Function Level Parallelism Lead by Data Dependencies

Function Level Parallelism Lead by Data Dependencies

Sean Rul, Hans Vandierendonck and Koen De Bosschere

Ghent University, ELIS-PARIS, Sint-Pietersnieuwstraat 41, 9000 Gent, Belgium

Sean Rul is supported by the Institute for the Promotion of Innovation through Science and Technology in Flanders

sean.rul@UGent.be http://www.elis.ugent.be/~srul

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Compression Decompression Total

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Original Heterogeneous Homogeneous

ConclusionConclusionConclusionConclusionResultsResultsResultsResults

ProblemProblemProblemProblem ApplicationsApplicationsApplicationsApplications

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Intercluster data stream

Intracluster data stream

FPGA

MethodMethodMethodMethod

Matching parallel constructsMatching parallel constructsMatching parallel constructsMatching parallel constructs

Call GraphCall GraphCall GraphCall Graph InterproceduralInterproceduralInterproceduralInterprocedural Data Flow GraphData Flow GraphData Flow GraphData Flow Graph Data Sharing GraphData Sharing GraphData Sharing GraphData Sharing Graph

Abstracting profiled informationAbstracting profiled informationAbstracting profiled informationAbstracting profiled information

ParallelizingParallelizingParallelizingParallelizing

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Sequential programSequential programSequential programSequential program

Multithreaded Multithreaded Multithreaded Multithreaded programprogramprogramprogram

Hybrid Hardware / Software or embedded

systems

Data Partitioning onCell processor

Besides parallelizing sequential programs:

Program Bzip2 (SPEC2000) with reference input

Executed on a quad Itanium® system

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# executions

% execution time

Read

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Cluster privateCluster shared

Write

•New microprocessor generation: Increase in parallel computing power

•Sequential programs: Cannot exploit these resources

•Parallelizing by hand: Difficult and time consuming

•Let the compiler do it:Setup framework for parallelism detection

•Call graph and interprocedural data flow graphare useful for detecting parallel constructs

•Data sharing graph reveals data affinitybetween functions

•Future work:- Find new parallel constructs- Investigate bidirectional data streams

Look for a balanced solution

Detect for examplea data pipeline

Minimize communication between threads Add synchronization and initialization code

Elliptic node:Data structure

Rectangular node: Function