[josephg]

Interesting to know! But even if those guys made super fast front ends, they would have been always limited by the speed of the llvm optimizer and code generation backend. Writing a compiler on llvm isn’t the same as writing a compiler from scratch.

[novok]

In swift's case it's a single threaded frontend that is fairly inefficient: https://github.com/apple/swift/blob/main/docs/CompilerPerfor...