Frelpt¶
Frelpt is a loop pushdown translation tool written in Python.
Loop pushdown is a type of inter-procedural loop transformations that pushes a loop down to terminal Fortran statements in the bottom of Fortran call stack.
Motivation of this transformation is in order for legacy Fortran code to run faster on modern processors such Graphical Processing Unit(GPU) and many-core Central Processing Unit(CPU). To be utilized fully, those modern processing units require a plenty of parallelization and/or vectorizatin opportunities concentrated on a relatively small code region. For example, to utilize GPU well, it is essential to create a computation intensive kernel and run the kernel on GPU as long as possible.
Loop pushdown effectively transforms a program structure such that loops are moved to the bottom of Fortran call stack so that computation intensity increases locally at the code regions pointed by the bottom of call stack.
Figure: Frelpt overview