Merge pull request #421 from zcash/ci-benchmarks

CI: Add benchmarks workflow

.github/workflows/bench.yml

@@ -0,0 +1,35 @@
+name: Benchmarks
+on:
+  push:
+    branches:
+      - main
+
+permissions:
+  contents: write
+  deployments: write
+
+jobs:
+  benchmark:
+    name: Performance regression check
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions-rs/toolchain@v1
+        with:
+          toolchain: 1.51.0
+          override: true
+      - name: Run benchmark
+        run: cargo bench | tee output.txt
+      - name: Store benchmark result
+        uses: benchmark-action/github-action-benchmark@v1
+        with:
+          name: halo2 Benchmark
+          tool: 'cargo'
+          output-file-path: output.txt
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          auto-push: true
+          # Show alert with commit comment on detecting possible performance regression
+          alert-threshold: '200%'
+          comment-on-alert: true
+          fail-on-alert: true
+          alert-comment-cc-users: '@str4d'