AITEC Contract Research Projects in FY1996 : Software

(4) An Optimization Technique of Efficient Goal Scheduling for KL1 Programs

Dr. Hiroshi Nakashima, Associate Professor, Kyoto University
(Currently - Toyohashi University of Technology)

Improved KLIC with Optimized Goal Scheduling


		Machines: Any Unix Machine
		Environment: UNIX
		Language: C, KL1
		Amount of Sources: 10MB
		Documents: User's Manual (Japanese only)

[Abstract]

An improved version of the parallel logic programming language system KLIC, with an optimized goal scheduler and a program analyzer for optimization.

[Features]

Since the original version of KLIC dynamically schedules the execution order of goals, its scheduling overhead may cause significant performance degradation if your program consists of, for example, communicating sequential processes.

This optimized version aims to reduce the scheduling overhead through compile-time dependency analysis to find threads. Since a thread consists of goals whose order of execution is statically determined, the runtime system efficiently executes the thread without scheduling overhead.

[Functions]

Compile-time dependency analysis for static scheduling of the goals in a thread.
Efficient runtime scheduling combining intra-thread static scheduling and inter-thread dynamic scheduling.
Intra-thread execution environment management with stacks to reduce GC frequency.
Optimized calling sequence for statically determined goal invocation.
"Reply-first" scheduling for quick response of inter-node communications.

NOTE: A limited set of built-in predicates is available due to the incompleteness of the dependency analyzer. Separated compilation is not available yet.

[File Directories]

The files in the following directories of the standard distribution of KLIC are modified.

compiler optimized version of compiler
runtime optimized version of runtime system
include/klic include files for optimized runtime system

The following directories are added to the standard distribution.

compiler/analyzer analyzer
sched-test test programs

[FTP]

README
Program and Documents in Japanese [1418K] (10.Apr.1998 New)

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