head 1.1; branch 1.1.1; access; symbols netbsd-11-0-RC4:1.1.1.3 netbsd-11-0-RC3:1.1.1.3 netbsd-11-0-RC2:1.1.1.3 netbsd-11-0-RC1:1.1.1.3 gcc-14-3-0:1.1.1.4 perseant-exfatfs-base-20250801:1.1.1.3 netbsd-11:1.1.1.3.0.14 netbsd-11-base:1.1.1.3 gcc-12-5-0:1.1.1.3 netbsd-10-1-RELEASE:1.1.1.3 perseant-exfatfs-base-20240630:1.1.1.3 gcc-12-4-0:1.1.1.3 perseant-exfatfs:1.1.1.3.0.12 perseant-exfatfs-base:1.1.1.3 netbsd-8-3-RELEASE:1.1.1.2 netbsd-9-4-RELEASE:1.1.1.3 netbsd-10-0-RELEASE:1.1.1.3 netbsd-10-0-RC6:1.1.1.3 netbsd-10-0-RC5:1.1.1.3 netbsd-10-0-RC4:1.1.1.3 netbsd-10-0-RC3:1.1.1.3 netbsd-10-0-RC2:1.1.1.3 netbsd-10-0-RC1:1.1.1.3 gcc-12-3-0:1.1.1.3 gcc-10-5-0:1.1.1.3 netbsd-10:1.1.1.3.0.10 netbsd-10-base:1.1.1.3 netbsd-9-3-RELEASE:1.1.1.3 gcc-10-4-0:1.1.1.3 cjep_sun2x-base1:1.1.1.3 cjep_sun2x:1.1.1.3.0.8 cjep_sun2x-base:1.1.1.3 cjep_staticlib_x-base1:1.1.1.3 netbsd-9-2-RELEASE:1.1.1.3 cjep_staticlib_x:1.1.1.3.0.6 cjep_staticlib_x-base:1.1.1.3 gcc-10-3-0:1.1.1.3 netbsd-9-1-RELEASE:1.1.1.3 gcc-9-3-0:1.1.1.3 gcc-7-5-0:1.1.1.3 phil-wifi-20200421:1.1.1.3 phil-wifi-20200411:1.1.1.3 is-mlppp:1.1.1.3.0.4 is-mlppp-base:1.1.1.3 phil-wifi-20200406:1.1.1.3 netbsd-8-2-RELEASE:1.1.1.2 gcc-8-4-0:1.1.1.3 netbsd-9-0-RELEASE:1.1.1.3 netbsd-9-0-RC2:1.1.1.3 netbsd-9-0-RC1:1.1.1.3 phil-wifi-20191119:1.1.1.3 gcc-8-3-0:1.1.1.3 netbsd-9:1.1.1.3.0.2 netbsd-9-base:1.1.1.3 phil-wifi-20190609:1.1.1.3 netbsd-8-1-RELEASE:1.1.1.2 netbsd-8-1-RC1:1.1.1.2 pgoyette-compat-merge-20190127:1.1.1.2.14.1 pgoyette-compat-20190127:1.1.1.3 gcc-7-4-0:1.1.1.3 pgoyette-compat-20190118:1.1.1.3 pgoyette-compat-1226:1.1.1.3 pgoyette-compat-1126:1.1.1.3 gcc-6-5-0:1.1.1.3 pgoyette-compat-1020:1.1.1.2 pgoyette-compat-0930:1.1.1.2 pgoyette-compat-0906:1.1.1.2 netbsd-7-2-RELEASE:1.1.1.1 pgoyette-compat-0728:1.1.1.2 netbsd-8-0-RELEASE:1.1.1.2 phil-wifi:1.1.1.2.0.16 phil-wifi-base:1.1.1.2 pgoyette-compat-0625:1.1.1.2 netbsd-8-0-RC2:1.1.1.2 pgoyette-compat-0521:1.1.1.2 pgoyette-compat-0502:1.1.1.2 pgoyette-compat-0422:1.1.1.2 netbsd-8-0-RC1:1.1.1.2 pgoyette-compat-0415:1.1.1.2 pgoyette-compat-0407:1.1.1.2 pgoyette-compat-0330:1.1.1.2 pgoyette-compat-0322:1.1.1.2 pgoyette-compat-0315:1.1.1.2 netbsd-7-1-2-RELEASE:1.1.1.1 pgoyette-compat:1.1.1.2.0.14 pgoyette-compat-base:1.1.1.2 gcc-6-4-0:1.1.1.2 netbsd-7-1-1-RELEASE:1.1.1.1 gcc-5-5-0:1.1.1.2 matt-nb8-mediatek:1.1.1.2.0.12 matt-nb8-mediatek-base:1.1.1.2 perseant-stdc-iso10646:1.1.1.2.0.10 perseant-stdc-iso10646-base:1.1.1.2 netbsd-8:1.1.1.2.0.8 netbsd-8-base:1.1.1.2 prg-localcount2-base3:1.1.1.2 prg-localcount2-base2:1.1.1.2 prg-localcount2-base1:1.1.1.2 prg-localcount2:1.1.1.2.0.6 prg-localcount2-base:1.1.1.2 pgoyette-localcount-20170426:1.1.1.2 bouyer-socketcan-base1:1.1.1.2 pgoyette-localcount-20170320:1.1.1.2 netbsd-7-1:1.1.1.1.0.14 netbsd-7-1-RELEASE:1.1.1.1 netbsd-7-1-RC2:1.1.1.1 netbsd-7-nhusb-base-20170116:1.1.1.1 bouyer-socketcan:1.1.1.2.0.4 bouyer-socketcan-base:1.1.1.2 pgoyette-localcount-20170107:1.1.1.2 netbsd-7-1-RC1:1.1.1.1 pgoyette-localcount-20161104:1.1.1.2 netbsd-7-0-2-RELEASE:1.1.1.1 localcount-20160914:1.1.1.2 netbsd-7-nhusb:1.1.1.1.0.12 netbsd-7-nhusb-base:1.1.1.1 pgoyette-localcount-20160806:1.1.1.2 pgoyette-localcount-20160726:1.1.1.2 pgoyette-localcount:1.1.1.2.0.2 pgoyette-localcount-base:1.1.1.2 gcc-5-4-0:1.1.1.2 netbsd-7-0-1-RELEASE:1.1.1.1 gcc-5-3-0:1.1.1.2 netbsd-7-0:1.1.1.1.0.10 netbsd-7-0-RELEASE:1.1.1.1 gcc-4-8-5-pre-gcc-old-import:1.1.1.1 netbsd-7-0-RC3:1.1.1.1 netbsd-7-0-RC2:1.1.1.1 post-gcc-4-8-5-merge:1.1.1.1 gcc-4-8-5:1.1.1.1 netbsd-7-0-RC1:1.1.1.1 gcc-4-8-4:1.1.1.1 gcc-4-8-20141009:1.1.1.1 tls-maxphys-base:1.1.1.1 tls-maxphys:1.1.1.1.0.8 netbsd-7:1.1.1.1.0.6 netbsd-7-base:1.1.1.1 gcc-4-8-3:1.1.1.1 yamt-pagecache:1.1.1.1.0.4 yamt-pagecache-base9:1.1.1.1 tls-earlyentropy:1.1.1.1.0.2 tls-earlyentropy-base:1.1.1.1 riastradh-xf86-video-intel-2-7-1-pre-2-21-15:1.1.1.1 riastradh-drm2-base3:1.1.1.1 gcc-4-8-3-pre-r208254:1.1.1.1 gcc-4-8-3-pre-r206687:1.1.1.1 FSF:1.1.1; locks; strict; comment @# @; 1.1 date 2014.03.01.08.41.30; author mrg; state Exp; branches 1.1.1.1; next ; commitid TtaB91QNTknAoYqx; 1.1.1.1 date 2014.03.01.08.41.30; author mrg; state Exp; branches 1.1.1.1.4.1 1.1.1.1.8.1; next 1.1.1.2; commitid TtaB91QNTknAoYqx; 1.1.1.2 date 2016.01.24.06.05.43; author mrg; state Exp; branches 1.1.1.2.14.1 1.1.1.2.16.1; next 1.1.1.3; commitid uWWfbLp08zOK79Sy; 1.1.1.3 date 2018.11.04.00.12.37; author mrg; state Exp; branches; next 1.1.1.4; commitid bulspy67pMB6EyYA; 1.1.1.4 date 2025.09.13.23.45.49; author mrg; state Exp; branches; next ; commitid KwhwN4krNWa6XBaG; 1.1.1.1.4.1 date 2014.03.01.08.41.30; author yamt; state dead; branches; next 1.1.1.1.4.2; commitid DX8bafDLmqEbpyBx; 1.1.1.1.4.2 date 2014.05.22.16.37.45; author yamt; state Exp; branches; next ; commitid DX8bafDLmqEbpyBx; 1.1.1.1.8.1 date 2014.03.01.08.41.30; author tls; state dead; branches; next 1.1.1.1.8.2; commitid jTnpym9Qu0o4R1Nx; 1.1.1.1.8.2 date 2014.08.19.23.54.46; author tls; state Exp; branches; next ; commitid jTnpym9Qu0o4R1Nx; 1.1.1.2.14.1 date 2018.11.26.01.50.57; author pgoyette; state Exp; branches; next ; commitid Zj4q5SspGdKXto1B; 1.1.1.2.16.1 date 2019.06.10.21.54.49; author christos; state Exp; branches; next ; commitid jtc8rnCzWiEEHGqB; desc @@ 1.1 log @Initial revision @ text @ Using
Using
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Using

