hanchenye-llvm-project

History

Gheorghe-Teodor Bercea 06e08f0b0a [OpenMP][libomptarget] New reduction scheme for team reductions Summary: This patch adds a more sophisticated team reduction scheme to the OpenMP libomptarget-nvptx runtime. The scheme uses a fixed size global memory buffer whose length can be adjusted via compiler flag: ``` -fopenmp-cuda-teams-reduction-recs-num=1024 ``` The global buffer is a structure of arrays (with default size of 1024 each and controlled by the above flag), one array for each reduction variable. Values in the buffer are processed by the last team to finish executing the body of the target region. In addition to adding support for the new flag, the compiler also emits special functions used for the reduction of the intermediate reduction values. These changes will be added in a separate compiler patch following this one. Reviewers: ABataev, caomhin Reviewed By: ABataev Subscribers: guansong, jfb, jdoerfert, openmp-commits Tags: #openmp Differential Revision: https://reviews.llvm.org/D58409 llvm-svn: 354471		2019-02-20 14:55:55 +00:00
..
cmake/Modules	Update more file headers across all of the LLVM projects in the monorepo	2019-01-19 10:56:40 +00:00
deviceRTLs	[OpenMP][libomptarget] New reduction scheme for team reductions	2019-02-20 14:55:55 +00:00
include	Update more file headers across all of the LLVM projects in the monorepo	2019-01-19 10:56:40 +00:00
plugins	Update more file headers across all of the LLVM projects in the monorepo	2019-01-19 10:56:40 +00:00
src	Update more file headers across all of the LLVM projects in the monorepo	2019-01-19 10:56:40 +00:00
test	[OpenMP] Add omp_get_device_num() and update several other device API functions	2019-01-03 21:14:19 +00:00
CMakeLists.txt	Update more file headers across all of the LLVM projects in the monorepo	2019-01-19 10:56:40 +00:00
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.