ALEX

ALEX is an Array Layout Evolution EXperiment designed to find cache-friendly Morton-esque multi-dimensional array layouts for specific workloads.

ALEX is designed to be used with Poetry. It can be installed simply by running the following command:

$ poetry install

This requires a C++20-capable compiler to be available.

ALEX provides two modes of operation, alex-evolve and alex-bench. The evolution command can be used to start an evolution experiment, e.g.:

$ poetry run alex-evolve -c caches/AMD_EPYC_7413.yaml -b 10:10 -t Cholesky -g 10 -v -j 3

This will run an experiment over 10 generations using 3 cores of Cholesky decomposition of 2¹⁰ × 2¹⁰ arrays with a simulated AMD EPYC 7413 CPU.

The benchmarking command is used to validate the real-world performance of layouts, e.g.:

$ poetry run alex-bench -c caches/Intel_Xeon_E5_2660_v3.yaml -i input.csv -r 10 -j 40 -o output.csv

This will calculate the fitness and actual performance of the layouts in input.csv with 10 repetitions for the benchmark and 40 cores for the fitness computation.