Parallel Computing On Qualcomm Platforms Using OpenCL - Uplinq

OpenCL Memory Model
• Memory Types
– Private: on-chip, temp register file
– Local: on-chip, read-write, shared within a compute
unit
– Constant: on-chip memory, read-only, shared within
compute unit
– Global: system memory, shared between all
compute units, can be on host or device
• Memory model
– OpenCL provides barrier mechanism for
synchronization
o Memory is assumed to be undefined across work items
unless explicitly synchronized
– Multiple distinct address spaces
– Address spaces can be collapsed depending on the
device’s memory subsystem
• Diagram shows typical memory layout for a
GPU architecture
t
Private
Memory
Private
Memory
Private
Memory
Private
Memory
ALU #1 ALU #M ALU #1 ALU #M
Local Memory
Compute Unit 1
Compute Device
Local Memory
Compute Unit N
Global / Constant Memory Data Cache
Global Memory
Compute Device Memory
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Qualcomm Proprietary