An Effective Way to Generate Complex Instructions for Media Processors

With the development of digital signal processing (DSP) processors, the design of retarget able C compiler is necessary. But the C compiler for media processors which is built by porting GCC can't generate effective complex instructions in its way of matching instruction pattern. So according to the features in architecture of RISC-DSP processor designed by us, this paper proposes implementing instruction scheduling and operand and type modifying at assemble level. Therefore, the compiler can generate effective complex instructions and improve the performance and density of object code. Statistic data show that the performance of object code may be improved by 14.6% average while the density of that may be improved by 12.4% average. This method is easier than tree pattern matching, and can be used in other DSP processors supporting complex instructions.