Preliminary Experiences with the Fortran D

Fortran D is a version of Fortran enhanced with data decomposition speciications. Case studies illustrate strengths and weaknesses of the prototype Fortran D compiler when compiling linear algebra codes and whole programs. Statement groups, execution conditions, inter-loop communication optimizations, multi-reductions, and array kills for replicated arrays are identiied as new compilation issues. On the Intel iPSC/860, the output of the prototype Fortran D compiler approaches the performance of hand-optimized code for parallel computations, but needs improvement for linear algebra and pipelined codes. The Fortran D compiler outperforms the CM Fortran compiler (2.1 beta) by a factor of four or more on the TMC CM-5 when not using vector units. Better analysis, run-time support , and exibility are required for the prototype compiler to be useful for a wider range of programs.