizeof(vp->value.integer);
-      long ssize = (signed)sig->size();
-
-      if (wid > iwid) wid = iwid;
-      long end = base + (signed)wid;
-      if (end > ssize) end = ssize;
-
-      vp->value.integer = 0;
-      for (long idx = (base < 0) ? 0 : base ;  idx < end ;  idx += 1) {
-	    if (sig->value(idx) == BIT4_1) {
-		  vp->value.integer |= 1<<(idx-base);
-	    }
-      }
+      vvp_vector4_t sub = sig->vec4_value().subvalue(base, wid);
+      long val = 0;
+      bool flag = vector4_to_value(sub, val, signed_flag);
+      if (! flag) val = 0;
+      vp->value.integer = val;
 }
 
 static void format_vpiRealVal(vvp_fun_signal_vec*sig, int base, unsigned wid,
@@ -653,7 +645,7 @@ static void signal_get_value(vpiHandle ref, s_vpi_value*vp)
       switch (vp->format) {
 
 	  case vpiIntVal:
-	    format_vpiIntVal(vsig, 0, wid, vp);
+	    format_vpiIntVal(vsig, 0, wid, rfp->signed_flag, vp);
 	    break;
 
 	  case vpiScalarVal:
@@ -1036,7 +1028,7 @@ static void PV_get_value(vpiHandle ref, p_vpi_value vp)
       switch (vp->format) {
 
 	  case vpiIntVal:
-	    format_vpiIntVal(sig, PV_get_base(rfp), rfp->width, vp);
+	    format_vpiIntVal(sig, PV_get_base(rfp), rfp->width, 0, vp);
 	    break;
 
 	  case vpiBinStrVal:
diff --git a/vvp/vvp_net.cc b/vvp/vvp_net.cc
index 662d9b058..01393d105 100644
--- a/vvp/vvp_net.cc
+++ b/vvp/vvp_net.cc
@@ -1078,6 +1078,34 @@ vvp_vector4_t double_to_vector4(double val, unsigned wid)
       return res;
 }
 
+bool vector4_to_value(const vvp_vector4_t&vec, long&val, bool is_signed)
+{
+      long res = 0;
+      long msk = 1;
+
+      for (unsigned idx = 0 ;  idx < vec.size() ;  idx += 1) {
+	    switch (vec.value(idx)) {
+		case BIT4_0:
+		  break;
+		case BIT4_1:
+		  res |= msk;
+		  break;
+		default:
+		  return false;
+	    }
+
+	    msk <<= 1L;
+      }
+
+      if (is_signed && vec.value(vec.size()-1) == BIT4_1) {
+	    if (vec.size() < 8*sizeof(val))
+		  res |= (-1L) << vec.size();
+      }
+
+      val = res;
+      return true;
+}
+
 bool vector4_to_value(const vvp_vector4_t&vec, unsigned long&val)
 {
       unsigned long res = 0;
diff --git a/vvp/vvp_net.h b/vvp/vvp_net.h
index 0caa36887..928bfb3a9 100644
--- a/vvp/vvp_net.h
+++ b/vvp/vvp_net.h
@@ -379,6 +379,7 @@ extern vvp_vector4_t double_to_vector4(double val, unsigned wid);
  * to real and integers) and the return value becomes false to
  * indicate an error.
  */
+extern bool vector4_to_value(const vvp_vector4_t&a, long&val, bool is_signed);
 extern bool vector4_to_value(const vvp_vector4_t&a, unsigned long&val);
 extern bool vector4_to_value(const vvp_vector4_t&a, double&val, bool is_signed);