fschlimb · Nov 11, 2026 · Nov 10, 2026 · Nov 10, 2026 · Nov 10, 2026 · Nov 10, 2026
diff --git a/.github/workflows/ci-cpu.yml b/.github/workflows/ci-cpu.yml
@@ -12,7 +12,8 @@ on:
 
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}
-  cancel-in-progress: true
+  # Let main runs finish populating the native SDK cache.
+  cancel-in-progress: ${{ github.event_name == 'pull_request' }}
 
 permissions:
   contents: read
@@ -46,63 +47,134 @@ jobs:
       - name: Check inline samples are up to date
         run: python test/tools/inline_samples.py --check
 
-  build:
-    name: Build CPU Wheel (Python 3.12)
+  native-sdk:
+    name: Native SDK
     runs-on: ubuntu-24.04
     timeout-minutes: 360
-    env:
-      CUTILE_BUILD_VARIANT: cpu
+    outputs:
+      key: ${{ steps.key.outputs.key }}
     steps:
       - name: Checkout repository
         uses: actions/checkout@v6
 
+      - name: Compute native SDK cache key
+        id: key
+        # Bump v1 when the SDK build commands below change.
+        run: echo "key=cpu-native-sdk-v1-${ImageOS:?}-${RUNNER_ARCH}-${{ hashFiles('backends/cmake/**', 'backends/cpu/toolchain.cmake') }}" >> "$GITHUB_OUTPUT"
+
+      - name: Look up native SDK cache
+        id: cache
+        uses: actions/cache/restore@v6
+        with:
+          path: native-sdk
+          key: ${{ steps.key.outputs.key }}
+          lookup-only: true
+
       - name: Set up Python
+        if: steps.cache.outputs.cache-hit != 'true'
         uses: actions/setup-python@v6
         with:
           python-version: "3.12"
 
-      - name: Install native build dependencies
+      - name: Build native SDK
+        if: steps.cache.outputs.cache-hit != 'true'
         run: |
           sudo apt-get update
           sudo apt-get install --yes clang lld g++
+          python -m pip install 'cmake>=3.24,<4' ninja
+          cmake -S . -B build/native-sdk -G Ninja \
+            -DCUTILE_BUILD_VARIANT=cpu \
+            -DCUTILE_BUILD_NATIVE_SDK=ON \
+            -DCMAKE_INSTALL_PREFIX="$PWD/native-sdk"
+          cmake --build build/native-sdk
+          cmake --install build/native-sdk --component cuTileNativeSDK
+
+      - name: Save native SDK cache
+        if: steps.cache.outputs.cache-hit != 'true'
+        uses: actions/cache/save@v6
+        with:
+          path: native-sdk
+          key: ${{ steps.key.outputs.key }}
+
+      - name: Verify native SDK cache
+        if: steps.cache.outputs.cache-hit != 'true'
+        # Save failures are only warnings; the wheel jobs need the entry.
+        uses: actions/cache/restore@v6
+        with:
+          path: native-sdk
+          key: ${{ steps.key.outputs.key }}
+          lookup-only: true
+          fail-on-cache-miss: true
+
+  build:
+    name: Build CPU Wheel (Python ${{ matrix.python-version }})
+    needs: native-sdk
+    runs-on: ubuntu-24.04
+    timeout-minutes: 60
+    strategy:
+      fail-fast: false
+      matrix:
+        python-version: &python-versions ["3.11", "3.12", "3.13", "3.14", "3.14t", "3.15", "3.15t"]
+    env:
+      CUTILE_BUILD_VARIANT: cpu
+      CMAKE_ARGS: -DCUTILE_NATIVE_SDK_DIR=${{ github.workspace }}/native-sdk
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v6
+
+      - name: Set up Python
+        uses: actions/setup-python@v6
+        with:
+          python-version: ${{ matrix.python-version }}
+
+      - name: Restore native SDK
+        uses: actions/cache/restore@v6
+        with:
+          path: native-sdk
+          key: ${{ needs.native-sdk.outputs.key }}
+          fail-on-cache-miss: true
 
       - name: Set up uv
         uses: astral-sh/setup-uv@v7
         with:
           enable-cache: true
 
       - name: Install CPU build dependencies
-        run: uv sync --group cpu --no-install-project
+        run: uv sync --group backend-build --no-install-project --python "$(command -v python)"
 
       - name: Build CPU wheel
         run: uv build --wheel --no-build-isolation --python .venv/bin/python
 
       - name: Upload CPU wheel
         uses: actions/upload-artifact@v6
         with:
-          name: wheel-cpu-py3.12-linux-x86_64
+          name: wheel-cpu-py${{ matrix.python-version }}-linux-x86_64
           path: dist/*.whl
           if-no-files-found: error
           retention-days: 7
 
   test-cpu:
-    name: CPU Tests (Python 3.12)
+    name: CPU Tests (Python ${{ matrix.python-version }})
     needs: build
     runs-on: ubuntu-24.04
     timeout-minutes: 360
+    strategy:
+      fail-fast: false
+      matrix:
+        python-version: *python-versions
     steps:
       - name: Checkout repository
         uses: actions/checkout@v6
 
       - name: Set up Python
         uses: actions/setup-python@v6
         with:
-          python-version: "3.12"
+          python-version: ${{ matrix.python-version }}
 
       - name: Download CPU wheel
         uses: actions/download-artifact@v7
         with:
-          name: wheel-cpu-py3.12-linux-x86_64
+          name: wheel-cpu-py${{ matrix.python-version }}-linux-x86_64
           path: dist/
 
       - name: Install test dependencies
@@ -111,13 +183,18 @@ jobs:
           python -m pip install dist/*.whl numpy pytest pytest-benchmark pytest-env
           python -m pip install setuptools==84.0.0 'cmake>=3.24,<4' ninja
 
+      - name: Check native extensions keep the GIL disabled
+        if: endsWith(matrix.python-version, 't')
+        # CPython only warns when an extension re-enables the GIL.
+        run: python -c "import sys, cuda.tile._cext, cuda.tile._backends._compiler, cuda.tile._backends.cpu._cpu; assert not sys._is_gil_enabled(), 'GIL re-enabled'"
+
       - name: Run CPU backend tests
         run: python -m pytest --durations=10 --junitxml=test-results.xml -m "not benchmark" backends/cpu backends/test
 
       - name: Upload test results
         if: ${{ !cancelled() }}
         uses: actions/upload-artifact@v6
         with:
-          name: cpu-test-results
+          name: cpu-test-results-py${{ matrix.python-version }}
           path: test-results.xml
           retention-days: 7
diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -6,6 +6,12 @@ cmake_minimum_required(VERSION 3.18)
 project(cuda-tile-python)
 enable_testing()
 
+option(CUTILE_BUILD_NATIVE_SDK "Build and install the Python-independent native SDK" OFF)
+if(CUTILE_BUILD_NATIVE_SDK)
+    add_subdirectory(backends)
+    return()
+endif()
+
 list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_LIST_DIR}/cmake")
 
 if (MSVC)

diff --git a/backends/CMakeLists.txt b/backends/CMakeLists.txt
@@ -26,6 +26,14 @@ endif()
 # dependencies, such as dlpack.
 set(CMAKE_INSTALL_DEFAULT_COMPONENT_NAME cuTileBackend)
 
+set(CUTILE_NATIVE_SDK_DIR "" CACHE PATH "Installed Python-independent native SDK")
+if(CUTILE_BUILD_NATIVE_SDK)
+    include("${CMAKE_CURRENT_SOURCE_DIR}/cmake/FetchTileIRToMLIR.cmake")
+    fetch_tileir_to_mlir()
+    include("${CMAKE_CURRENT_SOURCE_DIR}/cmake/TileIRToMLIR.cmake")
+    return()
+endif()
+
 find_package(Python REQUIRED COMPONENTS Interpreter Development.Module)
 execute_process(
     COMMAND "${Python_EXECUTABLE}" -m nanobind --cmake_dir
@@ -37,16 +45,34 @@ find_package(nanobind CONFIG REQUIRED)
 # Package directory of the backends, relative to the install prefix.
 set(CUTILE_BACKEND_INSTALL_DIR cuda/tile/_backends)
 
