Optimal Compilation of HPF Remappings
Fabien Coelho and Corinne Ancourt.
Report EMP CRI A-274, July 1995.
20 pages, 35 references.
This report is obsoleted by A-277 (abstract).
Applications with varying array access patterns in a parallel
distributed memory machine require to dynamically change array
mappings. HPF (High Performance Fortran) provides such
remappings, possibly on partially replicated data, explicitly
through the realign and redistribute directives
and implicitly at procedure calls and returns. However such
features are left out of the HPF subset or of the currently
discussed HPF kernel for efficiency reason. This paper
presents a new compilation technique to handle HPF
remappings for message-passing parallel architectures. The
first phase is global and removes all useless remappings that
naturally appear in procedures. The second phase generates
the actual remapping code and takes advantage of replications
to shorten the remapping time. A minimal number of messages,
containing only the required data, is sent over the network.