Add Intel oneAPI setup for OpenMP in GitHub Actions

Integrated Intel oneAPI into the workflow to enable OpenMP support for the project. Updated CMake configuration to include necessary OpenMP flags and library paths. This ensures compatibility with Intel's OpenMP runtime for improved parallelization.Simplify Intel oneAPI setup in CI workflow

Removed the explicit `rscohn2/setup-oneapi` action and streamlined the OpenMP configuration directly within the CMake command. This reduces external dependencies while maintaining compatibility with Intel's oneAPI tools.

Author: allnes

.github/workflows/main.yml

@@ -810,25 +810,37 @@ jobs:
           windows_compile_environment: msvc
       - name: Setup ninja
         uses: seanmiddleditch/gha-setup-ninja@v6
-      - name: Setup MSVC for Ninja again
+      - name: Setup MSVC for Ninja
         uses: ilammy/msvc-dev-cmd@v1
+      - name: Install Intel OpenMP via NuGet
+        run: |
+          nuget install intelopenmp.redist.win -Version 2025.1.1.9 -OutputDirectory intel-openmp
+        shell: pwsh
+      - name: Set environment variables for Intel OpenMP
+        shell: pwsh
+        run: |
+          echo "LIB=${{ github.workspace }}\\intel-openmp\\intelopenmp.redist.win.2025.1.1.9\\redist\\intel64\\compiler" >> $env:GITHUB_ENV
+          echo "PATH=${{ github.workspace }}\\intel-openmp\\intelopenmp.redist.win.2025.1.1.9\\redist\\intel64\\compiler;$env:PATH" >> $env:GITHUB_ENV
       - name: CMake configure
         run: >
-          cmake -S . -B build -G Ninja -D CMAKE_C_COMPILER=clang-cl -DCMAKE_CXX_COMPILER=clang-cl
-          -D CMAKE_C_COMPILER_LAUNCHER=ccache -D CMAKE_CXX_COMPILER_LAUNCHER=ccache
-          -D CMAKE_BUILD_TYPE=RELEASE -DCMAKE_INSTALL_PREFIX=install
+          cmake -S . -B build -G Ninja
+          -D CMAKE_C_COMPILER=clang-cl
+          -D CMAKE_CXX_COMPILER=clang-cl
+          -D CMAKE_C_COMPILER_LAUNCHER=ccache
+          -D CMAKE_CXX_COMPILER_LAUNCHER=ccache
+          -D CMAKE_BUILD_TYPE=Release
+          -D CMAKE_INSTALL_PREFIX=install
+          -D CMAKE_CXX_FLAGS="/clang:-fopenmp=libiomp5 /link libiomp5md.lib"
         env:
           CC: clang-cl
           CXX: clang-cl
       - name: Build project
-        run: |
-          cmake --build build --config Release --parallel
+        run: cmake --build build --config Release --parallel
         env:
           CC: clang-cl
           CXX: clang-cl
       - name: Install project
-        run: |
-          cmake --install build
+        run: cmake --install build
       - name: Archive installed package
         run: Compress-Archive -Path install -DestinationPath windows-clang-install.zip
         shell: pwsh