Name Strings

SPV_INTEL_global_variable_host_access

Contact

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

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

Contributors

  • Artem Radzikhovskyy, Intel

  • Michael Kinsner, Intel

  • Joe Garvey, Intel

  • Mohammad Fawaz, Intel

  • Gregory Lueck, Intel

Notice

Copyright (c) 2021-2023 Intel Corporation. All rights reserved.

Status

  • Complete

Version

Last Modified Date

2023-10-27

Revision

4

Dependencies

This extension is written against the SPIR-V Specification, Version 1.6 Revision 2.

This extension requires SPIR-V 1.0.

Overview

This extension adds a decoration that can be applied to global (module scope) variables. This decoration explicitly asserts that the global variable can be accessed outside the SPIR-V module.

Extension Name

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

OpExtension "SPV_INTEL_global_variable_host_access"

New Capabilities

This extension introduces a new capability:

GlobalVariableHostAccessINTEL

Token Number Assignments

GlobalVariableHostAccessINTEL

6187

HostAccessINTEL

6188

Modifications to the SPIR-V Specification, Version 1.6

Host Access Qualifier

After Section 3.18, add a new section "3.18a Host Access Qualifier" as follows

Defines the host system access permissions.

Used by HostAccessINTEL.

Host Access Qualifier Enabling Capabilities

0

NoneINTEL

The execution environment may neither read nor write the variable from the host. On an FPGA device, no memory port is exposed.

GlobalVariableHostAccessINTEL

1

ReadINTEL

The execution environment may read the variable from the host but will never write it. On an FPGA device, only a read memory port is exposed.

GlobalVariableHostAccessINTEL

2

WriteINTEL

The execution environment may write the variable from the host but will never read it. On an FPGA device, only a write memory port is exposed.

GlobalVariableHostAccessINTEL

3

ReadWriteINTEL

The execution environment may read or write the variable from the host. On an FPGA device, a read/write memory port is exposed.

GlobalVariableHostAccessINTEL

Decoration

Modify Section 3.20, Decoration, adding these rows to the Decoration table:

Decoration Extra Operands Enabling Capabilities

6188

HostAccessINTEL
Only valid on global (module scope) OpVariable.

The client API’s execution environment may provide a way to access a global variable’s value from the host system. If it does, this decoration provides two pieces of information. Access is an assertion by the producer about the types of these accesses, which may allow the consumer to perform certain optimizations. Name is a name which the client API’s execution environment may use to identify this variable.

If a global OpVariable is not decorated with HostAccessINTEL, the default behavior is defined by the client API specification.

Host Access Qualifier
Access

Literal String
Name

GlobalVariableHostAccessINTEL

Capability

Modify Section 3.31, Capability, adding a row to the Capability table:

Capability Implicitly Declares

6187

GlobalVariableHostAccessINTEL

Validation Rules

  • It is invalid for two HostAccessINTEL decorations in the same module to have the same Name operand.

Issues

None.

Revision History

Rev Date Author Changes

1

2022-11-1

Gregory Lueck

Initial revision

2

2023-04-25

Artem Radzikhovskyy

Address default behavior

3

2023-06-30

Artem Radzikhovskyy

Typo in capability

4

2023-10-27

Artem Radzikhovskyy

Reverting Capability ID