llvm-project

History

Johannes Doerfert f2c385934b [OpenMP] Remove shadow pointer map and introduce consistent locking The shadow pointer map was problematic as we scanned an entire list if an entry had shadow pointers. The new scheme stores the shadow pointers inside the entries. This allows easy access without any search. It also helps us, but also makes it necessary, to define a consistent locking scheme. The implicit locking of entries via TargetPointerResultTy makes this pretty effortless, however one has to: - Lock HDTTMap before locking an entry. - Do not lock HDTTMap while holding an entry lock. - Hold the entry lock to read or modify an entry. The changes to submitData and retrieveData have been made to ensure 2 when the LIBOMPTARGET_INFO flag is used. Most everything else happens by itself as TargetPointerResultTy acts as a lock_guard for the entry. It is a little complicated when we deal with multiple entries, especially as they can be equal. However, one can still follow the rules with reasonable effort. LookupResult are now finally also locking the entry before it is inspected. This is good even if we haven't run into a problem yet. Differential Revision: https://reviews.llvm.org/D123446		2023-03-21 19:16:27 -07:00
..
cmake/Modules	[Libomptarget] Update handling of architectures for DeviceRTL	2023-03-08 11:22:33 -06:00
DeviceRTL	[OpenMP] Remove restriction on the thread count for parallel regions	2023-03-21 19:16:13 -07:00
docs
include	[OpenMP] Remove shadow pointer map and introduce consistent locking	2023-03-21 19:16:27 -07:00
plugins	Revert "Reland "[CMake] Bumps minimum version to 3.20.0.""	2023-03-18 20:32:43 +01:00
plugins-nextgen	[Libomptarget] Add missing explicit moves on llvm::Error	2023-03-20 12:00:01 -05:00
src	[OpenMP] Remove shadow pointer map and introduce consistent locking	2023-03-21 19:16:27 -07:00
test	[OpenMP] Avoid zero size copies to the device	2023-03-21 19:16:13 -07:00
tools
utils
CMakeLists.txt
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.