[ivanbakel]

>How true is this really?

I’d be interested to see a more thorough analysis, but there is a simple way to gauge this - rip out all the parts of the compiler where aliasing information is propagated to LLVM, and see what happens to performance.

I found a claim that noalias contributes about 5% performance improvement in terms of runtimes[0], though the data is obviously very old.

https://github.com/rust-lang/rust/issues/54878#issuecomment-...

[kibwen]

> I found a claim that noalias contributes about 5% performance improvement

Note that that comment is implying a range, from 0% improvement on some benchmarks to 5% improvement on others. It suggests that 5% is generally in the ballpark of the upper bound of what you should expect from putting noalias on mutable references, but that some specific cases could see better results.