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Tinglue Wang

Publications and source records attributed to Tinglue Wang.

4 recordsLinked to original sources

Strix: Re-thinking NPU Reliability from a System Perspective

DNNs and LLMs increasingly rely on hardware accelerators, including in safety-critical domains, while technology scaling and growing model complexity make hardware faults more frequent. Existing system-level mechanisms typically treat the NPU as a monolithic unit, using coarse-grained replication that incurs prohibitive performance and hardware overheads, leaving a gap between reliability requirements and deployable solutions. To bridge this gap, we present Strix, a full-stack NPU reliability framework on an open-source SoC, spanning micro-architecture, ISA, and programming methods. Strix re-partitions the NPU along the system inference pipeline, identifies dominant failure modes, and attaches targeted safeguards, achieving sub-micro-second fault localisation, error detection, and correction with only 1.04$\times$ slowdown and minimal hardware overhead.

cs.AR

From Characterization to Microarchitecture: Designing an Elegant and Reliable BFP-Based NPU

Block Floating-Point (BFP) is emerging as an attractive data format for edge Neural Processing Units (NPUs), combining wide dynamic range with high hardware efficiency. However, its behavior under hardware faults and suitability for safety-critical deployments remain underexplored. Here, we present the first in-depth empirical reliability study of BFP-based NPUs. Using RTL-level fault injection on NPUs, our bit- and path-level analysis reveals pronounced heterogeneous vulnerabilities and shows conventional end-to-end check becomes ineffective under nonlinear block scaling. Guided by these insights, we design a fault-tolerant BFP-based NPU microarchitecture that aligns the BFP computational semantics with reliability constraints. The design uses a row/column-wise blocking strategy to decouple the fixed-point mantissa computations from the scalar exponent path, and introduces ultra-lightweight protection mechanisms for each. Experimental results demonstrate our design achieves near-dual modular redundancy reliability with only $3.55\%$ geometric mean performance overhead and less than $2\%$ hardware cost.

cs.AR

AkiraRust: Re-thinking LLM-aided Rust Repair Using a Feedback-guided Thinking Switch

Eliminating undefined behaviors (UBs) in Rust programs requires a deep semantic understanding to enable accurate and reliable repair. While existing studies have demonstrated the potential of LLMs to support Rust code analysis and repair, most frameworks remain constrained by inflexible templates or lack grounding in executable semantics, resulting in limited contextual awareness and semantic incorrectness. Here, we present AkiraRust, an LLM-driven repair and verification framework that incorporates a finite-state machine to dynamically adapt its detection and repair flow to runtime semantic conditions. AkiraRust introduces a dual-mode reasoning strategy that coordinates fast and slow thinking across multiple agents. Each agent is mapped to an FSM state, and a waveform-driven transition controller manages state switching, rollback decisions, and semantic check pointing, enabling context-aware and runtime-adaptive repair. Experimental results show that AkiraRust achieves about 92% semantic correctness and delivers a 2.2x average speedup compared to SOTA.

cs.SE

FlexStep: Enabling Flexible Error Detection in Multi/Many-core Real-time Systems

Reliability and real-time responsiveness in safety-critical systems have traditionally been achieved using error detection mechanisms, such as LockStep, which require pre-configured checker cores,strict synchronisation between main and checker cores, static error detection regions, or limited preemption capabilities. However, these core-bound hardware mechanisms often lead to significant resource over-provisioning, and diminished real-time responsiveness, particularly in modern systems where tasks with varying reliability requirements are consolidated on shared processors to improve efficiency, reduce costs, and save power. To address these challenges, this work presents FlexStep, a systematic solution that integrates hardware and software across the SoC, ISA, and OS scheduling layers. FlexStep features a novel microarchitecture that supports dynamic core configuration and asynchronous, preemptive error detection. The FlexStep architecture naturally allows for flexible task scheduling and error detection, enabling new scheduling algorithms that enhance both resource efficiency and real-time schedulability. We publicly release FlexStep's source code, at https://anonymous.4open.science/r/FlexStep-DAC25-7B0C.

cs.AR