status-im/Vulkan-Docs
2
0
Fork 0
mirror of https://github.com/status-im/Vulkan-Docs.git synced 2025-02-20 01:58:06 +00:00
Code Issues Projects Releases Wiki Activity
Vulkan-Docs/doc/specs/vulkan/appendices/spirvenv.txt
Jon Leech f4c4113d07 Change log for July 15, 2016 Vulkan 1.0.21 spec update: 
* Bump API patch number and header version number to 21 for this update.

Github Issues:

  * Clarify how <<features-supported-sample-counts,sample count queries>>
    relate to the limits in slink:VkPhysicalDeviceLimits. (public issue
    185).
  * Clarify in the <<interfaces-iointerfaces,Shader Input and Output
    Interfaces>> section that shader output variables have undefined values
    until the shader writes to them (public issue 240).
  * Specify the implicit value of image parameters that cannot be set in
    slink:VkSwapchainCreateInfo::pname:flags, pname:imageType,
    pname:mipLevels, pname:samples, pname:tiling, and pname:initialLayout
    (public issue 243).
  * Make use of code:NULL and code:VK_NULL_HANDLE consistent in the
    VK_KHR_swapchain extension (public issue 276).

Internal Issues:

  * Clarify that presenting an image to a display surface swapchain applies
    the display surface's mode, and that destroying a display surface
    swapchain may reset the display's mode, in the VK_KHR_display_swapchain
    extension (internal issue 247).
  * Better describe what a slink:VkSurfaceKHR is, and that creating one does
    not set a mode, in the VK_KHR_display extension. This is a round-about
    way of pointing out that mode setting is not covered by the extension,
    but rather is performed as a side effect of presentation (internal issue
    247).
  * Add more valid usage statements to flink:vkQueuePresentKHR command when
    the VK_KHR_display_swapchain extension is present (internal issue
    247).
  * Add more includes to the VK_KHR_swapchain extension to better document
    interactions with VK_KHR_display_swapchain (internal issue 247).
  * Clarify restrictions on location aliasing in the
    <<fxvertex,Fixed-Function Vertex Processing>> section (internal issue
    370).
  * Add mathematical description of blitting to flink:vkCmdBlitImage, and
    link it to the <<textures,Image Operations>> chapter. Use mathematical
    notation for ranges of texel coordinates in the <<textures,Image
    Operations>> chapter. Fixed miscellaneous validity statements for
    flink:vkCmdBlit and slink:VkImageBlit (internal issue 382).

Other Commits:

  * Added a valid usage rule to flink:VkGraphicsPipelineCreateInfo that the
    ename:VK_PRIMITIVE_TOPOLOGY_PATCH_LIST topology must only be used when
    tessellation shaders are used.
  * Expand the style guide into a formal "Procedures and Conventions"
    document. Add a API Naming Conventions section, move most of the API
    Specification Appendix C (Layers and Extensions) content into the new
    document, and define the resulting procedures as mandatory (where
    relevant). This more clearly separates use vs. specification of Vulkan
    APIs.
  * Update vk_platform.h to handle 32-bit ARMv8 binaries.
  * Various minor cleanups to the Makefile and build process.
2016-07-15 19:05:43 -07:00

254 lines
13 KiB
Plaintext
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

// Copyright (c) 2015-2016 The Khronos Group Inc.
// Copyright notice at https://www.khronos.org/registry/speccopyright.html
[appendix]
[[spirvenv]]
= Vulkan Environment for SPIR-V
Shaders for Vulkan are defined by the <<Khronos SPIR-V Specification>> as
well as the <<Khronos SPIR-V Extended Instructions for GLSL Specification>>.
This appendix defines additional SPIR-V requirements applying to Vulkan
shaders.
== Required Versions and Formats
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.
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
Implementations must: support the following capability operands declared by
code:OpCapability:
- code:Matrix
- code:Shader
- code:InputAttachment
- code:Sampled1D
- code:Image1D
- code:SampledBuffer
- code:ImageBuffer
- code:ImageQuery
- code:DerivativeControl
Implementations may: support features that are not required: by the
Specification, as described in the <<features-features,Features>> chapter.
If such a feature is supported, then any capability operand(s) corresponding
to that feature must: also be supported.
[[spirvenv-capabilities-table]]
.SPIR-V Capabilities which are not required:, and corresponding feature names
[options="header"]
|====
| SPIR-V OpCapability | Vulkan feature name
| code:Geometry | <<features-features-geometryShader,geometryShader>>
| code:Tessellation | <<features-features-tessellationShader,tessellationShader>>
| code:Float64 | <<features-features-shaderFloat64,shaderFloat64>>
| code:Int64 | <<features-features-shaderInt64,shaderInt64>>
| 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>>
|====
The application mustnot: 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 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*
** *Workgroup*
** *Invocation*
* The code:OriginLowerLeft execution mode mustnot: be used; fragment entry
points must: declare code:OriginUpperLeft.
* The code:PixelCenterInteger execution mode mustnot: be used. Pixels are
always centered at half-integer coordinates.
* Images
** 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:OpSampledImage must: only consume an ``Image'' operand whose type
has its ``Sampled'' operand set to 1.
** The ``(u, v)'' coordinates used for a code:SubpassData must: be the <id>
of a constant vector (0, 0), or if a layer coordinate is used, must: be
a vector that was formed with constant 0 for the ``u'' and ``v''
components.
** The ``Depth'' operand of code:OpTypeImage is ignored.
* Decorations
** The code:GLSLShared and code:GLSLPacked decorations mustnot: be used.
** The code:Flat, code:NoPerspective, code:Sample, and code:Centroid
decorations mustnot: 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 mustnot: be used on variables in the
interface of a vertex, geometry, or fragment shader stage's entry
point.
* code:OpTypeRuntimeArray must: only be used for the last member of an
code:OpTypeStruct in the code:Uniform storage class.
* Linkage: See <<interfaces,Shader Interfaces>> for additional linking and
validation rules.
* 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.
[[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>>, but subject to the precisions
allowed in the following table.
- Dividing a non-zero by a zero results in the appropriately signed <<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 is undefined.
- NaNs may: not be generated. Instructions that operate on a NaN may: not
result in a NaN.
- Support for signaling NaNs is optional: and exceptions are never raised.
The precision of double-precision instructions is at least that of single
precision. 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) | latexmath:[$(3 + 2 \times \|x\|)$] ULP.
| code:log(), code:log2() | 3 ULP outside the range [0.5, 2.0]. Absolute error < 2^-21^ inside the range [0.5, 2.0].
| code:pow(x, y) | Inherited from code:exp2(y × 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
-------------------------------------------------------------
[cols="2*", options="header"]
|===
|SPIR-V Image Format |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
|===
Reference in New Issue View Git Blame Copy Permalink