Windows Support

TheRock aims to support as many subprojects as possible on "native" Windows (as opposed to WSL 1 or WSL 2) using standard build tools like MSVC.

Supported subprojects

ROCm is composed of many subprojects, some of which are supported on Windows:

• https://rocm.docs.amd.com/en/latest/what-is-rocm.html
• https://rocm.docs.amd.com/projects/install-on-windows/en/latest/conceptual/component-support.html
• https://rocm.docs.amd.com/projects/install-on-windows/en/latest/about/release-versioning.html#windows-builds-from-source

This table tracks current support status for each subproject in TheRock on Windows. Some subprojects may need extra patches to build within TheRock (on mainline, in open source, using MSVC, etc.).

Building TheRock from source

These instructions mostly mirror the instructions in the root README.md, with some extra Windows-specific callouts.

Validating your environment

Before diving into the full setup, you can run the environment validation script to check that all prerequisites are met:

.\build_tools\validate_windows_install.ps1

The script checks RAM, disk space, long path support, symlink capability, MSVC, CMake, Ninja, Git, Python, DVC, Strawberry Perl/gfortran, ccache, and git configuration. It is safe to re-run at any time.

Prerequisites

Set up your system

• You will need a powerful system with sufficient RAM (16GB+), CPU (8+ cores), and storage (200GB+) for a full source build. Partial source builds bootstrapped from prebuilt binaries are on our roadmap to enable.

  • To set expectations, on powerful build servers, the full source build can still take over an hour.

  • The Windows build uses hard links to save space, but storage sizes do not often account for this savings. Reported size used and actual size used may differ substantially.

• Long path support is required. There are a few ways to enable it:

  • Registry (most reliable): set HKLM\SYSTEM\CurrentControlSet\Control\FileSystem\LongPathsEnabled to 1 (requires admin):

    reg add HKLM\SYSTEM\CurrentControlSet\Control\FileSystem /v LongPathsEnabled /t REG_DWORD /d 1 /f
    

  • GUI toggle (Windows 11, after enabling Developer Mode): go to Settings > System > For developers and enable the "Enable Long Paths" toggle, then reboot. Note: this toggle may not appear until Developer Mode is on, and has been reported as unreliable on some systems — verify with the validation script after rebooting.

  • See also: https://learn.microsoft.com/en-us/windows/win32/fileio/maximum-file-path-limitation?tabs=registry#registry-setting-to-enable-long-paths

• There are some known issues with preexisting HIP SDK / ROCm installs causing errors during the build process. Until these are resolved, we recommend uninstalling the HIP SDK before trying to build TheRock.

• A Dev Drive is recommended, due to how many source and build files are used. See the Set up a Dev Drive on Windows 11 article for setup instructions.

• Symlink support is recommended. If symlink support is not enabled, enable developer mode and/or grant your account the "Create symbolic links" permission. These resources may help:

  • https://portal.perforce.com/s/article/3472
  • https://learn.microsoft.com/en-us/previous-versions/windows/it-pro/windows-10/security/threat-protection/security-policy-settings/create-symbolic-links
  • https://stackoverflow.com/a/59761201

• We recommend cmd or git bash over PowerShell. Some developers also report good experiences with Windows Terminal and Cmder.

Install tools

winget install --id Microsoft.VisualStudio.2022.BuildTools --source winget --override "--add Microsoft.VisualStudio.Component.VC.Tools.x86.x64 --add
Microsoft.VisualStudio.Component.VC.CMake.Project --add Microsoft.VisualStudio.Component.VC.ATL --add
Microsoft.VisualStudio.Component.Windows11SDK.22621"
winget install --id Git.Git -e --source winget --custom "/o:PathOption=CmdTools"
winget install cmake
winget install ninja-build.ninja ccache python strawberryperl bloodrock.pkg-config-lite
winget install --id Iterative.DVC --silent --accept-source-agreements

If you prefer to install tools manually, you will need:

• The MSVC compiler from https://visualstudio.microsoft.com/downloads/ (Using either "Visual Studio" or "Build Tools for Visual Studio"), including these components:

  • MSVC version 19.43+ (Visual Studio 2022 17.13+). Older versions will fail at link time because prebuilt libraries reference STL internals introduced in 19.43. See Issue#5029.
  • C++ CMake tools for Windows
  • C++ ATL
  • C++ AddressSanitizer (optional)

• Git: https://git-scm.com/downloads

  • With "Use Git and optional Unix tools from the Windows Command Prompt" as certain build scripts use Bash.

