covector

lld has parallelism here and there, as well as ld64. I do believe ld64 is technically the first linker that started parsing object files in parallel.

Parallel linking was conjectured impossible for a while without breaking static archive semantics (AB-BA problem). Michael has a good explanation in https://www.youtube.com/watch?v=ONGVraXbJOo (minute 3 and beyond).

Documentation at

https://developer.apple.com/documentation/xcode/configuring-...

> ld64 is a fork of the old and slow GCC ld linker.

ld64 was a complete rewrite, circa 2005, courtesy of Nick Kledzik. `opensource.apple.com` has still the old Changelog(s). https://github.com/rotten-apples/ld64/blob/master/ChangeLog

It looks like the gap between the two is very little (< 100ms) and the Apple linker performs slightly better than mold on large applications: https://twitter.com/SmileyKeith/status/1666168273199845377