diff -r bfac87aa5771 -r c874d053e378 src/python/m5/stats/info.py
--- a/src/python/m5/stats/info.py	Wed Apr 24 11:26:04 2013 +0100
+++ b/src/python/m5/stats/info.py	Wed Apr 24 11:27:04 2013 +0100
@@ -91,11 +91,14 @@
 ## @brief Sum all of the values for a stat.
 # @return The sum.
 def total(stat):
-    val = values(stat)
     try:
+        val = values(stat)
         return sum(val)
-    except TypeError:
-        return val
+    except AttributeError:
+        if type(stat) is float:
+            return stat
+        else:
+            return value(stat)
 
 ## @brief Get the length of a stat.
 # @return The length.
@@ -219,7 +222,7 @@
 
     ## @brief Get the value of the constant.
     # @return The value of the constant.
-    def __value__(self):
+    def __value__(self, *args):
         return self.constant
 
     ## @brief Get the length of the stat.
@@ -580,9 +583,58 @@
             g = dict(total=total,
                      ScalarConstant=ScalarConstant,
                      VectorConstant=VectorConstant)
-            self._the_value = eval(self.formula, g, self.context)
+
+            try:
+                self._the_value = eval(self.formula, g, self.context)
+            except (ZeroDivisionError, ValueError):
+                print "Warning: unable to evaluate: " + self.name
+                print "Supplied formula is: " + self.formula
+
+                # If we failed to evaluate the formula, then we return
+                # NaN. We need to wrap the value to make sure that the
+                # stats system gets a statistic, rather than a float.
+                self._the_value = WrapValue(float('NaN'))
+
             return self._the_value
 
+        # If we want to get the total,evaluate it and return the result.
+        if attr == 'total':
+            import ast
+
+            ## @brief Class which vists every node in an AST and adds in the
+            # total calculation
+            class AddTotal(ast.NodeTransformer):
+                def visit_BinOp(self, node):
+                    if isinstance(node.op, ast.Div):
+                        leftTemp = node.left
+                        rightTemp = node.right
+                        node.left = ast.Call(func=ast.Name(id='total',
+                                             ctx=ast.Load()), args=[leftTemp],
+                                             keywords = [], starargs=None,
+                                             kwargs=None )
+                        node.right = ast.Call(func=ast.Name(id='total',
+                                              ctx=ast.Load()), args=[rightTemp],
+                                              keywords = [], starargs=None,
+                                              kwargs=None )
+                    return node
+
+            g = dict(total=total,
+                     ScalarConstant=ScalarConstant,
+                     VectorConstant=VectorConstant)
+
+            parsedFormula = ast.parse("total(" + self.formula + ")",
+                                      mode='eval')
+            AddTotal().visit(parsedFormula)
+            parsedFormula = ast.fix_missing_locations(parsedFormula)
+
+            try:
+                self.total = eval(compile(parsedFormula, '<string>', 'eval'), g,
+                                  self.context)
+            except (ZeroDivisionError, ValueError):
+                self.total = float('nan')
+
+            return self.total
+
         # Return the properties of the value.
         if attr in ('__scalar__', '__vector__', '__value__', '__len__'):
             return getattr(self._the_value, attr)