[Github][RFC] Add workflow to diff codegen on llvm-test-suite

.github/workflows/test-suite.yml

@@ -0,0 +1,110 @@
+# When /test-suite is commented on a PR, checks out the PR, builds clang and
+# then the test-suite in several configurations. It then checks out the base of
+# the PR, builds clang and the test-suite again, and then uploads the diff of
+# the codegen.
+
+name: Diff test-suite codegen
+
+on:
+  issue_comment:
+    types:
+      - created
+
+jobs:
+  test-suite:
+    name: Build and diff
+    runs-on: ubuntu-24.04
+    permissions:
+      issues: write
+    if: >-
+      !startswith(github.event.comment.body, '<!--IGNORE-->') &&
+      github.event.issue.pull_request && contains(github.event.comment.body, '/test-suite')
+    steps:
+      - id: get-pr
+        uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd # v8.0.0
+        with:
+          script: |
+            const { data: pr } = await github.rest.pulls.get({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              pull_number: context.payload.issue.number
+            })
+            if (!pr.mergeable)
+              await github.rest.issues.createComment({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                body: "Can't diff PR, PR isn't mergeable"
+              })
+            return pr
+      - if: ${{ !fromJSON(steps.get-pr.outputs.result).mergeable }}
+        run: exit 1
+      - uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd # v8.0.0
+        with:
+          script: |
+            github.rest.reactions.createForIssueComment({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              comment_id: context.payload.comment.id,
+              content: '+1'
+            })
+      - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
+        with:
+          ref: ${{ fromJSON(steps.get-pr.outputs.result).merge_commit_sha }}
+          repository: ${{ fromJSON(steps.get-pr.outputs.result).head.repo.full_name }}
+          fetch-depth: 2
+      - run: |
+          echo "HEAD_SHA=$(git rev-parse HEAD)" >> $GITHUB_ENV
+          echo "BASE_SHA=$(git rev-parse HEAD^)" >> $GITHUB_ENV
+          echo "$GITHUB_WORKSPACE/.github/workflows/test-suite" >> $GITHUB_PATH
+      - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
+        with:
+          repository: llvm/llvm-test-suite
+          path: llvm-test-suite
+      - name: Install system dependencies
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y cmake ninja-build libc6-dev-{arm64,riscv64}-cross libgcc-14-dev-{arm64,riscv64}-cross libstdc++-14-dev-{arm64,riscv64}-cross
+      - name: Configure Clang
+        run: cmake -B build -DCMAKE_BUILD_TYPE=Release -DLLVM_TARGETS_TO_BUILD='AArch64;X86;RISCV' -DLLVM_ENABLE_PROJECTS='clang;lld' -DLLVM_APPEND_VC_REV=OFF llvm -GNinja
+      - name: Build Clang @ head
+        run: ninja -C build
+      - name: Configure and build test-suite @ head
+        run: |
+          build-and-configure.sh rva23u64-O3-b riscv64.cmake
+          build-and-configure.sh armv9-a-O3-b aarch64.cmake
+          build-and-configure.sh x86_64-O3-b x86_64.cmake
+        working-directory: llvm-test-suite
+      - name: Build test-suite @ base
+        run: git checkout $BASE_SHA && ninja -C build
+      - name: Configure and build test-suite @ base
+        run: |
+          build-and-configure.sh rva23u64-O3-a riscv64.cmake
+          build-and-configure.sh armv9-a-O3-a aarch64.cmake
+          build-and-configure.sh x86_64-O3-a x86_64.cmake
+        working-directory: llvm-test-suite
+      - run: |
+          mkdir diffs
+          ./utils/tdiff.py -a build.rva23u64-O3-a -b build.rva23u64-O3-b -s all > diffs/rva23u64-O3.diff || true
+          ./utils/tdiff.py -a build.armv9-a-O3-a -b build.armv9-a-O3-b -s all > diffs/armv9-a-O3.diff || true
+          ./utils/tdiff.py -a build.x86_64-O3-a -b build.x86_64-O3-b -s all > diffs/x86_64-O3.diff || true
+        working-directory: llvm-test-suite
+      - uses: actions/upload-artifact@bbbca2ddaa5d8feaa63e36b76fdaad77386f024f #v7.0.0
+        id: upload-diffs
+        with:
+          name: diffs
+          path: llvm-test-suite/diffs
+      - uses: actions/upload-artifact@bbbca2ddaa5d8feaa63e36b76fdaad77386f024f #v7.0.0
+        with:
+          name: results
+          path: llvm-test-suite/results*.json
+      - uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd # v8.0.0
+        env:
+          DIFF_URL: ${{ steps.upload-diffs.outputs.artifact-url }}
+        with:
+          script: |
+            github.rest.issues.createComment({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              issue_number: context.issue.number,
+              body: `test-suite diff from ${process.env.BASE_SHA}...${process.env.HEAD_SHA}: ${process.env.DIFF_URL}`
+            })

