a094ff9590
Pass arguments up to 2*usize by value In https://github.com/rust-lang/rust/pull/77434#discussion_r498719533, `@eddyb` said: > I wonder if it makes sense to limit this to returns [...] Let's do a perf run and find out. It seems the `extern "C"` ABI will pass arguments up to 2*usize in registers: https://godbolt.org/z/n8E6zc. (modified from https://github.com/rust-lang/rust/issues/26494#issuecomment-619506345) r? `@nagisa`