A Combinatorial Architecture for InstructionLevel Parallelism

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A Combinatorial Architecture for
Instruction-Level Parallelism

• Prepared by HongJun Yu

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Regulated Elements By Universal Scheme (REBUS)
EXECUTABLE PROGRAM
Partitioned Instruction Streams
Processing Elements with Replicated Scratchpad
Registers
Combinatorial Interconnection Structure
MCU
MCU
MCU
Sliced Memory Hierarchy
MEMORY SYSTEM
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Processing Elements (PE) and Memory Coordination
Units (MCU)
1 7 5
2 1 6
3 2 7
4 3 1
5 4 2
6 5 3
7 6 4
Reg
PE
2
3
4
5
6
7
1

2
3
4
5
6
7
1
MCU
(X1, X2, X3, X4, X5, X6, X7) using (7, 7, 3, 3 ,1)
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Structure of MCU and its connections
Processing Element
Processing Element
Processing Element
To other MCUs
Scratchpad Registers
Unit Controller
Cache Memory
To and From Main Memory
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Structure of PE
Global Signals Management
Processor With Private Memory
Queues of Scratchpad Copies
R2
R1
MCU Interface
R3
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Pairwise-balanced combinatorial interconnection

• Xx1, X2, X3, X4, X5, X6, X7, X8, X9 a
  Balanced Incomplete Block (BIB) with
  configuration (b, v, r, k, ?)
• v element number b number of k-subsets r
  each element appears exactly in r subsets ?
  each pair of elements appears exactly in ?
  subsets
• vrbk
• For example (12,9,4,3,1) is a BIB

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Cont

• A program can be partitioned amongst the PEs by
  having an instructions operand pair determine
  the PE to which the instruction should be
  designated
• ADD R1 R7
• MULT R2 R6
• DIV R4 R5

PE 1
PE 2
PE 5
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Excellent ideas

• Implementing ultra parallelism using balanced
  incomplete block(BIB)
• Expand parallelism from instruction level to
  assembly code level
• Parallelism is not restricted in a small size
  window of code
• Support parallelism among a group of connected
  processors
• Compatible to current technologies using in
  compiler and superscalar.
• Could benefit to both RISC and CISC.

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Characteristics

• Using fixed format of assembly code
• Usage of memory coordination units (MCU)
• Need data replication

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Future work

• Apply on multi-threaded processing
• Various instruction format support