Vulkan-Docs/appendices/spirvenv.txt

// Copyright (c) 2015-2018 Khronos Group. This work is licensed under a
// Creative Commons Attribution 4.0 International License; see
// http://creativecommons.org/licenses/by/4.0/

[appendix]
[[spirvenv]]
= Vulkan Environment for SPIR-V

Shaders for Vulkan are defined by the <<spirv-spec,Khronos SPIR-V
Specification>> as well as the <<spirv-extended,Khronos SPIR-V Extended
Instructions for GLSL>> Specification.
This appendix defines additional SPIR-V requirements applying to Vulkan
shaders.

== Versions and Formats

ifdef::VK_VERSION_1_1[]
A Vulkan 1.1 implementation must: support the 1.0, 1.1, 1.2, and 1.3
versions of SPIR-V and the 1.0 version of the SPIR-V Extended Instructions
for GLSL.
endif::VK_VERSION_1_1[]
ifndef::VK_VERSION_1_1[]
A Vulkan 1.0 implementation must: support the 1.0 version of SPIR-V and the
1.0 version of the SPIR-V Extended Instructions for GLSL.
endif::VK_VERSION_1_1[]

A SPIR-V module passed into flink:vkCreateShaderModule is interpreted as a
series of 32-bit words in host endianness, with literal strings packed as
described in section 2.2 of the SPIR-V Specification.
The first few words of the SPIR-V module must: be a magic number and a
SPIR-V version number, as described in section 2.3 of the SPIR-V
Specification.


[[spirvenv-capabilities]]
== Capabilities

The SPIR-V capabilities listed below must: be supported if the corresponding
feature or extension is enabled, or if no features or extensions are listed
for that capability.
Extensions are only listed when there is not also a feature bit associated
with that capability.

[[spirvenv-capabilities-table]]
.List of SPIR-V Capabilities and enabling features or extensions
[options="header"]
|====
| SPIR-V code:OpCapability                | Vulkan feature or extension name

