Branch prediction apparatus, systems, and methods

An apparatus and a system, as well as a method and article, may operate to predict a branch within a first operating context, such as a user context, using a first strategy; and to predict a branch within a second operating context, such as an operating system context, using a second strategy. In some embodiments, apparatus and systems may comprise one or more first storage locations to store branch history information associated with a first operating context, and one ore more second storage locations to store branch history information associated with a second operating context.Board of Regents, University of Texas Syste

Mechanistic modeling of architectural vulnerability factor

Reliability to soft errors is a significant design challenge in modern microprocessors owing to an exponential increase in the number of transistors on chip and the reduction in operating voltages with each process generation. Architectural Vulnerability Factor (AVF) modeling using microarchitectural simulators enables architects to make informed performance, power, and reliability tradeoffs. However, such simulators are time-consuming and do not reveal the microarchitectural mechanisms that influence AVF. In this article, we present an accurate first-order mechanistic analytical model to compute AVF, developed using the first principles of an out-of-order superscalar execution. This model provides insight into the fundamental interactions between the workload and microarchitecture that together influence AVF. We use the model to perform design space exploration, parametric sweeps, and workload characterization for AVF

Exploiting compiler-generated schedules for energy savings in high-performance processors

This paper develops a technique that uniquely combines the advantages of static scheduling and dynamic scheduling to reduce the energy consumed in modern superscalar processors with out-of-order issue logic. In this Hybrid-Scheduling paradigm, regions of the application containing large amounts of parallelism visible at compile-time completely bypass the dynamic scheduling logic and execute in a low power static mode. Simulation studies using the Wattch framework on several media and scientific benchmarks demonstrate large improvements in overall energy consumption of 43 % in kernels and 25 % in full applications with only a 2.8 % performance degradation on average

Apparatus and method for accelerating java translation

An apparatus and method for accelerating Java translation are provided. The apparatus includes a lookup table which stores an lookup table having arrangements of bytecodes and native codes corresponding to the bytecodes, a decoder which generates pointer to the native code corresponding to the feed bytecode in the lookup table, a parameterized bytecode processing unit which detects parameterized bytecode among the feed bytecode, and generating pointer to native code required for constant embedding in the lookup table, a constant embedding unit which embeds constants into the native code with the pointer generated by the parameterized bytecode processing unit, and a native code buffer which stores the native code generated by the decoder or the constant embedding unit.Board of Regents, University of Texas Syste

HLSDataset: Open-Source Dataset for ML-Assisted FPGA Design using High Level Synthesis

Machine Learning (ML) has been widely adopted in design exploration using high level synthesis (HLS) to give a better and faster performance, and resource and power estimation at very early stages for FPGA-based design. To perform prediction accurately, high-quality and large-volume datasets are required for training ML models.This paper presents a dataset for ML-assisted FPGA design using HLS, called HLSDataset. The dataset is generated from widely used HLS C benchmarks including Polybench, Machsuite, CHStone and Rossetta. The Verilog samples are generated with a variety of directives including loop unroll, loop pipeline and array partition to make sure optimized and realistic designs are covered. The total number of generated Verilog samples is nearly 9,000 per FPGA type. To demonstrate the effectiveness of our dataset, we undertake case studies to perform power estimation and resource usage estimation with ML models trained with our dataset. All the codes and dataset are public at the github repo.We believe that HLSDataset can save valuable time for researchers by avoiding the tedious process of running tools, scripting and parsing files to generate the dataset, and enable them to spend more time where it counts, that is, in training ML models.Comment: 8 pages, 5 figure

PIMSAB: A Processing-In-Memory System with Spatially-Aware Communication and Bit-Serial-Aware Computation

Bit-serial Processing-In-Memory (PIM) is an attractive paradigm for accelerator architectures, for parallel workloads such as Deep Learning (DL), because of its capability to achieve massive data parallelism at a low area overhead and provide orders-of-magnitude data movement savings by moving computational resources closer to the data. While many PIM architectures have been proposed, improvements are needed in communicating intermediate results to consumer kernels, for communication between tiles at scale, for reduction operations, and for efficiently performing bit-serial operations with constants. We present PIMSAB, a scalable architecture that provides spatially aware communication network for efficient intra-tile and inter-tile data movement and provides efficient computation support for generally inefficient bit-serial compute patterns. Our architecture consists of a massive hierarchical array of compute-enabled SRAMs (CRAMs) and is codesigned with a compiler to achieve high utilization. The key novelties of our architecture are: (1) providing efficient support for spatially-aware communication by providing local H-tree network for reductions, by adding explicit hardware for shuffling operands, and by deploying systolic broadcasting, and (2) taking advantage of the divisible nature of bit-serial computations through adaptive precision, bit-slicing and efficient handling of constant operations. When compared against a similarly provisioned modern Tensor Core GPU (NVIDIA A100), across common DL kernels and an end-to-end DL network (Resnet18), PIMSAB outperforms the GPU by 3x, and reduces energy by 4.2x. We compare PIMSAB with similarly provisioned state-of-the-art SRAM PIM (Duality Cache) and DRAM PIM (SIMDRAM) and observe a speedup of 3.7x and 3.88x respectively.Comment: Aman Arora and Jian Weng are co-first authors with equal contributio