Difficulties in Computing the WCET for Processors with Speculative Execution
暂无分享,去创建一个
In real-time applications, the Worst-Case Execution Time often needs to be estimated to check that deadlines will be respected. With the trend of using up-to-date processors, WCET computation techniques continuously have to evolve in order to take into account the most recent hardware features. In this paper, we show that ignoring speculative execution can lead to underestimated execution times, and we explain why modelling it is not straightforward. We feel that pure static analysis might not allow safe WCET computation, due to the fact that speculative execution prevents the decoupling between the high-level (path) analysis and the low-level (timing) analysis.
[1] Isabelle Puaut,et al. Worst Case Execution Time Analysis for a Processor with Branch Prediction , 2004, Real-Time Systems.
[2] Yale N. Patt,et al. The effects of mispredicted-path execution on branch prediction structures , 1996, Proceedings of the 1996 Conference on Parallel Architectures and Compilation Technique.
[3] Trevor N. Mudge,et al. Wrong-path instruction prefetching , 1996, Proceedings of the 29th Annual IEEE/ACM International Symposium on Microarchitecture. MICRO 29.