| code:Matrix                             |
| code:Shader                             |
| code:InputAttachment                    |
| code:Sampled1D                          |
| code:Image1D                            |
| code:SampledBuffer                      |
| code:ImageBuffer                        |
| code:ImageQuery                         |
| code:DerivativeControl                  |
| code:Geometry                           | <<features-features-geometryShader,geometryShader>>
| code:Tessellation                       | <<features-features-tessellationShader,tessellationShader>>
| code:Float64                            | <<features-features-shaderFloat64,shaderFloat64>>
| code:Int64                              | <<features-features-shaderInt64,shaderInt64>>
ifdef::VK_KHR_shader_atomic_int64[]
[[spirvenv-capabilities-table-int64atomics]]
| code:Int64Atomics                       | <<VK_KHR_shader_atomic_int64,VK_KHR_shader_atomic_int64>>
endif::VK_KHR_shader_atomic_int64[]
| code:Int16                              | <<features-features-shaderInt16,shaderInt16>>
| code:TessellationPointSize              | <<features-features-shaderTessellationAndGeometryPointSize,shaderTessellationAndGeometryPointSize>>
| code:GeometryPointSize                  | <<features-features-shaderTessellationAndGeometryPointSize,shaderTessellationAndGeometryPointSize>>
| code:ImageGatherExtended                | <<features-features-shaderImageGatherExtended,shaderImageGatherExtended>>
| code:StorageImageMultisample            | <<features-features-shaderStorageImageMultisample,shaderStorageImageMultisample>>
| code:UniformBufferArrayDynamicIndexing  | <<features-features-shaderUniformBufferArrayDynamicIndexing,shaderUniformBufferArrayDynamicIndexing>>
| code:SampledImageArrayDynamicIndexing   | <<features-features-shaderSampledImageArrayDynamicIndexing,shaderSampledImageArrayDynamicIndexing>>
| code:StorageBufferArrayDynamicIndexing  | <<features-features-shaderStorageBufferArrayDynamicIndexing,shaderStorageBufferArrayDynamicIndexing>>
| code:StorageImageArrayDynamicIndexing   | <<features-features-shaderStorageImageArrayDynamicIndexing,shaderStorageImageArrayDynamicIndexing>>
| code:ClipDistance                       | <<features-features-shaderClipDistance,shaderClipDistance>>
| code:CullDistance                       | <<features-features-shaderCullDistance,shaderCullDistance>>
| code:ImageCubeArray                     | <<features-features-imageCubeArray,imageCubeArray>>
| code:SampleRateShading                  | <<features-features-sampleRateShading,sampleRateShading>>
| code:SparseResidency                    | <<features-features-shaderResourceResidency,shaderResourceResidency>>
| code:MinLod                             | <<features-features-shaderResourceMinLod,shaderResourceMinLod>>
| code:SampledCubeArray                   | <<features-features-imageCubeArray,imageCubeArray>>
| code:ImageMSArray                       | <<features-features-shaderStorageImageMultisample,shaderStorageImageMultisample>>
| code:StorageImageExtendedFormats        | <<features-features-shaderStorageImageExtendedFormats,shaderStorageImageExtendedFormats>>
| code:InterpolationFunction              | <<features-features-sampleRateShading,sampleRateShading>>
| code:StorageImageReadWithoutFormat      | <<features-features-shaderStorageImageReadWithoutFormat,shaderStorageImageReadWithoutFormat>>
| code:StorageImageWriteWithoutFormat     | <<features-features-shaderStorageImageWriteWithoutFormat,shaderStorageImageWriteWithoutFormat>>
| code:MultiViewport                      | <<features-features-multiViewport,multiViewport>>
ifdef::VK_VERSION_1_1,VK_KHR_shader_draw_parameters[]
| code:DrawParameters                     |
ifdef::VK_VERSION_1_1[]
<<features-features-shaderDrawParameters,shaderDrawParameters>>
endif::VK_VERSION_1_1[]
ifdef::VK_KHR_shader_draw_parameters+VK_VERSION_1_1[]
or
endif::VK_KHR_shader_draw_parameters+VK_VERSION_1_1[]
ifdef::VK_KHR_shader_draw_parameters[]
<<VK_KHR_shader_draw_parameters>>
endif::VK_KHR_shader_draw_parameters[]
endif::VK_VERSION_1_1,VK_KHR_shader_draw_parameters[]
ifdef::VK_VERSION_1_1,VK_KHR_multiview[]
[[spirvenv-capabilities-multiview]]
| code:MultiView                          |
ifndef::VK_VERSION_1_1[]
<<VK_KHR_multiview,VK_KHR_multiview>>
endif::VK_VERSION_1_1[]
endif::VK_VERSION_1_1,VK_KHR_multiview[]
ifdef::VK_VERSION_1_1,VK_KHR_device_group[]
| code:DeviceGroup                        |
ifndef::VK_VERSION_1_1[]
<<VK_KHR_device_group,VK_KHR_device_group>>
endif::VK_VERSION_1_1[]
endif::VK_VERSION_1_1,VK_KHR_device_group[]
ifdef::VK_VERSION_1_1,VK_KHR_variable_pointers[]
[[spirvenv-capabilities-table-variablepointers]]
| code:VariablePointersStorageBuffer      | <<features-features-variablePointersStorageBuffer,variablePointersStorageBuffer>>
| code:VariablePointers                   | <<features-features-variablePointers,variablePointers>>
endif::VK_VERSION_1_1,VK_KHR_variable_pointers[]
ifdef::VK_EXT_shader_stencil_export[]
[[spirvenv-capabilities-table-shaderstencilexportext]]
| code:StencilExportEXT                   | `<<VK_EXT_shader_stencil_export>>`
endif::VK_EXT_shader_stencil_export[]
ifdef::VK_EXT_shader_subgroup_ballot[]
[[spirvenv-capabilities-table-subgroupballot]]
| code:SubgroupBallotKHR                  | `<<VK_EXT_shader_subgroup_ballot>>`
endif::VK_EXT_shader_subgroup_ballot[]
ifdef::VK_EXT_shader_subgroup_vote[]
[[spirvenv-capabilities-table-subgroupvote]]
| code:SubgroupVoteKHR                    | `<<VK_EXT_shader_subgroup_vote>>`
endif::VK_EXT_shader_subgroup_vote[]
ifdef::VK_AMD_shader_image_load_store_lod[]
[[spirvenv-capabilities-table-imagereadwritelodamd]]
| code:ImageReadWriteLodAMD               | `<<VK_AMD_shader_image_load_store_lod>>`
endif::VK_AMD_shader_image_load_store_lod[]
ifdef::VK_AMD_texture_gather_bias_lod[]
[[spirvenv-capabilities-table-imagegatherbiaslodamd]]
| code:ImageGatherBiasLodAMD              | `<<VK_AMD_texture_gather_bias_lod>>`
endif::VK_AMD_texture_gather_bias_lod[]
ifdef::VK_AMD_shader_fragment_mask[]
[[spirvenv-capabilities-table-fragmentmaskamd]]
| code:FragmentMaskAMD                    | `<<VK_AMD_shader_fragment_mask>>`
endif::VK_AMD_shader_fragment_mask[]
ifdef::VK_NV_sample_mask_override_coverage[]
[[spirvenv-capabilities-table-samplemaskoverridecoverage]]
| code:SampleMaskOverrideCoverageNV       | `<<VK_NV_sample_mask_override_coverage>>`
endif::VK_NV_sample_mask_override_coverage[]
ifdef::VK_NV_geometry_shader_passthrough[]
[[spirvenv-capabilities-table-geometryshaderpassthrough]]
| code:GeometryShaderPassthroughNV        | `<<VK_NV_geometry_shader_passthrough>>`
endif::VK_NV_geometry_shader_passthrough[]
ifdef::VK_EXT_shader_viewport_index_layer[]
[[spirvenv-capabilities-table-shader-viewport-index-layer]]
| code:ShaderViewportIndexLayerEXT        | `<<VK_EXT_shader_viewport_index_layer>>`
