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Optimizations performed at link time or directly applied to final program executables have received increased attention in recent years. This paper discusses the discovery and elimination of redundant load operations in the context of a link-time optimizer, an optimization that we call Load Redundancy Elimination (LRE). Our experiments show that between 50% and 75% of a program's memory references can be considered redundant because they are accessing memory locations that have been referenced less than 200–400 instructions away. We then present three profile-based LRE algorithms targeted at optimizing away these redundancies. Our results show that between 5% and 30% of the redundancy detected can indeed be eliminated, which translates into program speedups of around 8%. We also test our algorithm assuming different cache latencies, and show that, if latencies continue to grow, the load redundancy elimination will become more important. Copyright © 2003 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Feautrier's scheduling algorithm is the most powerful existing algorithm for parallelism detection and extraction, but it has always been known to be suboptimal. However, the question as to whether it may miss some parallelism because of its design has not been answered. We show that this is not the case. Therefore, for an algorithm to find more parallelism than this algorithm, one needs to remove some of the hypotheses underlying its framework. Copyright © 2003 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]