The SARC architecture is composed of multiple processor types and a set of user-managed direct memory access (DMA) engines that let the runtime scheduler overlap data transfer and computation. The runtime system automatically allocates tasks on the heterogeneous cores and schedules the data transfers through the DMA engines. SARC's programming model supports various highly parallel applications, with matching support from specialized accelerator processors.

To handle the stringent performance requirements of future exascale-class applications, High Performance Computing (HPC) systems need ultra-efficient heterogeneous compute nodes. To reduce power and increase performance, such compute nodes will require hardware accelerators with a high degree of specialization. Ideally, dynamic reconfiguration will be an intrinsic feature, so that specific HPC application features can be optimally accelerated, even if they regularly change over time. In the EXTRA project, we create a new and flexible exploration platform for developing reconfigurable architectures, design tools and HPC applications with run-time reconfiguration built-in as a core fundamental feature instead of an add-on. EXTRA covers the entire stack from architecture up to the application, focusing on the fundamental building blocks for run-time reconfigurable exascale HPC systems: new chip architectures with very low reconfiguration overhead, new tools that truly take reconfiguration as a central design concept, and applications that are tuned to maximally benefit from the proposed run-time reconfiguration techniques. Ultimately, this open platform will improve Europe's competitive advantage and leadership in the field.

This paper studies the implementability of performance efficient multi-lane Polymorphic Register Files (PRFs). Our PRF implementation uses a 2D array of p × q linearly addressable memory banks, with customized addressing functions to avoid address routing circuits. We target one single-view and a set of four non redundant multi-view parallel memory schemes that cover all widely used access patterns in scientific and multimedia applications: 1) p × q rectangle, p · q row, p · q main and secondary diagonals; 2) p × q rectangle, p · q column, p · q main and secondary diagonals; 3) p · q row, p · q column, aligned p × q rectangle; 4) p × q, q × p rectangles (transposition). Reconfigurable hardware was chosen for the implementation due to its potential in enhancing the PRF runtime adaptability. For a proof of concept, we prototyped a 2 read, 1 write ports PRF on a Virtex-7 XC7VX1140T-2 FPGA. We consider four sizes for the 16 lanes PRFs - 16 × 16, 32 × 32, 64 × 64 and 128 × 128 and three multi-lane configurations, 8, 16 and 32, for the 128 × 128 PRF. Synthesis results suggest clock frequencies between 111 MHz and 326 MHz while utilizing less than 10% of the available LUTs. By using customized addressing functions, the LUT usage is reduced by up to 29% and the clock frequency is up to 77% higher compared to a straight-forward implementation.