endif::VK_EXT_shader_viewport_index_layer[]
ifdef::VK_NV_viewport_array2[]
[[spirvenv-capabilities-table-viewportarray2]]
| code:ShaderViewportIndexLayerNV         | `<<VK_NV_viewport_array2>>`
| code:ShaderViewportMaskNV               | `<<VK_NV_viewport_array2>>`
endif::VK_NV_viewport_array2[]
ifdef::VK_NVX_multiview_per_view_attributes[]
[[spirvenv-capabilities-table-perviewattributes]]
| code:PerViewAttributesNV                | `<<VK_NVX_multiview_per_view_attributes>>`
endif::VK_NVX_multiview_per_view_attributes[]
ifdef::VK_VERSION_1_1,VK_KHR_16bit_storage[]
[[spirvenv-capabilities-table-16bitstorage]]
| code:StorageBuffer16BitAccess           | <<features-features-storageBuffer16BitAccess, StorageBuffer16BitAccess>>
| code:UniformAndStorageBuffer16BitAccess | <<features-features-uniformAndStorageBuffer16BitAccess,UniformAndStorageBuffer16BitAccess>>
| code:StoragePushConstant16              | <<features-features-storagePushConstant16,storagePushConstant16>>
| code:StorageInputOutput16               | <<features-features-storageInputOutput16,storageInputOutput16>>
endif::VK_VERSION_1_1,VK_KHR_16bit_storage[]
ifdef::VK_VERSION_1_1[]
[[spirvenv-capabilities-table-subgroup]]
| code:GroupNonUniform                    | <<features-features-subgroup-basic,VK_SUBGROUP_FEATURE_BASIC_BIT>>
| code:GroupNonUniformVote                | <<features-features-subgroup-vote,VK_SUBGROUP_FEATURE_VOTE_BIT>>
| code:GroupNonUniformArithmetic          | <<features-features-subgroup-arithmetic,VK_SUBGROUP_FEATURE_ARITHMETIC_BIT>>
| code:GroupNonUniformBallot              | <<features-features-subgroup-ballot,VK_SUBGROUP_FEATURE_BALLOT_BIT>>
| code:GroupNonUniformShuffle             | <<features-features-subgroup-shuffle,VK_SUBGROUP_FEATURE_SHUFFLE_BIT>>
| code:GroupNonUniformShuffleRelative     | <<features-features-subgroup-shuffle-relative,VK_SUBGROUP_FEATURE_SHUFFLE_RELATIVE_BIT>>
| code:GroupNonUniformClustered           | <<features-features-subgroup-clustered,VK_SUBGROUP_FEATURE_CLUSTERED_BIT>>
| code:GroupNonUniformQuad                | <<features-features-subgroup-quad,VK_SUBGROUP_FEATURE_QUAD_BIT>>
ifdef::VK_NV_shader_subgroup_partitioned[]
| code:GroupNonUniformPartitionedNV       | <<features-features-subgroup-partitioned,VK_SUBGROUP_FEATURE_PARTITIONED_BIT_NV>>
endif::VK_NV_shader_subgroup_partitioned[]
endif::VK_VERSION_1_1[]
ifdef::VK_EXT_post_depth_coverage[]
[[spirvenv-capabilities-table-postdepthcoverage]]
| code:SampleMaskPostDepthCoverage        | `<<VK_EXT_post_depth_coverage>>`
endif::VK_EXT_post_depth_coverage[]
ifdef::VK_EXT_descriptor_indexing[]
[[spirvenv-capabilities-table-descriptorindexing]]
| code:ShaderNonUniformEXT                   | `<<VK_EXT_descriptor_indexing>>`
| code:RuntimeDescriptorArrayEXT             | <<features-features-runtimeDescriptorArray,runtimeDescriptorArray>>
| code:InputAttachmentArrayDynamicIndexingEXT | <<features-features-shaderInputAttachmentArrayDynamicIndexing,shaderInputAttachmentArrayDynamicIndexing>>
| code:UniformTexelBufferArrayDynamicIndexingEXT | <<features-features-shaderUniformTexelBufferArrayDynamicIndexing,shaderUniformTexelBufferArrayDynamicIndexing>>
| code:StorageTexelBufferArrayDynamicIndexingEXT | <<features-features-shaderStorageTexelBufferArrayDynamicIndexing,shaderStorageTexelBufferArrayDynamicIndexing>>
| code:UniformBufferArrayNonUniformIndexingEXT | <<features-features-shaderUniformBufferArrayNonUniformIndexing,shaderUniformBufferArrayNonUniformIndexing>>
| code:SampledImageArrayNonUniformIndexingEXT | <<features-features-shaderSampledImageArrayNonUniformIndexing,shaderSampledImageArrayNonUniformIndexing>>
| code:StorageBufferArrayNonUniformIndexingEXT | <<features-features-shaderStorageBufferArrayNonUniformIndexing,shaderStorageBufferArrayNonUniformIndexing>>
| code:StorageImageArrayNonUniformIndexingEXT | <<features-features-shaderStorageImageArrayNonUniformIndexing,shaderStorageImageArrayNonUniformIndexing>>
| code:InputAttachmentArrayNonUniformIndexingEXT | <<features-features-shaderInputAttachmentArrayNonUniformIndexing,shaderInputAttachmentArrayNonUniformIndexing>>
| code:UniformTexelBufferArrayNonUniformIndexingEXT | <<features-features-shaderUniformTexelBufferArrayNonUniformIndexing,shaderUniformTexelBufferArrayNonUniformIndexing>>
| code:StorageTexelBufferArrayNonUniformIndexingEXT | <<features-features-shaderStorageTexelBufferArrayNonUniformIndexing,shaderStorageTexelBufferArrayNonUniformIndexing>>
endif::VK_EXT_descriptor_indexing[]
ifdef::VK_AMD_gpu_shader_half_float[]
| code:Float16                            | `<<VK_AMD_gpu_shader_half_float>>`
endif::VK_AMD_gpu_shader_half_float[]
ifdef::VK_KHR_8bit_storage[]
[[spirvenv-capabilities-table-8bitstorage]]
| code:StorageBuffer8BitAccess            | <<features-features-storageBuffer8BitAccess,StorageBuffer8BitAccess>>
| code:UniformAndStorageBuffer8BitAccess  | <<features-features-uniformAndStorageBuffer8BitAccess,UniformAndStorageBuffer8BitAccess>>
| code:StoragePushConstant8               | <<features-features-storagePushConstant8,StoragePushConstant8>>
endif::VK_KHR_8bit_storage[]
ifdef::VK_KHR_vulkan_memory_model[]
[[spirvenv-capabilities-table-memorymodel]]
| code:VulkanMemoryModelKHR               | <<features-features-vulkanMemoryModel,vulkanMemoryModel>>
| code:VulkanMemoryModelDeviceScopeKHR    | <<features-features-vulkanMemoryModel,vulkanMemoryModelDeviceScope>>
endif::VK_KHR_vulkan_memory_model[]
ifdef::VK_NV_compute_shader_derivatives[]
[[spirvenv-capabilities-table-computederivatives-quads]]
| code:ComputeDerivativeGroupQuadsNV      | <<features-features-computeShaderDerivativesQuads,computeDerivativeGroupQuads>>
[[spirvenv-capabilities-table-computederivatives-linear]]
| code:ComputeDerivativeGroupLinearNV     | <<features-features-computeShaderDerivativesLinear,computeDerivativeGroupLinear>>
endif::VK_NV_compute_shader_derivatives[]
ifdef::VK_NV_fragment_shader_barycentric[]
[[spirvenv-capabilities-fragment-barycentric]]
| code:FragmentBarycentricNV              | <<features-features-fragmentShaderBarycentric,fragmentShaderBarycentric>>
endif::VK_NV_fragment_shader_barycentric[]
ifdef::VK_NV_shader_image_footprint[]
[[spirvenv-capabilities-table-imagefootprint]]
| code:ImageFootprintNV                   | <<features-features-imageFootprint,imageFootprint>>
endif::VK_NV_shader_image_footprint[]
ifdef::VK_NV_shading_rate_image[]
| code:ShadingRateImageNV | <<features-features-shadingRateImage,shadingRateImage>>
endif::VK_NV_shading_rate_image[]
ifdef::VK_NV_mesh_shader[]
[[spirvenv-capabilities-table-meshshading]]
| code:MeshShadingNV                      | `<<VK_NV_mesh_shader>>`
endif::VK_NV_mesh_shader[]
ifdef::VK_NVX_raytracing[]
[[spirvenv-capabilities-table-raytracing]]
| code:RaytracingNVX                       | `<<VK_NVX_raytracing>>`
endif::VK_NVX_raytracing[]
|====

