Contributing to stdsimd

The stdsimd crate is more than willing to accept contributions! First you'll probably want to check out the repository and make sure that tests pass for you:

$ git clone https://github.com/rust-lang-nursery/stdsimd
$ cd stdsimd
$ cargo +nightly test

To run codegen tests, run in release mode:

$ cargo +nightly test --release -p coresimd

Remember that this repository requires the nightly channel of Rust! If any of the above steps don't work, please let us know!

Next up you can find an issue to help out on, we‘ve selected a few with the help wanted and impl-period tags which could particularly use some help. You may be most interested in #40, implementing all vendor intrinsics on x86. That issue’s got some good pointers about where to get started!

If you've got general questions feel free to join us on gitter and ask around! Feel free to ping either @BurntSushi or @alexcrichton with questions.

How to write examples for stdsimd intrinsics

There are a few features that must be enabled for the given intrinsic to work properly and the example must only be run by cargo test --doc when the feature is supported by the CPU. As a result, the default fn main that is generated by rustdoc will not work (in most cases). Consider using the following as a guide to ensure your example works as expected.

/// # // We need cfg_target_feature to ensure the example is only
/// # // run by `cargo test --doc` when the CPU supports the feature
/// # #![feature(cfg_target_feature)]
/// # // We need target_feature for the intrinsic to work
/// # #![feature(target_feature)]
/// #
/// # // rustdoc by default uses `extern crate stdsimd`, but we need the
/// # // `#[macro_use]`
/// # #[macro_use] extern crate stdsimd;
/// #
/// # // The real main function
/// # fn main() {
/// #     // Only run this if `<target feature>` is supported
/// #     if cfg_feature_enabled!("<target feature>") {
/// #         // Create a `worker` function that will only be run if the target feature
/// #         // is supported and ensure that `target_feature` is enabled for your worker
/// #         // function
/// #         #[target_feature(enable = "<target feature>")]
/// #         unsafe fn worker() {
///
/// // Write your example here. Feature specific intrinsics will work here! Go wild!
///
/// #         }
/// #         unsafe { worker(); }
/// #     }
/// # }

If some of the above syntax does not look familiar, the Documentation as tests section of the Rust Book describes the rustdoc syntax quite well. As always, feel free to join us on gitter and ask us if you hit any snags, and thank you for helping to improve the documentation of stdsimd!