fortran-transpiler

Fortran source-to-source compiler based on the LARA framework.

Previous Work

This compiler will be heavily inspired by Clava, a C/C++ source-to-source compiler that is also based on the LARA framework.

Clava already supports the following transformations:

• Automatic insertion of OpenMP pragmas
• Function inlining
• Function outlining
• Array flattening
• Constant folding and propagation
• Struct decomposition
• Function voidification
• Normalizing code to a subset of the language, including:
  • Decomposition of complex statements into several, simpler statements
  • Converting static local variables to static global variables
• Conversion of switch statements to ifs
• Loop conversion (for to while, do to while)
• Ensure there is a single return in a function
• Remove variable shadowing
• Simplify ternary operator
• Simplify compound assignments

Roadmap

The next steps for the Fortran source-to-source compiler are as follows:

• Developing an AST-based IR to represent Fortran that is capable of generating Fortran code back from the IR [Java]
• Dumper based on the Flang parser capable of outputting the necessary information to reconstruct an IR of the source code [C++]
• Base API [TypeScript]
• Library for Fortran transformations, which should include [TypeScript]:
  • Loop unrolling
  • Loop tiling
  • Loop interchange
  • Loop fission
  • Loop fusion
  • Loop-invariant code motion
  • Loop peeling
  • Loop strip-mining
  • OpenMP directive transformations. These tranformations should transform code with OpenMP directives not-yet supported by Flang into code with supported directives. The particular transformations to target are dependent of inputs from partners