-include("${CMAKE_CURRENT_SOURCE_DIR}/cmake/FetchTileIRToMLIR.cmake")
-fetch_tileir_to_mlir()
-include("${CMAKE_CURRENT_SOURCE_DIR}/cmake/TileIRToMLIR.cmake")
-
-install(FILES "${CUTILE_COMPILER_PATH}" DESTINATION "${CUTILE_BACKEND_INSTALL_DIR}")
-install(FILES "${CUTILE_LLVM_LICENSE_PATH}"
-    DESTINATION "${CUTILE_BACKEND_INSTALL_DIR}/_licenses/llvm")
-install(FILES "${CUTILE_TILEIR_TO_MLIR_DIR}/LICENSE"
-    DESTINATION "${CUTILE_BACKEND_INSTALL_DIR}/_licenses/tileir-to-mlir")
-install(FILES "${CUTILE_CUDA_TILE_SOURCE_DIR}/LICENSE.txt"
-    DESTINATION "${CUTILE_BACKEND_INSTALL_DIR}/_licenses/cuda-tile")
+if(CUTILE_NATIVE_SDK_DIR)
+    list(PREPEND CMAKE_PREFIX_PATH "${CUTILE_NATIVE_SDK_DIR}")
+    find_package(TileIRToMLIR REQUIRED CONFIG
+        PATHS "${CUTILE_NATIVE_SDK_DIR}" NO_DEFAULT_PATH)
+    find_package(LLD REQUIRED CONFIG)
+    add_library(TileIRToMLIR ALIAS TileIRToMLIR::TileIRToMLIR)
+    if(NOT TARGET CudaTileBytecodeReader)
+        add_library(CudaTileBytecodeReader ALIAS TileIRToMLIR::CudaTileBytecodeReader)
+    endif()
+    include("${CMAKE_CURRENT_SOURCE_DIR}/compiler.cmake")
+    install(FILES "${CUTILE_NATIVE_SDK_DIR}/share/cutile/llvm/LICENSE.TXT"
+        DESTINATION "${CUTILE_BACKEND_INSTALL_DIR}/_licenses/llvm")
+    install(FILES "${CUTILE_NATIVE_SDK_DIR}/share/TileIRToMLIR/LICENSE"
+        DESTINATION "${CUTILE_BACKEND_INSTALL_DIR}/_licenses/tileir-to-mlir")
+    install(FILES "${CUTILE_NATIVE_SDK_DIR}/share/TileIRToMLIR/cuda-tile/LICENSE.txt"
+        DESTINATION "${CUTILE_BACKEND_INSTALL_DIR}/_licenses/cuda-tile")
+else()
+    include("${CMAKE_CURRENT_SOURCE_DIR}/cmake/FetchTileIRToMLIR.cmake")
+    fetch_tileir_to_mlir()
+    include("${CMAKE_CURRENT_SOURCE_DIR}/cmake/TileIRToMLIR.cmake")
+
+    install(FILES "${CUTILE_COMPILER_PATH}" DESTINATION "${CUTILE_BACKEND_INSTALL_DIR}")
+    install(FILES "${CUTILE_LLVM_LICENSE_PATH}"
+        DESTINATION "${CUTILE_BACKEND_INSTALL_DIR}/_licenses/llvm")
+    install(FILES "${CUTILE_TILEIR_TO_MLIR_DIR}/LICENSE"
+        DESTINATION "${CUTILE_BACKEND_INSTALL_DIR}/_licenses/tileir-to-mlir")
+    install(FILES "${CUTILE_CUDA_TILE_SOURCE_DIR}/LICENSE.txt"
+        DESTINATION "${CUTILE_BACKEND_INSTALL_DIR}/_licenses/cuda-tile")
+endif()
 
 add_subdirectory("${CUTILE_BUILD_VARIANT}")
diff --git a/backends/cmake/CheckoutLLVM.cmake b/backends/cmake/CheckoutLLVM.cmake
@@ -56,16 +56,57 @@ if(DEFINED REVISION AND NOT REVISION STREQUAL "")
     set(_selected_revision "${REVISION}")
 endif()
 
