Platform microbenchmarks benchmarks specific low-level operations used by the gecko platform. If a test regresses, it could result in the degradation in the performance of some user-visible feature.
The list of tests and their descriptions is currently incomplete. If something is missing, please search for it in the gecko source and update this page (or ask the original author to do so, if you’re still not sure).
These tests measure the amount of time it takes to perform a large number of operations on low-level strings.