About

JIEZI Simulator is a high-performance RISC-V performance simulator developed by Tencent Penglai Laboratory. The current version archieved 13.9/GHz Speccpu2006 score, 12.2/GHz specint2006 and 15.6/GHz specfp2006. We have gone through two stages:

The micro-architecture of key performance components are aligned with the micro-architecture of Xiangshan Nanhu CPU.
Optimizing performance and exploring micro-architecture based on the aligned micro-architecture.

Performance optimization and microarchitectural exploration including:

Front-end: Implemented Enhanced SC Predictor, Loop Predictor, and RAS Predictor based on speculative chain-list stack and commit stack, and Icache performance-related optimization.
Back-end: Analyzed and optimized the configuration of out-of-order components such as LSQ and ROB. Implemented a mixed RMAP and HBMAP solution to enhance the rename table recovery solution. Merge the move eliminate feature in XS-gem5, and fix a bug which a long-term occupation of physical registers that not be released.
Memory System: Implimented the Bingo and SPP Prefetcher, which are located in mixed Cache Level and prefetch to Current or Low Level Cache.

Key performance component alignments including:

Front-end: Align Decoupled BPU, fetch bundle-based uBTB, BTB, TAGE, ITAGE, and FTQ components, align 4-stage instruction fetch pipeline stages and instruction prefetch performance
Back-end: Align the function, quantity, and delay of execution units such as Branch Unit and ALU, and align the width of instruction issue and commit
Memory system: Align the behavior and specifications of the Memory Voilation Predictor Storeset, and align some of the cache configuration parameters and performance statistics

The front-end is contributed by yuweiyan (严余伟) and henglong (龙衡), the back-end is contributed by denniskhu (胡凯) and zhuoli (李卓), and the memory system is contributed by qianlnzhang (张乾龙) and deweichchen (陈德炜).

JIEZI Simulator is based on opensource Gem5 and reused the features of XS-GEM5 below:

RVGC simpoint flow
SoC evironment setting and debug tools
TLB and PTW
Move Elimilate

A Short Doc

GCC & libboost

Use GCC > 9.4.0.
Install libboost.

Building gem5

official building docs
git clone GEM5

DRAMSim3

cd ext/dramsim3
git clone https://github.com/umd-memsys/DRAMsim3.git
cd DRAMsim3 && mkdir build
cd build
cmake ..
make

Notes:
    - Must rebuild gem5 after install DRAMSim3
    - Must use DRAMSim3 with our costumized config

gem5.opt ... --mem-type=DRAMsim3 --dramsim3-ini=$gem5_home/xiangshan_DDR4_8Gb_x8_2400.ini ...

mold linker(5 times faster than the default linker)

wget https://github.com/rui314/mold/releases/download/v1.10.1/mold-1.10.1-x86_64-linux.tar.gz
tar zxvf mold-1.10.1-x86_64-linux.tar.gz
cp -r mold-1.10.1-x86_64-linux/bin/* /usr/local/bin
cp -r mold-1.10.1-x86_64-linux/lib/* /usr/local/lib/
cp -r mold-1.10.1-x86_64-linux/libexec/* /usr/local/libexec/
cp -r mold-1.10.1-x86_64-linux/libexec/* /usr/local/libexec/mold/
cp -r mold-1.10.1-x86_64-linux/share/* /usr/local/share/

xs-env

https://xiangshan-doc.readthedocs.io/zh_CN/latest/tools/xsenv/

gem5

python3 $(which scons) build/RISCV/gem5.opt  --linker=mold -j`nproc`
or 
bash scripts/build.sh

Bringup

bash scripts/run_dhrystone.sh   # with print "Dhrystone PASS"
bash scripts/run_helloWorld.sh  # with print "Hello world!"

Produce RVGCpt checkpoints with NEMU

Please refer to the checkpoint tutorial for Xiangshan and Build Linux kernel for Xiangshan

The process of SimPoint checkpointing includes 3 individual steps

SimPoint Profiling to get BBVs. (To save space, they often output in compressed formats such as bbv.gz.)
SimPoint clustering. You can also opt to Python and sk-learn to do k-means clustering. (In this step, what is typically obtained are the positions selected by SimPoint and their weights.)
Taking checkpoints according to clustering results. (In the RVGCpt process, this step generates the checkpoints that will be used for simulation.)

If you have problem generating SPECCPU checkpoints, following links might help you.

Spec2006 preparation

bash scripts/run_spec2006_single.sh # print usage

Notes:

set --rerun to 9999 for the first time to generate task_info.txt(index of each checkpoint) in --gcpt_path

Running spec2006

Single

bash scripts/run_spec2006_single.sh

Range

bash scripts/run_spec2006_range.sh

All

bash scripts/run_spec2006_all.sh

Report

bash scripts/run_spec2006_report.sh

OpenXiangShan/PenglaiJiezi