forked from OSchip/llvm-project
bdb0a2ffaa
The value returned by __kmp_now_nsec() can overflow 32-bit values causing incorrect values to be returned. The overflow can end up causing a divide by zero error because in __kmp_initialize_system_tick(), the value (__kmp_now_nsec() - nsec) can end up being much larger than the numerator: 1e6 * (delay + (now - goal)) during a pathological timing where the current time calculated is much larger than nsec. When this happens, the value of __kmp_ticks_per_msec is set to zero which is then used as the denominator in the KMP_NOW_MSEC() macro leading to the divide by zero error. Differential Revision: https://reviews.llvm.org/D55300 llvm-svn: 349090 |
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| .. | ||
| cmake | ||
| doc | ||
| src | ||
| test | ||
| tools | ||
| .clang-format | ||
| CMakeLists.txt | ||
| README.txt | ||
README.txt
README for the LLVM* OpenMP* Runtime Library
============================================
How to Build Documentation
==========================
The main documentation is in Doxygen* format, and this distribution
should come with pre-built PDF documentation in doc/Reference.pdf.
However, an HTML version can be built by executing:
% doxygen doc/doxygen/config
in the runtime directory.
That will produce HTML documentation in the doc/doxygen/generated
directory, which can be accessed by pointing a web browser at the
index.html file there.
If you don't have Doxygen installed, you can download it from
www.doxygen.org.
How to Build the LLVM* OpenMP* Runtime Library
==============================================
In-tree build:
$ cd where-you-want-to-live
Check out openmp 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 omp
Out-of-tree build:
$ cd where-you-want-to-live
Check out openmp
$ cd where-you-want-to-live/openmp/runtime
$ 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
=======================
* IA-32 architecture
* Intel(R) 64 architecture
* Intel(R) Many Integrated Core Architecture
* ARM* architecture
* Aarch64 (64-bit ARM) architecture
* IBM(R) Power architecture (big endian)
* IBM(R) Power architecture (little endian)
* MIPS and MIPS64 architecture
Supported RTL Build Configurations
==================================
Supported Architectures: IA-32 architecture, Intel(R) 64, and
Intel(R) Many Integrated Core Architecture
----------------------------------------------
| icc/icl | gcc | clang |
--------------|---------------|----------------------------|
| Linux* OS | Yes(1,5) | Yes(2,4) | Yes(4,6,7) |
| FreeBSD* | No | No | Yes(4,6,7,8) |
| OS X* | Yes(1,3,4) | No | Yes(4,6,7) |
| Windows* OS | Yes(1,4) | No | No |
------------------------------------------------------------
(1) On IA-32 architecture and Intel(R) 64, icc/icl versions 12.x are
supported (12.1 is recommended).
(2) GCC* version 4.7 is supported.
(3) For icc on OS X*, OS X* version 10.5.8 is supported.
(4) Intel(R) Many Integrated Core Architecture not supported.
(5) On Intel(R) Many Integrated Core Architecture, icc/icl versions 13.0
or later are required.
(6) Clang* version 3.3 is supported.
(7) Clang* currently does not offer a software-implemented 128 bit extended
precision type. Thus, all entry points reliant on this type are removed
from the library and cannot be called in the user program. The following
functions are not available:
__kmpc_atomic_cmplx16_*
__kmpc_atomic_float16_*
__kmpc_atomic_*_fp
(8) Community contribution provided AS IS, not tested by Intel.
Supported Architectures: IBM(R) Power 7 and Power 8
-----------------------------
| gcc | clang |
--------------|------------|--------------|
| Linux* OS | Yes(1,2) | Yes(3,4) |
-------------------------------------------
(1) On Power 7, gcc version 4.8.2 is supported.
(2) On Power 8, gcc version 4.8.2 is supported.
(3) On Power 7, clang version 3.7 is supported.
(4) On Power 8, clang version 3.7 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 the OpenMP development branch at
http://clang-omp.github.io/ ), Intel compilers, GCC. See the documentation
for more details.
-----------------------------------------------------------------------
Notices
=======
*Other names and brands may be claimed as the property of others.