dxil-spirv

This project aims to provide translation of DXIL (SM 6.x) shaders to SPIR-V which can be used in the vkd3d project, which implements D3D12 on top of Vulkan. Using dxbc-spirv it also handles legacy DXBC shaders.

Building

Dependencies

Check out submodules first with git submodule update --init --recursive. No external dependencies apart from the submodules are required to build.

This project implements a "small" LLVM C++ API subset which acts as a drop-in replacement for the full LLVM. It is possible to build against the true LLVM C++ API if llvm is checked out in external/llvm and -DDXIL_SPIRV_NATIVE_LLVM=ON CMake option is used. See checkout_llvm.sh script.

Build

Standard CMake build.

mkdir build
cd build
cmake .. -DCMAKE_BUILD_TYPE=Release
cmake --build . --config Release

Linking against dxil-spirv

Only the C API is installed and is expected to be kept ABI/API stable when it releases.

pkg-config

pkg-config dxil-spirv-c-shared --cflags --libs

CMake module

Something like:

find_package(dxil_spirv_c_shared)
if (dxil_spirv_c_shared_FOUND)
	message("Found dxil-spirv! Enabling DXIL support.")
	target_link_libraries(vkd3d-shader PRIVATE dxil-spirv-c-shared)
	target_compile_definitions(vkd3d-shader PRIVATE HAVE_DXIL_SPV)
	target_sources(vkd3d-shader PRIVATE vkd3d/libs/vkd3d-shader/dxil.c)
else()
	message("Did not find dxil-spirv :( Disabling DXIL support.")
endif()

Testing

The primary method of testing dxil-spirv and avoiding regressions is through a reference shader suite.

Build DXC

First, build DXC. To keep output consistent, we must use a fixed version of DXC. Currently, this only works on Linux, the Windows build of DXC does not seem to support CMake properly.

./checkout_dxc.sh
./build_dxc.sh

The test suite accepts an arbitrary path to DXC, so if you have a standalone binary somewhere, that can work as well.

Run test suite

When adding new tests, place the HLSL test in shaders/ somewhere and run:

./test_shaders.py shaders --dxc external/dxc-build/bin/dxc --dxil-spirv cmake-build-debug/dxil-spirv

If there is any mismatch, the test script will complain. If there are legitimate changes to be made, add --update to the command. The updated files should now be committed alongside the dxil-spirv change. --parallel can (and should) be used to speed up the process.

To update DXBC references, run:

./cmake-build-debug/dxbc-spirv-sandbox ./reference-dxbc

Running large repro suites

For internal development, we also have an extensive repro suite which cover real-world content. These cannot be made public for obvious reasons, so the intent is that symlinks are set up during development. Shaders can be dumped with VKD3D_SHADER_DUMP_PATH.

# The scripts might not work properly if the paths aren't laid out like this.
ln -s ${DXIL_SPIRV_REPO}/shaders shaders-dxil
ln -s ${DXBC_SPIRV_REPO}/shaders shaders-dxbc
ln -s ${DXIL_SPIRV_REPO}/reference/shaders reference/shaders-dxil
ln -s ${DXBC_SPIRV_REPO}/reference/shaders reference/shaders-dxbc

./test_shaders.py shaders-dxil --dxil-spirv cmake-build-release/dxil-spirv --parallel --update
./test_shaders.py shaders-dxbc --dxil-spirv cmake-build-release/dxil-spirv --parallel --update

To import shaders into the suite:

mkdir shaders-dxil/dxilgame
mkdir shaders-dxbc/dxbcgame
# For DXIL
./copy_reference_shaders.py --dxil /tmp/path/to/vkd3d-shader-dump-path --raw --output shaders-dxil/dxilgame
# For DXBC
./copy_reference_shaders.py --dxbc /tmp/path/to/vkd3d-shader-dump-path --raw --output shaders-dxbc/dxbcgame

To run an isolated subfolder only, there's --subfolder.

License

dxil-spirv is currently licensed as MIT. See LICENSE.MIT for more details.

/* Copyright (c) 2019-2025 Hans-Kristian Arntzen for Valve Corporation
 *
 * SPDX-License-Identifier: MIT
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 * a copy of this software and associated documentation files (the
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 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
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 */