Fix compile time evaluation of < operator.

eval_tree.cc

@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #ifdef HAVE_CVS_IDENT
-#ident "$Id: eval_tree.cc,v 1.62.2.3 2005/09/09 02:17:08 steve Exp $"
+#ident "$Id: eval_tree.cc,v 1.62.2.4 2007/03/23 20:59:25 steve Exp $"
 #endif
 
 # include "config.h"
@@ -243,8 +243,10 @@ NetEConst* NetEBComp::eval_less_()
 	   equal to the largest value the left side can possibly
 	   have. */
       assert(left_->expr_width() > 0);
-      verinum lv (verinum::V1, left_->expr_width());
+      verinum lv (verinum::V1, left_->expr_width() + 1);
-      if (lv < rv) {
+      lv.set(left_->expr_width(), verinum::V0);
+      lv.has_sign( left_->has_sign() );
+      if ((lv < rv) == verinum::V1) {
 	    verinum result(verinum::V1, 1);
 	    return new NetEConst(result);
       }
@@ -1549,6 +1551,9 @@ NetEConst* NetEUReduce::eval_tree()
 
 /*
  * $Log: eval_tree.cc,v $
+ * Revision 1.62.2.4  2007/03/23 20:59:25  steve
+ *  Fix compile time evaluation of < operator.
+ *
  * Revision 1.62.2.3  2005/09/09 02:17:08  steve
  *  Evaluate  magnitude compare with real operands.
  *

verinum.cc

@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #ifdef HAVE_CVS_IDENT
-#ident "$Id: verinum.cc,v 1.43.2.2 2005/12/07 03:28:44 steve Exp $"
+#ident "$Id: verinum.cc,v 1.43.2.3 2007/03/23 20:59:26 steve Exp $"
 #endif
 
 # include "config.h"
@@ -317,6 +317,20 @@ bool verinum::is_zero() const
       return true;
 }
 
+bool verinum::is_negative() const
+{
+      if (! has_sign_)
+	    return false;
+
+      if (nbits_ == 0)
+	    return false;
+
+      if (bits_[nbits_-1] == verinum::V1)
+	    return true;
+
+      return false;
+}
+
 /*
  * This function returns a version of the verinum that has only as
  * many bits as are needed to accurately represent the value. It takes
@@ -501,6 +515,18 @@ verinum::V operator <= (const verinum&left, const verinum&right)
 
 verinum::V operator < (const verinum&left, const verinum&right)
 {
+      if (left.has_sign() && right.has_sign()) {
+	    if (!left.is_defined())
+		  return verinum::Vx;
+	    if (!right.is_defined())
+		  return verinum::Vx;
+	    long diff = left.as_long() - right.as_long();
+	    if (diff < 0)
+		  return verinum::V1;
+	    else
+		  return verinum::V0;
+      }
+
       unsigned idx;
       for (idx = left.len() ; idx > right.len() ;  idx -= 1) {
 	    if (left[idx-1] != verinum::V0) return verinum::V0;
@@ -960,6 +986,9 @@ verinum::V operator ^ (verinum::V l, verinum::V r)
 
 /*
  * $Log: verinum.cc,v $
+ * Revision 1.43.2.3  2007/03/23 20:59:26  steve
+ *  Fix compile time evaluation of < operator.
+ *
  * Revision 1.43.2.2  2005/12/07 03:28:44  steve
  *  Support constant concatenation of constants.
  *

verinum.h

@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #ifdef HAVE_CVS_IDENT
-#ident "$Id: verinum.h,v 1.26.2.3 2005/12/07 03:28:45 steve Exp $"
+#ident "$Id: verinum.h,v 1.26.2.4 2007/03/23 20:59:26 steve Exp $"
 #endif
 
 # include  <string>
@@ -74,6 +74,7 @@ class verinum {
 	// A number is "defined" if there are no x or z bits in its value.
       bool is_defined() const;
       bool is_zero() const;
+      bool is_negative() const;
 
 	// A number is "a string" if its value came directly from
 	// an ASCII description instead of a number value.
@@ -151,6 +152,9 @@ extern verinum v_not(const verinum&left);
 
 /*
  * $Log: verinum.h,v $
+ * Revision 1.26.2.4  2007/03/23 20:59:26  steve
+ *  Fix compile time evaluation of < operator.
+ *
  * Revision 1.26.2.3  2005/12/07 03:28:45  steve
  *  Support constant concatenation of constants.
  *