SPV_ALTERA_fpga_memory

Name Strings

SPV_ALTERA_fpga_memory_attributes

Contact

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

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

Contributors

Ben Ashbaugh, Intel
Mohammad Fawaz, Intel
Joe Garvey, Intel
Michael Kinsner, Intel
Julian Packer, Intel
Artem Radzikhovksyy, Intel

Notice

Status

Final draft

Version

Last Modified Date

2023-10-03

Revision

Dependencies

This extension is written against the SPIR-V Specification, Version 1.5 Revision 2.

This extension requires SPIR-V 1.0.

Overview

This extension adds decorations that influence compiler generation of memory structures on an FPGA target.

Extension Name

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

OpExtension "SPV_ALTERA_fpga_memory_attributes"

New capabilities

This extension introduces a new capability:

FPGAMemoryAttributesALTERA

New Decorations

Decorations added under the FPGAMemoryAttributes capability:

RegisterALTERA
MemoryALTERA
NumbanksALTERA
BankwidthALTERA
MaxPrivateCopiesALTERA
SinglepumpALTERA
DoublepumpALTERA
MaxReplicatesALTERA
SimpleDualPortALTERA
MergeALTERA
BankBitsALTERA
ForcePow2DepthALTERA
StridesizeALTERA
WordsizeALTERA
TrueDualPortALTERA

Token Number Assignments

FPGAMemoryAttributesALTERA	5824
RegisterALTERA	5825
MemoryALTERA	5826
NumbanksALTERA	5827
BankwidthALTERA	5828
MaxPrivateCopiesALTERA	5829
SinglepumpALTERA	5830
DoublepumpALTERA	5831
MaxReplicatesALTERA	5832
SimpleDualPortALTERA	5833
MergeALTERA	5834
BankBitsALTERA	5835
ForcePow2DepthALTERA	5836
StridesizeALTERA	5883
WordsizeALTERA	5884
TrueDualPortALTERA	5885

Modifications to the SPIR-V Specification, Version 1.5

Decoration

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

Decoration	Extra Operands	Enabling Capabilities
5825	RegisterALTERA Apply to a variable or a structure-type member. Request, to the extent possible, that the variable or structure member should be implemented in logic and carried through the datapath.		FPGAMemoryAttributesALTERA
5826	MemoryALTERA Apply to a variable or a structure-type member. Request, to the extent possible, that the variable or structure member should be implemented in memory of the specified type. Supported strings: DEFAULT: Implemenation defined what memory resource is used to implement the variable MLAB: data is stored in special Adaptive Logic Modules (ALMs), called memory-logic array blocks BLOCK_RAM: data is stored in dedicated block RAM modules	Literal String Memory Type	FPGAMemoryAttributesALTERA
5827	NumbanksALTERA Apply to a variable or a structure-type member. Request, to the extent possible, that the variable or structure member should be implemented in a memory with the specified number of banks.	Literal Number Banks	FPGAMemoryAttributesALTERA
5828	BankwidthALTERA Apply to a variable or a structure-type member. Request, to the extent possible, that the variable or structure member should be implemented in a memory whose banks have the specified width in bytes.	Literal Number Bank Width	FPGAMemoryAttributesALTERA
5829	MaxPrivateCopiesALTERA Apply to a variable or a structure-type member. Request, to the extent possible, that no more than the specified number of independent copies of the memory synthesized for the variable or structure member should be created for the purpose of enabling concurrent thread or loop iteration accesses.	Literal Number Maximum Copies	FPGAMemoryAttributesALTERA
5830	SinglepumpALTERA Apply to a variable or a structure-type member. Request, to the extent possible, that the variable or structure member should be implemented in a memory that is clocked at the same rate as accesses to it.		FPGAMemoryAttributesALTERA
5831	DoublepumpALTERA Apply to a variable or a structure-type member. Request, to the extent possible, that the variable or structure member should be implemented in a memory that is clocked at twice the rate of accesses to it.		FPGAMemoryAttributesALTERA
5832	MaxReplicatesALTERA Apply to a variable or a structure-type member. Request, to the extent possible, that each copy of the memory synthesized for the variable or structure member should be replicated no more than the specified number of times for the purpose of enabling simultaneous accesses from different load/store sites in the program.	Literal Number Maximum Replicates	FPGAMemoryAttributesALTERA
5833	SimpleDualPortALTERA Apply to a variable or a structure-type member. Request, to the extent possible, that the variable or structure member should be implemented in a memory that is configured such that no memory port services both stores and loads.		FPGAMemoryAttributesALTERA
5834	MergeALTERA Apply to a variable or a structure-type member. Request, to the extent possible, that the variable or structure member should be implemented in a memory that is merged with any memories synthesized from arrays or structure members that are decorated with this decoration and the same specified merge key. The mechanism of this merging is specified as a subsequent literal string.	Literal String Merge Key	Literal String Merge Type	FPGAMemoryAttributesALTERA
5835	BankBitsALTERA Apply to a variable or a structure-type member. Request, to the extent possible, that the variable or structure member should be implemented in a banked memory system, where the bits specified determine the pointer address bits to bank on.	Literal Number, Literal Number, … Bank Bits	FPGAMemoryAttributesALTERA
5836	ForcePow2DepthALTERA Apply to a variable or a structure-type member. Request that the variable or structure member should be implemented in a memory that is a power-of-2 deep. This option is enabled if the subsequent literal number specified is 1, and disabled if the subsequent literal number specified is 0.	Literal Number Force Power-Of-2 Depth	FPGAMemoryAttributesALTERA
5883	StridesizeALTERA Apply to a variable or a structure-type member of array type. Request, to the extent possible, that Stride Size worth of consecutive array elements be placed in the same memory bank.	Literal Number Stride Size	FPGAMemoryAttributesALTERA
5884	WordsizeALTERA Apply to a variable or a structure-type member of array type. Request, to the extent possible, the size in array elements of a single memory transaction.	Literal Number Word Size	FPGAMemoryAttributesALTERA
5885	TrueDualPortALTERA Apply to a variable or a structure-type member. Request, to the extent possible, that the variable or structure member should be implemented in a memory that is configured such that all memory ports can service both stores and loads.		FPGAMemoryAttributesALTERA

Decoration

Extra Operands

Enabling Capabilities

5825

RegisterALTERA
Apply to a variable or a structure-type member. Request, to the extent possible, that the variable or structure member should be implemented in logic and carried through the datapath.