Compiler transformation of pointers to explicit array accesses in dsp applications

Abstract

Efficient implementation of DSP applications is critical for embedded systems. However, current applications written in C, make extensive use of pointer arithmetic making compiler analysis and optimisation difficult. This paper presents a method for conversion of a restricted class of pointer-based memory accesses typically found in DSP codes into array accesses with explicit index functions. C programs with pointer accesses to array elements, data independent pointer arithmetic and structured loops can be converted into semantically equivalent representations with explicit array accesses. This technique has been applied to several DSPstone benchmarks on three different processors where initial results show that this technique can give on average a 11.95% reduction in execution time after transforming pointer-based array accesses into explicit array accesses.