Retargetable Code Optimization for Predicated Execution

Retargetable C compilers are key components of today´s embedded processor design platforms for quickly obtaining compiler support and performing early processor architecture exploration. The inherent problem of the retargetable compilation approach, though, is the well known trade-off between the compiler´s flexibility and the quality of generated code. However, it can be circumvented by designing flexible, configurable code optimization techniques applicable to a certain range of target architectures. This paper focuses on target machines with predicated execution support which is wide-spread in deeply pipelined and highly parallel embedded processors used in next generation high-end video, multimedia and wireless devices. We present an efficient and quickly retargetable code optimization technique for predicated execution that is integrated into an industrial retargetable C compiler. Experimental results for several embedded processors demonstrate that the proposed technique is applicable to real-life target machines and that it produces significant code quality improvements for control intensive applications.