Company

LOGO

Team Members:

Dan Legorreta Moshe Looks Shobana Padmanabhan

Specialized Clustering Microprocessor

Graduate Computer Architecture I Fall Semester 2005

Final Presentation

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LOGO Project Goals

Long Term:

Make it possible to cluster a high-volume stream of documents in real time.

This Course:

Develop a specialized microprocessor which runs a specific clustering algorithm very

efficiently.

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LOGO Clustering

Problem Clustering algorithms are currently very slow

~ O(n2d) or worse Spend a lot of time “scoring” the clusters Scoring is done using “concept vectors” A “concept vector” is the average/summation of a

document vector

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LOGO Solution

Develop a processor specifically designed for clustering

Base new processor on LEON2 Modify processor to improve clustering application performance

Synthesize and demonstrate improvement on liquid architecture platform Developed at Washington University, by ARL-FPX and DOC

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LOGO

No compiler changes needed But C application changes are needed

Clustering as APB DeviceLEON2 Processor

Lower latency with faster data bus

Clustering as Coprocessor Device

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LOGO Circuit Design - IntroductionStep 1: Represent documents as bit vectors

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LOGO Circuit Design - IntroductionStep 1: Represent documents as bit vectorsStep 2: Compute the bit-wise sumsStep 3: Compute the dot-product for each document

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LOGO Circuit Design - IntroductionStep 3: Compute the dot-product for each documentStep 4: Analyze the quality of the cluster

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LOGO Circuit Design - IntroductionStep 4: Analyze the quality of the cluster

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LOGO Circuit Design - Limitations

Coprocessor Interface Inputs

Data 1 – 64 bits Data 2 – 64 bits Opcode – 9 bits

Outputs Result – 64 bits

Latency 4 clock cycles between each opcode

Cannot access main memory directly

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LOGO Circuit Design – 1st Approach

101010101010110100010101010101010100101000101011010111010011101010111010101010101010010100110010011010101010101101000101010101010101001010001010110101110100111010101110101010101010100101001100001010110101010101011010001010101010101010010100010101101011101001110101011101010101010101001010

101010101101010101010110100010101010101010100101000101011010111010011101010111010101010101010010

101010101010101010110100010101010101010100101000101011010111010011101010111010101010101010010100

101010101010110100010101010101010100101000101011010111010011101010111010101010101010010100110010011010101010101101000101010101010101001010001010110101110100111010101110101010101010100101001100001010110101010101011010001010101010101010010100010101101011101001110101011101010101010101001010

101010101101010101010110100010101010101010100101000101011010111010011101010111010101010101010010

101010101010101010110100010101010101010100101000101011010111010011101010111010101010101010010100

…..

N D

ocu

men

ts

< - 4000 Bits - >

sums

Coprocessor Commands: +3232 +32 +32 +32 +32 +32 +32 +32 +32 +32+ ………. = 32 * N

• Dot Product• Bitwise Sum

32 Additional Coprocessor commands ≈ .5 kb of memory needed per document

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LOGO Circuit Implementation

101010101010110100010101010101010100101000101011010111010011101010111010101010101010010100110010011010101010101101000101010101010101001010001010110101110100111010101110101010101010100101001100001010110101010101011010001010101010101010010100010101101011101001110101011101010101010101001010

101010101101010101010110100010101010101010100101000101011010111010011101010111010101010101010010

101010101010101010110100010101010101010100101000101011010111010011101010111010101010101010010100

101010101010110100010101010101010100101000101011010111010011101010111010101010101010010100110010011010101010101101000101010101010101001010001010110101110100111010101110101010101010100101001100001010110101010101011010001010101010101010010100010101101011101001110101011101010101010101001010

101010101101010101010110100010101010101010100101000101011010111010011101010111010101010101010010

101010101010101010110100010101010101010100101000101011010111010011101010111010101010101010010100

…..

