VK_KHR_shader_clock

Other Extension Metadata

Last Modified Date

2019-4-25

IP Status

No known IP claims.

Interactions and External Dependencies

• This extension provides API support for GL_ARB_shader_clock and GL_EXT_shader_realtime_clock

Contributors

• Aaron Hagan, AMD
• Daniel Koch, NVIDIA

Description

This extension advertises the SPIR-V ShaderClockKHR capability for Vulkan, which allows a shader to query a real-time or monotonically incrementing counter at the subgroup level or across the device level. The two valid SPIR-V scopes for OpReadClockKHR are Subgroup and Device.

When using GLSL source-based shading languages, the clockRealtime*EXT() timing functions map to the OpReadClockKHR instruction with a scope of Device, and the clock*ARB() timing functions map to the OpReadClockKHR instruction with a scope of Subgroup.

New Structures

• Extending VkPhysicalDeviceFeatures2, VkDeviceCreateInfo:
  • VkPhysicalDeviceShaderClockFeaturesKHR

New Enum Constants

• VK_KHR_SHADER_CLOCK_EXTENSION_NAME
• VK_KHR_SHADER_CLOCK_SPEC_VERSION
• Extending VkStructureType:
  • VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_SHADER_CLOCK_FEATURES_KHR

New SPIR-V Capabilities

• ShaderClockKHR

Version History

• Revision 1, 2019-4-25 (Aaron Hagan)
  • Initial revision