Optimization of embedded DSP programs using post-pass data-flow analysis

We investigate the problem of code generation for DSP systems on a chip. Such systems devote a limited quantity of silicon to program ROM, so application software must be maximally dense. Additionally, the software must be written so as to meet various high-performance constraints, which may include hard real-time constraints. Unfortunately, current compiler technology is unable to generate dense, high-performance code for DSPs, whose architectures are highly irregular. Consequently, designers often resort to programming application software in assembly-a Time-consuming, error-prone, and non-portable task. Thus, DSP compiler technology must be improved substantially. We describe some optimizations that significantly improve the quality of compiler-generated code. Our optimizations are applied globally and even across procedure calls. Additionally, they are applied to the machine-dependent assembly representation of the source program. Our target architecture is the Texas Instruments' TMS320C25 DSP