Prerequisite Compiler Flags

Any use of parallel functionality requires additional compiler and runtime support, in particular support for OpenMP. Adding this support is not difficult: just compile your application with the compiler flag -fopenmp. This will link in libgomp, the OpenMP GNU implementation, whose presence is mandatory.

In addition, hardware that supports atomic operations and a compiler capable of producing atomic operations is mandatory: GCC defaults to no support for atomic operations on some common hardware architectures. Activating atomic operations may require explicit compiler flags on some targets (like sparc and x86), such as -march=i686, -march=native or -mcpu=v9. See the GCC manual for more information.

Using Parallel Mode

To use the libstdc++ parallel mode, compile your application with the prerequisite flags as detailed above, and in addition add -D_GLIBCXX_PARALLEL. This will convert all use of the standard (sequential) algorithms to the appropriate parallel equivalents. Please note that this doesn't necessarily mean that everything will end up being executed in a parallel manner, but rather that the heuristics and settings coded into the parallel versions will be used to determine if all, some, or no algorithms will be executed using parallel variants.

Note that the _GLIBCXX_PARALLEL define may change the sizes and behavior of standard class templates such as std::search, and therefore one can only link code compiled with parallel mode and code compiled without parallel mode if no instantiation of a container is passed between the two translation units. Parallel mode functionality has distinct linkage, and cannot be confused with normal mode symbols.

