Brief Note on Simulating SPEC2017 on GEM5

This is a brief note on how to simulate SPEC2017 on gem5. SPEC2017 has complicated compile scripts. The basic workflow is to compile it, do a fake run to get the arguments for the binary, and finally simulate it in gem5. This is by no means the official instructions or guaranteed to work on your machine. You can also follow the instructions on the official website of SPEC2017.

Compile SPEC2017

First go to the folder of SPEC2017, and set up the environment. This gives you many useful commands to navigate through the SPEC2017, compile and run it.

> source shrc

Here we use lbm_s as an example. For other workloads it should be similar. Now let’s go to where lbm_s is:

> go lbm_s

The first thing is to do fake run. This will let the building system set up all the folder, inputs and so on. You can also do a full run, which will take much longer time to finish, but it’s a good way to verify that you SPEC2017 works on your native machine.

# Remove existing build
> rm -r build
> runcpu --fake --config gcc-linux-x86 lbm_s

This should create build and run folder. Now let’s compile the program:

> cd build/build_base_mytest-m64.0000
> specmake

This should compile and gives a lbm_s binary in the folder.

Simulate it in GEM5

First we need to get arguments to run the binary. Go the the run directory.

> go lbm_s 
> cd run/run_base_refspeed_mytest-m64.0000
> specinvoke -n
../run_base_refspeed_mytest-m64.0000/lbm_s_base.mytest-m64 2000 reference.dat 0 0 200_200_260_ldc.of > lbm.out 2>> lbm.err

This gives us the command line arguments to run lbm_s:

2000 reference.dat 0 0 200_200_260_ldc.of

Now simulate it in gem5. This command will start to simulate lbm_s using AtomicSimpleCPU. You can also specify other CPU types and add cache, and there are detailed instructions here.

> /where/gem5/is/build/X86/gem5.opt \
> /where/gem5/is/configs/example/se.py \
> --cmd=../../build/build_base_mytest-m64.0000/lbm_s \
> --options="2000 reference.dat 0 0 200_200_260_ldc.of" \
> --mem-size=8GB

As an example to simulate using O3 cpu:

> /where/gem5/is/build/X86/gem5.opt \
> /where/gem5/is/configs/example/se.py \
> --cmd=../../build/build_base_mytest-m64.0000/lbm_s \
> --options="2000 reference.dat 0 0 200_200_260_ldc.of" \
> --mem-size=8GB \
> --cpu-type=DerivO3CPU \
> --caches --l2cache \
> --l1d_size=32kB --l1i_size=32kB --l2_size=512kB

Finally, here is how you can fast forward using AtomicSimpleCPU for 1 million instructions and then switch to DerivO3CPU:

> /where/gem5/is/build/X86/gem5.opt \
> /where/gem5/is/configs/example/se.py \
> --cmd=../../build/build_base_mytest-m64.0000/lbm_s \
> --options="2000 reference.dat 0 0 200_200_260_ldc.of" \
> --mem-size=8GB \
> --cpu-type=DerivO3CPU \
> --caches --l2cache \
> --l1d_size=32kB --l1i_size=32kB --l2_size=512kB \
> --fast-forward=1000000