Compiler Technology for Future Microprocessors

Advances in hardware technology have made it possible for microprocessors to execute a large number of instructions concurrently (i.e., in parallel). These microprocessors take advantage of the opportunity to execute instructions in parallel to increase the execution speed of a program. As in other forms of parallel processing, the performance of these microprocessors can vary greatly depending on the quality of the software. In particular, the quality of compilers can make an order of magnitude difference in performance. This paper presents a new generation of compiler technology that has emerged to deliver the large amount of instruction-level-parallelism that is already required by some current state-of-the-art microprocessors and will be required by more future microprocessors. We introduce critical components of the technology which deal with difficult problems that are encountered when compiling programs for a high degree of instruction-level-parallelism. We present examples to illustrate the functional requirements of these components. To provide more insight into the challenges involved, we present in-depth case studies on predicated compilation and maintenance of dependence information, two of the components that are largely missing from most current commercial compilers.