add benchmark action

.github/workflows/benchmark.yaml

@@ -0,0 +1,52 @@
+# Do not run this workflow on pull request since this workflow has permission to modify contents.
+on:
+  push:
+    branches:
+      - main
+
+permissions:
+  # deployments permission to deploy GitHub pages website
+  deployments: write
+  # contents permission to update benchmark contents in gh-pages branch
+  contents: write
+
+jobs:
+  benchmark:
+    name: Performance regression check
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: Install libs
+        run: |
+          sudo apt-get update
+          sudo apt-get install build-essential libreadline-dev
+      - name: Compile
+        run: make TARGET=release
+      - name: Run benchmark
+        run: |
+          gettimems() { date '+%s%3N'; }
+
+          NTIMES=3
+          sum=0
+          for i in $(seq $NTIMES); do
+            before=$(gettimems)
+            CBCVM_PATH=lib ./cbcvm bf.rbcvm bench.b
+            after=$(gettimems)
+            elapsed=$((after - before))
+            sum=$((sum + elapsed))
+          done
+
+          avg=$((sum / NTIMES))
+          printf '[{"name":"bench.b","value":%f,"unit":"ms"}]' avg > output.txt
+      # gh-pages branch is updated and pushed automatically with extracted benchmark data
+      - name: Store benchmark result
+        uses: benchmark-action/github-action-benchmark@v1
+        with:
+          name: c-bytecode-vm benchmark
+          tool: customSmallerIsBetter
+          output-file-path: output.txt
+          # Access token to deploy GitHub Pages branch
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          # Push and deploy GitHub pages branch automatically
+          auto-push: true
+          comment-on-alert: true

Makefile

@@ -17,7 +17,7 @@ endif
 endif
 
 cbcvm: *.c *.h modules/*.c modules/*.h
-	$(CC) $(CFLAGS) $(LDFLAGS) -o cbcvm *.c modules/*.c
+	$(CC) $(CFLAGS) -o cbcvm *.c modules/*.c $(LDFLAGS)
 
 # Generate a release binary using profile-guided optimization
 profile-opt: