Project Leaders

• Jean-Luc Gaudiot, University of Southern California
• Wim Bohm and Walid Najjar, Colorado State University
• John Feo and Patrick Miller, Lawrence Livermore National Laboratory

Objectives

• Design, develop, and deliver
  • high-performance, mixed-language compilers and runtime systems for NOWs, MPPs, and multi-threaded architectures
  • a seamless, high-performance mixed-language interface
  • architecture-independent, inter-operable debugging and performance monitoring tools
• Mixed-Language Programming
  • Integrate the implementation of Sisal 90 compilers and runtime systems with Fortran, C, and C++
  • promotes code re-use
  • increases the appeal of functional programming
• Automate the Sisal Foreign Language Interface
  • exchange of non-scalar objects
  • exchange of data distribution and alignment information

An example using a FORTRAN molecular dynamics code

In the original code, 90% of the work was done by 10% of the code (the modules NON-BOND and OTHER-FORCES). This kernel was parallelized by converting it to SISAL. This had some impact on FORCE-RUN and CALC-FORCES, but the rest of the code was unchanged. This leveraged the development time put into the old code (I/O interface, etc...) into the new parallel code. Parts of the algorithm were rethought, but the effects were confined.

Mixed-Language Debugging

• Only a sequential debugger is necessary since Sisal's functional semantics guarantee determinate behavior
• Incorporate Sisal source information into the C code generated by the Sisal compiler
• Extend dbx to understand and make use of the incorporated Sisal source information

Distributed-memory Implementations

• Develop static analysis for array and loop distribution
• Include directives and pragmas for data distribution and alignment
• Develop a compiler and runtime system based on Split-C and one based on MPI
• Exploit computation/communication overlap

Impact

• code reuse
• implicit parallelism (eliminate time-dependent errors)
• seamless language interface and inter-operable tools
• Robust Sisal, Fortran, C, and C++ tools available on commercial MPP systems.

Current Work

• Sisal 90 front-end
• Automatic Foreign language Interface
• Semantic array and loop analysis
• Array distribution and alignment pragmas
• Mixed-language debugger
• Sisal to Split-C
• Sisal to C+MPI