CISC 879 - Machine Learning for Solving Systems Problems

Presented by: Sameer KulkarniDept of Computer & Information Sciences

University of Delaware

Improving Both the Performance Benefits and Speed of Optimization

Phase Sequence Searches- Kulkarni, Jantz and Whalley

CISC 879 - Machine Learning for Solving Systems Problems

Terms used

• Phase Ordering• Genetic Algorithms• Performance measurements• Benchmarks• Search granularity

CISC 879 - Machine Learning for Solving Systems Problems

Introduction

• Function vs. program level Granularity• Embedded Systems

• Emulation• Cost benefits

• Hybrid Search

CISC 879 - Machine Learning for Solving Systems Problems

Ideal Solution?

• Oracle Perfect sequence at the very start

• Wise Man Solution Given the present code predict the best optimization solution

CISC 879 - Machine Learning for Solving Systems Problems

Wise Man

?• Understand

Compilers

• Optimizations

• Source Code

CISC 879 - Machine Learning for Solving Systems Problems

Possible Solutions• Pruning the search space

• Genetic Algorithms

• Estimating running times

• Precompiled choices

CISC 879 - Machine Learning for Solving Systems Problems

Genetic Algorithms

Fast Searches for Effective Optimization Phase Sequences, Kulkarni et al. PLDI ‘04

CISC 879 - Machine Learning for Solving Systems Problems

Exhaustive vs Heuristic [2]

CISC 879 - Machine Learning for Solving Systems Problems

Related Work

• Genetic Algorithms• Other Evolutionary Techniques

• HMMs (CGO 06)• Other Statistical methods

• Optimization Space Exploration

CISC 879 - Machine Learning for Solving Systems Problems

Present work

• Granularity• Function Level• File Level• Program Level• Hybrid

CISC 879 - Machine Learning for Solving Systems Problems

Experimental Setup

• VPO (Very Portable Optimizer)• Base Genetic Algorithm• Redundancy elimination

CISC 879 - Machine Learning for Solving Systems Problems

VPO

• Single IR• Simplified phase ordering• Configurable/modifiable

CISC 879 - Machine Learning for Solving Systems Problems

Redundancy Elimination

• Identical Sequence• Identical Active Sequence• Identical Function instance• Equivalent Function

Instance

CISC 879 - Machine Learning for Solving Systems Problems

Improvement…?

120 days > 12.5 days

CISC 879 - Machine Learning for Solving Systems Problems

Granularities Studied…

• Function Level

• File Level

• Program Level

• Hybrid

…all compared to batch compilation

CISC 879 - Machine Learning for Solving Systems Problems

Graphs, graphs and more graphs…

CISC 879 - Machine Learning for Solving Systems Problems

Search Requirements

http://www.ittc.ku.edu/~kulkarni/research/papers/lctes59f-preprint.pdf

CISC 879 - Machine Learning for Solving Systems Problems

Are they any good?

http://www.ittc.ku.edu/~kulkarni/research/papers/lctes59f-preprint.pdf

CISC 879 - Machine Learning for Solving Systems Problems

Performance ??

http://www.ittc.ku.edu/~kulkarni/research/papers/lctes59f-preprint.pdf

CISC 879 - Machine Learning for Solving Systems Problems

Future Work• Other machine learning algorithms• Reduce granularity• Use a cluster to reduce search /

learning time

CISC 879 - Machine Learning for Solving Systems Problems

Conclusion• Reduced search overhead

CISC 879 - Machine Learning for Solving Systems Problems

Questions