Registered Extension Number

568

Revision

1

Ratification Status

Not ratified

Extension and Version Dependencies

None

API Interactions

  • Interacts with VK_KHR_cooperative_matrix

SPIR-V Dependencies

Contact

Extension Proposal

Other Extension Metadata

Last Modified Date

2025-04-16

IP Status

No known IP claims.

Contributors
  • Kévin Petit, Arm Ltd.

  • Stu Smith, AMD

  • Jeff Bolz, NVIDIA

  • Craig Graham, Samsung

Description

This extension enables support for 8-bit floating-point data types as defined in SPV_EXT_float8.

New Structures

New Enum Constants

  • VK_EXT_SHADER_FLOAT8_EXTENSION_NAME

  • VK_EXT_SHADER_FLOAT8_SPEC_VERSION

  • Extending VkStructureType:

    • VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_SHADER_FLOAT8_FEATURES_EXT

If VK_KHR_cooperative_matrix is supported:

  • Extending VkComponentTypeKHR:

    • VK_COMPONENT_TYPE_FLOAT8_E4M3_EXT

    • VK_COMPONENT_TYPE_FLOAT8_E5M2_EXT

New SPIR-V Capabilities

Issues

1) Resolve interactions with the changes VK_KHR_shader_float16 makes to rules for denorm flushing (always allowed by default for all FP formats). How to describe the requirement to preserve subnormals?

+ RESOLVED: Subnormals are always preserved when converting FP8 values to IEEE 754 binary 16. In all other cases, subnormals may be flushed to zero.

+

Version History

  • Revision 1, 2025-04-16 (Kévin Petit)

    • Initial draft

See Also

No cross-references are available

Document Notes

For more information, see the Vulkan Specification

This page is a generated document. Fixes and changes should be made to the generator scripts, not directly.

Copyright 2014-2025 The Khronos Group Inc.

SPDX-License-Identifier: CC-BY-4.0