ifdef::VK_VERSION_1_1,VK_KHR_variable_pointers[]
The application can: pass a SPIR-V module to flink:vkCreateShaderModule that
uses the `SPV_KHR_variable_pointers` SPIR-V extension.
endif::VK_VERSION_1_1,VK_KHR_variable_pointers[]

ifdef::VK_AMD_shader_explicit_vertex_parameter[]
The application can: pass a SPIR-V module to flink:vkCreateShaderModule that
uses the `SPV_AMD_shader_explicit_vertex_parameter` SPIR-V extension.
endif::VK_AMD_shader_explicit_vertex_parameter[]

ifdef::VK_AMD_gcn_shader[]
The application can: pass a SPIR-V module to flink:vkCreateShaderModule that
uses the `SPV_AMD_gcn_shader` SPIR-V extension.
endif::VK_AMD_gcn_shader[]

ifdef::VK_AMD_gpu_shader_half_float[]
The application can: pass a SPIR-V module to flink:vkCreateShaderModule that
uses the `SPV_AMD_gpu_shader_half_float` SPIR-V extension.
endif::VK_AMD_gpu_shader_half_float[]

ifdef::VK_AMD_gpu_shader_int16[]
The application can: pass a SPIR-V module to flink:vkCreateShaderModule that
uses the `SPV_AMD_gpu_shader_int16` SPIR-V extension.
endif::VK_AMD_gpu_shader_int16[]

ifdef::VK_AMD_shader_ballot[]
The application can: pass a SPIR-V module to flink:vkCreateShaderModule that
uses the `SPV_AMD_shader_ballot` SPIR-V extension.
endif::VK_AMD_shader_ballot[]

ifdef::VK_AMD_shader_fragment_mask[]
The application can: pass a SPIR-V module to flink:vkCreateShaderModule that
uses the `SPV_AMD_shader_fragment_mask` SPIR-V extension.
endif::VK_AMD_shader_fragment_mask[]

ifdef::VK_AMD_shader_image_load_store_lod[]
The application can: pass a SPIR-V module to flink:vkCreateShaderModule that
uses the `SPV_AMD_shader_image_load_store_lod` SPIR-V extension.
endif::VK_AMD_shader_image_load_store_lod[]

ifdef::VK_AMD_shader_trinary_minmax[]
The application can: pass a SPIR-V module to flink:vkCreateShaderModule that
uses the `SPV_AMD_shader_trinary_minmax` SPIR-V extension.
endif::VK_AMD_shader_trinary_minmax[]

ifdef::VK_AMD_texture_gather_bias_lod[]
The application can: pass a SPIR-V module to flink:vkCreateShaderModule that
uses the `SPV_AMD_texture_gather_bias_lod` SPIR-V extension.
endif::VK_AMD_texture_gather_bias_lod[]

ifdef::VK_VERSION_1_1,VK_KHR_shader_draw_parameters[]
The application can: pass a SPIR-V module to flink:vkCreateShaderModule that
uses the `SPV_KHR_shader_draw_parameters` SPIR-V extension.
endif::VK_VERSION_1_1,VK_KHR_shader_draw_parameters[]

ifdef::VK_KHR_8bit_storage[]
The application can: pass a SPIR-V module to flink:vkCreateShaderModule that
uses the `SPV_KHR_8bit_storage` SPIR-V extension.
endif::VK_KHR_8bit_storage[]

ifdef::VK_VERSION_1_1,VK_KHR_16bit_storage[]
The application can: pass a SPIR-V module to flink:vkCreateShaderModule that
uses the
https://www.khronos.org/registry/spir-v/extensions/KHR/SPV_KHR_16bit_storage.html[`SPV_KHR_16bit_storage`]
SPIR-V extension.
endif::VK_VERSION_1_1,VK_KHR_16bit_storage[]

ifdef::VK_VERSION_1_1,VK_KHR_storage_buffer_storage_class[]
The application can: pass a SPIR-V module to flink:vkCreateShaderModule that
uses the
https://www.khronos.org/registry/spir-v/extensions/KHR/SPV_KHR_storage_buffer_storage_class.html[`SPV_KHR_storage_buffer_storage_class`]
SPIR-V extension.
endif::VK_VERSION_1_1,VK_KHR_storage_buffer_storage_class[]

ifdef::VK_EXT_post_depth_coverage[]
The application can: pass a SPIR-V module to flink:vkCreateShaderModule that
uses the `SPV_KHR_post_depth_coverage` SPIR-V extension.
endif::VK_EXT_post_depth_coverage[]

ifdef::VK_EXT_shader_stencil_export[]
The application can: pass a SPIR-V module to flink:vkCreateShaderModule that
uses the `SPV_EXT_shader_stencil_export` SPIR-V extension.
endif::VK_EXT_shader_stencil_export[]

ifdef::VK_EXT_shader_subgroup_ballot[]
The application can: pass a SPIR-V module to flink:vkCreateShaderModule that
uses the `SPV_KHR_shader_ballot` SPIR-V extension.
endif::VK_EXT_shader_subgroup_ballot[]

ifdef::VK_EXT_shader_subgroup_vote[]
The application can: pass a SPIR-V module to flink:vkCreateShaderModule that
uses the `SPV_KHR_subgroup_vote` SPIR-V extension.
endif::VK_EXT_shader_subgroup_vote[]