N D

ocu

men

ts

sums

< - 64 Bits - > < - 64 Bits - > < - 64 Bits - >

sums sums

Local Memory

101010101010101010111001010110010101001010101010101010101011

10101010101010101011

sums

10010101100101010010

1010101010101010101110010101100101010010101010101010101010111001010110010101001010101010101010101011

Dot-Product Circuit Partial Dot Product

101010101010101010111001010110010101001010101010101010101011

1010101010101010101110010101100101010010

1010101010101010101110010101100101010010101010101010101010111001010110010101001010101010101010101011

Full Dot Product

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LOGO Circuit Diagram

Cop

roce

ssor

Inte

rfa

ce

Control/Opcode Decode

FIFO(Data Input)

FIFO(Dot

Product)

Dot Product Circuit 1

Dot Product Circuit 2

Adder

Data 1Data 2

Opcode

Result

To LEON

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LOGO Circuit Testing

C program uses inline assembly to issue coprocessor/ dot-product opcodes

Compiled using Liquid development platform, to use sparc-elf-gcc for LEON

Platform creates IP packet based simulation files for ModelSim

Platform uses Synplicity to synthesize, Xilinx tools for building and place-n-route, and creates a bit file

To test on hardware, Liquid web interface to load program into SRAM start LEON (execute program) Read memory, to read results

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LOGO Circuit Testing – C Programlong long op1 = 0x0E000000000000001F;long long op2 = 0x190000000000000022;

// Inline assembly to load address of C vars into gen purpose registersasm(" mov %0, %%l0" : : "r" (&op1)); // Place op1 address in %l0asm(" mov %0, %%l1" : : "r" (&op2)); // Place op2 address in %l1 asm(" mov %0, %%l2" : : "r" (&result)); // Place result addres in %l2

// Load 64-bit op1 value into (%c0,%c1), 64-bit op2 value into (%c2,%c3)asm("ldd [%l0], %c0");asm("ldd [%l1], %c2");

// Load Interal Coprocessor Register 0 with 128-bit value (%c2 & %c1)asm(cpop1(HCLUST_STG1, "0x00", "0x02", "0x30"));

// Store 64-bit value from coproc register file location %c3 to result[0]asm("set 0x40040040, %l2"); // Set bit maskasm("std %c3, [%l2]"); //Store 64-bit value from coproc reg file at (%c1e,%c1f) to

result[0]

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LOGO Circuit Testing

Test cluster contains 4 128 bit vectors Document 1 = 0x0E000000000000001F Document 2 = 0x190000000000000022 Document 3 = 0x220000000000000019 Document 4 = 0x1F000000000000000F

Expected scores Document 1 = 0x15 Document 2 = 0x0B Document 3 = 0x0C Document 4 = 0x17

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LOGO Circuit Testing - Inputs1st Set of Inputs:

0E

19

2nd Set of Inputs

22

1F

3rd Set of Inputs

1F

22

4th Set of Inputs

19

0F

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LOGO Circuit Testing - Outputs

1st Set of Results

2nd Set of Results

15 0B

0C 17

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LOGO Performance Gain Estimate

Assuming n data points, data dimensionality (k) is 4000

Unaccelerated (lower bound) Summation: = 4,000*n cycles Dot Product: = 8,000*n cycles Total: = 12,000*n cycles

Accelerated (upper bound) Stage One: (1.5 * n) * k / 64 = 95*n cycles Stage Two: 2 * k / 64 = 125 cycles Stage Three: 4 * n = 4*n cycles Total: = 97*n + 125 cycles

Clustering is hierarchal, so cumulative speedup factor is: At least: 12,000 / (97 + 125) ~= 54 At most: 12,000 / 97 ~= 124

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LOGO Questions

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LOGO

Modified clustering application to run on Leon Challenges

25 MHz No OS and so no system calls, no I/O, only 4MB SRAM &

32KB icache & dcache each Recursion/ function calls restricted to 7 levels No debugger, other than reading from memory

Some of these addressed with a new cross-compiler but profiler not upgraded for the new cross-compiler

Progress – part 1: Clustering App

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LOGO Progress – part 2: APB device

Implemented APB device interface Challenges

Huge Leon code-base Integrate the device, decode memory-mapped registers

Designed dot-product circuit to gain 50% speedup But for more speedup, we switched to Co-

processor interface

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LOGO Progress – part 3: Co-processor

Extended hardware implementation to do scoring besides dot-product. Prof. Young helped with design.

Implemented both circuits (3 stages). Tested integration of stage1 with LEON.

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LOGO Sample C code for APB

// Dot-product Device Registersint *PDevice_Init = (int *) 0x800000D0; // Initailize Deviceint *PDevice_Status = (int *) 0x800000D0; // Device Statusint *PDevice_Data = (int *) 0x800000D4; // Device Inputint *PDevice_Length = (int *) 0x800000D8; // Device Result

int recieveBuffer[300]; // Store the result

main() {

PDevice_Init[0] = 0;

if (PDevice_Status[0] == 0) { recieveBuffer[0] = PDevice_Data[0]; }}

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LOGO APB Device

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LOGO Co-processor