Add support building llvmlite wheels for Windows ARM64

.github/workflows/llvmlite/bld_llvm_winarm64.bat

@@ -0,0 +1,81 @@
+@echo off
+setlocal enabledelayedexpansion
+
+set "LLVM_VERSION=20.1.8"
+set "WORKSPACE=%CD%"
+set "LLVM_SRC_DIR=%WORKSPACE%\llvm-project-%LLVM_VERSION%"
+set "BUILD_DIR=%WORKSPACE%\build-arm64"
+set "INSTALL_PREFIX=%WORKSPACE%\llvm-arm64-install"
+
+REM Use existing vcpkg from runner
+if not defined VCPKG_INSTALLATION_ROOT set "VCPKG_INSTALLATION_ROOT=C:\vcpkg"
+set "VCPKG_DIR=%VCPKG_INSTALLATION_ROOT%"
+
+REM Setup VS2022 ARM64 environment
+call "C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Auxiliary\Build\vcvarsall.bat" arm64
+
+REM Install dependencies using vcpkg
+"%VCPKG_DIR%\vcpkg.exe" install zlib:arm64-windows-static zstd:arm64-windows-static libxml2:arm64-windows-static
+
+REM Download and extract LLVM source
+if not exist "%LLVM_SRC_DIR%\llvm" (
+    if not exist "llvm-project-%LLVM_VERSION%.src.tar.xz" (
+        curl -L -o "llvm-project-%LLVM_VERSION%.src.tar.xz" "https://github.com/llvm/llvm-project/releases/download/llvmorg-%LLVM_VERSION%/llvm-project-%LLVM_VERSION%.src.tar.xz"
+    )
+    tar -xf "llvm-project-%LLVM_VERSION%.src.tar.xz"
+    if exist "llvm-project-%LLVM_VERSION%.src" move "llvm-project-%LLVM_VERSION%.src" "llvm-project-%LLVM_VERSION%"
+)
+
+REM Configure
+if exist "%BUILD_DIR%" rmdir /S /Q "%BUILD_DIR%"
+mkdir "%BUILD_DIR%"
+cd /d "%BUILD_DIR%"
+
+cmake -G "Ninja" ^
+    -DCMAKE_BUILD_TYPE=Release ^
+    -DCMAKE_INSTALL_PREFIX=%INSTALL_PREFIX% ^
+    -DCMAKE_TOOLCHAIN_FILE=%VCPKG_DIR%\scripts\buildsystems\vcpkg.cmake ^
+    -DVCPKG_TARGET_TRIPLET=arm64-windows-static ^
+    -DLLVM_USE_INTEL_JITEVENTS=OFF ^
+    -DLLVM_ENABLE_LIBXML2=FORCE_ON ^
+    -DLLVM_ENABLE_RTTI=OFF ^
+    -DLLVM_ENABLE_ZLIB=FORCE_ON ^
+    -DLLVM_ENABLE_ZSTD=FORCE_ON ^
+    -DLLVM_INCLUDE_BENCHMARKS=OFF ^
+    -DLLVM_INCLUDE_DOCS=OFF ^
+    -DLLVM_INCLUDE_EXAMPLES=OFF ^
+    -DLLVM_INCLUDE_TESTS=ON ^
+    -DLLVM_INCLUDE_UTILS=ON ^
+    -DLLVM_INSTALL_UTILS=ON ^
+    -DLLVM_UTILS_INSTALL_DIR=libexec/llvm ^
+    -DLLVM_BUILD_LLVM_C_DYLIB=no ^
+    -DLLVM_EXPERIMENTAL_TARGETS_TO_BUILD=WebAssembly ^
+    -DCMAKE_POLICY_DEFAULT_CMP0111=NEW ^
+    -DLLVM_ENABLE_PROJECTS:STRING=lld;compiler-rt ^
+    -DLLVM_ENABLE_ASSERTIONS=ON ^
+    -DLLVM_ENABLE_DIA_SDK=OFF ^
+    -DCOMPILER_RT_BUILD_BUILTINS=OFF ^
+    -DCOMPILER_RT_BUILTINS_HIDE_SYMBOLS=OFF ^
+    -DCOMPILER_RT_BUILD_LIBFUZZER=OFF ^
+    -DCOMPILER_RT_BUILD_CRT=OFF ^
+    -DCOMPILER_RT_BUILD_MEMPROF=OFF ^
+    -DCOMPILER_RT_BUILD_PROFILE=OFF ^
+    -DCOMPILER_RT_BUILD_SANITIZERS=OFF ^
+    -DCOMPILER_RT_BUILD_XRAY=OFF ^
+    -DCOMPILER_RT_BUILD_GWP_ASAN=OFF ^
+    -DCOMPILER_RT_BUILD_ORC=OFF ^
+    -DCOMPILER_RT_INCLUDE_TESTS=OFF ^
+    "%LLVM_SRC_DIR%\llvm"
+
+if !ERRORLEVEL! neq 0 exit /B 1
+
+REM Build
+cmake --build . --config Release
+if !ERRORLEVEL! neq 0 exit /B 1
+
+REM Install
+cmake --build . --target install --config Release
+if !ERRORLEVEL! neq 0 exit /B 1
+
+cd /d "%WORKSPACE%"
+exit /B 0