Using Specific Parallel Components

When it is not feasible to recompile your entire application, or only specific algorithms need to be parallel-aware, individual parallel algorithms can be made available explicitly. These parallel algorithms are functionally equivalent to the standard drop-in algorithms used in parallel mode, but they are available in a separate namespace as GNU extensions and may be used in programs compiled with either release mode or with parallel mode.

An example of using a parallel version of std::sort, but no other parallel algorithms, is: 

#include <vector>
#include <parallel/algorithm>

int main()
{
  std::vector<int> v(100);

  // ...

  // Explicitly force a call to parallel sort.
  __gnu_parallel::sort(v.begin(), v.end());
  return 0;
}

Then compile this code with the prerequisite compiler flags (-fopenmp and any necessary architecture-specific flags for atomic operations.)

The following table provides the names and headers of all the parallel algorithms that can be used in a similar manner:

Table 18.1. Parallel Algorithms

AlgorithmHeaderParallel algorithmParallel header
std::accumulatenumeric__gnu_parallel::accumulateparallel/numeric
std::adjacent_differencenumeric__gnu_parallel::adjacent_differenceparallel/numeric
std::inner_productnumeric__gnu_parallel::inner_productparallel/numeric
std::partial_sumnumeric__gnu_parallel::partial_sumparallel/numeric
std::adjacent_findalgorithm__gnu_parallel::adjacent_findparallel/algorithm
std::countalgorithm__gnu_parallel::countparallel/algorithm
std::count_ifalgorithm__gnu_parallel::count_ifparallel/algorithm
std::equalalgorithm__gnu_parallel::equalparallel/algorithm
std::findalgorithm__gnu_parallel::findparallel/algorithm
std::find_ifalgorithm__gnu_parallel::find_ifparallel/algorithm
std::find_first_ofalgorithm__gnu_parallel::find_first_ofparallel/algorithm
std::for_eachalgorithm__gnu_parallel::for_eachparallel/algorithm
std::generatealgorithm__gnu_parallel::generateparallel/algorithm
std::generate_nalgorithm__gnu_parallel::generate_nparallel/algorithm
std::lexicographical_comparealgorithm__gnu_parallel::lexicographical_compareparallel/algorithm
std::mismatchalgorithm__gnu_parallel::mismatchparallel/algorithm
std::searchalgorithm__gnu_parallel::searchparallel/algorithm
std::search_nalgorithm__gnu_parallel::search_nparallel/algorithm
std::transformalgorithm__gnu_parallel::transformparallel/algorithm
std::replacealgorithm__gnu_parallel::replaceparallel/algorithm
std::replace_ifalgorithm__gnu_parallel::replace_ifparallel/algorithm
std::max_elementalgorithm__gnu_parallel::max_elementparallel/algorithm
std::mergealgorithm__gnu_parallel::mergeparallel/algorithm
std::min_elementalgorithm__gnu_parallel::min_elementparallel/algorithm
std::nth_elementalgorithm__gnu_parallel::nth_elementparallel/algorithm
std::partial_sortalgorithm__gnu_parallel::partial_sortparallel/algorithm
std::partitionalgorithm__gnu_parallel::partitionparallel/algorithm
std::random_shufflealgorithm__gnu_parallel::random_shuffleparallel/algorithm
std::set_unionalgorithm__gnu_parallel::set_unionparallel/algorithm
std::set_intersectionalgorithm__gnu_parallel::set_intersectionparallel/algorithm
std::set_symmetric_differencealgorithm__gnu_parallel::set_symmetric_differenceparallel/algorithm
std::set_differencealgorithm__gnu_parallel::set_differenceparallel/algorithm
std::sortalgorithm__gnu_parallel::sortparallel/algorithm
std::stable_sortalgorithm__gnu_parallel::stable_sortparallel/algorithm
std::unique_copyalgorithm__gnu_parallel::unique_copyparallel/algorithm

