include::meta/VK_NV_cooperative_matrix.txt[]

*Last Modified Data*::
    2019-02-05
*Contributors*::
  - Jeff Bolz, NVIDIA
  - Markus Tavenrath, NVIDIA
  - Daniel Koch, NVIDIA

This extension adds support for using cooperative matrix types in SPIR-V.
Cooperative matrix types are medium-sized matrices that are primarily
supported in compute shaders, where the storage for the matrix is spread
across all invocations in some scope (usually a subgroup) and those
invocations cooperate to efficiently perform matrix multiplies.

Cooperative matrix types are defined by the
http://htmlpreview.github.io/?https://github.com/KhronosGroup/SPIRV-Registry/blob/master/extensions/NV/SPV_NV_cooperative_matrix.html[+SPV_NV_cooperative_matrix+]
SPIR-V extension and can be used with the
https://github.com/KhronosGroup/GLSL/blob/master/extensions/nv/GLSL_NV_cooperative_matrix.txt[+GL_NV_cooperative_matrix+]
GLSL extension.

This extension includes support for enumerating the matrix types and
dimensions that are supported by the implementation.

=== New Object Types

None.

=== New Enum Constants

  * Extending elink:VkStructureType:

  ** ename:VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_COOPERATIVE_MATRIX_FEATURES_NV
  ** ename:VK_STRUCTURE_TYPE_COOPERATIVE_MATRIX_PROPERTIES_NV
  ** ename:VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_COOPERATIVE_MATRIX_PROPERTIES_NV

=== New Enums

  * elink:VkScopeNV
  * elink:VkComponentTypeNV

=== New Structures

  * Extending slink:VkPhysicalDeviceFeatures2:
  ** slink:VkPhysicalDeviceCooperativeMatrixFeaturesNV

  * Extending slink:VkPhysicalDeviceProperties2:
  ** slink:VkPhysicalDeviceCooperativeMatrixPropertiesNV

  * slink:VkCooperativeMatrixPropertiesNV

=== New Functions

  * flink:vkGetPhysicalDeviceCooperativeMatrixPropertiesNV

=== New SPIR-V Capabilities

  * <<spirvenv-capabilities-table-cooperativeMatrix,CooperativeMatrixNV>>

=== Issues

(1) What matrix properties will be supported in practice?

RESOLVED: In NVIDIA's initial implementation, we will support:

    * AType = BType = fp16 CType = DType = fp16 MxNxK = 16x8x16 scope =
      Subgroup
    * AType = BType = fp16 CType = DType = fp16 MxNxK = 16x8x8 scope =
      Subgroup
    * AType = BType = fp16 CType = DType = fp32 MxNxK = 16x8x16 scope =
      Subgroup
    * AType = BType = fp16 CType = DType = fp32 MxNxK = 16x8x8 scope =
      Subgroup

=== Version History

  * Revision 1, 2019-02-05 (Jeff Bolz)
    - Internal revisions