Name Strings

SPV_EXT_shader_64bit_indexing

Contact

To report problems with this extension, please open a new issue at:

https://github.com/KhronosGroup/SPIRV-Headers

Contributors

  • Jeff Bolz, NVIDIA

Notice

Copyright (c) 2025 The Khronos Group Inc. Copyright terms at http://www.khronos.org/registry/speccopyright.html

Status

  • Approved by the SPIR-V Working Group: 2025-09-03

  • Approved by the Khronos Board of Promoters: 2025-10-17

Version

Last Modified Date

2025-10-22

Revision

1

Dependencies

This extension is written against the SPIR-V Specification, Version 1.6, Revision 5, Unified.

This extension requires SPIR-V 1.0.

This extension interacts with SPV_NV_cooperative_vector.

This extension interacts with SPV_KHR_untyped_pointers.

Overview

This extension allows shaders to request 64-bit addressing calculations, as defined in the VK_EXT_shader_64bit_indexing extension.

Extension Name

To use this extension within a SPIR-V module, the following OpExtension must be present in the module:

OpExtension "SPV_EXT_shader_64bit_indexing"

Modifications to the SPIR-V Specification, Version 1.6

3.6 Execution Mode

Modify Section 3.6, "Execution Mode", adding these rows to the Execution Mode table:

Execution Mode Extra Operands Enabling Capabilities

5427

Shader64BitIndexingEXT
Requests the use of 64-bit indexing, as defined by the execution environment.

Shader64BitIndexingEXT

3.3.8. Memory Instructions

Modify OpArrayLength and OpUntypedArrayLengthKHR, to replace:

"Result Type must be an OpTypeInt with 32-bit Width and 0 Signedness."

with:

"Result Type must be an OpTypeInt with 32- or 64-bit Width and 0 Signedness."

3.42.X Cooperative Vector Instructions

Modify OpCooperativeVectorMatrixMulAddNV, to replace:

"MatrixOffset must be a 32 bit integer." and "BiasOffset must be a 32 bit integer."

with:

"MatrixOffset must be a 32- or 64-bit integer." and "BiasOffset must be a 32- or 64-bit integer."

Modify OpCooperativeVectorLoadNV, OpCooperativeVectorStoreNV, OpCooperativeVectorOuterProductAccumulateNV, and OpCooperativeVectorReduceSumAccumulateNV, to replace:

"Offset must be a 32 bit integer."

with:

"Offset must be a 32- or 64-bit integer."

3.31 Capabilities

Modify Section 3.31, "Capability", adding these rows to the Capability table:

Capability Implicitly Declares

5426

Shader64BitIndexingEXT
Enables the Shader64BitIndexingEXT execution mode.

Issues

Revision History

Rev Date Author Changes

1

2025-10-22

Jeff Bolz

Initial revision of SPV_EXT_shader_64bit_indexing