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@ 1.1.1.1 log @import GCC 4.8 branch at r206687. highlights from: http://gcc.gnu.org/gcc-4.6/changes.html GCC now has stricter checks for invalid command-line options New -Wunused-but-set-variable and -Wunused-but-set-parameter warnings Many platforms have been obsoleted Link-time optimization improvements A new switch -fstack-usage has been added A new function attribute leaf was introduced A new warning, enabled by -Wdouble-promotion Support for selectively enabling and disabling warnings via #pragma GCC diagnostic has been added There is now experimental support for some features from the upcoming C1X revision of the ISO C standard Improved experimental support for the upcoming C++0x ISO C++ standard G++ now issues clearer diagnostics in several cases Updates for ARM, x86, MIPS, PPC/PPC64, SPARC Darwin, FreeBSD, Solaris 2, MinGW and Cygwin now all support __float128 on 32-bit and 64-bit x86 targets. [*1] highlights from: http://gcc.gnu.org/gcc-4.7/changes.html The -fconserve-space flag has been deprecated Support for a new parameter --param case-values-threshold=n was added Interprocedural and Link-time optimization improvements A new built-in, __builtin_assume_aligned, has been added A new warning option -Wunused-local-typedefs was added A new experimental command-line option -ftrack-macro-expansion was added Support for atomic operations specifying the C++11/C11 memory model has been added There is support for some more features from the C11 revision of the ISO C standard Improved experimental support for the new ISO C++ standard, C++11 Updates for ARM, x86, MIPS, PPC/PPC64, SH, SPARC, TILE* A new option (-grecord-gcc-switches) was added highlights from: http://gcc.gnu.org/gcc-4.8/changes.html GCC now uses C++ as its implementation language. This means that to build GCC from sources, you will need a C++ compiler that understands C++ 2003 DWARF4 is now the default when generating DWARF debug information A new general optimization level, -Og, has been introduced A new option -ftree-partial-pre was added The option -fconserve-space has been removed The command-line options -fipa-struct-reorg and -fipa-matrix-reorg have been removed Interprocedural and Link-time optimization improvements AddressSanitizer, a fast memory error detector, has been added [*2] A new -Wsizeof-pointer-memaccess warning has been added G++ now supports a -std=c++1y option for experimentation with features proposed for the next revision of the standard, expected around 2014 Improved experimental support for the new ISO C++ standard, C++11 A new port has been added to support AArch64 Updates for ARM, x86, MIPS, PPC/PPC64, SH, SPARC, TILE* [*1] we should support this too! [*2] we should look into this. https://code.google.com/p/address-sanitizer/ @ text @@ 1.1.1.2 log @import GCC 5.3.0. see these urls for details which are too large to include here: http://gcc.gnu.org/gcc-4.9/changes.html http://gcc.gnu.org/gcc-5/changes.html (note that GCC 5.x is a release stream like GCC 4.9.x, 4.8.x, etc.) the main issues we will have are: The default mode for C is now -std=gnu11 instead of -std=gnu89. ARM: The deprecated option -mwords-little-endian has been removed. The options -mapcs, -mapcs-frame, -mtpcs-frame and -mtpcs-leaf-frame which are only applicable to the old ABI have been deprecated. MIPS: The o32 ABI has been modified and extended. The o32 64-bit floating-point register support is now obsolete and has been removed. It has been replaced by three ABI extensions FPXX, FP64A, and FP64. The meaning of the -mfp64 command-line option has changed. It is now used to enable the FP64A and FP64 ABI extensions. @ text @d8 1 a8 2 GNU Offloading and Multi Processing Runtime Library, d65 1 a65 1

Table 18.1. Parallel Algorithms

AlgorithmHeaderParallel algorithmParallel header
std::accumulatenumeric__gnu_parallel::accumulateparallel/numeric
std::adjacent_differencenumeric__gnu_parallel::adjacent_differenceparallel/numeric
std::inner_productnumeric__gnu_parallel::inner_productparallel/numeric
std::partial_sumnumeric__gnu_parallel::partial_sumparallel/numeric
std::adjacent_findalgorithm__gnu_parallel::adjacent_findparallel/algorithm
std::countalgorithm__gnu_parallel::countparallel/algorithm
std::count_ifalgorithm__gnu_parallel::count_ifparallel/algorithm
std::equalalgorithm__gnu_parallel::equalparallel/algorithm
std::findalgorithm__gnu_parallel::findparallel/algorithm
std::find_ifalgorithm__gnu_parallel::find_ifparallel/algorithm
std::find_first_ofalgorithm__gnu_parallel::find_first_ofparallel/algorithm
std::for_eachalgorithm__gnu_parallel::for_eachparallel/algorithm
std::generatealgorithm__gnu_parallel::generateparallel/algorithm
std::generate_nalgorithm__gnu_parallel::generate_nparallel/algorithm
std::lexicographical_comparealgorithm__gnu_parallel::lexicographical_compareparallel/algorithm
std::mismatchalgorithm__gnu_parallel::mismatchparallel/algorithm
std::searchalgorithm__gnu_parallel::searchparallel/algorithm
std::search_nalgorithm__gnu_parallel::search_nparallel/algorithm
std::transformalgorithm__gnu_parallel::transformparallel/algorithm
std::replacealgorithm__gnu_parallel::replaceparallel/algorithm
std::replace_ifalgorithm__gnu_parallel::replace_ifparallel/algorithm
std::max_elementalgorithm__gnu_parallel::max_elementparallel/algorithm
std::mergealgorithm__gnu_parallel::mergeparallel/algorithm
std::min_elementalgorithm__gnu_parallel::min_elementparallel/algorithm
std::nth_elementalgorithm__gnu_parallel::nth_elementparallel/algorithm
std::partial_sortalgorithm__gnu_parallel::partial_sortparallel/algorithm
std::partitionalgorithm__gnu_parallel::partitionparallel/algorithm
std::random_shufflealgorithm__gnu_parallel::random_shuffleparallel/algorithm
std::set_unionalgorithm__gnu_parallel::set_unionparallel/algorithm
std::set_intersectionalgorithm__gnu_parallel::set_intersectionparallel/algorithm
std::set_symmetric_differencealgorithm__gnu_parallel::set_symmetric_differenceparallel/algorithm
std::set_differencealgorithm__gnu_parallel::set_differenceparallel/algorithm
std::sortalgorithm__gnu_parallel::sortparallel/algorithm
std::stable_sortalgorithm__gnu_parallel::stable_sortparallel/algorithm
std::unique_copyalgorithm__gnu_parallel::unique_copyparallel/algorithm

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@ 1.1.1.2.16.1 log @Sync with HEAD @ text @d2 1 a2 1 Using
Using
Prev Chapter 18. Parallel Mode Next

