Build instructions for Windows (#3584)

Fixes #3127.

.github/README.md

@@ -22,6 +22,8 @@ Intel® XPU Backend for Triton\* is a out of tree backend module for [Triton](ht
 
 Note that Intel® XPU Backend for Triton\* is not compatible with Intel® Extension for PyTorch\* and Intel® oneAPI Base Toolkit\*.
 
+See also: [experimental support for Windows](WINDOWS.md).
+
 # Quick Installation
 
 ## Prerequisites

.github/WINDOWS.md

@@ -0,0 +1,193 @@
+# Intel® XPU Backend for Triton\* on Windows
+
+Intel® XPU Backend for Triton\* support for Windows is currently experimental and requires compiling PyTorch and Intel® XPU Backend for Triton\* from source.
+
+## 1. Prerequisites
+
+* Windows 11
+
+* GPU card
+  * Intel® Arc™ A-Series Graphics for Desktops
+    * [Intel® Arc™ A750](https://www.intel.com/content/www/us/en/products/sku/227954/intel-arc-a750-graphics/specifications.html)
+    * [Intel® Arc™ A770](https://www.intel.com/content/www/us/en/products/sku/229151/intel-arc-a770-graphics-16gb/specifications.html)
+  * Intel® Arc™ B-Series Graphics for Desktops
+    * [Intel® Arc™ B570](https://www.intel.com/content/www/us/en/products/sku/241676/intel-arc-b570-graphics/specifications.html)
+    * [Intel® Arc™ B580](https://www.intel.com/content/www/us/en/products/sku/241598/intel-arc-b580-graphics/specifications.html)
+
+* Latest [GPU driver](https://www.intel.com/content/www/us/en/download/785597/intel-arc-iris-xe-graphics-windows.html)
+
+In the following sections, all commands need to be executed in [PowerShell](https://learn.microsoft.com/en-us/powershell/scripting/install/installing-powershell-on-windows?view=powershell-7.5).
+
+## 2. Tools and dependencies
+
+### Enable Windows long paths
+
+Enable long paths for Windows file system.
+
+```
+Set-ItemProperty -Path 'HKLM:\SYSTEM\CurrentControlSet\Control\FileSystem' -Name 'LongPathsEnabled' -Value 1
+```
+
+Reboot your computer to apply the change to the file system.
+
+### Microsoft Visual Studio 2022
+
+Install Microsoft Visual Studio 2022 and make sure the following [components](https://learn.microsoft.com/en-us/visualstudio/install/workload-component-id-vs-community?view=vs-2022&preserve-view=true) are installed:
+  * Microsoft.VisualStudio.Component.VC.Tools.x86.x64
+  * Microsoft.VisualStudio.Component.Windows11SDK.22621
+  * Microsoft.VisualStudio.Component.VC.CMake.Project
+
+### Intel® Deep Learning Essentials
+
+Install the latest [Intel® Deep Learning Essentials](https://www.intel.com/content/www/us/en/developer/tools/oneapi/base-toolkit-download.html?packages=dl-essentials&dl-essentials-os=windows&dl-win=offline).
+By default, it is installed to `C:\Program Files (x86)\Intel\oneAPI`.
+
+### Level Zero SDK
+
+Identify Level Zero version installed with the GPU Driver:
+
+```shell
+(Get-Item C:\Windows\system32\ze_loader.dll).VersionInfo.ProductVersion
+```
+
+Find the corresponding release in https://github.com/oneapi-src/level-zero/releases, download its archive and extract to `c:\level_zero` or other location.
+
+### Chocolatey
+
+```
+Invoke-Expression ((New-Object System.Net.WebClient).DownloadString('https://community.chocolatey.org/install.ps1'))
+```
+
+Restart your PowerShell session to make sure `chocolatey` is properly initialized.
+
+### Python
+
+If you do not have a system Python installed at this step, you can install one with `chocolatey`.
+For example:
+
+```
+choco install python --version=3.9.13
+```
+
+### Git
+
+Install `git` with other POSIX tools, such as `bash`:
+
+```
+choco install -y git.install --params "'/GitAndUnixToolsOnPath /WindowsTerminal /NoAutoCrlf'"
+```
+
+Restart your PowerShell session to make sure `git` and other tools are properly initialized.
+
+Enable symbolic links and long paths:
+
+```
+git config --global core.longpaths true
+git config --global core.symlinks true
+```
+
+### Ninja
+
+```
+choco install -y ninja
+```
+
+### Pscx
+
+The module [Pscx](https://github.com/Pscx/Pscx) is required for `Invoke-BatchFile`, a command to call bat/cmd script and set environment variables in the existing PowerShell session.
+
+```
+Install-PackageProvider -Name NuGet -MinimumVersion 2.8.5.201 -Force
+Install-Module Pscx -Scope CurrentUser -Force -AllowClobber
+```
+
+## 3. Build environment
+
+Clone repository:
+
+```
+git clone https://github.com/intel/intel-xpu-backend-for-triton.git
+```
+
+Create a new virtual environment:
+
+```
+cd intel-xpu-backend-for-triton
+python -m venv .venv
+```
+
+
+## 4. PyTorch
+
+Activate the virtual environment:
+
+```
+.venv\Scripts\activate.ps1
+```
+
+Initialize Intel® Deep Learning Essentials, for example:
+
+```
+Invoke-BatchFile "C:\Program Files (x86)\Intel\oneAPI\setvars.bat"
+```
+
+Set `ZE_PATH` to the location of Level Zero SDK, for example:
+
+```
+$env:ZE_PATH = "C:\level_zero"
+```
+
+Build and install PyTorch:
+
+```
+$env:CMAKE_SHARED_LINKER_FLAGS = "/FORCE:MULTIPLE"
+$env:CMAKE_MODULE_LINKER_FLAGS = "/FORCE:MULTIPLE"
+$env:CMAKE_EXE_LINKER_FLAGS = "/FORCE:MULTIPLE"
+bash -c "./scripts/install-pytorch.sh --source"
+```
+
+Check that PyTorch is installed:
+
+```
+python -c 'import torch;print(torch.__version__)'
+```
+
+## 5. Triton
+
+Install build dependencies:
+
+```
+pip install -U wheel pybind11 cython cmake 'setuptools>=65.6.1'
+```
+
+Build and install Triton:
+
+```
+cd python
+pip install -v --no-build-isolation '.[build,tests,tutorials]'
+cd ..
+```
+
+Check that Triton is installed:
+
+```
+python -c 'import triton; print(triton.__version__)'
+```
+
+## 6. New PowerShell session
+
+In a new PowerShell session, make sure the current directory is `intel-xpu-backend-for-triton` (a clone of the repository).
+Initialize environment variables:
+
+```
+.venv\Scripts\activate.ps1
+Invoke-BatchFile "C:\Program Files (x86)\Intel\oneAPI\setvars.bat"
+$env:ZE_PATH = "C:\level_zero"
+```
+
+Check that PyTorch and Triton are available:
+
+```
+python -c 'import torch;print(torch.__version__)'
+python -c 'import triton; print(triton.__version__)'
+```