Minimization of Data Address Computation Overhead in DSP Programs

Modern digital signal processors (DSPs) provide dedicated address generation units (AGUs) which support data memory access by indirect addressing with automatic address modification in parallel to other machine operations. There is no address computation overhead if the next address is within the auto-modify range. Typically, optimization of data memory layout and address register assignment allows to reduce both execution time and code size of DSP programs. In this paper, we present an optimization technique for integrated data memory layout generation and address register assignment. We use a generic AGU model which captures important addressing capabilities of DSPs such as linear addressing, modulo addressing, auto-modifying, and indexing within a given auto-modify range. Experimental results demonstrate that the proposed technique significantly outperforms existing optimization strategies. This revised version was published online in July 2006 with corrections to the Cover Date.