• CMake: https://cmake.org/download/

• Ninja: https://ninja-build.org/

• (Optional) ccache: https://ccache.dev/, or sccache: https://github.com/mozilla/sccache

• gfortran, recommended from Strawberry Perl: https://strawberryperl.com/

• nasm, recommended from Strawberry Perl: https://strawberryperl.com/

• patch, available in Strawberry Perl or Git.

• dvc: https://dvc.org/doc/install/windows

• Python: https://www.python.org/downloads/ (3.11+ recommended)

Important tool settings

git config --global core.symlinks true
git config --global core.longpaths true

Set the locale

If the build system is a non-English system. Make sure to switch to utf-8.

chcp 65001

Clone and fetch sources

# Clone the repository
git clone https://github.com/ROCm/TheRock.git
cd TheRock

# Init python virtual environment and install python dependencies
python -m venv .venv
.venv\Scripts\Activate.bat
pip install -r requirements.txt

# Download submodules and apply patches
python ./build_tools/fetch_sources.py

Build configuration

Unsupported subprojects like RCCL are automatically disabled on Windows. See the instructions in the root README for other options you may want to set.

cmake -B build -GNinja . -DTHEROCK_AMDGPU_FAMILIES=gfx110X-all

If iterating and wishes to use ccache, see CCache usage on Windows

-- The C compiler identification is MSVC 19.42.34436.0
-- The CXX compiler identification is MSVC 19.42.34436.0

CMake build usage

cmake --build build --target therock-artifacts therock-dist

This will start building using MSVC. Once the amd-llvm subproject is built, subprojects like the ROCm math libraries will be compiled using clang.exe and other tools from the amd-llvm toolchain.

When the builds complete, you should have a build of ROCm / the HIP SDK in build/dist/rocm/ and artifacts in build/artifacts. See the Build Artifacts guide for more information about the build outputs.

Building ROCm Python wheels

To build Python wheels, you will need an "artifacts" directory, either from a source build of therock-artifacts (see above) or by running the fetch_artifacts.py script to download artifacts from a CI run.

Once you have an artifacts directory, you can run the build_python_packages.py script.

Building PyTorch

PyTorch builds require Python wheels, either by building from source (see above) or by downloading from one of TheRock's release indices. See the instructions at external-builds/pytorch.

Run tests

Test builds can be enabled with -DBUILD_TESTING=ON (the default).

Some subproject tests have been validated on Windows, like rocPRIM:

ctest --test-dir build/math-libs/rocPRIM/dist/bin/rocprim --output-on-failure

Build troubleshooting and known issues

No such file or directory: (long path to a source file)

If the build looks for a source file with a long path that does not exist, ensure that you have long path support enabled in git (see Important tool settings), then re-run

python ./build_tools/fetch_sources.py

Once the git operations have run with the new setting, confirm that the missing files now exist.

error: directive requires gfx90a+

Errors like this indicate that the value of -DTHEROCK_AMDGPU_FAMILIES= or -DTHEROCK_AMDGPU_TARGETS= is currently unsupported by one or more libraries.

lld-link: m.lib does not exist

Since msvc 14+, m.lib has become an implicit dependency and should not be linked (it does not exist). TheRock does not link it, but cmake could decide on its own to try and link it because it found a libm.a in the path, coming from leftover installs on the build machine, like a w64devkit or msys2 install.

lld-link: error: duplicate symbol

Several developers have reported link errors in rocBLAS and rocSPARSE like

[rocSPARSE] lld-link: error: duplicate symbol: __hip_cuid_2f7b343d50a9613
[rocSPARSE] >>> defined at library/CMakeFiles/rocsparse.dir/src/level3/csrmm/row_split/csrmm_device_row_split_256_16_8_3_4.cpp.obj
[rocSPARSE] >>> defined at library/CMakeFiles/rocsparse.dir/src/level3/csrmm/row_split/csrmm_device_row_split_256_16_8_7_4.cpp.obj

