Faster alternative implementations of Arrays.hashCode(byte[])

This repository contains implementations of Arrays.hashCode(byte[]), which beat the performance of the implementations in OpenJDK 24.0.1. Please see this blog post for more details.

Benchmark Results

The figure below shows the benchmark results obtained on an AWS c5.metal instance with disabled Turbo Boost (P-state set to 1).

Running Benchmarks

To perform the benchmarks execute

sudo sh -c "echo 1 > /sys/devices/system/cpu/intel_pstate/no_turbo"; ./gradlew jmh; sudo sh -c "echo 0 > /sys/devices/system/cpu/intel_pstate/no_turbo"

Turbo Boost is turned off during the benchmark's execution to achieve more reproducible results on Intel CPUs. The benchmark results will be copied to the benchmark-results folder.

Generating Charts

To generate charts from the results stored in the benchmark-results folder, execute

python .\python\evaluation.py

in the root directory. The generated figures are put into the benchmark-results folder.