68 lines
1.7 KiB
Plaintext
68 lines
1.7 KiB
Plaintext
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include::meta/VK_NV_compute_shader_derivatives.txt[]
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*Last Modified Date*::
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2018-07-19
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*IP Status*::
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No known IP claims.
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*Contributors*::
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- Pat Brown, NVIDIA
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This extension adds Vulkan support for the
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`SPV_NV_compute_shader_derivatives` SPIR-V extension.
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The SPIR-V extension provides two new execution modes, both of which allow
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compute shaders to use built-ins that evaluate compute derivatives
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explicitly or implicitly.
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Derivatives will be computed via differencing over a 2x2 group of shader
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invocations.
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The code:DerivativeGroupQuadsNV execution mode assembles shader invocations
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into 2x2 groups, where each group has x and y coordinates of the local
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invocation ID of the form (2m+{0,1}, 2n+{0,1}).
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The code:DerivativeGroupLinearNV execution mode assembles shader invocations
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into 2x2 groups, where each group has local invocation index values of the
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form 4m+{0,1,2,3}.
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=== New Object Types
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None.
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=== New Enum Constants
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* Extending elink:VkStructureType:
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** ename:VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_COMPUTE_SHADER_DERIVATIVES_FEATURES_NV
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=== New Enums
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None.
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=== New Structures
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* slink:VkPhysicalDeviceComputeShaderDerivativesFeaturesNV
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=== New Functions
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None.
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=== New SPIR-V Capability
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* <<spirvenv-capabilities-table-computederivatives-quads,ComputeDerivativeGroupQuadsNV>>
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* <<spirvenv-capabilities-table-computederivatives-linear,ComputeDerivativeGroupLinearNV>>
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=== Issues
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(1) Should we specify that the groups of four shader invocations used for
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derivatives in a compute shader are the same groups of four invocations
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that form a "quad" in shader subgroups?
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*RESOLVED*: Yes.
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=== Examples
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None.
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=== Version History
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* Revision 1, 2018-07-19 (Pat Brown)
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- Initial draft
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