Function signatures that use polymorphic types are mangled differently in 32-bit and 64-bit builds. The following example shows a class member function declaration, followed by its mangled signature in the two builds:
class AcDbObjectId { Adesk::IntPtr asOldId () const; ... };
32-bit mangling:
?asOldId@AcDbObjectId@@QBEJXZ (public: long __thiscall AcDbObjectId::asOldId(void)const )
64-bit mangling:
?asOldId@AcDbObjectId32@@QEBA_JXZ (public: __int64 __cdecl AcDbObjectId32::asOldId(void)const )