Using

Prerequisite Compiler Flags

d66 1 a66 1

Table 18.1. Parallel Algorithms

AlgorithmHeaderParallel algorithmParallel header
std::accumulatenumeric__gnu_parallel::accumulateparallel/numeric
std::adjacent_differencenumeric__gnu_parallel::adjacent_differenceparallel/numeric
std::inner_productnumeric__gnu_parallel::inner_productparallel/numeric
std::partial_sumnumeric__gnu_parallel::partial_sumparallel/numeric
std::adjacent_findalgorithm__gnu_parallel::adjacent_findparallel/algorithm
std::countalgorithm__gnu_parallel::countparallel/algorithm
std::count_ifalgorithm__gnu_parallel::count_ifparallel/algorithm
std::equalalgorithm__gnu_parallel::equalparallel/algorithm
std::findalgorithm__gnu_parallel::findparallel/algorithm
std::find_ifalgorithm__gnu_parallel::find_ifparallel/algorithm
std::find_first_ofalgorithm__gnu_parallel::find_first_ofparallel/algorithm
std::for_eachalgorithm__gnu_parallel::for_eachparallel/algorithm
std::generatealgorithm__gnu_parallel::generateparallel/algorithm
std::generate_nalgorithm__gnu_parallel::generate_nparallel/algorithm
std::lexicographical_comparealgorithm__gnu_parallel::lexicographical_compareparallel/algorithm
std::mismatchalgorithm__gnu_parallel::mismatchparallel/algorithm
std::searchalgorithm__gnu_parallel::searchparallel/algorithm
std::search_nalgorithm__gnu_parallel::search_nparallel/algorithm
std::transformalgorithm__gnu_parallel::transformparallel/algorithm
std::replacealgorithm__gnu_parallel::replaceparallel/algorithm
std::replace_ifalgorithm__gnu_parallel::replace_ifparallel/algorithm
std::max_elementalgorithm__gnu_parallel::max_elementparallel/algorithm
std::mergealgorithm__gnu_parallel::mergeparallel/algorithm
std::min_elementalgorithm__gnu_parallel::min_elementparallel/algorithm
std::nth_elementalgorithm__gnu_parallel::nth_elementparallel/algorithm
std::partial_sortalgorithm__gnu_parallel::partial_sortparallel/algorithm
std::partitionalgorithm__gnu_parallel::partitionparallel/algorithm
std::random_shufflealgorithm__gnu_parallel::random_shuffleparallel/algorithm
std::set_unionalgorithm__gnu_parallel::set_unionparallel/algorithm
std::set_intersectionalgorithm__gnu_parallel::set_intersectionparallel/algorithm
std::set_symmetric_differencealgorithm__gnu_parallel::set_symmetric_differenceparallel/algorithm
std::set_differencealgorithm__gnu_parallel::set_differenceparallel/algorithm
std::sortalgorithm__gnu_parallel::sortparallel/algorithm
std::stable_sortalgorithm__gnu_parallel::stable_sortparallel/algorithm
std::unique_copyalgorithm__gnu_parallel::unique_copyparallel/algorithm

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@ 1.1.1.2.14.1 log @Sync with HEAD, resolve a couple of conflicts @ text @d2 1 a2 1 Using
Using
Prev Chapter 18. Parallel Mode Next

Using

Prerequisite Compiler Flags

d66 1 a66 1

Table 18.1. Parallel Algorithms

AlgorithmHeaderParallel algorithmParallel header
std::accumulatenumeric__gnu_parallel::accumulateparallel/numeric
std::adjacent_differencenumeric__gnu_parallel::adjacent_differenceparallel/numeric
std::inner_productnumeric__gnu_parallel::inner_productparallel/numeric
std::partial_sumnumeric__gnu_parallel::partial_sumparallel/numeric
std::adjacent_findalgorithm__gnu_parallel::adjacent_findparallel/algorithm
std::countalgorithm__gnu_parallel::countparallel/algorithm
std::count_ifalgorithm__gnu_parallel::count_ifparallel/algorithm
std::equalalgorithm__gnu_parallel::equalparallel/algorithm
std::findalgorithm__gnu_parallel::findparallel/algorithm
std::find_ifalgorithm__gnu_parallel::find_ifparallel/algorithm
std::find_first_ofalgorithm__gnu_parallel::find_first_ofparallel/algorithm
std::for_eachalgorithm__gnu_parallel::for_eachparallel/algorithm
std::generatealgorithm__gnu_parallel::generateparallel/algorithm
std::generate_nalgorithm__gnu_parallel::generate_nparallel/algorithm
std::lexicographical_comparealgorithm__gnu_parallel::lexicographical_compareparallel/algorithm
std::mismatchalgorithm__gnu_parallel::mismatchparallel/algorithm
std::searchalgorithm__gnu_parallel::searchparallel/algorithm
std::search_nalgorithm__gnu_parallel::search_nparallel/algorithm
std::transformalgorithm__gnu_parallel::transformparallel/algorithm
std::replacealgorithm__gnu_parallel::replaceparallel/algorithm
std::replace_ifalgorithm__gnu_parallel::replace_ifparallel/algorithm
std::max_elementalgorithm__gnu_parallel::max_elementparallel/algorithm
std::mergealgorithm__gnu_parallel::mergeparallel/algorithm
std::min_elementalgorithm__gnu_parallel::min_elementparallel/algorithm
std::nth_elementalgorithm__gnu_parallel::nth_elementparallel/algorithm
std::partial_sortalgorithm__gnu_parallel::partial_sortparallel/algorithm
std::partitionalgorithm__gnu_parallel::partitionparallel/algorithm
std::random_shufflealgorithm__gnu_parallel::random_shuffleparallel/algorithm
std::set_unionalgorithm__gnu_parallel::set_unionparallel/algorithm
std::set_intersectionalgorithm__gnu_parallel::set_intersectionparallel/algorithm
std::set_symmetric_differencealgorithm__gnu_parallel::set_symmetric_differenceparallel/algorithm
std::set_differencealgorithm__gnu_parallel::set_differenceparallel/algorithm
std::sortalgorithm__gnu_parallel::sortparallel/algorithm
std::stable_sortalgorithm__gnu_parallel::stable_sortparallel/algorithm
std::unique_copyalgorithm__gnu_parallel::unique_copyparallel/algorithm

