Simulating a Multi-core x86_64 Architecture with Hardware ISA Extension Supporting a Data-Flow Execution Model

The trend to develop increasingly more intelligent systems leads directly to a considerable demand for more and more computational power. Programming models that aid to exploit the application parallelism with current multi-core systems exist but with limitations. From this perspective, new execution models are arising to surpass limitations to scale up the number of processing elements, while dedicated hardware can help the scheduling of the threads in many-core systems. This paper depicts a data-flow based execution model that exposes to the multi-core x86\_64 architecture up to millions of fine-grain threads. We propose to augment the existing architecture with a hardware thread scheduling unit. The functionality of this unit is exposed by means of four dedicated instructions. Results with a pure data-flow application (i.e., Recursive Fibonacci) show that the hardware scheduling unit can load the computing cores (up to 32 in our tests) in a more efficient way than run-time managed threads generated by programming models (e.g., OpenMP and Cilk). Further, our solution shows better scaling and smaller saturation when the number of workers increases