73d411d1b2
The semantic of depend(out:omp_all_memory) is quite similar to taskwait in that it separates all tasks (with dependency) created before an all_memory-task from all tasks (with dependency) created after an all_memory-task. Only a single of such tasks can execute at a time. Similar to taskwait, we have a CV (AllMemory[1]) in the generating task to express the dependency sink semantic of an all_memory-task. In addition, AllMemory[0] describes the dependency source semantic of an all_memory-task. All tasks with dependency create an HB-arc towards the sink and terminate an HB-arc from the source. Since we expect that not many applications will use such dependency, the support for handling the synchronization semantic is off by default and can be turned on using ARCHER_OPTION="all_memory=1". The most costly part is the precautionary posting of an HB-arc towards the sink, which represents a potentially contentious write from all concurrently executing sibling tasks. A warning is printed at runtime, when the option is off while such dependency is observed. In most cases the lazy activation will still lead to false alerts. Differential Revision: https://reviews.llvm.org/D111895
The LLVM Compiler Infrastructure
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.
Getting the Source Code and Building LLVM
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.
Getting in touch
Join the LLVM Discourse forums, Discord chat, or #llvm IRC channel on OFTC.
The LLVM project has adopted a code of conduct for participants to all modes of communication within the project.