VK_EXT_shader_demote_to_helper_invocation

Other Extension Metadata

Last Modified Date

2019-06-01

IP Status

No known IP claims.

Interactions and External Dependencies

• This extension provides API support for GL_EXT_demote_to_helper_invocation

Contributors

• Jeff Bolz, NVIDIA

Description

This extension adds Vulkan support for the SPV_EXT_demote_to_helper_invocation SPIR-V extension. That SPIR-V extension provides a new instruction OpDemoteToHelperInvocationEXT allowing shaders to demote a fragment shader invocation to behave like a helper invocation for its duration. The demoted invocation will have no further side effects and will not output to the framebuffer, but remains active and can participate in computing derivatives and in group operations. This is a better match for the discard instruction in HLSL.

New Structures

• Extending VkPhysicalDeviceFeatures2, VkDeviceCreateInfo:
  • VkPhysicalDeviceShaderDemoteToHelperInvocationFeaturesEXT

New Enum Constants

• VK_EXT_SHADER_DEMOTE_TO_HELPER_INVOCATION_EXTENSION_NAME
• VK_EXT_SHADER_DEMOTE_TO_HELPER_INVOCATION_SPEC_VERSION
• Extending VkStructureType:
  • VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_SHADER_DEMOTE_TO_HELPER_INVOCATION_FEATURES_EXT

New SPIR-V Capability

• DemoteToHelperInvocationEXT

Promotion to Vulkan 1.3

Functionality in this extension is included in core Vulkan 1.3, with the EXT suffix omitted. The original type, enum and command names are still available as aliases of the core functionality.

Version History

• Revision 1, 2019-06-01 (Jeff Bolz)
  • Initial draft