Use only actions/checkout and do parallel benchmark.

Author: cedric-appdirect

.github/workflows/bench.yml

@@ -9,8 +9,10 @@ on:
     pull_request:
 
 jobs:
-    benchmark:
+    benchmark-pr:
         runs-on: ubuntu-latest
+        outputs:
+          result: ${{ steps.benchmark.outputs.result }}
         steps:
           - name: Setup go
             uses: actions/setup-go@v5
@@ -20,14 +22,40 @@ jobs:
             uses: actions/checkout@v4
 
           - name: Run benchmark on commit
-            run: go test -bench=. -benchmem -count=20 -run=^# > pr.bench
+            id: benchmark
+            run: |
+              echo "result<<EOF" >> "$GITHUB_OUTPUT"
+              go test -bench=. -benchmem -count=20 -run=^# >> "$GITHUB_OUTPUT"
+              echo "EOF" >> "$GITHUB_OUTPUT"
 
+    benchmark-master:
+        runs-on: ubuntu-latest
+        outputs:
+          result: ${{ steps.benchmark.outputs.result }}
+        steps:
+          - name: Setup go
+            uses: actions/setup-go@v5
+            with:
+              go-version: "1.21"
           - name: Switch to master branch
-            run: git checkout master
+            uses: actions/checkout@v4
+            with:
+              ref: master
           - name: Run benchmark on master
-            id: benchmark-master
-            run: go test -bench=. -benchmem -count=20 -run=^# > master.bench
+            id: benchmark
+            run: |
+              echo "result<<EOF" >> "$GITHUB_OUTPUT"
+              go test -bench=. -benchmem -count=20 -run=^# >> "$GITHUB_OUTPUT"
+              echo "EOF" >> "$GITHUB_OUTPUT"
 
+    benchmark:
+        runs-on: ubuntu-latest
+        needs: [benchmark-pr, benchmark-master]
+        steps:
+          - name: Setup go
+            uses: actions/setup-go@v5
+            with:
+              go-version: "1.21"
           - name: Restore benchstat
             id: cache-benchstat
             uses: actions/cache@v3
@@ -47,6 +75,8 @@ jobs:
           - name: Compare benchmarks
             id: compare
             run: |
+              echo "${{ needs.benchmark-pr.outputs.result }}" > pr.bench
+              echo "${{ needs.benchmark-master.outputs.result }}" > master.bench
               echo "STAT<<EOF" >> "$GITHUB_OUTPUT"
               benchstat pr.bench master.bench >> "$GITHUB_OUTPUT"
               echo "EOF" >> "$GITHUB_OUTPUT"