rust/.github/workflows/ci.yml

name: CI

on:
  pull_request:
  push:
    branches:
      - master

env:
  CARGO_NET_RETRY: 10
  RUSTUP_MAX_RETRIES: 10

jobs:
  x86-tests:
    name: "${{ matrix.target_feature }} on ${{ matrix.target }}"
    runs-on: ${{ matrix.os }}
    strategy:
      fail-fast: false
      matrix:
        target: [x86_64-pc-windows-msvc, i686-pc-windows-msvc, i586-pc-windows-msvc, x86_64-unknown-linux-gnu, x86_64-apple-darwin]
        # `default` means we use the default target config for the target,
        # `native` means we run with `-Ctarget-cpu=native`, and anything else is
        # an arg to `-Ctarget-feature`
        target_feature: [default, native, +sse3, +ssse3, +sse4.1, +sse4.2, +avx, +avx2]

        exclude:
          # The macos runners seem to only reliably support up to `avx`.
          - { target: x86_64-apple-darwin, target_feature: +avx2 }
          # These features are statically known to be present for all 64 bit
          # macs, and thus are covered by the `default` test
          - { target: x86_64-apple-darwin, target_feature: +sse3 }
          - { target: x86_64-apple-darwin, target_feature: +ssse3 }
          # -Ctarget-cpu=native sounds like bad-news if target != host
          - { target: i686-pc-windows-msvc, target_feature: native }
          - { target: i586-pc-windows-msvc, target_feature: native }

        include:
          # Populate the `matrix.os` field
          - { target: x86_64-apple-darwin,      os: macos-latest }
          - { target: x86_64-unknown-linux-gnu, os: ubuntu-latest }
          - { target: x86_64-pc-windows-msvc,   os: windows-latest }
          - { target: i686-pc-windows-msvc,     os: windows-latest }
          - { target: i586-pc-windows-msvc,     os: windows-latest }

          # These are globally available on all the other targets.
          - { target: i586-pc-windows-msvc, target_feature: +sse, os: windows-latest }
          - { target: i586-pc-windows-msvc, target_feature: +sse2, os: windows-latest }

          # Annoyingly, the x86_64-unknown-linux-gnu runner *almost* always has
          # avx512vl, but occasionally doesn't. As a result, we still run that
          # one under travis.

    steps:
      - uses: actions/checkout@v2
      - name: Setup Rust
        run: |
          rustup update nightly --no-self-update
          rustup default nightly
          rustup target add ${{ matrix.target }}

      - name: Configure RUSTFLAGS
        shell: bash
        run: |
          case "${{ matrix.target_feature }}" in
            default)
              ;;
            native)
              echo "RUSTFLAGS=-Ctarget-cpu=native" >> $GITHUB_ENV
              ;;
            *)
              echo "RUSTFLAGS=-Ctarget-feature=${{ matrix.target_feature }}" >> $GITHUB_ENV
              ;;
          esac

      # Super useful for debugging why a SIGILL occurred.
      - name: Dump target configuration and support
        run: |
          rustc -Vv

          echo "Caveat: not all target features are expected to be logged"

          echo "## Requested target configuration (RUSTFLAGS=$RUSTFLAGS)"
          rustc --print=cfg --target=${{ matrix.target }} $RUSTFLAGS

          echo "## Supported target configuration for --target=${{ matrix.target }}"
          rustc --print=cfg --target=${{ matrix.target }} -Ctarget-cpu=native

          echo "## Natively supported target configuration"
          rustc --print=cfg -Ctarget-cpu=native

      - name: Test (debug)
        run: cargo test --verbose --target=${{ matrix.target }}

      - name: Test (release)
        run: cargo test --verbose --target=${{ matrix.target }} --release

  cross-tests:
    name: "${{ matrix.target }} (via cross)"
    runs-on: ubuntu-latest
    strategy:
      fail-fast: false
      # TODO: Sadly, we cant configure target-feature in a meaningful way
      # because `cross` doesn't tell qemu to enable any non-default cpu
      # features, nor does it give us a way to do so.
      #
      # Ultimately, we'd like to do something like [rust-lang/stdarch][stdarch].
      # This is a lot more complex... but in practice it's likely that we can just
      # snarf the docker config from around [here][1000-dockerfiles].
      #
      # [stdarch]: https://github.com/rust-lang/stdarch/blob/a5db4eaf/.github/workflows/main.yml#L67
      # [1000-dockerfiles]: https://github.com/rust-lang/stdarch/tree/a5db4eaf/ci/docker

      matrix:
        target:
          - i586-unknown-linux-gnu
          # 32-bit arm has a few idiosyncracies like having subnormal flushing
          # to zero on by default. Ideally we'd set
          - armv7-unknown-linux-gnueabihf
          # Note: The issue above means neither of these mips targets will use
          # MSA (mips simd) but MIPS uses a nonstandard binary representation
          # for NaNs which makes it worth testing on despite that.
          - mips-unknown-linux-gnu
          - mips64-unknown-linux-gnuabi64
          - riscv64gc-unknown-linux-gnu

    steps:
      - uses: actions/checkout@v2
      - name: Setup Rust
        run: |
          rustup update nightly --no-self-update
          rustup default nightly
          rustup target add ${{ matrix.target }}
          rustup component add rust-src

      - name: Install Cross
        # Equivalent to `cargo install cross`, but downloading a prebuilt
        # binary. Ideally we wouldn't hardcode a version, but the version number
        # being part of the tarball means we can't just use the download/latest
        # URL :(
        run: |
          CROSS_URL=https://github.com/rust-embedded/cross/releases/download/v0.2.1/cross-v0.2.1-x86_64-unknown-linux-gnu.tar.gz
          mkdir -p "$HOME/.bin"
          curl -sfSL --retry-delay 10 --retry 5 "${CROSS_URL}" | tar zxf - -C "$HOME/.bin"
          echo "$HOME/.bin" >> $GITHUB_PATH

      - name: Test (debug)
        run: cross test --verbose --target=${{ matrix.target }}

      - name: Test (release)
        run: cross test --verbose --target=${{ matrix.target }} --release