12bbcd627f
This fixes a bug where functions generated by the MLIR Math dialect, for example ipowi, would fail to link with link.exe on Windows due to having linkonce linkage but no associated comdat. Adding the comdat on ELF also allows linkers to perform better garbage collection in the binary. Simply adding comdats to all functions with this linkage type should also cover future cases where linkonce or linkonce_odr functions might be necessary. (cherry picked from commit 5f476b80e3d472f672f5f6a719eebe2c0aadf52c)
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.