Automatically partitioning the code in compilers and applying the code overlay technique is one of the key techniques for exploiting the performance of processors with small memory capacity. With the occuring of heterogeneous multicore processors, such a kind of processor usually acts as a synergistic processing unit. The paper presents a practical automatic code partitioning algorithm and implements it by the GNU tool chain for the Cell processors. It finds the hot points in call graphs according to the calling frequency, and then adopts a simplified clustering method to perform hotpointdirected partition clustering. Finally, it performs capacitydirected partition merging. The experimental results show that the algorithm can work perfectly with lower complexity.