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@ 1.1.1.3 log @import GCC 6.5.0. this is largely a maint release with no particularly features listed here: http://gcc.gnu.org/gcc-6/changes.html this fixes over 250 PRs in the GCC bugzilla: https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=6.5 @ text @d2 1 a2 1 Using
Using
Prev Chapter 18. Parallel Mode Next

Using

Prerequisite Compiler Flags

d66 1 a66 1

Table 18.1. Parallel Algorithms

AlgorithmHeaderParallel algorithmParallel header
std::accumulatenumeric__gnu_parallel::accumulateparallel/numeric
std::adjacent_differencenumeric__gnu_parallel::adjacent_differenceparallel/numeric
std::inner_productnumeric__gnu_parallel::inner_productparallel/numeric
std::partial_sumnumeric__gnu_parallel::partial_sumparallel/numeric
std::adjacent_findalgorithm__gnu_parallel::adjacent_findparallel/algorithm
std::countalgorithm__gnu_parallel::countparallel/algorithm
std::count_ifalgorithm__gnu_parallel::count_ifparallel/algorithm
std::equalalgorithm__gnu_parallel::equalparallel/algorithm
std::findalgorithm__gnu_parallel::findparallel/algorithm
std::find_ifalgorithm__gnu_parallel::find_ifparallel/algorithm
std::find_first_ofalgorithm__gnu_parallel::find_first_ofparallel/algorithm
std::for_eachalgorithm__gnu_parallel::for_eachparallel/algorithm
std::generatealgorithm__gnu_parallel::generateparallel/algorithm
std::generate_nalgorithm__gnu_parallel::generate_nparallel/algorithm
std::lexicographical_comparealgorithm__gnu_parallel::lexicographical_compareparallel/algorithm
std::mismatchalgorithm__gnu_parallel::mismatchparallel/algorithm
std::searchalgorithm__gnu_parallel::searchparallel/algorithm
std::search_nalgorithm__gnu_parallel::search_nparallel/algorithm
std::transformalgorithm__gnu_parallel::transformparallel/algorithm
std::replacealgorithm__gnu_parallel::replaceparallel/algorithm
std::replace_ifalgorithm__gnu_parallel::replace_ifparallel/algorithm
std::max_elementalgorithm__gnu_parallel::max_elementparallel/algorithm
std::mergealgorithm__gnu_parallel::mergeparallel/algorithm
std::min_elementalgorithm__gnu_parallel::min_elementparallel/algorithm
std::nth_elementalgorithm__gnu_parallel::nth_elementparallel/algorithm
std::partial_sortalgorithm__gnu_parallel::partial_sortparallel/algorithm
std::partitionalgorithm__gnu_parallel::partitionparallel/algorithm
std::random_shufflealgorithm__gnu_parallel::random_shuffleparallel/algorithm
std::set_unionalgorithm__gnu_parallel::set_unionparallel/algorithm
std::set_intersectionalgorithm__gnu_parallel::set_intersectionparallel/algorithm
std::set_symmetric_differencealgorithm__gnu_parallel::set_symmetric_differenceparallel/algorithm
std::set_differencealgorithm__gnu_parallel::set_differenceparallel/algorithm
std::sortalgorithm__gnu_parallel::sortparallel/algorithm
std::stable_sortalgorithm__gnu_parallel::stable_sortparallel/algorithm
std::unique_copyalgorithm__gnu_parallel::unique_copyparallel/algorithm

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@ 1.1.1.4 log @initial import of GCC 14.3.0. major changes in GCC 13: - improved sanitizer - zstd debug info compression - LTO improvements - SARIF based diagnostic support - new warnings: -Wxor-used-as-pow, -Wenum-int-mismatch, -Wself-move, -Wdangling-reference - many new -Wanalyzer* specific warnings - enhanced warnings: -Wpessimizing-move, -Wredundant-move - new attributes to mark file descriptors, c++23 "assume" - several C23 features added - several C++23 features added - many new features for Arm, x86, RISC-V major changes in GCC 14: - more strict C99 or newer support - ia64* marked deprecated (but seemingly still in GCC 15.) - several new hardening features - support for "hardbool", which can have user supplied values of true/false - explicit support for stack scrubbing upon function exit - better auto-vectorisation support - added clang-compatible __has_feature and __has_extension - more C23, including -std=c23 - several C++26 features added - better diagnostics in C++ templates - new warnings: -Wnrvo, Welaborated-enum-base - many new features for Arm, x86, RISC-V - possible ABI breaking change for SPARC64 and small structures with arrays of floats. @ text @d8 1 a8 1 GNU Offloading and @ 1.1.1.1.8.1 log @file parallel_mode_using.html was added on branch tls-maxphys on 2014-08-19 23:54:46 +0000 @ text @d1 65 @ 1.1.1.1.8.2 log @Rebase to HEAD as of a few days ago. @ text @a0 65 Using
Using
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Using

Prerequisite Compiler Flags

Any use of parallel functionality requires additional compiler and runtime support, in particular support for OpenMP. Adding this support is not difficult: just compile your application with the compiler flag -fopenmp. This will link in libgomp, the OpenMP GNU implementation, whose presence is mandatory.

