A lot of effort is spent to reduce the size of structs in the Rust compiler https://nnethercote.github.io/2023/03/24/how-to-speed-up-the-rust-compiler-in-march

A lot of effort is spent to reduce the size of structs in the Rust compiler https://nnethercote.github.io/2023/03/24/how-to-speed-up-the-rust-compiler-in-march-2023.html#ast-shrinkage https://nnethercote.github.io/2023/03/24/how-to-speed-up-the... 3% and 6% of improvement doesn't seem like much, but at the level of rustc those big wins Performance of Rustc must be continously tracked (here https://perf.rust-lang.org/ https://perf.rust-lang.org/) because if you don't proactively fight against bloat, the tendency is that the code will become slower over time (due to new features etc)