CMake-only fork of https://dawn.googlesource.com/dawn with cleaned, vendored dependencies
4ae315b0d1
Certain Vulkan ICDs (Intel ones notably) will compile SPIR-V
shaders with an liberal, compiler-selected, subgroup size (i.e.
either 8, 16 or 32). For more context, see [1].
This can be a problem for compute, when one shader stores data
in device memory using a subgroup-size dependent layout, to be
consumed by a another shader. Problems arise when the compiler
decides to compile both shaders with different subgroup sizes.
To work-around this, the VK_EXT_subgroup_size_control device
extension was introduced recently: it allows the device to
report the min/max subgroup sizes it provides, and allows
the Vulkan program to control the subgroup size precisely
if it wants to.
This patch adds support to the Vulkan backend to report and
enable the extension if it is available. Note that:
- The corresponding VkStructureType enum values and
struct types are not rolled to the third-party Vulkan
headers used by Dawn yet, so vulkan_platform.h has been
modified to define them if necessary. This can be
removed in the future when the Vulkan-Headers are
updated in a different patch.
- This modifies VulkanDeviceInfo::GatherDeviceInfo() to
use VkGetPhysicalDevice{Properties2,Features2} if the
VK_KHR_get_device_properties2 instance extension is
available. Otherwise, the Vulkan 1.0 APIs
VkGetPhysicalDevice{Properties,Features} are used instead
(and it is assumed that no subgroup size control is
possible).
- This changes the definition of VulkanDeviceKnobs to
make room for the required pNext-linked chains of
extensions.
- A helper class, PNextChainBuilder is also provided in
UtilsVulkan.h to make it easy to build pNext-linked
extension struct chains at runtime, as required when
probing device propertires/features, or when
creating a new VkDevice handle.
Apart from that, there is no change in behaviour in this CL.
I.e. a later CL might force a specific subgroup size for
consistency, or introduce a new API to let Dawn clients
select a fixed subgroup size.
[1] https://bugs.freedesktop.org/show_bug.cgi?id=108875
Change-Id: I524af6ff3479f25b0a8bb139a062fe632c826893
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/16020
Reviewed-by: Austin Eng <enga@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Corentin Wallez <cwallez@chromium.org>
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| generator | ||
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| third_party | ||
| .clang-format | ||
| .gitattributes | ||
| .gitignore | ||
| .gn | ||
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| BUILD.gn | ||
| CMakeLists.txt | ||
| CONTRIBUTING.md | ||
| DEPS | ||
| LICENSE | ||
| OWNERS | ||
| PRESUBMIT.py | ||
| README.chromium | ||
| README.md | ||
| codereview.settings | ||
| dawn.json | ||
| dawn_wire.json | ||
README.md
Dawn, a WebGPU implementation
Dawn is an open-source and cross-platform implementation of the work-in-progress WebGPU standard.
More precisely it implements webgpu.h that is a one-to-one mapping with the WebGPU IDL.
Dawn is meant to be integrated as part of a larger system and is the underlying implementation of WebGPU in Chromium.
Dawn provides several WebGPU building blocks:
- WebGPU C/C++ headers that applications and other building blocks use.
- The
webgpu.hversion that Dawn implements. - A C++ wrapper for the
webgpu.h.
- The
- A "native" implementation of WebGPU using platforms' GPU APIs:
- D3D12 on Windows 10
- Metal on macOS and iOS
- Vulkan on Windows, Linux, ChromeOS, Android and Fuchsia
- OpenGL as best effort where available
- A client-server implementation of WebGPU for applications that are in a sandbox without access to native drivers
Helpful links:
- Dawn's bug tracker if you find issues with Dawn.
- Dawn's mailing list for other discussions related to Dawn.
- Dawn's source code
Documentation table of content
Developer documentation:
User documentation: (TODO, figure out what overlaps with webgpu.h docs)
Status
(TODO)
License
Apache 2.0 Public License, please see LICENSE.
Disclaimer
This is not an officially supported Google product.