Peter Sestoft will give a talk about his work on Experiments with low-level performance on modern CPUs. Details below.
SPEAKER
Peter Sestoft, Prof., ITU.
TITLE
Experiments with low-level performance on modern CPUs
ABSTRACT
As preparation for understanding the performance of multi-threaded programs on multicore hardware, I am studying also single-threaded programs and how they perform on modern CPUs. Aspects to take into account are instruction-level parallelism, pipelines and branch prediction, memory hierarchy and caches, cache lines, spatial and temporal locality, cache prefetching mechanisms, and (for the multicore setting) the cache coherence protocol, and programming style (eg conditional expressions can reduce branch mispredictions). This will be illustrated with small program fragments and empirical measurements. A general observation is that performance challenges lead to technical solutions that lead to new, subtler, performance challenges. Very much preliminary work, hopefully in progress.