llvm-project/openmp/libomptarget
Joseph Huber d83ca624a1 [OpenMP] Fix data-race in new device RTL
This patch fixes a data-race observed when using the new device runtime
library. The Internal control variable for the parallel level is read in
the `__kmpc_parallel_51` function while it could potentially be written
by other threads. This causes data corruption and will cause
nondetermistic behaviour in the runtime. This patch fixes this by adding
an explicit synchronization before the region starts.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D110366
2021-09-23 17:28:07 -04:00
..
DeviceRTL [OpenMP] Fix data-race in new device RTL 2021-09-23 17:28:07 -04:00
cmake/Modules [NFC][libomptarget] Fixed -DLLVM_ENABLE_RUNTIMES="openmp" build. 2021-06-18 09:20:10 -07:00
deviceRTLs [OpenMP][Offloading] Change `bool IsSPMD` to `int8_t Mode` in `__kmpc_target_init` and `__kmpc_target_deinit` 2021-09-22 17:16:41 -04:00
include [OpenMP][libomptarget] Add __tgt_target_return_t enum for __tgt_target_XXX return int 2021-09-10 16:11:08 -05:00
plugins [OpenMP][Offloading] Use bitset to indicate execution mode instead of value 2021-09-22 11:40:52 -04:00
src [OpenMP][libomptarget] Add __tgt_target_return_t enum for __tgt_target_XXX return int 2021-09-10 16:11:08 -05:00
test [OpenMP] Add support for dynamic shared memory in new RTL 2021-09-17 21:25:36 -04:00
tools [OpenMP] Fixing llvm-omp-device-info compilation with runtimes 2021-07-30 13:09:08 -05:00
utils Revert "[OpenMP] Codegen aggregate for outlined function captures" 2021-09-21 13:20:39 -07:00
CMakeLists.txt [openmp] Add OMPT initialization in libomptarget 2021-08-04 18:00:11 +02:00
README.txt

README.txt

    README for the LLVM* OpenMP* Offloading Runtime Library (libomptarget)
    ======================================================================

How to Build the LLVM* OpenMP* Offloading Runtime Library (libomptarget)
========================================================================
In-tree build:

$ cd where-you-want-to-live
Check out openmp (libomptarget lives under ./libomptarget) into llvm/projects
$ cd where-you-want-to-build
$ mkdir build && cd build
$ cmake path/to/llvm -DCMAKE_C_COMPILER=<C compiler> -DCMAKE_CXX_COMPILER=<C++ compiler>
$ make omptarget

Out-of-tree build:

$ cd where-you-want-to-live
Check out openmp (libomptarget lives under ./libomptarget)
$ cd where-you-want-to-live/openmp/libomptarget
$ mkdir build && cd build
$ cmake path/to/openmp -DCMAKE_C_COMPILER=<C compiler> -DCMAKE_CXX_COMPILER=<C++ compiler>
$ make

For details about building, please look at README.rst in the parent directory.

Architectures Supported
=======================
The current library has been only tested in Linux operating system and the
following host architectures:
* Intel(R) 64 architecture
* IBM(R) Power architecture (big endian)
* IBM(R) Power architecture (little endian)
* ARM(R) AArch64 architecture (little endian)

The currently supported offloading device architectures are:
* Intel(R) 64 architecture (generic 64-bit plugin - mostly for testing purposes)
* IBM(R) Power architecture (big endian) (generic 64-bit plugin - mostly for testing purposes)
* IBM(R) Power architecture (little endian) (generic 64-bit plugin - mostly for testing purposes)
* ARM(R) AArch64 architecture (little endian) (generic 64-bit plugin - mostly for testing purposes)
* CUDA(R) enabled 64-bit NVIDIA(R) GPU architectures

Supported RTL Build Configurations
==================================
Supported Architectures: Intel(R) 64, IBM(R) Power 7 and Power 8

              ---------------------------
              |   gcc      |   clang    |
--------------|------------|------------|
| Linux* OS   |  Yes(1)    |  Yes(2)    |
-----------------------------------------

(1) gcc version 4.8.2 or later is supported.
(2) clang version 3.7 or later is supported.


Front-end Compilers that work with this RTL
===========================================

The following compilers are known to do compatible code generation for
this RTL:
  - clang (from https://github.com/clang-ykt )
  - clang (development branch at http://clang.llvm.org - several features still
    under development)

-----------------------------------------------------------------------

Notices
=======
This library and related compiler support is still under development, so the
employed interface is likely to change in the future.

*Other names and brands may be claimed as the property of others.