ifdef::VK_NV_sample_mask_override_coverage[]
The application can: pass a SPIR-V module to flink:vkCreateShaderModule that
uses the `SPV_NV_sample_mask_override_coverage` SPIR-V extension.
endif::VK_NV_sample_mask_override_coverage[]

ifdef::VK_NV_geometry_shader_passthrough[]
The application can: pass a SPIR-V module to flink:vkCreateShaderModule that
uses the `SPV_NV_geometry_shader_passthrough` SPIR-V extension.
endif::VK_NV_geometry_shader_passthrough[]

ifdef::VK_NV_mesh_shader[]
The application can: pass a SPIR-V module to flink:vkCreateShaderModule that
uses the `SPV_NV_mesh_shader` SPIR-V extension.
endif::VK_NV_mesh_shader[]

ifdef::VK_NV_viewport_array2[]
The application can: pass a SPIR-V module to flink:vkCreateShaderModule that
uses the `SPV_NV_viewport_array2` SPIR-V extension.
endif::VK_NV_viewport_array2[]

ifdef::VK_EXT_shader_viewport_index_layer[]
The application can: pass a SPIR-V module to flink:vkCreateShaderModule that
uses the `SPV_EXT_shader_viewport_index_layer` SPIR-V extension.
endif::VK_EXT_shader_viewport_index_layer[]

ifdef::VK_NVX_multiview_per_view_attributes[]
The application can: pass a SPIR-V module to flink:vkCreateShaderModule that
uses the `SPV_NVX_multiview_per_view_attributes` SPIR-V extension.
endif::VK_NVX_multiview_per_view_attributes[]

ifdef::VK_EXT_descriptor_indexing[]
The application can: pass a SPIR-V module to flink:vkCreateShaderModule that
uses the `SPV_EXT_descriptor_indexing` SPIR-V extension.
endif::VK_EXT_descriptor_indexing[]

ifdef::VK_KHR_vulkan_memory_model[]
The application can: pass a SPIR-V module to flink:vkCreateShaderModule that
uses the `SPV_KHR_vulkan_memory_model` SPIR-V extension.
endif::VK_KHR_vulkan_memory_model[]

ifdef::VK_NV_compute_shader_derivatives[]
The application can: pass a SPIR-V module to flink:vkCreateShaderModule that
uses the `SPV_NV_compute_shader_derivatives` SPIR-V extension.
endif::VK_NV_compute_shader_derivatives[]

ifdef::VK_NV_fragment_shader_barycentric[]
The application can: pass a SPIR-V module to flink:vkCreateShaderModule that
uses the `SPV_NV_fragment_shader_barycentric` SPIR-V extension.
endif::VK_NV_fragment_shader_barycentric[]

ifdef::VK_NV_shader_image_footprint[]
The application can: pass a SPIR-V module to flink:vkCreateShaderModule that
uses the `SPV_NV_shader_image_footprint` SPIR-V extension.
endif::VK_NV_shader_image_footprint[]

ifdef::VK_NV_shading_rate_image[]
The application can: pass a SPIR-V module to flink:vkCreateShaderModule that
uses the `SPV_NV_shading_rate` SPIR-V extension.
endif::VK_NV_shading_rate_image[]

ifdef::VK_NVX_raytracing[]
The application can: pass a SPIR-V module to flink:vkCreateShaderModule that
uses the `SPV_NVX_raytracing` SPIR-V extension.
endif::VK_NVX_raytracing[]

The application must: not pass a SPIR-V module containing any of the
following to flink:vkCreateShaderModule:

  * any OpCapability not listed above,
  * an unsupported capability, or
  * a capability which corresponds to a Vulkan feature or extension which
    has not been enabled.


[[spirvenv-module-validation]]
== Validation Rules within a Module

A SPIR-V module passed to flink:vkCreateShaderModule must: conform to the
following rules:

  * Every entry point must: have no return value and accept no arguments.
  * Recursion: The static function-call graph for an entry point must: not
    contain cycles.
  * The *Logical* addressing model must: be selected.
  * *Scope* for execution must: be limited to:
  ** *Workgroup*
  ** *Subgroup*
  * *Scope* for memory must: be limited to:
  ** *Device*
ifdef::VK_KHR_vulkan_memory_model[]
  *** If <<features-features-vulkanMemoryModel,pname:vulkanMemoryModel>> is
      enabled and
      <<features-features-vulkanMemoryModelDeviceScope,pname:vulkanMemoryModelDeviceScope>>
      is not enabled, *Device* scope must: not be used.
  *** If <<features-features-vulkanMemoryModel,pname:vulkanMemoryModel>> is
      not enabled, *Device* scope only extends to the queue family, not the
      whole device.
endif::VK_KHR_vulkan_memory_model[]
ifndef::VK_KHR_vulkan_memory_model[]
  *** *Device* scope only extends to the queue family, not the whole device.
endif::VK_KHR_vulkan_memory_model[]
ifdef::VK_KHR_vulkan_memory_model[]
  ** *QueueFamilyKHR*
  *** If <<features-features-vulkanMemoryModel,pname:vulkanMemoryModel>> is
      not enabled, *QueueFamilyKHR* must: not be used.
endif::VK_KHR_vulkan_memory_model[]
  ** *Workgroup*
ifdef::VK_VERSION_1_1[]
  ** *Subgroup*
endif::VK_VERSION_1_1[]
  ** *Invocation*
ifdef::VK_VERSION_1_1[]
  * *Scope* for *Non Uniform Group Operations* must: be limited to:
  ** *Subgroup*
endif::VK_VERSION_1_1[]
  * *Storage Class* must: be limited to:
  ** *UniformConstant*
  ** *Input*
  ** *Uniform*
  ** *Output*
  ** *Workgroup*
  ** *Private*
  ** *Function*
  ** *PushConstant*
  ** *Image*
ifdef::VK_VERSION_1_1,VK_KHR_storage_buffer_storage_class[]
  ** *StorageBuffer*
endif::VK_VERSION_1_1,VK_KHR_storage_buffer_storage_class[]
  * Memory semantics must: obey the following rules:
  ** *Acquire* must: not be used with code:OpAtomicStore.
  ** *Release* must: not be used with code:OpAtomicLoad.
  ** *AcquireRelease* must: not be used with code:OpAtomicStore or
     code:OpAtomicLoad.
  ** Sequentially consistent atomics and barriers are not supported and
     *SequentiallyConsistent* is treated as *AcquireRelease*.
     *SequentiallyConsistent* should: not be used.
  ** code:OpMemoryBarrier must: use one of *Acquire*, *Release*,
     *AcquireRelease*, or *SequentiallyConsistent* and must: include at
     least one storage class.
  ** If the semantics for code:OpControlBarrier includes one of *Acquire*,
     *Release*, *AcquireRelease*, or *SequentiallyConsistent*, then it must:
     include at least one storage class.
  ** *SubgroupMemory*, *CrossWorkgroupMemory*, and *AtomicCounterMemory* are
     ignored.
  * Any code:OpVariable with an code:Initializer operand must: have one of
    the following as its code:Storage code:Class operand:
  ** *Output*
  ** *Private*
  ** *Function*
  * The code:OriginLowerLeft execution mode must: not be used; fragment
    entry points must: declare code:OriginUpperLeft.
  * The code:PixelCenterInteger execution mode must: not be used.
    Pixels are always centered at half-integer coordinates.
  * Images and Samplers
  ** code:OpTypeImage must: declare a scalar 32-bit float or 32-bit integer
     type for the "`Sampled Type`".
     (code:RelaxedPrecision can: be applied to a sampling instruction and to
     the variable holding the result of a sampling instruction.)
  ** code:OpTypeImage must: have a "`Sampled`" operand of 1 (sampled image)
     or 2 (storage image).
  ** If
     <<features-features-shaderStorageImageReadWithoutFormat,shaderStorageImageReadWithoutFormat>>
     is not enabled and an code:OpTypeImage has "`Image Format`" operand of
     code:Unknown, any variables created with the given type must be
     decorated with code:NonReadable.
  ** If
     <<features-features-shaderStorageImageWriteWithoutFormat,shaderStorageImageWriteWithoutFormat>>
     is not enabled and an code:OpTypeImage has "`Image Format`" operand of
     code:Unknown, any variables created with the given type must be
     decorated with code:NonWritable.
  ** code:OpImageQuerySizeLod, and code:OpImageQueryLevels must: only
     consume an "`Image`" operand whose type has its "`Sampled`" operand set
     to 1.
  ** The [eq]#(u,v)# coordinates used for a code:SubpassData must: be the
     <id> of a constant vector [eq]#(0,0)#, or if a layer coordinate is
     used, must: be a vector that was formed with constant 0 for the [eq]#u#
     and [eq]#v# components.
  ** The "`Depth`" operand of code:OpTypeImage is ignored.
  ** Objects of types code:OpTypeImage, code:OpTypeSampler,
     code:OpTypeSampledImage, and arrays of these types must: not be stored
     to or modified.
  * Decorations
  ** The code:GLSLShared and code:GLSLPacked decorations must: not be used.
  ** The code:Flat, code:NoPerspective, code:Sample, and code:Centroid
     decorations must: not be used on variables with storage class other
     than code:Input or on variables used in the interface of non-fragment
     shader entry points.
  ** The code:Patch decoration must: not be used on variables in the
     interface of a vertex, geometry, or fragment shader stage's entry
     point.
ifdef::VK_NV_viewport_array2[]
  ** The code:ViewportRelativeNV decoration must: only be used on a variable
     decorated with code:Layer in the vertex, tessellation evaluation, or
     geometry shader stages.
  ** The code:ViewportRelativeNV decoration must: not be used unless a
     variable decorated with one of code:ViewportIndex or
     code:ViewportMaskNV is also statically used by the same
     code:OpEntryPoint.
  ** The code:ViewportMaskNV and code:ViewportIndex decorations must: not
     both be statically used by one or more code:OpEntryPoint's that form
     the vertex processing stages of a graphics pipeline.
endif::VK_NV_viewport_array2[]
ifdef::VK_VERSION_1_1,VK_KHR_16bit_storage[]
  ** Only the round-to-nearest-even and the round-to-zero rounding modes
     can: be used for the code:FPRoundingMode decoration.
  ** The code:FPRoundingMode decoration can: only be used for the
     floating-point conversion instructions as described in the
     https://www.khronos.org/registry/spir-v/extensions/KHR/SPV_KHR_16bit_storage.html[`SPV_KHR_16bit_storage`]
     SPIR-V extension.
endif::VK_VERSION_1_1,VK_KHR_16bit_storage[]
  ** code:DescriptorSet and code:Binding decorations must: obey the
     constraints on storage class, type, and descriptor type described in
     <<interfaces-resources-setandbinding,DescriptorSet and Binding
     Assignment>>
  * code:OpTypeRuntimeArray must: only be used for:
  ** the last member of an code:OpTypeStruct
ifdef::VK_VERSION_1_1,VK_KHR_storage_buffer_storage_class[]
     that is in the code:StorageBuffer storage class decorated as
     code:Block, or
endif::VK_VERSION_1_1,VK_KHR_storage_buffer_storage_class[]
     that is in the code:Uniform storage class decorated as
     code:BufferBlock.
ifdef::VK_EXT_descriptor_indexing[]
  ** If the code:RuntimeDescriptorArrayEXT capability is supported, an array
     of variables with storage class code:Uniform,
ifdef::VK_VERSION_1_1,VK_KHR_storage_buffer_storage_class[]
     code:StorageBuffer,
endif::VK_VERSION_1_1,VK_KHR_storage_buffer_storage_class[]
     or code:UniformConstant, or for the outermost dimension of an array of
     arrays of such variables.
endif::VK_EXT_descriptor_indexing[]
  * Linkage: See <<interfaces,Shader Interfaces>> for additional linking and
    validation rules.
ifdef::VK_VERSION_1_1[]
  * If code:OpControlBarrier is used in fragment, vertex, tessellation
    evaluation, or geometry stages, the execution Scope must: be
    code:Subgroup.
endif::VK_VERSION_1_1[]
  * Compute Shaders
  ** For each compute shader entry point, either a code:LocalSize execution
     mode or an object decorated with the code:WorkgroupSize decoration
     must: be specified.
ifdef::VK_NV_compute_shader_derivatives[]
  ** For compute shaders using the code:DerivativeGroupQuadsNV execution
     mode, the first two dimensions of the local workgroup size must: be a
     multiple of two.
  ** For compute shaders using the code:DerivativeGroupLinearNV execution
     mode, the product of the dimensions of the local workgroup size must:
     be a multiple of four.
endif::VK_NV_compute_shader_derivatives[]
ifdef::VK_VERSION_1_1[]
  * "`Result Type`" for *Non Uniform Group Operations* must: be limited to
    32-bit float, 32-bit integer, boolean, or vectors of these types.
    If the code:Float64 capability is enabled, double and vector of double
    types are also permitted.
  * "`Mask`" for code:OpGroupNonUniformShuffleXor must: be a specialization
    constant or a constant, or if the dynamic instance is called within a
    loop construct it must: be one of:
    . A specialization constant.
    . A constant.
    . An arthimetic operation whose operands are 1., 2., or 4.
    . A phi node whose operands are 1., 2., or 3.
  * If code:OpGroupNonUniformBallotBitCount is used, the group operation
    must: be one of:
  ** *Reduce*
  ** *InclusiveScan*
  ** *ExclusiveScan*
endif::VK_VERSION_1_1[]
  * Atomic instructions must: declare a scalar 32-bit integer type,
ifdef::VK_KHR_shader_atomic_int64[]
    or a scalar 64-bit integer type if the code:Int64Atomics capability is
    enabled,
endif::VK_KHR_shader_atomic_int64[]
    for the _Result Type_ and the type of the value pointed to by _Pointer_.
ifdef::VK_KHR_shader_atomic_int64[]
    ** <<features-features-shaderBufferInt64Atomics,shaderBufferInt64Atomics>>
     must: be enabled for 64-bit integer atomic operations to be supported
     on buffers.
    ** <<features-features-shaderSharedInt64Atomics,shaderSharedInt64Atomics>>
     must: be enabled for 64-bit integer atomic operations to be supported
     on shared variables.
endif::VK_KHR_shader_atomic_int64[]
ifdef::VK_EXT_descriptor_indexing[]
  * If an instruction loads from or stores to a resource (including atomics
    and image instructions) and the resource descriptor being accessed is
    not dynamically uniform, then the operand corresponding to that resource
    (e.g. the pointer or sampled image operand) must: be decorated with
    code:NonUniformEXT.
endif::VK_EXT_descriptor_indexing[]


