add github action

.github/workflows/build-tandem.yml

@@ -0,0 +1,91 @@
+name: tandem-build
+
+on:
+  push:
+
+env:
+  PETSC_CACHE_FOLDER: ${{ github.workspace }}/.petsc
+  ARCHITECTURE: arch-linux-c-opt
+
+jobs:
+  build-and-test:
+    runs-on: ubuntu-24.04
+    strategy:
+      fail-fast: false
+      matrix:
+        compiler:
+          - cc: gcc-13
+            cxx: g++-13
+          - cc: clang-18
+            cxx: clang++-18
+    steps:
+      - name: Checkout Repository
+        uses: actions/checkout@v4
+        with:
+          submodules: recursive
+
+      - name: Install Dependencies and Compilers
+        run: |
+            sudo apt-get update
+            sudo apt-get install -y \
+              gcc-13 g++-13 \
+              cmake \
+              openmpi-bin libopenmpi-dev \
+              libmetis-dev libparmetis-dev \
+              libeigen3-dev python3-numpy \
+              libopenblas0 libopenblas-dev \
+              liblua5.3-0 liblua5.3-dev \
+              libomp-dev libgomp1
+            # libxsmm
+            git clone --depth 1 --branch 1.17 https://github.com/libxsmm/libxsmm.git gitbuild && \
+            mkdir -p gitbuild && cd gitbuild && \
+            make generator -j $(nproc) && sudo cp bin/libxsmm_gemm_generator /usr/bin && \
+            cd .. && rm -rf gitbuild
+
+      - name: Get Ubuntu and PETSc Version
+        id: get_version
+        run: |
+          UBUNTU_VERSION=$(lsb_release -r | awk '{print $2}')
+          echo "UBUNTU_VERSION=$UBUNTU_VERSION" >> $GITHUB_ENV
+          petsc_version=$(curl -s https://pypi.org/pypi/petsc/json | jq -r '.info.version')
+          echo "PETSC_VERSION=$petsc_version" >> $GITHUB_ENV
+
+      - name: Cache PETSc Installation
+        id: cache-petsc
+        uses: actions/cache@v4
+        with:
+          path: ${{ env.PETSC_CACHE_FOLDER }}
+          key: ubuntu-${{ env.UBUNTU_VERSION }}-petsc-${{ env.PETSC_VERSION }}-${{ matrix.compiler.cc }}-${{ env.ARCHITECTURE }}
+          restore-keys: ubuntu-${{ env.UBUNTU_VERSION }}-petsc-${{ env.PETSC_VERSION }}-${{ matrix.compiler.cc }}-${{ env.ARCHITECTURE }}
+
+      - name: Install PETSc
+        if: steps.cache-petsc.outputs.cache-hit != 'true'
+        run: |
+          set -euo pipefail
+          install_dir=${{ env.PETSC_CACHE_FOLDER }}
+          version=${{ env.PETSC_VERSION }}
+          mkdir -p ${install_dir}
+          wget https://web.cels.anl.gov/projects/petsc/download/release-snapshots/petsc-${version}.tar.gz
+          tar -xvf petsc-${version}.tar.gz
+          cd petsc-${version}
+          ./configure --with-fortran-bindings=0 --with-debugging=0 \
+              --with-memalign=32 --with-64-bit-indices \
+              --with-cc=${{ matrix.compiler.cc }} --with-cxx=${{ matrix.compiler.cxx }} --with-fc=0 --prefix=${install_dir} \
+              --COPTFLAGS="-g -O3" --CXXOPTFLAGS="-g -O3" --with-mpi-dir=/usr/lib/x86_64-linux-gnu/openmpi 
+          make PETSC_DIR=`pwd` PETSC_ARCH=${{ env.ARCHITECTURE }} -j$(nproc)
+          make PETSC_DIR=`pwd` PETSC_ARCH=${{ env.ARCHITECTURE }} install
+          cd ..
+
+      - name: Build and Test Tandem
+        run: |
+          set -euo pipefail
+          mkdir build && cd build
+          cmake .. \
+                -DCMAKE_PREFIX_PATH=${{ env.PETSC_CACHE_FOLDER }} \
+                -DDOMAIN_DIMENSION=3 \
+                -DPOLYNOMIAL_DEGREE=2 \
+                -DCMAKE_C_COMPILER=${{ matrix.compiler.cc }} \
+                -DCMAKE_CXX_COMPILER=${{ matrix.compiler.cxx }} 
+     
+          make -j$(nproc)
+          make test