In addition, hardware that supports atomic operations and a compiler capable of producing atomic operations is mandatory: GCC defaults to no support for atomic operations on some common hardware architectures. Activating atomic operations may require explicit compiler flags on some targets (like sparc and x86), such as -march=i686, -march=native or -mcpu=v9. See the GCC manual for more information.

Using Parallel Mode

To use the libstdc++ parallel mode, compile your application with the prerequisite flags as detailed above, and in addition add -D_GLIBCXX_PARALLEL. This will convert all use of the standard (sequential) algorithms to the appropriate parallel equivalents. Please note that this doesn't necessarily mean that everything will end up being executed in a parallel manner, but rather that the heuristics and settings coded into the parallel versions will be used to determine if all, some, or no algorithms will be executed using parallel variants.

Note that the _GLIBCXX_PARALLEL define may change the sizes and behavior of standard class templates such as std::search, and therefore one can only link code compiled with parallel mode and code compiled without parallel mode if no instantiation of a container is passed between the two translation units. Parallel mode functionality has distinct linkage, and cannot be confused with normal mode symbols.

Using Specific Parallel Components

When it is not feasible to recompile your entire application, or only specific algorithms need to be parallel-aware, individual parallel algorithms can be made available explicitly. These parallel algorithms are functionally equivalent to the standard drop-in algorithms used in parallel mode, but they are available in a separate namespace as GNU extensions and may be used in programs compiled with either release mode or with parallel mode.

An example of using a parallel version of std::sort, but no other parallel algorithms, is: 

#include <vector>
#include <parallel/algorithm>

int main()
{
  std::vector<int> v(100);

  // ...

  // Explicitly force a call to parallel sort.
  __gnu_parallel::sort(v.begin(), v.end());
  return 0;
}

Then compile this code with the prerequisite compiler flags (-fopenmp and any necessary architecture-specific flags for atomic operations.)

The following table provides the names and headers of all the parallel algorithms that can be used in a similar manner:

Table 18.1. Parallel Algorithms

AlgorithmHeaderParallel algorithmParallel header
std::accumulatenumeric__gnu_parallel::accumulateparallel/numeric
std::adjacent_differencenumeric__gnu_parallel::adjacent_differenceparallel/numeric
std::inner_productnumeric__gnu_parallel::inner_productparallel/numeric
std::partial_sumnumeric__gnu_parallel::partial_sumparallel/numeric
std::adjacent_findalgorithm__gnu_parallel::adjacent_findparallel/algorithm
std::countalgorithm__gnu_parallel::countparallel/algorithm
std::count_ifalgorithm__gnu_parallel::count_ifparallel/algorithm
std::equalalgorithm__gnu_parallel::equalparallel/algorithm
std::findalgorithm__gnu_parallel::findparallel/algorithm
std::find_ifalgorithm__gnu_parallel::find_ifparallel/algorithm
std::find_first_ofalgorithm__gnu_parallel::find_first_ofparallel/algorithm
std::for_eachalgorithm__gnu_parallel::for_eachparallel/algorithm
std::generatealgorithm__gnu_parallel::generateparallel/algorithm
std::generate_nalgorithm__gnu_parallel::generate_nparallel/algorithm
std::lexicographical_comparealgorithm__gnu_parallel::lexicographical_compareparallel/algorithm
std::mismatchalgorithm__gnu_parallel::mismatchparallel/algorithm
std::searchalgorithm__gnu_parallel::searchparallel/algorithm
std::search_nalgorithm__gnu_parallel::search_nparallel/algorithm
std::transformalgorithm__gnu_parallel::transformparallel/algorithm
std::replacealgorithm__gnu_parallel::replaceparallel/algorithm
std::replace_ifalgorithm__gnu_parallel::replace_ifparallel/algorithm
std::max_elementalgorithm__gnu_parallel::max_elementparallel/algorithm
std::mergealgorithm__gnu_parallel::mergeparallel/algorithm
std::min_elementalgorithm__gnu_parallel::min_elementparallel/algorithm
std::nth_elementalgorithm__gnu_parallel::nth_elementparallel/algorithm
std::partial_sortalgorithm__gnu_parallel::partial_sortparallel/algorithm
std::partitionalgorithm__gnu_parallel::partitionparallel/algorithm
std::random_shufflealgorithm__gnu_parallel::random_shuffleparallel/algorithm
std::set_unionalgorithm__gnu_parallel::set_unionparallel/algorithm
std::set_intersectionalgorithm__gnu_parallel::set_intersectionparallel/algorithm
std::set_symmetric_differencealgorithm__gnu_parallel::set_symmetric_differenceparallel/algorithm
std::set_differencealgorithm__gnu_parallel::set_differenceparallel/algorithm
std::sortalgorithm__gnu_parallel::sortparallel/algorithm
std::stable_sortalgorithm__gnu_parallel::stable_sortparallel/algorithm
std::unique_copyalgorithm__gnu_parallel::unique_copyparallel/algorithm

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@ 1.1.1.1.4.1 log @file parallel_mode_using.html was added on branch yamt-pagecache on 2014-05-22 16:37:45 +0000 @ text @d1 65 @ 1.1.1.1.4.2 log @sync with head. for a reference, the tree before this commit was tagged as yamt-pagecache-tag8. this commit was splitted into small chunks to avoid a limitation of cvs. ("Protocol error: too many arguments") @ text @a0 65 Using
Using
Prev Chapter 18. Parallel Mode Next

Using

Prerequisite Compiler Flags

Any use of parallel functionality requires additional compiler and runtime support, in particular support for OpenMP. Adding this support is not difficult: just compile your application with the compiler flag -fopenmp. This will link in libgomp, the OpenMP GNU implementation, whose presence is mandatory.

