infer_clone/infer/documentation/checkers/LoopHoisting.md

This checker detects opportunities to hoist function calls that are invariant to outside of loop bodies. The hoisting analysis relies on purity analysis to determine whather a function is pure or not.

It has an additional mode that reports loop-invariant functions that are expensive (i.e. at least linear). This is enabled by the flag --hoisting-report-only-expensive.