From 200951275cde23fd03a8176a8f42ec566244aad8 Mon Sep 17 00:00:00 2001
From: Martin Whitaker <icarus@martin-whitaker.me.uk>
Date: Mon, 28 Jan 2013 21:15:51 +0000
Subject: [PATCH] Fix logic value returned for unambiguous HiZ1 strength.

If a strength aware net has an unambiguous HiZ1 strength, VVP treats
it as a logic '1'. It should be treated as a logic 'z'. An ambiguous
HiZ1/HiZ0 strength should also be treated as a logic 'z'.
---
 vvp/vvp_net.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/vvp/vvp_net.h b/vvp/vvp_net.h
index b46520158..4085c4d8c 100644
--- a/vvp/vvp_net.h
+++ b/vvp/vvp_net.h
@@ -682,7 +682,7 @@ class vvp_scalar_t {
       unsigned strength1() const;
 
       bool eeq(vvp_scalar_t that) const { return value_ == that.value_; }
-      bool is_hiz() const { return value_ == 0; }
+      bool is_hiz() const { return (value_ & 0x77) == 0; }
 
     private:
       unsigned char value_;
@@ -718,7 +718,7 @@ inline vvp_scalar_t::vvp_scalar_t(vvp_bit4_t val, unsigned str0, unsigned str1)
 
 inline vvp_bit4_t vvp_scalar_t::value() const
 {
-      if (value_ == 0) {
+      if ((value_ & 0x77) == 0) {
 	    return BIT4_Z;
       } else switch (value_ & 0x88) {
 	  case 0x00: