Tweak managed/undefined checks in QV4::Value for 32bit systems

On 32 bit systems, the pointers can only be 32 bit. So instead of
shifting bits 32-49 away in the upper part of the 64 bit value,
we can just check if the tag (the upper 32 bits) is 0.

Change-Id: I25e6542676e8aa2c566f10c70c532dd8bf5c7192
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>

1 files changed, 16 insertions, 2 deletions

diff --git a/src/qml/jsruntime/qv4value_p.h b/src/qml/jsruntime/qv4value_p.h
index 20a84beccd..b1cae8796f 100644
--- a/src/qml/jsruntime/qv4value_p.h
+++ b/src/qml/jsruntime/qv4value_p.h
@@ -281,8 +281,22 @@ struct Q_QML_PRIVATE_EXPORT Value
 
     inline bool isUndefined() const { return _val == 0; }
     inline bool isDouble() const { return (_val >> IsDouble_Shift); }
-    inline bool isManaged() const { return _val && ((_val >> IsManagedOrUndefined_Shift) == 0); }
-    inline bool isManagedOrUndefined() const { return ((_val >> IsManagedOrUndefined_Shift) == 0); }
+    inline bool isManaged() const
+    {
+#if QT_POINTER_SIZE == 4
+        return value() && tag() == Managed_Type_Internal;
+#else
+        return _val && ((_val >> IsManagedOrUndefined_Shift) == 0);
+#endif
+    }
+    inline bool isManagedOrUndefined() const
+    {
+#if QT_POINTER_SIZE == 4
+        return tag() == Managed_Type_Internal;
+#else
+        return ((_val >> IsManagedOrUndefined_Shift) == 0);
+#endif
+    }
 
     inline bool isIntOrBool() const {
         return (_val >> IsIntegerOrBool_Shift) == 3;