.github/workflows/llvmlite/llvmdev_build.yml

@@ -0,0 +1,65 @@
+name: llvmdev
+
+on:
+  pull_request:
+    paths:
+      - .github/workflows/llvmlite/llvmdev_build.yml
+  label:
+    types: [created]
+  workflow_dispatch:
+    inputs:
+      platform:
+        description: LLVM DEV for Windows ARM64
+        default: all
+        required: true
+        type: choice
+        options:
+          - win-arm64
+      recipe:
+        description: Recipe to build
+        default: all
+        required: true
+        type: choice
+        options:
+          - llvmdev_for_wheel
+
+env:
+  ARTIFACT_RETENTION_DAYS: 30
+
+jobs:
+  build:
+    name:  llvmdev_for_wheel-win-arm64
+    runs-on: windows-11-arm
+    defaults:
+      run:
+        shell: bash -el {0}
+    strategy:
+      fail-fast: false
+
+    steps:
+      - name: Checkout main branch
+        uses: actions/checkout@v5
+
+      - name: Build LLVM package - Windows ARM64 platform
+        shell: cmd
+        env:
+          ARTIFACT_DIR: llvm_arm64_artifact
+        run: |
+          call "%GITHUB_WORKSPACE%\.github\workflows\llvmlite\bld_llvm_winarm64.bat"
+          if %ERRORLEVEL% neq 0 exit /B %ERRORLEVEL%
+          mkdir "%ARTIFACT_DIR%"
+          xcopy /E /I /Y llvm-arm64-install "%ARTIFACT_DIR%\llvm-arm64-install"
+
+      - name: Upload Windows ARM64 LLVM artifacts
+        uses: actions/upload-artifact@b7c566a772e6b6bfb58ed0dc250532a479d7789f # v6.0.0
+        with:
+          name: llvmdev_for_wheel-win-arm64
+          path: llvm_arm64_artifact
+          compression-level: 0
+          retention-days: ${{ env.ARTIFACT_RETENTION_DAYS }}
+          if-no-files-found: error      
+
+      - name: Get Workflow Run ID
+        run: |
+          echo "Current workflow run ID: ${{ github.run_id }}"
+          echo "Use this ID when triggering llvmlite workflow"

.github/workflows/llvmlite/patches/0001-Support-LLVMlite-on-Windows-ARM64.patch

@@ -0,0 +1,72 @@
+From a1d77515c87e40ca9ec75ed52fcea0063211edb9 Mon Sep 17 00:00:00 2001
+From: MugundanMCW <mugunthan.selvanayagam@multicorewareinc.com>
+Date: Wed, 28 Jan 2026 09:20:06 +0530
+Subject: [PATCH] Support LLVMlite on Windows ARM64
+
+---
+ ffi/build.py | 27 +++++++++++++++++++++------
+ 1 file changed, 21 insertions(+), 6 deletions(-)
+
+diff --git a/ffi/build.py b/ffi/build.py
+index ef0c2625..c03eda40 100755
+--- a/ffi/build.py
++++ b/ffi/build.py
+@@ -12,15 +12,22 @@ import shutil
+ import sys
+ import tempfile
+ import warnings
+-
++import platform
+
+ here_dir = os.path.abspath(os.path.dirname(__file__))
+ build_dir = os.path.join(here_dir, 'build')
+ target_dir = os.path.join(os.path.dirname(here_dir), 'llvmlite', 'binding')
+
+-
+-is_64bit = sys.maxsize >= 2**32
+-
++is_windows = sys.platform == "win32"
++is_arm64 = False
++is_64bit = False
++if is_windows:
++    machine = platform.machine().lower()
++    if machine in ("arm64", "aarch64"):
++        is_arm64 = True
++    elif machine in ("amd64", "x86_64"):
++        is_64bit = True
++        
+
+ def env_var_options_to_cmake_options():
+     # This is not ideal, it exists to put env var options into CMake. Whilst it
+@@ -146,15 +153,22 @@ def find_windows_generator():
+         generators.append(
+             (env_generator, env_arch, env_toolkit)
+         )
++    if is_arm64:
++        arch = "ARM64"
++    elif is_64bit:
++        arch = "x64"
++    else:
++        arch = "Win32"
+
+     generators.extend([
+         # use VS2022 first
+-        ('Visual Studio 17 2022', ('x64' if is_64bit else 'Win32'), 'v143'),
++        ('Visual Studio 17 2022', arch, 'v143'),
+         # try VS2019 next
+-        ('Visual Studio 16 2019', ('x64' if is_64bit else 'Win32'), 'v142'),
++        ('Visual Studio 16 2019', arch, 'v142'),
+         # # This is the generator configuration for VS2017
+         # ('Visual Studio 15 2017' + (' Win64' if is_64bit else ''), None, None)
+     ])
++
+     for generator in generators:
+         build_dir = tempfile.mkdtemp()
+         print("Trying generator %r" % (generator,))
+@@ -207,3 +221,4 @@ def main():
+
+ if __name__ == "__main__":
+     main()
++
+-- 
+2.43.0