In addition, hardware that supports atomic operations and a compiler capable of producing atomic operations is mandatory: GCC defaults to no support for atomic operations on some common hardware architectures. Activating atomic operations may require explicit compiler flags on some targets (like sparc and x86), such as -march=i686, -march=native or -mcpu=v9. See the GCC manual for more information.

Using Parallel Mode

To use the libstdc++ parallel mode, compile your application with the prerequisite flags as detailed above, and in addition add -D_GLIBCXX_PARALLEL. This will convert all use of the standard (sequential) algorithms to the appropriate parallel equivalents. Please note that this doesn't necessarily mean that everything will end up being executed in a parallel manner, but rather that the heuristics and settings coded into the parallel versions will be used to determine if all, some, or no algorithms will be executed using parallel variants.

Note that the _GLIBCXX_PARALLEL define may change the sizes and behavior of standard class templates such as std::search, and therefore one can only link code compiled with parallel mode and code compiled without parallel mode if no instantiation of a container is passed between the two translation units. Parallel mode functionality has distinct linkage, and cannot be confused with normal mode symbols.

Using Specific Parallel Components

When it is not feasible to recompile your entire application, or only specific algorithms need to be parallel-aware, individual parallel algorithms can be made available explicitly. These parallel algorithms are functionally equivalent to the standard drop-in algorithms used in parallel mode, but they are available in a separate namespace as GNU extensions and may be used in programs compiled with either release mode or with parallel mode.

An example of using a parallel version of std::sort, but no other parallel algorithms, is: 

#include <vector>
#include <parallel/algorithm>

int main()
{
  std::vector<int> v(100);

  // ...

  // Explicitly force a call to parallel sort.
  __gnu_parallel::sort(v.begin(), v.end());
  return 0;
}

Then compile this code with the prerequisite compiler flags (-fopenmp and any necessary architecture-specific flags for atomic operations.)

The following table provides the names and headers of all the parallel algorithms that can be used in a similar manner:

Table 18.1. Parallel Algorithms

AlgorithmHeaderParallel algorithmParallel header
std::accumulatenumeric__gnu_parallel::accumulateparallel/numeric
std::adjacent_differencenumeric__gnu_parallel::adjacent_differenceparallel/numeric
std::inner_productnumeric__gnu_parallel::inner_productparallel/numeric
std::partial_sumnumeric__gnu_parallel::partial_sumparallel/numeric
std::adjacent_findalgorithm__gnu_parallel::adjacent_findparallel/algorithm
std::countalgorithm__gnu_parallel::countparallel/algorithm
std::count_ifalgorithm__gnu_parallel::count_ifparallel/algorithm
std::equalalgorithm__gnu_parallel::equalparallel/algorithm
std::findalgorithm__gnu_parallel::findparallel/algorithm
std::find_ifalgorithm__gnu_parallel::find_ifparallel/algorithm
std::find_first_ofalgorithm__gnu_parallel::find_first_ofparallel/algorithm
std::for_eachalgorithm__gnu_parallel::for_eachparallel/algorithm
std::generatealgorithm__gnu_parallel::generateparallel/algorithm
std::generate_nalgorithm__gnu_parallel::generate_nparallel/algorithm
std::lexicographical_comparealgorithm__gnu_parallel::lexicographical_compareparallel/algorithm
std::mismatchalgorithm__gnu_parallel::mismatchparallel/algorithm
std::searchalgorithm__gnu_parallel::searchparallel/algorithm
std::search_nalgorithm__gnu_parallel::search_nparallel/algorithm
std::transformalgorithm__gnu_parallel::transformparallel/algorithm
std::replacealgorithm__gnu_parallel::replaceparallel/algorithm
std::replace_ifalgorithm__gnu_parallel::replace_ifparallel/algorithm
std::max_elementalgorithm__gnu_parallel::max_elementparallel/algorithm
std::mergealgorithm__gnu_parallel::mergeparallel/algorithm
std::min_elementalgorithm__gnu_parallel::min_elementparallel/algorithm
std::nth_elementalgorithm__gnu_parallel::nth_elementparallel/algorithm
std::partial_sortalgorithm__gnu_parallel::partial_sortparallel/algorithm
std::partitionalgorithm__gnu_parallel::partitionparallel/algorithm
std::random_shufflealgorithm__gnu_parallel::random_shuffleparallel/algorithm
std::set_unionalgorithm__gnu_parallel::set_unionparallel/algorithm
std::set_intersectionalgorithm__gnu_parallel::set_intersectionparallel/algorithm
std::set_symmetric_differencealgorithm__gnu_parallel::set_symmetric_differenceparallel/algorithm
std::set_differencealgorithm__gnu_parallel::set_differenceparallel/algorithm
std::sortalgorithm__gnu_parallel::sortparallel/algorithm
std::stable_sortalgorithm__gnu_parallel::stable_sortparallel/algorithm
std::unique_copyalgorithm__gnu_parallel::unique_copyparallel/algorithm

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@