perf.yml

name: perf

on:
  pull_request:
    paths-ignore:
      - 'spec/**'
      - 'changelog/**'
      - '**/*.md'
  push:
    branches: [master]

concurrency:
  group: perf-${{ github.event.pull_request.number || github.ref }}
  cancel-in-progress: ${{ github.event_name == 'pull_request' }}

permissions:
  contents: read

jobs:
  perf:
    runs-on: ubuntu-24.04
    timeout-minutes: 60
    env:
      OS_NAME: linux
      MODEL: 64
      FULL_BUILD: false
      HOST_DMD: ldc-1.42.0
      ENABLE_LTO: 1
    defaults:
      run:
        shell: bash
    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 0

      - name: Set parallelism
        run: echo "N=$(nproc)" >> "$GITHUB_ENV"

      - name: Compute base/head SHAs
        id: refs
        run: |
          set -uexo pipefail
          HEAD_SHA="${{ github.event.pull_request.head.sha || github.sha }}"
          echo "head=$HEAD_SHA" >> "$GITHUB_OUTPUT"
          echo "branch=${GITHUB_BASE_REF:-master}" >> "$GITHUB_OUTPUT"

          # A pushed commit is its own merge-base with master, so nothing
          # to diff against there. Measure alone and record it as history.
          if [ "${{ github.event_name }}" = pull_request ]; then
            git fetch --no-tags origin master
            echo "base=$(git merge-base "$HEAD_SHA" origin/master)" >> "$GITHUB_OUTPUT"
          else
            BEFORE="${{ github.event.before }}"
            # All zeroes on the first push to a branch.
            git rev-parse -q --verify "$BEFORE^{commit}" > /dev/null || BEFORE="$HEAD_SHA~"
            echo "base=" >> "$GITHUB_OUTPUT"
            echo "before=$BEFORE" >> "$GITHUB_OUTPUT"
            echo "commits=$(git rev-list --count "$BEFORE..$HEAD_SHA")" >> "$GITHUB_OUTPUT"
            echo "date=$(TZ=UTC git show -s --format=%cd --date=iso-strict-local "$HEAD_SHA")" >> "$GITHUB_OUTPUT"
          fi

      - name: Install prerequisites
        run: |
          sudo apt-get update
          sudo apt-get install -y valgrind time
          valgrind --version

      - name: Install host compiler
        run: |
          ci/run.sh install_host_compiler
          source ~/dlang/*/activate
          which ldc-profdata
          deactivate

      - name: Build dmd at base and head
        run: |
          set -uexo pipefail
          source ~/dlang/*/activate
          built=generated/$OS_NAME/release/$MODEL
          profile="$RUNNER_TEMP/pgo/merged.data"
          BASE_SHA="${{ steps.refs.outputs.base }}"
          mkdir -p "$RUNNER_TEMP/pgo"

          # Check out a ref and build a plain dmd + phobos
          setup_ref() {
            local dir="$RUNNER_TEMP/$2/dmd"
            mkdir -p "$RUNNER_TEMP/$2"
            git worktree add --force "$dir" "$1"
            ( cd "$dir" && ci/run.sh setup_repos "${{ steps.refs.outputs.branch }}" )
            ( cd "$dir" && $DMD -of=generated/build -g compiler/src/build.d )
            ( cd "$dir" && generated/build HOST_DMD=$DMD MODEL=$MODEL -j$N )
            ( cd "$dir/../phobos" && make -j$N MODEL=$MODEL )
          }

          setup_ref "${{ steps.refs.outputs.head }}" head
          if [ -n "$BASE_SHA" ]; then
            setup_ref "$BASE_SHA" base
            train=base
          else
            train=head
          fi

          # dmd-pgo trains and rebuilds $train with the merged profile, the other ref just reuses it
          ( cd "$RUNNER_TEMP/$train/dmd" && generated/build HOST_DMD=$DMD MODEL=$MODEL dmd-pgo -j$N --force )
          cp "$RUNNER_TEMP/$train/dmd/$built/dmd_profdata/merged.data" "$profile"
          if [ -n "$BASE_SHA" ]; then
            ( cd "$RUNNER_TEMP/head/dmd" && generated/build HOST_DMD=$DMD MODEL=$MODEL \
                ENABLE_RELEASE=1 ENABLE_LTO=1 \
                DFLAGS="-fprofile-instr-use=$profile -wi" -j$N --force )
          fi
          deactivate

      - name: Cache dub packages
        uses: actions/cache@v4
        with:
          path: ~/.dub/packages
          key: dub-packages-${{ hashFiles('tools/perfrunner/workloads/vibed/dub.selections.json') }}

      - name: Measure
        run: |
          set -uexo pipefail
          source ~/dlang/*/activate
          built=generated/$OS_NAME/release/$MODEL/dmd
          BASE_SHA="${{ steps.refs.outputs.base }}"

          args=(
            --head-dmd "$RUNNER_TEMP/head/dmd/$built"
            --head-phobos "$RUNNER_TEMP/head/phobos"
            --head-src "$RUNNER_TEMP/head/dmd"
            --head-sha "${{ steps.refs.outputs.head }}"
            --os ubuntu-24.04
            --host-dmd "$HOST_DMD"
            --host-dmd-bin "$DMD"
            --out "$GITHUB_WORKSPACE/results.json"
          )
          if [ -n "$BASE_SHA" ]; then
            args+=(
              --base-dmd "$RUNNER_TEMP/base/dmd/$built"
              --base-phobos "$RUNNER_TEMP/base/phobos"
              --base-src "$RUNNER_TEMP/base/dmd"
              --base-sha "$BASE_SHA"
              --pr "${{ github.event.pull_request.number || 0 }}"
            )
          else
            args+=(
              --before "${{ steps.refs.outputs.before }}"
              --commits "${{ steps.refs.outputs.commits }}"
              --committed-at "${{ steps.refs.outputs.date }}"
            )
          fi

          cd tools/perfrunner
          dub run -- "${args[@]}"

      - name: Show results
        run: cat "$GITHUB_WORKSPACE/results.json"

      # perf-comment.yml picks this up and posts the comment.
      - name: Upload results
        if: github.event_name == 'pull_request'
        uses: actions/upload-artifact@v4
        with:
          name: perf-results
          path: results.json

      - name: Publish to the history repo
        if: github.event_name == 'push' && vars.PERF_DATA_REPO != ''
        env:
          PERF_DATA_REPO: ${{ vars.PERF_DATA_REPO }}
          PERF_DATA_KEY: ${{ secrets.PERF_DATA_KEY }}
          SHA: ${{ steps.refs.outputs.head }}
          COMMITTED_AT: ${{ steps.refs.outputs.date }}
        run: .github/scripts/perf_publish.sh "$GITHUB_WORKSPACE/results.json"