Making legacy Fortran code type safe through automated program transformation

Abstract Fortran is still widely used in scientific computing, and a very large corpus of legacy as well new code written FORTRAN 77. In general this not type safe, so that incorrect programs can compile without errors. paper, we present formal approach to ensure safety through automated program transformation. The objective work reduce programming errors by guaranteeing safety. We the first rigorous analysis 77 novel transformation checking algorithms required convert subroutines functions into pure, side-effect free 90. have implemented these source-to-source compiler which checks automatically transforms code. show resulting safe referentially transparent readily be offloaded accelerators.