+set(_patch "")
+if(DEFINED PATCH AND NOT PATCH STREQUAL "")
+    file(READ "${PATCH}" _patch)
+endif()
+execute_process(
+    COMMAND "${GIT_EXECUTABLE}" -C "${SOURCE_DIR}" rev-parse --absolute-git-dir
+    OUTPUT_VARIABLE _git_dir
+    OUTPUT_STRIP_TRAILING_WHITESPACE
+    COMMAND_ERROR_IS_FATAL ANY)
+# Copy of the patch applied to the working tree, needed to revert it.
+set(_applied_patch "${_git_dir}/cutile-llvm.patch")
+set(_applied "")
+if(EXISTS "${_applied_patch}")
+    file(READ "${_applied_patch}" _applied)
+endif()
+
 execute_process(
     COMMAND "${GIT_EXECUTABLE}" -C "${SOURCE_DIR}" rev-parse HEAD
     RESULT_VARIABLE _head_result
     OUTPUT_VARIABLE _head_revision
     OUTPUT_STRIP_TRAILING_WHITESPACE
     ERROR_QUIET)
-if(_head_result EQUAL 0 AND _head_revision STREQUAL _selected_revision)
+if(_head_result EQUAL 0 AND _head_revision STREQUAL _selected_revision
+   AND _applied STREQUAL _patch)
     return()
 endif()
 
-execute_process(
-    COMMAND "${GIT_EXECUTABLE}" -C "${SOURCE_DIR}" checkout --detach "${_selected_revision}"
-    COMMAND_ERROR_IS_FATAL ANY)
+if(EXISTS "${_applied_patch}")
+    execute_process(
+        COMMAND "${GIT_EXECUTABLE}" -C "${SOURCE_DIR}" apply --reverse "${_applied_patch}"
+        COMMAND_ERROR_IS_FATAL ANY)
+    file(REMOVE "${_applied_patch}")
+endif()
+
+if(NOT _head_revision STREQUAL _selected_revision)
+    execute_process(
+        COMMAND "${GIT_EXECUTABLE}" -C "${SOURCE_DIR}" checkout --detach "${_selected_revision}"
+        COMMAND_ERROR_IS_FATAL ANY)
+endif()
+
+if(NOT _patch STREQUAL "")
+    # Newer LLVM revisions may already contain the patch.
+    execute_process(
+        COMMAND "${GIT_EXECUTABLE}" -C "${SOURCE_DIR}" apply --reverse --check "${PATCH}"
+        RESULT_VARIABLE _patch_present
+        OUTPUT_QUIET
+        ERROR_QUIET)
+    if(NOT _patch_present EQUAL 0)
+        execute_process(
+            COMMAND "${GIT_EXECUTABLE}" -C "${SOURCE_DIR}" apply "${PATCH}"
+            COMMAND_ERROR_IS_FATAL ANY)
+        file(WRITE "${_applied_patch}" "${_patch}")
+    endif()
+endif()
diff --git a/backends/cmake/FetchTileIRToMLIR.cmake b/backends/cmake/FetchTileIRToMLIR.cmake
@@ -4,10 +4,10 @@
 
 set(TILEIR_TO_MLIR_REPOSITORY "https://github.com/libxsmm/tileir-to-mlir"
     CACHE STRING "TileIRToMLIR repo URL")
-set(TILEIR_TO_MLIR_REVISION "ba6c9e50274522089b7ad99b3e8a571480481330"
+set(TILEIR_TO_MLIR_REVISION "7eeb1655cb4af986cc5aa53ca35ff87e7770d005"
     CACHE STRING "TileIRToMLIR revision")
 set(TILEIR_TO_MLIR_REVISION_SHA256
-    "f39644ec0eb4d98db8de6b8bcf51f82d67ea80081080e6c397695a20369eb0d4"
+    "c3946e02afeb443d4961dd81739f7d3fd3b94383871490df6f2cb2153b513c00"
     CACHE STRING "Expected SHA256 of the pinned TileIRToMLIR archive")
 
 set(CUDA_TILE_REPOSITORY "https://github.com/NVIDIA/cuda-tile"