How to speed up the Rust compiler in September 2026
Rust compiler benchmarks improved by an average 4.57% in wall time over two months, with 555 of 629 measurements improving. The report connects those results to specific work across LLVM 23, Clippy PGO, the new borrow checker and trait solver, allocation paths, and dataflow analysis.
One especially striking case: changing a compiler dataflow traversal cut fixpoint iterations from 1.5 million to 90,000 for a function with more than 18,000 basic blocks, reducing that crate’s check build time by about 30%. The overall figures are benchmark-suite results, not a promise that every project will compile faster; the post also notes regressions in a minority of cases as new compiler components land.
The linked Lobsters discussion page did not expose readable comments when checked, so I can’t summarize reactions.