[[spirvenv-precision-operation]]
== Precision and Operation of SPIR-V Instructions

The following rules apply to both single and double-precision floating point
instructions:

  * Positive and negative infinities and positive and negative zeros are
    generated as dictated by <<ieee-754,IEEE 754>>, but subject to the
    precisions allowed in the following table.
  * Dividing a non-zero by a zero results in the appropriately signed
    <<ieee-754,IEEE 754>> infinity.
  * Any denormalized value input into a shader or potentially generated by
    any instruction in a shader may: be flushed to 0.
  * The rounding mode cannot: be set, and results will be <<Correctly
    Rounded>>, as described below.
  * [eq]##NaN##s may: not be generated.
    Instructions that operate on a [eq]#NaN# may: not result in a [eq]#NaN#.
  * Support for signaling [eq]##NaN##s is optional: and exceptions are never
    raised.

The precision of double-precision instructions is at least that of single
precision.

The precision of operations is defined either in terms of rounding, as an
error bound in ULP, or as inherited from a formula as follows.

.Correctly Rounded
Operations described as "correctly rounded" will return the infinitely
precise result, [eq]#x#, rounded so as to be representable in
floating-point.
The rounding mode used is not defined but if [eq]#x# is exactly
representable then [eq]#x# will be returned.
Otherwise, either the floating-point value closest to and no less than
[eq]#x# or the value closest to and no greater than [eq]#x# will be
returned.

.ULP
Where an error bound of [eq]#n# ULP (units in the last place) is given, for
an operation with infinitely precise result #x# the value returned must be
in the range #[x - n * ulp(x), x + n * ulp(x)]#.
The function #ulp(x)# is defined as follows:

 :: If there exist non-equal floating-point numbers #a# and #b# such that
[eq]#a {leq} x {leq} b# then #ulp(x)# is the minimum possible distance
between such numbers, latexmath:[ulp(x) = \mathrm{min}_{a,b} | b - a |].
If such numbers do not exist then #ulp(x)# is defined to be the difference
between the two finite floating-point numbers nearest to #x#.

Where the range of allowed return values includes any value of magnitude
larger than that of the largest representable finite floating-point number,
operations may return an infinity of the appropriate sign.
If the infinitely precise result of the operation is not mathematically
defined then the value returned is undefined:.

.Inherited From ...
Where an operation's precision is described as being inherited from a
formula, the result returned must be at least as accurate as the result of
computing an approximation to [eq]#x# using a formula equivalent to the
given formula applied to the supplied inputs.
Specifically, the formula given may be transformed using the mathematical
associativity, commutativity and distributivity of the operators involved to
yield an equivalent formula.
The SPIR-V precision rules, when applied to each such formula and the given
input values, define a range of permitted values.
If [eq]#NaN# is one of the permitted values then the operation may return
any result, otherwise let the largest permitted value in any of the ranges
be [eq]#F~max~# and the smallest be [eq]#F~min~#.
The operation must return a value in the range [eq]#[x - E, x + E]# where
latexmath:[E = \mathrm{max} \left( | x - F_{\mathrm{min}} |, | x -
F_{\mathrm{max}} | \right) ].

