A method and apparatus to generate code to represent a graphical model formed of multiple graphical modeling components and at least one variable-sized signal is presented. Each variable-sized signal is represented using a size-vector in the generated code. The generated code is optimized by representing multiple variable-sized signals with the same size-vector such that at least two variable-sized signals share a size-vector in the generated code. The size of the variable-sized signal is capable of changing during the execution of the graphical model. The method and apparatus also identifies the owners of the variable-sized signals.