Portable Targeted Sampling Framework Using LLVM
Zhantong Qiu, Mahyar Samani, Jason Lowe-Power
Published: 2025/9/2
Abstract
Comprehensive architectural evaluation of full workloads is throttled by slow simulation and per-binary sampling pipelines. We present Nugget, a flexible framework for portable sampling across simulators and real hardware, ISAs, and libraries. Nugget operates at the LLVM IR level to perform binary-agnostic interval analysis, then emits lightweight, cross-platform executables--nuggets--that can be validated on real machines before driving simulation. Across SPEC CPU2017, NPB, and LSMS, Nugget cuts interval-analysis cost by orders of magnitude relative to functional simulation (up to ~578X on multithreaded NPB), keeps single-thread overhead low, and enables native-speed validation of selected samples. Case studies with gem5 show that nuggets support evaluation of system performance and model accuracy. Nugget makes sampling methodology research faster and more portable.