Compiling Dynamic Mappings with Array Copies TR EMP CRI A To appear in PPoPP

Array remappings are useful to many applications on dis tributed memory parallel machines They are available in High Performance Fortran a Fortran based data parallel language This paper describes techniques to handle dy namic mappings through simple array copies array remap pings are translated into copies between statically mapped distinct versions of the array It discusses the language re strictions required to do so The remapping graph which captures all remapping and liveness information is pre sented as well as additional data ow optimizations that can be performed on this graph so as to avoid useless remap pings at run time Such useless remappings appear for arrays that are not used after a remapping Live array copies are also kept to avoid other ow dependent useless remappings Finally the code generation and runtime required by our scheme are discussed These techniques are implemented in our prototype HPF compiler