Synthesis of application specific instructions for embedded DSP software

Application specific instructions play an important role in reducing the required code size and increasing performance. This paper describes a new approach to generate application specific instructions for DSP applications. The proposed approach is based on a modified subset-sum problem, and can support multi-cycle complex instructions as well as single cycle instructions, while the previous state-of-the-art approaches can generate only the single-cycle instructions or can just select instructions from the fixed super-set of possible instructions. In addition, the proposed approach can also be applicable to the case that instructions are predefined. The experimental results on real applications show that the proposed approach is effective in making the instructions meet the given constraints without attaching special hardware accelerators.