Name
NV_shader_atomic_int64
Name Strings
GL_NV_shader_atomic_int64
Contact
Pat Brown, NVIDIA (pbrown 'at' nvidia.com)
Contributors
Pat Brown, NVIDIA
Jeff Bolz, NVIDIA
Cyril Crassin, NVIDIA
Christoph Kubisch, NVIDIA
Status
Shipping
Version
Last Modified Date: March 13, 2014
NVIDIA Revision: 2
Number
OpenGL Extension #455
Dependencies
This extension is written against version 4.40 (revision 8) of the OpenGL
Shading Language Specification, dated January 22, 2014.
This extension interacts with NV_shader_buffer_store and NV_gpu_shader5.
This extension interacts with NV_gpu_program5, NV_compute_program5, and
NV_shader_storage_buffer_object.
Overview
This extension provides additional GLSL built-in functions and assembly
opcodes allowing shaders to perform additional atomic read-modify-write
operations on 64-bit signed and unsigned integers stored in buffer object
memory.
New Procedures and Functions
None.
New Tokens
None.
Additions to OpenGL 4.4 Specification
None.
Additions to the AGL/GLX/WGL Specifications
None.
GLX Protocol
None.
Modifications to the OpenGL Shading Language Specification, Version 4.40
(revision 8)
Including the following line in a shader can be used to control the
language features described in this extension:
#extension GL_NV_shader_atomic_int64 :
where is as specified in section 3.3.
New preprocessor #defines are added to the OpenGL Shading Language:
#define GL_NV_shader_atomic_int64 1
Modify Section 8.11, Atomic Memory Functions, p. 168
Add the following new functions to the table on p. 173:
uint64_t atomicMin(inout uint64_t mem, uint64_t data);
uint64_t atomicMax(inout uint64_t mem, uint64_t data);
uint64_t atomicAnd(inout uint64_t mem, uint64_t data);
uint64_t atomicOr (inout uint64_t mem, uint64_t data);
uint64_t atomicXor(inout uint64_t mem, uint64_t data);
int64_t atomicMin(inout int64_t mem, int64_t data);
int64_t atomicMax(inout int64_t mem, int64_t data);
int64_t atomicAnd(inout int64_t mem, int64_t data);
int64_t atomicOr (inout int64_t mem, int64_t data);
int64_t atomicXor(inout int64_t mem, int64_t data);
int64_t atomicAdd(inout int64_t mem, int64_t data);
int64_t atomicExchange(inout int64_t mem, int64_t data);
int64_t atomicCompSwap(inout int64_t mem, int64_t data);
Dependencies on NV_shader_buffer_store and NV_gpu_shader5
If NV_shader_buffer_store and NV_gpu_shader5 are supported, the following
functions should be added to the "Section 8.Y, Shader Memory Functions"
language in the NV_shader_buffer_store specification:
uint64_t atomicMin(uint64_t *address, uint64_t data);
uint64_t atomicMax(uint64_t *address, uint64_t data);
uint64_t atomicAnd(uint64_t *address, uint64_t data);
uint64_t atomicOr (uint64_t *address, uint64_t data);
uint64_t atomicXor(uint64_t *address, uint64_t data);
int64_t atomicMin(int64_t *address, int64_t data);
int64_t atomicMax(int64_t *address, int64_t data);
int64_t atomicAnd(int64_t *address, int64_t data);
int64_t atomicOr (int64_t *address, int64_t data);
int64_t atomicXor(int64_t *address, int64_t data);
int64_t atomicAdd(int64_t *address, int64_t data);
int64_t atomicExchange(int64_t *address, int64_t data);
int64_t atomicCompSwap(int64_t *address, int64_t data);
Dependencies on NV_gpu_program5, NV_compute_program5, and
NV_shader_storage_buffer_object
If NV_gpu_program5 is supported and "OPTION NV_shader_atomic_uint64" is
specified in an assembly program, new combinations of atomic operations
and storage modifiers are supported for the ATOM, ATOMB, and ATOMS
instructions. (Note: ATOMB comes from NV_shader_storage_buffer_object
and ATOMS comes from NV_compute_program5.) "S64" should be allowed as a
storage modifier for the atomic operations "MIN', "MAX", "AND", "OR",
"XOR", "ADD", "EXCH", and "CSWAP". "U64" should be allowed a s storage
modifier for the atomic operations "MIN", "MAX", "AND", "OR", and "XOR".
(Add to "Section 2.X.6, Program Options" of the NV_gpu_program4 extension,
as extended by NV_gpu_program5:)
+ Extended 64-bit Atomic Operations (NV_shader_atomic_uint64)
If a program specifies the "NV_shader_atomic_uint64" option, it may
use the "S64" storage modifier with the atomic operations "MIN',
"MAX", "AND", "OR", "XOR", "ADD", "EXCH", and "CSWAP", and the "U64"
storage modifier with the atomic operations "MIN", "MAX", "AND", "OR",
and "XOR".
(Add "U64" and or "S64" opcode modifiers to the table in "Section 2.X.8.Z:
ATOM" in NV_gpu_program5, "Section 2.X.8.Z: ATOMS" in
NV_compute_program5, and "Section 2.X.8.Z: ATOMB" in
NV_shader_storage_buffer_object)
atomic storage
modifier modifiers operation
-------- ------------------ --------------------------------------
ADD U32, S32, U64, S64 compute a sum
MIN U32, S32, U64, S64 compute minimum
MAX U32, S32, U64, S64 compute maximum
AND U32, S32, U64, S64 compute bit-wise AND
OR U32, S32, U64, S64 compute bit-wise OR
XOR U32, S32, U64, S64 compute bit-wise XOR
EXCH U32, S32, U64, S64 exchange memory with operand
CSWAP U32, S32, U64, S64 compare-and-swap
No new support is provided for the IWRAP and DWRAP atomic operations.
Errors
None.
New State
None.
New Implementation Dependent State
None.
Issues
None.
Revision History
Revision 2, March 13, 2014 (pbrown)
Update to OpenGL 4.4 / GLSL 4.40, plus minor clarifications.
Revision 1, November 8, 2013 (ckubisch)
Initial revision.