Collecting signatures to model latency tolerance in high-level simulations of microthreaded cores

The current many-core architectures are generally evaluated by a detailed emulation with a cycle-accurate simulation of the execution time. However this detailed simulation of the architecture makes the evaluation of large programs very slow. Since the focus in many-core architecture is shifting from the performance of the individual core to the overall behavior of chip, high-level simulations are becoming neces- sary, which evaluate the same architecture at less detailed level and allow the designer to make quick and reasonably accurate design decisions. We have developed a high-level simulator for the design space exploration of the Microgrid, which is a many-core architecture comprised of many fine- grained multi-threaded cores. This simulator allows us to investigate mapping and scheduling strategies of families (i.e. groups of threads) in developing an operating environ- ment for the Microgrid. The previous method to evaluate the workload counted in basic blocks was inaccurate. The key problem is that with many concurrent threads the la- tency of certain instructions are hidden because of the multi- threaded nature of the core. This paper presents a technique to manage the execution time of different types of instruc- tions with thread concurrency. We believe to achieve high accuracy in evaluating programs in the high-level simulator

Microgrid - The microthreaded many-core architecture

Traditional processors use the von Neumann execution model, some other processors in the past have used the dataflow execution model. A combination of von Neuman model and dataflow model is also tried in the past and the resultant model is referred as hybrid dataflow execution model. We describe a hybrid dataflow model known as the microthreading. It provides constructs for creation, synchronization and communication between threads in an intermediate language. The microthreading model is an abstract programming and machine model for many-core architecture. A particular instance of this model is named as the microthreaded architecture or the Microgrid. This architecture implements all the concurrency constructs of the microthreading model in the hardware with the management of these constructs in the hardware.Comment: 30 pages, 16 figure

SL: a "quick and dirty" but working intermediate language for SVP systems

The CSA group at the University of Amsterdam has developed SVP, a framework to manage and program many-core and hardware multithreaded processors. In this article, we introduce the intermediate language SL, a common vehicle to program SVP platforms. SL is designed as an extension to the standard C language (ISO C99/C11). It includes primitive constructs to bulk create threads, bulk synchronize on termination of threads, and communicate using word-sized dataflow channels between threads. It is intended for use as target language for higher-level parallelizing compilers. SL is a research vehicle; as of this writing, it is the only interface language to program a main SVP platform, the new Microgrid chip architecture. This article provides an overview of the language, to complement a detailed specification available separately.Comment: 22 pages, 3 figures, 18 listings, 1 tabl