[jdoerfert]

Clang will not "reduce compilation effort" and I do not believe GCC does that. There are heuristics that look at things like function size but I don't think that is what they mean. Generally speaking, translation units are independent if you do not run link-time-optimizations (LTO) and optimizations follow a (basically) predetermined order which might be influence by the input but not by the amount of work done.

[thedance]

I’ve never heard of or experienced gcc using some kind of cost model for compilation time, either. With all these huge protobuf-generated files you’d think I would have noticed if it existed.