I doubt it, specially if you compare agains the GCC rustc backend. I would expect most of the difference (If any) to come from the frontend. For example, if it

I doubt it, specially if you compare agains the GCC rustc backend. I would expect most of the difference (If any) to come from the frontend. For example, if it doesn't do borrow checking, it might be able to shave off a bit of time. But at that point, it highly depends on the workload (i.e the code you're compiling). I would expect the vast majority of rust code to bottleneck on codegen, in which case there should be approximately 0 difference. For code bottlenecked on borrow checking (Which I would expect to be an outlier), gccrs should be faster while ignoring borrow checking (Although my understanding is they plan to eventually use polonius for borrow checking, a rust library/project that originally intended to replace the current borrow checker in rustc but still hasn't. In which case, it would probably be faster for some borrow checking and slower for others)