Name Strings
SPV_INTEL_unstructured_loop_controls
Contact
To report problems with this extension, please open a new issue at:
Contributors
-
Joe Garvey, Intel
-
Michael Kinsner, Intel
-
Ben Ashbaugh, Intel
-
Alexey Sotkin, Intel
Notice
Copyright (c) 2019 Intel Corporation. All rights reserved.
Status
Final draft
Version
Last Modified Date |
2019-06-12 |
Revision |
1 |
Dependencies
This extension is written against the SPIR-V Specification, Version 1.4 Revision 1.
This extension requires SPIR-V 1.0.
Overview
This extension introduces a new instruction that allows loop control parameters to be applied to unstructured loops. This instruction can be used in place of an OpLoopMerge on such loops. As both must be the second-to-last instruction in a loop header block, they can’t co-exist and there can’t be multiple instances of either in the same loop.
Extension Name
To use this extension within a SPIR-V module, the following OpExtension must be present in the module:
OpExtension "SPV_INTEL_unstructured_loop_controls"
New Capabilities
This extension introduces a new capability:
UnstructuredLoopControlsINTEL
New Instructions
Instructions added under the UnstructuredLoopControlsINTEL capability:
OpLoopControlINTEL
Token Number Assignments
UnstructuredLoopControlsINTEL |
5886 |
OpLoopControlINTEL |
5887 |
Modifications to the SPIR-V Specification, Version 1.4
Loop Control
In Section 3.23, Loop Control, add OpLoopControlINTEL to the set of instructions that can use Loop Controls:
Used by OpLoopMerge and OpLoopControlINTEL.
Capability
Modify Section 3.31, Capability, adding a row to the Capability table:
| Capability | Implicitly Declares | |
|---|---|---|
5886 |
UnstructuredLoopControlsINTEL |
|
Instructions
In section 3.32.17, Control-Flow Instructions, add a new instruction, OpLoopControlINTEL, as follows:
OpLoopControlINTEL Declare a loop. This instruction must be in a block that is the target of a back edge and that block must dominate the back-edge block from which that edge originated. This instruction must immediately precede either an OpBranch or OpBranchConditional instruction. That is, it must be the second-to-last instruction in its block. Loop Control Parameters appear in Loop Control-table order for any Loop Control setting that requires such a parameter. |
Capability: UnstructuredLoopControlsINTEL |
||
2 + variable |
5887 |
Loop Control |
Literal, Literal, … |
Issues
None.
Revision History
| Rev | Date | Author | Changes |
|---|---|---|---|
1 |
2019-06-12 |
Joe Garvey |
Initial public release |