SPV_KHR_8bit

Name Strings

SPV_KHR_8bit_storage

Contact

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

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

Contributors

Alexander Galazin, Arm
Ruihao Zhang, Qualcomm

Notice

Status

Complete
Approved by the SPIR Working Group: 2018-03-28

Version

Last Modified Date

2019-06-10

Revision

4

Dependencies

This extension is written against the SPIR-V Specification, Version 1.3 Revision 1.

This extension requires SPIR-V 1.0.

This extension requires SPV_KHR_storage_buffer_storage_class.

This extension interacts with SPV_KHR_16bit_storage.

Overview

This extension adds new StorageBuffer8BitAccess, UniformAndStorageBuffer8BitAccess, and StoragePushConstant8 capabilities to allow accesses to 8-bit integer types in the StorageBuffer, Uniform, and PushConstant storage classes.

Extension Name

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

OpExtension "SPV_KHR_8bit_storage"

Modifications to the SPIR-V Specification, Version 1.1

Modify Section 3.31, Capability, adding the following rows to the Capability table:

Capability	Depends On
4448	StorageBuffer8BitAccess Allows an OpTypePointer to an 8-bit OpTypeInt type used as a member of a structure in the StorageBuffer storage class. The 8-bit object pointed to by such a pointer may be the result of a width-only conversion instruction (OpSConvert, or OpUConvert) from another type or of an OpLoad, and may be used as an operand to a width-only conversion instruction to another type or as the Object operand of an OpStore. Other uses of 8-bit types are not enabled by this capability.
4449	UniformAndStorageBuffer8BitAccess Allows an OpTypePointer to an 8-bit OpTypeInt type used as a member of a structure in either of the Uniform or StorageBuffer storage classes. The 8-bit object pointed to by such a pointer may be the result of a width-only conversion instruction (OpSConvert, or OpUConvert) from another type or of an OpLoad, and may be used as an operand to a width-only conversion instruction to another type or as the Object operand of an OpStore. Other uses of 8-bit types are not enabled by this capability.	StorageBuffer8BitAccess
4450	StoragePushConstant8 Allows an OpTypePointer to an 8-bit OpTypeInt type used as a member of a structure in the PushConstant storage class. The 8-bit object pointed to by such a pointer may be the result of a width-only conversion instruction (OpSConvert, or OpUConvert) from another type or of an OpLoad. Other uses of 8-bit types are not enabled by this capability.

Capability

Depends On

4448

StorageBuffer8BitAccess
Allows an OpTypePointer to an 8-bit OpTypeInt type used as a member of a structure in the StorageBuffer storage class.

The 8-bit object pointed to by such a pointer may be the result of a width-only conversion instruction (OpSConvert, or OpUConvert) from another type or of an OpLoad, and may be used as an operand to a width-only conversion instruction to another type or as the Object operand of an OpStore.

Other uses of 8-bit types are not enabled by this capability.

4449

UniformAndStorageBuffer8BitAccess
Allows an OpTypePointer to an 8-bit OpTypeInt type used as a member of a structure in either of the Uniform or StorageBuffer storage classes.

The 8-bit object pointed to by such a pointer may be the result of a width-only conversion instruction (OpSConvert, or OpUConvert) from another type or of an OpLoad, and may be used as an operand to a width-only conversion instruction to another type or as the Object operand of an OpStore.

Other uses of 8-bit types are not enabled by this capability.

StorageBuffer8BitAccess

4450

StoragePushConstant8
Allows an OpTypePointer to an 8-bit OpTypeInt type used as a member of a structure in the PushConstant storage class.

The 8-bit object pointed to by such a pointer may be the result of a width-only conversion instruction (OpSConvert, or OpUConvert) from another type or of an OpLoad.

Other uses of 8-bit types are not enabled by this capability.

Interactions with optional types

If the Int8 capability is declared, then the 8-bit OpTypeInt instruction mentioned earlier can be used as an operand or a result to any supported instruction with an 8-bit result type or an 8-bit operand type.

If the Int16 or the Float16 capability is declared, then the 8-bit OpTypeInt instruction mentioned earlier can be used as an operand or a result to any supported conversion instruction with a 16-bit result type or a 16-bit operand type.

If the Int64 or the Float64 capability is declared, then the 8-bit OpTypeInt instruction mentioned earlier can be used as an operand or result to any supported conversion instruction with a 64-bit result type or a 64-bit operand type.

Interactions with SPV_KHR_16bit_storage

If any capability is declared from the SPV_KHR_16bit_storage extension, then the object produced by dereferencing a pointer pointing to 8-bit data can be used as an operand or a result to a width-only conversion instruction with a 16-bit result type or a 16-bit operand type, and in addition, the object produced by dereferencing a pointer pointing to 16-bit data mentioned in the Capability section of the SPV_KHR_16bit_storage extension can be used as an operand or a result to a width-only conversion instruction with an 8-bit result type or an 8-bit operand type.

Issues

Revision History

Rev	Date	Author	Changes
1	2017-10-05	Alexander Galazin	Initial revision
2	2017-11-01	Alexander Galazin	Assigned token numbers
3	2018-03-28	David Neto	Record approval by SPIR Working Group
4	2019-06-10	John Kessenich	Rationalize and clean up