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Comment by FooBarWidget | Hacker News Reader

Rust also has (relatively) bad compile times due to generics. Not as bad as C++, but you can notice it's significantly worse than Go.

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Rust does compile slower than Go, but it's not due to generics. It's mostly due to LLVM codegen and procedural macros. Go has the benefit of not relying on LLVM and not having procedural macros.

A lot of the IR comes from expanding huge stacks of generic functions. I don't think the issue can't be neatly partitioned up like that.

Absolutely true. I’d add that Rust is also doing a lot more expensive optimizations in release builds.

Until recently Go didn't even use registers for passing arguments, it just put everything on the stack like in a 1965 textbook (https://go.googlesource.com/proposal/+/refs/changes/78/24817...)

If you mean for function calls, I believe you're correct, not taking into account inline functions.

However, for code generation Go obviously uses registers since way before the 1.0 days.

You are right of course about LLVM being source of slowness.

In general discussion I see around is that all Rust's perf optimizations are to Rust's credit (nothing about LLVM optimization) while all woes around Rust's compile time lay at step of LLVM and Rust is not be blamed.

D, Ada, Eiffel, Delphi go as counter example, and C++ modules are already proving a much better experience in VC++.

Delphi didn't have generics. Not sure about more modern versions, but the power of the generics also impacts compile times. Java generics barely impact compile times at all but they're also nowhere as powerful as Rust and C++ ones.

You stop using Delphi long time ago, I would say.

To pick one of my examples, D templates and compile time metaprogramming are even more powerfull than Rust and C++ ones, yet it compiles just as fast.

Delphi added generics in 2009

So it had them roughly as long as Go existed

There is tinygo with llvm backend and the build times are abysmal.

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