[flang][docs] Add note about Cray pointers and the TARGET attribute (#137993) We found some tests checking for loops assigning between Cray pointer handles and their pointees which produced "incorrect" results with optimizations enabled; this is because the compiler expects Cray pointers not to alias with any other entity. [The HPE documentation for Cray Fortran extensions specifies:](https://support.hpe.com/hpesc/public/docDisplay?docId=a00113911en_us&docLocale=en_US&page=Types.html#cray-poiter-type) > the compiler assumes that the storage of a pointee is > never overlaid on the storage of another variable Jean pointed out that if a user's code uses entities that alias via Cray pointers, they may add the TARGET attribute to inform Flang of this aliasing, but that Flang's behavior is in line with Cray's own documentation and we should not make any changes to our alias analysis to try and detect this case. Updating documentation so that users that encounter this situation have a way to allow their code to compile as they intend.
Welcome to the LLVM project!
This repository contains the source code for LLVM, a toolkit for the construction of highly optimized compilers, optimizers, and run-time environments.
The LLVM project has multiple components. The core of the project is itself called “LLVM”. This contains all of the tools, libraries, and header files needed to process intermediate representations and convert them into object files. Tools include an assembler, disassembler, bitcode analyzer, and bitcode optimizer.
C-like languages use the Clang frontend. This component compiles C, C++, Objective-C, and Objective-C++ code into LLVM bitcode -- and from there into object files, using LLVM.
Other components include: the libc++ C++ standard library, the LLD linker, and more.
Consult the Getting Started with LLVM page for information on building and running LLVM.
For information on how to contribute to the LLVM project, please take a look at the Contributing to LLVM guide.
Join the LLVM Discourse forums, Discord chat, LLVM Office Hours or Regular sync-ups.
The LLVM project has adopted a code of conduct for participants to all modes of communication within the project.