d790a217a7
Add a method to the CallOpInterface to get a mutable operand range over the function arguments. This allows to add, remove, or change the type of call arguments in a generic manner without having to assume that the argument operand range is at the end of the operand list, or having to type switch on all supported concrete operation kinds. Alternatively, a new OpInterface could be added which inherits from CallOpInterface and appends it with the mutable variants of the base interface. There will be two users of this new function in the beginning: (1) A few passes in the Arc dialect in CIRCT already use a downstream implementation of the alternative case mentioned above: https://github.com/llvm/circt/blob/main/include/circt/Dialect/Arc/ArcInterfaces.td#L15 (2) The BufferDeallocation pass will be modified to be able to pass ownership of memrefs to called private functions if the caller does not need the memref anymore by appending the function argument list with a boolean value per memref, thus enabling earlier deallocation of the memref which can lead to lower peak memory usage. Reviewed By: ftynse Differential Revision: https://reviews.llvm.org/D156675
Flang
Flang is a ground-up implementation of a Fortran front end written in modern C++. It started off as the f18 project (https://github.com/flang-compiler/f18) with an aim to replace the previous flang project (https://github.com/flang-compiler/flang) and address its various deficiencies. F18 was subsequently accepted into the LLVM project and rechristened as Flang.
Please note that flang is not ready yet for production usage.
Getting Started
Read more about flang in the docs directory. Start with the compiler overview.
To better understand Fortran as a language and the specific grammar accepted by flang, read Fortran For C Programmers and flang's specifications of the Fortran grammar and the OpenMP grammar.
Treatment of language extensions is covered in this document.
To understand the compilers handling of intrinsics, see the discussion of intrinsics.
To understand how a flang program communicates with libraries at runtime, see the discussion of runtime descriptors.
If you're interested in contributing to the compiler, read the style guide and also review how flang uses modern C++ features.
If you are interested in writing new documentation, follow LLVM's Markdown style guide.
Consult the Getting Started with Flang for information on building and running flang.