forked from OSchip/llvm-project
9982f33e2c
This patch does the following: 1) Introduce kmp_topology_t as the runtime-friendly structure (the corresponding global variable is __kmp_topology) to determine the exact machine topology which can vary widely among current and future architectures. The current design is not easy to expand beyond the assumed three layer topology: sockets, cores, and threads so a rework capable of using the existing KMP_AFFINITY mechanisms is required. This new topology structure has: * The depth and types of the topology * Ratio count for each consecutive level (e.g., number of cores per socket, number of threads per core) * Absolute count for each level (e.g., 2 sockets, 16 cores, 32 threads) * Equivalent topology layer map (e.g., Numa domain is equivalent to socket, L1/L2 cache equivalent to core) * Whether it is uniform or not The hardware threads are represented with the kmp_hw_thread_t structure. This structure contains the ids (e.g., socket 0, core 1, thread 0) and other information grabbed from the previous Address structure. The kmp_topology_t structure contains an array of these. 2) Generalize the KMP_HW_SUBSET envirable for the new kmp_topology_t structure. The algorithm doesn't assume any order with tiles,numa domains,sockets,cores,threads. Instead it just parses the envirable, makes sure it is consistent with the detected topology (including taking into account equivalent layers) and then trims away the unneeded subset of hardware threads. To enable this, a new kmp_hw_subset_t structure is introduced which contains a vector of items (hardware type, number user wants, offset). Any keyword within __kmp_hw_get_keyword() can be used as a name and can be shortened as well. e.g., KMP_HW_SUBSET=1s,2numa,4tile,2c,3t can be used on the KNL SNC-4 machine. 3) Simplify topology detection functions so they only do the singular task of detecting the machine's topology. Printing, and all canonicalizing functionality is now done afterwards. So many lines of duplicated code are eliminated. 4) Add new ll_caches and numa_domains to OMP_PLACES, and consequently, KMP_AFFINITY's granularity setting. All the names within __kmp_hw_get_keyword() are available for use in OMP_PLACES or KMP_AFFINITY's granularity setting. 5) Simplify and future-proof code where explicit lists of allowed affinity settings keywords inside if() conditions. 6) Add x86 CPUID leaf 4 cache detection to existing x2apic id method so equivalent caches could be detected (in particular for the ll_caches place). Differential Revision: https://reviews.llvm.org/D100997 |
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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
* RISCV64 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.