# optimisations ## Basic idea Semantics-preserving program transformations that make code run faster or smaller. Classical optimisations operate on basic blocks or control-flow graphs and are framed as data-flow analyses. ## Key facts * Data-flow analyses solve fixpoints over a lattice on the CFG. * Common: constant propagation, dead-code elimination, CSE, loop-invariant code motion, inlining, peephole. * SSA form makes most of these one-pass and local. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://isubasinghe.gitbook.io/isithas-wiki/computer_science/programming_language_theory/optimisations.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.