.github/workflows/test-suite/aarch64.cmake

@@ -0,0 +1,9 @@
+set(CMAKE_SYSTEM_NAME Linux)
+set(CMAKE_C_COMPILER $ENV{GITHUB_WORKSPACE}/build/bin/clang)
+set(CMAKE_CXX_COMPILER $ENV{GITHUB_WORKSPACE}/build/bin/clang++)
+set(CMAKE_C_COMPILER_TARGET aarch64-linux-gnu)
+set(CMAKE_CXX_COMPILER_TARGET aarch64-linux-gnu)
+set(CMAKE_C_FLAGS_INIT "-march=armv9-a -save-temps=obj")
+set(CMAKE_CXX_FLAGS_INIT "-march=armv9-a -save-temps=obj")
+set(CMAKE_SYSTEM_PROCESSOR arm64)
+set(CMAKE_LINKER_TYPE LLD)

.github/workflows/test-suite/configure-and-build.sh

@@ -0,0 +1,12 @@
+#!/bin/bash
+
+set -eux
+
+cmake -B build.$1 \
+      --toolchain $GITHUB_WORKSPACE/.github/workflows/test-suite/$2 \
+      -C cmake/caches/O3.cmake \
+      -GNinja \
+      -DTEST_SUITE_BENCHMARKING_ONLY=ON \
+      -DTEST_SUITE_RUN_BENCHMARKS=OFF
+ninja -C build.$1
+$GITHUB_WORKSPACE/build/bin/llvm-lit build.$1 -o results.$1.json

.github/workflows/test-suite/riscv64.cmake

@@ -0,0 +1,9 @@
+set(CMAKE_SYSTEM_NAME Linux)
+set(CMAKE_C_COMPILER $ENV{GITHUB_WORKSPACE}/build/bin/clang)
+set(CMAKE_CXX_COMPILER $ENV{GITHUB_WORKSPACE}/build/bin/clang++)
+set(CMAKE_C_COMPILER_TARGET riscv64-linux-gnu)
+set(CMAKE_CXX_COMPILER_TARGET riscv64-linux-gnu)
+set(CMAKE_C_FLAGS_INIT "-march=rva23u64 -save-temps=obj")
+set(CMAKE_CXX_FLAGS_INIT "-march=rva23u64 -save-temps=obj")
+set(CMAKE_SYSTEM_PROCESSOR riscv64)
+set(CMAKE_LINKER_TYPE LLD)

.github/workflows/test-suite/x86_64.cmake

@@ -0,0 +1,5 @@
+set(CMAKE_C_COMPILER $ENV{GITHUB_WORKSPACE}/build/bin/clang)
+set(CMAKE_CXX_COMPILER $ENV{GITHUB_WORKSPACE}/build/bin/clang++)
+set(CMAKE_C_FLAGS_INIT "-save-temps=obj")
+set(CMAKE_CXX_FLAGS_INIT "-save-temps=obj")
+set(CMAKE_LINKER_TYPE LLD)