For single precision (32 bit) instructions, precisions are required: to be
at least as follows, unless decorated with RelaxedPrecision:

.Precision of core SPIR-V Instructions
[options="header"]
|====
| Instruction                                               | Precision
| code:OpFAdd                                               | Correctly rounded.
| code:OpFSub                                               | Correctly rounded.
| code:OpFMul                                               | Correctly rounded.
| code:OpFOrdEqual, code:OpFUnordEqual                      | Correct result.
| code:OpFOrdLessThan, code:OpFUnordLessThan                | Correct result.
| code:OpFOrdGreaterThan, code:OpFUnordGreaterThan          | Correct result.
| code:OpFOrdLessThanEqual, code:OpFUnordLessThanEqual      | Correct result.
| code:OpFOrdGreaterThanEqual, code:OpFUnordGreaterThanEqual| Correct result.
| code:OpFDiv                                               | 2.5 ULP for b in the range [2^-126^, 2^126^].
| conversions between types                                 | Correctly rounded.
|====

.Precision of GLSL.std.450 Instructions
[options="header"]
|====
|Instruction                 | Precision
| code:fma()                 | Inherited from code:OpFMul followed by code:OpFAdd.
| code:exp(x),  code:exp2(x) | [eq]#3 {plus} 2 {times} {vert}x{vert}# ULP.
| code:log(),  code:log2()   | 3 ULP outside the range [eq]#[0.5, 2.0]#. Absolute error < [eq]#2^-21^# inside the range [eq]#[0.5, 2.0]#.
| code:pow(x, y)             | Inherited from code:exp2(y {times} code:log2(x)).
| code:sqrt()                | Inherited from 1.0 / code:inversesqrt().
| code:inversesqrt()         | 2 ULP.
|====

GLSL.std.450 extended instructions specifically defined in terms of the
above instructions inherit the above errors.
GLSL.std.450 extended instructions not listed above and not defined in terms
of the above have undefined: precision.
These include, for example, the trigonometric functions and determinant.

For the code:OpSRem and code:OpSMod instructions, if either operand is
negative the result is undefined:.

[NOTE]
.Note
====
While the code:OpSRem and code:OpSMod instructions are supported by the
Vulkan environment, they require non-negative values and thus do not enable
additional functionality beyond what code:OpUMod provides.
====


[[spirvenv-image-formats]]
== Compatibility Between SPIR-V Image Formats And Vulkan Formats

Images which are read from or written to by shaders must: have SPIR-V image
formats compatible with the Vulkan image formats backing the image under the
circumstances described for <<textures-operation-validation,texture image
validation>>.
The compatibile formats are:

.SPIR-V and Vulkan Image Format Compatibility
[cols="2*", options="header"]
|====
|SPIR-V Image Format    |Compatible Vulkan Format
|code:Rgba32f           |ename:VK_FORMAT_R32G32B32A32_SFLOAT
|code:Rgba16f           |ename:VK_FORMAT_R16G16B16A16_SFLOAT
|code:R32f              |ename:VK_FORMAT_R32_SFLOAT
|code:Rgba8             |ename:VK_FORMAT_R8G8B8A8_UNORM
|code:Rgba8Snorm        |ename:VK_FORMAT_R8G8B8A8_SNORM
|code:Rg32f             |ename:VK_FORMAT_R32G32_SFLOAT
|code:Rg16f             |ename:VK_FORMAT_R16G16_SFLOAT
|code:R11fG11fB10f      |ename:VK_FORMAT_B10G11R11_UFLOAT_PACK32
|code:R16f              |ename:VK_FORMAT_R16_SFLOAT
|code:Rgba16            |ename:VK_FORMAT_R16G16B16A16_UNORM
|code:Rgb10A2           |ename:VK_FORMAT_A2B10G10R10_UNORM_PACK32
|code:Rg16              |ename:VK_FORMAT_R16G16_UNORM
|code:Rg8               |ename:VK_FORMAT_R8G8_UNORM
|code:R16               |ename:VK_FORMAT_R16_UNORM
|code:R8                |ename:VK_FORMAT_R8_UNORM
|code:Rgba16Snorm       |ename:VK_FORMAT_R16G16B16A16_SNORM
|code:Rg16Snorm         |ename:VK_FORMAT_R16G16_SNORM
|code:Rg8Snorm          |ename:VK_FORMAT_R8G8_SNORM
|code:R16Snorm          |ename:VK_FORMAT_R16_SNORM
|code:R8Snorm           |ename:VK_FORMAT_R8_SNORM
|code:Rgba32i           |ename:VK_FORMAT_R32G32B32A32_SINT
|code:Rgba16i           |ename:VK_FORMAT_R16G16B16A16_SINT
|code:Rgba8i            |ename:VK_FORMAT_R8G8B8A8_SINT
|code:R32i              |ename:VK_FORMAT_R32_SINT
|code:Rg32i             |ename:VK_FORMAT_R32G32_SINT
|code:Rg16i             |ename:VK_FORMAT_R16G16_SINT
|code:Rg8i              |ename:VK_FORMAT_R8G8_SINT
|code:R16i              |ename:VK_FORMAT_R16_SINT
|code:R8i               |ename:VK_FORMAT_R8_SINT
|code:Rgba32ui          |ename:VK_FORMAT_R32G32B32A32_UINT
|code:Rgba16ui          |ename:VK_FORMAT_R16G16B16A16_UINT
|code:Rgba8ui           |ename:VK_FORMAT_R8G8B8A8_UINT
|code:R32ui             |ename:VK_FORMAT_R32_UINT
|code:Rgb10a2ui         |ename:VK_FORMAT_A2B10G10R10_UINT_PACK32
|code:Rg32ui            |ename:VK_FORMAT_R32G32_UINT
|code:Rg16ui            |ename:VK_FORMAT_R16G16_UINT
|code:Rg8ui             |ename:VK_FORMAT_R8G8_UINT
|code:R16ui             |ename:VK_FORMAT_R16_UINT
|code:R8ui              |ename:VK_FORMAT_R8_UINT
|====