[rocBLAS] lld-link: error: duplicate symbol: rocblas_stbsv_batched
[rocBLAS] >>> defined at library/src/CMakeFiles/rocblas.dir/blas2/rocblas_tbsv_batched.cpp.obj
[rocBLAS] >>> defined at library/src/CMakeFiles/rocblas.dir/handle.cpp.obj
[rocBLAS]
[rocBLAS] lld-link: error: duplicate symbol: rocblas_dtbsv_batched
[rocBLAS] >>> defined at library/src/CMakeFiles/rocblas.dir/blas2/rocblas_tbsv_batched.cpp.obj
[rocBLAS] >>> defined at library/src/CMakeFiles/rocblas.dir/handle.cpp.obj
[rocBLAS]
[rocBLAS] lld-link: error: duplicate symbol: __hip_cuid_a201499d9a86b1da

These have been worked around by disabling ccache.

pyYAML cannot be found by cmake

It is recommended to build TheRock using the .venv python3 virtual environment. The build steps explain that you must do a pip install -r requirements.txt that installs PyYAML in the venv so maybe this step was not done.

The problem can also be that you have another python install available in your path and that cmake chose to use it. Make sure to check which python points to the python in your .venv

gfortran cannot be found by cmake

If you have installed strawberry perl as recommended but gfortran cannot be found by cmake, you can create a FC environment variable pointing to where gfortran.exe is located.

Other notes

Platform support lessons, tips, and gotchas

Filesystem paths

• Windows paths may have spaces in them, so properly quote paths
• Windows paths may use \ instead of / as a component delimiter
  • The \ character is often an escape character in raw strings, so properly escape paths if passing them between systems
  • In Python, pathlib has good support for performing transformations on paths like joining or splitting components in a cross-platform way, but some outgoing uses still need to use .resolve(), .as_posix(), and other functions to resolve symlinks, convert slashes, etc.
  • In C++, <filesystem> has good support for performing transformations on paths like joining or splitting components in a cross-platform way. See https://github.com/ROCm/rocm-libraries/pull/948 for example.
  • In CMake, take care when loading environment variables into strings and treating them as paths. Use https://cmake.org/cmake/help/latest/command/file.html#path-conversion and https://cmake.org/cmake/help/latest/command/cmake_path.html instead of working with strings directly, like so:

    -set(HIP_PATH $ENV{HIP_PATH})
    +file(TO_CMAKE_PATH "$ENV{HIP_PATH}" HIP_PATH)`
    

• Windows paths (and commands) can have max length limitations, so avoid long file names
• Windows paths do not allow some characters (https://learn.microsoft.com/en-us/windows/win32/fileio/naming-a-file)

Other platform differences

• Symlink support on Windows is not always available
• Windows uses [library].dll files instead of lib[library].so files, which use different APIs for loading/linking (and have different versioning in the file names too). CMake can use https://cmake.org/cmake/help/latest/variable/CMAKE_SHARED_LIBRARY_PREFIX.html and https://cmake.org/cmake/help/latest/variable/CMAKE_SHARED_LIBRARY_SUFFIX.html
• Windows uses the .exe extension for executables while Linux uses files with no suffix. CMake can use https://cmake.org/cmake/help/latest/variable/CMAKE_EXECUTABLE_SUFFIX.html
• GitHub actions can use bash.exe, cmd.exe, and powershell on Windows. Switching workflows to use Python scripts helps a bit, but some actions / steps / tools / scripts still expect paths in a certain format or with a certain escaping style, or expect certain tools to be available (e.g. sed, grep)

Building CLR from partial sources

We are working on enabling flexible open source builds of https://github.com/ROCm/clr (notably for amdhip64_7.dll) on Windows. Historically this has been a closed source component due to the dependency on Platform Abstraction Library (PAL) and providing a fully open source build will take more time. As an incremental step towards a fully open source build, we are using an interop folder containing header files and static library .lib files for PAL and related components.

An incremental rollout is planned:

1. The interop folder must be manually copied into place in the source tree. This will allow AMD developers to iterate on integration into TheRock while we work on making this folder or more source files available.
2. The interop folder will be available publicly (currently at https://github.com/ROCm/rocm-systems/tree/develop/shared/amdgpu-windows-interop).
3. (We are here today) The interop folder will be included automatically from a git repository using dvc.
4. A more permanent open source strategy for building the CLR (the HIP runtime) from source on Windows will eventually be available.

If configured correctly, outputs like build/core/clr/dist/bin/amdhip64_6.dll should be generated by the build.

If the interop folder is not available, sub-project support is limited and features should be turned off:

-DTHEROCK_ENABLE_CORE=OFF \
-DTHEROCK_ENABLE_MATH_LIBS=OFF \
-DTHEROCK_ENABLE_ML_LIBS=OFF \