GSIM: A Fast RTL Simulator for Large-Scale Designs

GSIM accepts chirrtl, and compiles it to C++

Prerequisites

• Install GMP, clang 19(+).

Quike Start

• GSIM provides 4 RISC-V cores ready for simulation: ysyx3, Rocket, BOOM, XiangShan.

• To try GSIM, using

  $ make init
  $ make run dutName=core
  

• Set core to ysyx3, rocket, small-boom, large-boom, minimal-xiangshan or default-xiangshan

Usage

• Run make build-gsim to build GSIM
• Build a static binary locally with make STATIC=1 build-gsim (CI artifacts are built statically).
• Run build/gsim/gsim $(chirrtl-file) to compile chirrtl to C++
• Refer to build/gsim/gsim --help for more information
• See C++ harness example to know how it interacts with the emitted C++ code.

Papers and Presentations

GSIM: Accelerating RTL Simulation for Large-Scale Design

Lu Chen, Dingyi Zhao, Zihao Yu, Ninghui Sun, Yungang Bao

Design Automation Conference (DAC), 2025

Paper PDF | Slides | Chinese Slides