.github/workflows/llvmlite_win-arm64_wheel_builder.yml

@@ -0,0 +1,110 @@
+name: llvmlite_win-arm64_wheel_builder
+
+on:
+  pull_request:
+    paths:
+      - .github/workflows/llvmlite_win-arm64_wheel_builder.yml
+  workflow_dispatch:
+    inputs:
+      llvmdev_run_id:
+        description: 'llvmdev workflow run ID (optional)'
+        required: false
+        type: string
+      upload_wheel_to_anaconda:
+        description: 'Upload wheel to Anaconda Cloud - numba channel'
+        required: false
+        type: boolean
+        default: false
+
+env:
+  VALIDATION_PYTHON_VERSION: "3.12"
+  ARTIFACT_RETENTION_DAYS: 7
+
+jobs:
+  win-arm64-build:
+    name: win-arm64-build
+    runs-on: windows-11-arm
+    defaults:
+      run:
+        shell: cmd
+    strategy:
+      matrix:
+        python-version: ["3.11", "3.12", "3.13", "3.14"]
+      fail-fast: false
+
+    steps:
+      - name: Checkout PyEnv-WoA-State repository
+        uses: actions/checkout@v4
+
+      - name: Clone llvmlite repository
+        run: |
+          git clone https://github.com/numba/llvmlite.git llvmlite_src
+          cd llvmlite_src
+          git apply "%GITHUB_WORKSPACE%\.github\workflows\llvmlite\patches\0001-Support-LLVMlite-on-Windows-ARM64.patch"
+
+      - name: Setup Python
+        uses: actions/setup-python@83679a892e2d95755f2dac6acb0bfd1e9ac5d548
+        with:
+          python-version: ${{ matrix.python-version }}
+          allow-prereleases: true
+
+      - name: Download llvmdev Artifact
+        if: ${{ inputs.llvmdev_run_id != '' }}
+        uses: actions/download-artifact@37930b1c2abaa49bbe596cd826c3c89aef350131
+        with:
+          name: llvmdev_for_wheel-win-arm64
+          path: llvm_install
+          run-id: ${{ inputs.llvmdev_run_id }}
+          repository: ${{ github.repository }}
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Cache vcpkg installed packages
+        uses: actions/cache@v4
+        with:
+          path: C:\vcpkg\installed
+          key: vcpkg-installed-windows-arm64-static-v1
+          restore-keys: |
+            vcpkg-installed-windows-arm64-static
+
+      - name: Install build dependencies
+        env:
+          VCPKG_DIR: C:\vcpkg
+        run: |
+          "%VCPKG_DIR%\vcpkg.exe" install zlib:arm64-windows-static zstd:arm64-windows-static libxml2:arm64-windows-static
+          python -m pip install build wheel setuptools delvewheel
+
+      - name: Build wheel
+        working-directory: llvmlite_src
+        env:
+          CMAKE_ARGS: -DCMAKE_PREFIX_PATH=C:\vcpkg\installed\arm64-windows-static
+          LLVM_DIR: ${{ github.workspace }}\llvm_install\llvm-arm64-install\lib\cmake\llvm
+          LLVMLITE_PACKAGE_FORMAT: "wheel"
+        run: python -m build --wheel --no-isolation
+
+      - name: Repair wheel with delvewheel
+        run: |
+          if not exist wheel_temp mkdir wheel_temp
+          move llvmlite_src\dist\*.whl wheel_temp\
+          python -m delvewheel repair --analyze-existing -w dist wheel_temp\*.whl
+          dir dist
+
+      - name: Upload llvmlite wheel
+        uses: actions/upload-artifact@b7c566a772e6b6bfb58ed0dc250532a479d7789f
+        with:
+          name: llvmlite-win-arm64-py${{ matrix.python-version }}
+          path: dist/*.whl
+          compression-level: 0
+          retention-days: ${{ env.ARTIFACT_RETENTION_DAYS }}
+          if-no-files-found: error
+
+      - name: Create GitHub Release
+        if: github.event_name == 'workflow_dispatch'
+        uses: softprops/action-gh-release@v2
+        with:
+          tag_name: llvmlite-win-arm64-${{ github.run_number }}
+          name: llvmlite Windows ARM64 Wheels - Build ${{ github.run_number }}
+          prerelease: true
+          files: dist/*.whl
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+