Hardware Parameters of Vliw Cores and Code Quality Factors Affecting Alias

Recent studies have shown that the ability of disambiguating memory addresses (often referred to as alias analysis) gives concrete performance benefits to the compilation of C code for VLIW machines. This experimental research studies which factors, though external to alias analysis, strongly determine its impact on the performance of compiled code. These factors belong to two categories: architectural parameters of the target machine and optimizations performed by the compiler. Sensitivity analysis of the benefit coming from alias analysis as a function of these parameters was performed with an industrial compiler for a commercially available VLIW family and the main results are presented. Such results can help hardware designers to evaluate the need for memory disambiguation in order to fully exploit their architecture. On the other hand, once the target machine has been defined, the results can also help compiler writers to decide how much effort to invest in memory disambiguation.