ACE: And/Or-Parallel Implementation of Prolog
This project aims to build a high performance parallel implementation
of Prolog on multiprocessor architectures based on the the ACE model. The
ACE model uses stack-copying and a novel memory mapping scheme to represent
the multiple environment that exist at runtime. To date, a system has been
built that runs on the Sequent Symmetry and the Sun Sparc Multiprocessor.
The ACE system exploits or-parallelism, independent and-parallelism, dependent
and-parallelism and their data-parallel forms. The system is extremely
efficient (approximately 5% parallel overhead) and has shown excellent
speed-ups on a variety of benchmarks (some as long as 35,000 lines, written
by others). The ACE project has been funded by grants from the National
Science Foundation. The most comprehensive document describing the ACE
system can be found in Enrico Pontelli's 1997 Ph.D. Thesis. The project
has been done in collaboration with Universidad Politecnica de Madrid and
University of Porto.
There are numerous papers written on all aspects of the ACE system, ranging
from implementation techniques, performance evaluation, execution vizualization,
run-time optimization, to extensions.
Click here to
see a report (pdf) on the ACE Project.
G. Gupta, M. Hermenegildo, V. Santos Costa, "And-Or Parallel Prolog: A
Recomputation Based Approach," (selected papers from International conference
on Fifth Generation Computer Systems 1992), New Generation Computing:
An International Journal, Vol. 11 (3,4), June 1993, pp. 298-321.
G. Gupta and V. Santos Costa, "Optimal Implementation of And-Or Parallel
Prolog," (selected papers from PARLE'92: Parallel Architectures and Languages
Europe), Journal of Future Generation Computer Systems, Vol 10,
No. 1 pp. 71-92, Elsevier Science Publishers, Apr. 1994.
G. Gupta, E. Pontelli, M. Hermenegildo, V. Santos Costa, "A Stack-copying
Approach to Parallel Execution of Prolog." Proceedings of the International
Conference on Logic Programming '94, Italy. MIT Press. pp. 93-109.
E. Pontelli, G. Gupta, "Implementation Mechanisms for Dependent And-parallelism"
In Proc. International Conference on Logic Programming, MIT Press,
July 1997. pp. 123-137.
G. Gupta, M. Hermenegildo, "Recomputation based Implementations of And-Or
Parallel Prolog," In Proceedings of the International Conference on
Fifth Generation Computer Systems (FGCS '92), Tokyo, Japan, June '92,
G. Gupta and M. Hermenegildo, "ACE: And/Or-parallel Copying-based Execution
of Logic-programs," In Proceedings of ICLP '91 Workshop on Parallel
Execution of Logic Programs, Springer Verlag, Lecture Notes in Computer
Science 569, Dec. 1991.
G. Gupta, V. Santos Costa "And-Or Parallelism in Full Prolog with Paged
Binding Arrays," In Proceedings of Parallel Architectures and Languages
Europe (PARLE), Springer Verlag Lecture Notes Computer Science 605,
Paris, June 1992, pp. 617-632.
G. Gupta, V. Santos Costa, E. Pontelli, "Shared Paged Binding Array: A
Universal Data-structure for Parallel Logic Programming," In Proc. NSF/ICOT
workshop on Parallel Logic Programming, T. Chikayama and E. Tick (Eds).
University of Oregon CIS-TR-94-04. Mar. 1994.
G. Gupta, V. Santos Costa, R. Yang, M. Hermenegildo, "IDIOM: A Model for
Integrating Dependent-and, Independent-and and Or-parallelism," In Proceedings
of International Logic Programming Symposium, MIT Press, 1991, pages
G. Gupta, V. Santos Costa, "Cuts and Side-effects in And-Or Parallel Prolog,"
Journal of Logic Programming, Vol 27(1), April 96, 45-71.
G. Gupta, V. Santos Costa "Complete and Efficient Methods for supporting
Cuts and Side-effects in And/Or Parallel Prolog," In Proceedings of
IEEE International Symposium on Parallel and Distributed Processing,
IEEE Computer Society Press, pages 288-295, Dec., 1992.
Run-time Optimizations and Efficiency Issues
E. Pontelli, G. Gupta, D. Tang, M. Hermenegildo, M. Carro, "Improving the
Efficiency of Non-deterministic Independent And-parallel Logic Programming
Systems," Journal of Computer Languages, Vol. 22, No. 2-3, pp. 115-142,
E. Pontelli, G. Gupta, "Efficient Parallel Implementation of Backtracking
in Non-deterministic Languages" In International Conference on Parallel
Processing, IEEE Press, Aug, 1998, pp. 338-345.
G. Gupta and E. Pontelli, "Optimization Schemas for Non-deterministic Systems
and Languages," (Extended Paper). In Proceedings of the 1997 IEEE on
Parallel Processing Symposium. IEEE Press, Apr '97. pp. 428-435.
G. Gupta and E. Pontelli, "Last Alternative Optimization," In Proceedings
of the 1996 IEEE Symposium on Parallel and Distributed Computing. IEEE
Press, pp. 538-541.
E. Pontelli, G. Gupta, "Nested Parallel Call Optimization" In Proceedings
of the 10th IEEE International Parallel Processing Symposium, IEEE
Press, Waikiki, Hawaii, April '96.
E. Pontelli, G. Gupta, "On the Duality between Or-parallelism and And-parallelism,"
In European Conference on Parallel Processing '95, Stockholm, Sweden,
Springer Verlag Lecture Notes 966, pp. 43-54.
E. Pontelli, G. Gupta "Data-parallel Logic Programming in &-ACE" In
Proceedings of the 1995 IEEE Syposium on Parallel and Distributed Computing.
IEEE Press, pp. 424-431, TX, Oct. '95.<
E. Pontelli, G. Gupta, D. Tang, "Determinacy Driven Optimization of And-parallel
Logic Programming Systems" In Proc. 1995 International Conference on
Logic Programming, MIT Press, Tokyo, pp. 615-630. June '95.
G. Gupta and B. Jayaraman, "Optimizing And-Or Parallel Implementations,"
In Proceedings of International Logic Programming Symposium, MIT
Press, Oct. 1990, pp. 737-756.
E. Pontelli and G. Gupta, "Parallel Symbolic Computation with ACE," In
Annals of Artificial Intelligence and Mathematics, 21 (1997) 359-395,
G. Gupta, E. Pontelli. "ACE: A High Performance Parallel Prolog System,"
Proceedings of Joint Conference on Declarative Programming. June
1997, pp. 25-31. Invited talk by G. Gupta.
G. Gupta, V. Santos Costa "A Systematic Approach to exploiting Implicit
Parallelism in Prolog," In 26th Hawaii International Conference on System
Sciences, Maui Island, Jan., 1993, pages 417-295.
E. Pontelli, G. Gupta, "Exploiting Maximal Parallelism in Prolog" In 8th
International Conference on Parallel and Distributed Systems, Orlando,
FL, pp. 131-136.
E. Pontelli, G. Gupta, J. Wiebe, D. Farwell, "Natural Language Multiprocessing:
A Case Study," In Proc. AAAI '98, pp. 76-82. July 1998.
E. Pontelli, G. Gupta, M. Hermenegildo, "&-ACE: A High Performance
Parallel Prolog System," In Proc. 9th International Parallel Processing
Symposium, IEEE Press, 1995, pp. 564-571.