forked from OSchip/llvm-project
e34ddc09f4
From https://secure.phabricator.com/book/phabricator/article/arcanist_new_project/: > An .arcconfig file is a JSON file which you check into your project's root. I've done some experimentation, and it looks like the subproject .arcconfigs just get ignored, as the documentation says. Given that we're fully on the monorepo now, it's safe to remove them. Differential Revision: https://reviews.llvm.org/D74996 |
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cmake | ||
docs | ||
include | ||
test | ||
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CMakeLists.txt | ||
CREDITS.txt | ||
LICENSE.txt | ||
README.md |
README.md
Parallel STL
Parallel STL is an implementation of the C++ standard library algorithms with support for execution policies, as specified in ISO/IEC 14882:2017 standard, commonly called C++17. The implementation also supports the unsequenced execution policy specified in Parallelism TS version 2 and proposed for the next version of the C++ standard in the C++ working group paper P1001. Parallel STL offers efficient support for both parallel and vectorized execution of algorithms. For sequential execution, it relies on an available implementation of the C++ standard library.
Prerequisites
To use Parallel STL, you must have the following software installed:
- C++ compiler with:
- Support for C++11
- Support for OpenMP* 4.0 SIMD constructs
- Threading Building Blocks (TBB) which is available for download at https://github.com/01org/tbb/
Known issues and limitations
unseq
andpar_unseq
policies only have effect with compilers that support#pragma omp simd
or#pragma simd
.- Parallel and vector execution is only supported for the algorithms if random access iterators are provided, while for other iterator types the execution will remain serial.
- The following algorithms do not allow efficient SIMD execution:
includes
,inplace_merge
,merge
,nth_element
,partial_sort
,partial_sort_copy
,set_difference
,set_intersection
,set_symmetric_difference
,set_union
,sort
,stable_partition
,stable_sort
,unique
. - The initial value type for
exclusive_scan
,inclusive_scan
,transform_exclusive_scan
,transform_inclusive_scan
shall be DefaultConstructible. A default constructed-instance of the initial value type shall be the identity element for the specified binary operation. - For
max_element
,min_element
,minmax_element
,partial_sort
,partial_sort_copy
,sort
,stable_sort
the dereferenced value type of the provided iterators shall be DefaultConstructible. - For
remove
,remove_if
,unique
the dereferenced value type of the provided iterators shall be MoveConstructible. - The following algorithms require additional O(n) memory space for parallel execution:
copy_if
,inplace_merge
,partial_sort
,partial_sort_copy
,partition_copy
,remove
,remove_if
,rotate
,sort
,stable_sort
,unique
,unique_copy
.