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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>Chapter 18. Parallel Mode</title><meta name="generator" content="DocBook XSL Stylesheets Vsnapshot" /><meta name="keywords" content="C++, library, parallel" /><meta name="keywords" content="ISO C++, library" /><meta name="keywords" content="ISO C++, runtime, library" /><link rel="home" href="../index.html" title="The GNU C++ Library" /><link rel="up" href="extensions.html" title="Part III.  Extensions" /><link rel="prev" href="debug_mode_design.html" title="Design" /><link rel="next" href="parallel_mode_semantics.html" title="Semantics" /></head><body><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Chapter 18. Parallel Mode</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="debug_mode_design.html">Prev</a> </td><th width="60%" align="center">Part III. 
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</th><td width="20%" align="right"> <a accesskey="n" href="parallel_mode_semantics.html">Next</a></td></tr></table><hr /></div><div class="chapter"><div class="titlepage"><div><div><h2 class="title"><a id="manual.ext.parallel_mode"></a>Chapter 18. Parallel Mode</h2></div></div></div><div class="toc"><p><strong>Table of Contents</strong></p><dl class="toc"><dt><span class="section"><a href="parallel_mode.html#manual.ext.parallel_mode.intro">Intro</a></span></dt><dt><span class="section"><a href="parallel_mode_semantics.html">Semantics</a></span></dt><dt><span class="section"><a href="parallel_mode_using.html">Using</a></span></dt><dd><dl><dt><span class="section"><a href="parallel_mode_using.html#parallel_mode.using.prereq_flags">Prerequisite Compiler Flags</a></span></dt><dt><span class="section"><a href="parallel_mode_using.html#parallel_mode.using.parallel_mode">Using Parallel Mode</a></span></dt><dt><span class="section"><a href="parallel_mode_using.html#parallel_mode.using.specific">Using Specific Parallel Components</a></span></dt></dl></dd><dt><span class="section"><a href="parallel_mode_design.html">Design</a></span></dt><dd><dl><dt><span class="section"><a href="parallel_mode_design.html#parallel_mode.design.intro">Interface Basics</a></span></dt><dt><span class="section"><a href="parallel_mode_design.html#parallel_mode.design.tuning">Configuration and Tuning</a></span></dt><dd><dl><dt><span class="section"><a href="parallel_mode_design.html#parallel_mode.design.tuning.omp">Setting up the OpenMP Environment</a></span></dt><dt><span class="section"><a href="parallel_mode_design.html#parallel_mode.design.tuning.compile">Compile Time Switches</a></span></dt><dt><span class="section"><a href="parallel_mode_design.html#parallel_mode.design.tuning.settings">Run Time Settings and Defaults</a></span></dt></dl></dd><dt><span class="section"><a href="parallel_mode_design.html#parallel_mode.design.impl">Implementation Namespaces</a></span></dt></dl></dd><dt><span class="section"><a href="parallel_mode_test.html">Testing</a></span></dt><dt><span class="bibliography"><a href="parallel_mode.html#parallel_mode.biblio">Bibliography</a></span></dt></dl></div><p> The libstdc++ parallel mode is an experimental parallel
implementation of many algorithms of the C++ Standard Library.
</p><p>
Several of the standard algorithms, for instance
<code class="function">std::sort</code>, are made parallel using OpenMP
annotations. These parallel mode constructs can be invoked by
explicit source declaration or by compiling existing sources with a
specific compiler flag.
</p><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>
    The parallel mode has not been kept up to date with recent C++ standards
    and so it only conforms to the C++03 requirements.
    That means that move-only predicates may not work with parallel mode
    algorithms, and for C++20 most of the algorithms cannot be used in
    <code class="code">constexpr</code> functions.
  </p><p>
    For C++17 and above there are new overloads of the standard algorithms
    which take an execution policy argument. You should consider using those
    instead of the non-standard parallel mode extensions.
  </p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="manual.ext.parallel_mode.intro"></a>Intro</h2></div></div></div><p>The following library components in the include
<code class="filename">numeric</code> are included in the parallel mode:</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p><code class="function">std::accumulate</code></p></li><li class="listitem"><p><code class="function">std::adjacent_difference</code></p></li><li class="listitem"><p><code class="function">std::inner_product</code></p></li><li class="listitem"><p><code class="function">std::partial_sum</code></p></li></ul></div><p>The following library components in the include
<code class="filename">algorithm</code> are included in the parallel mode:</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p><code class="function">std::adjacent_find</code></p></li><li class="listitem"><p><code class="function">std::count</code></p></li><li class="listitem"><p><code class="function">std::count_if</code></p></li><li class="listitem"><p><code class="function">std::equal</code></p></li><li class="listitem"><p><code class="function">std::find</code></p></li><li class="listitem"><p><code class="function">std::find_if</code></p></li><li class="listitem"><p><code class="function">std::find_first_of</code></p></li><li class="listitem"><p><code class="function">std::for_each</code></p></li><li class="listitem"><p><code class="function">std::generate</code></p></li><li class="listitem"><p><code class="function">std::generate_n</code></p></li><li class="listitem"><p><code class="function">std::lexicographical_compare</code></p></li><li class="listitem"><p><code class="function">std::mismatch</code></p></li><li class="listitem"><p><code class="function">std::search</code></p></li><li class="listitem"><p><code class="function">std::search_n</code></p></li><li class="listitem"><p><code class="function">std::transform</code></p></li><li class="listitem"><p><code class="function">std::replace</code></p></li><li class="listitem"><p><code class="function">std::replace_if</code></p></li><li class="listitem"><p><code class="function">std::max_element</code></p></li><li class="listitem"><p><code class="function">std::merge</code></p></li><li class="listitem"><p><code class="function">std::min_element</code></p></li><li class="listitem"><p><code class="function">std::nth_element</code></p></li><li class="listitem"><p><code class="function">std::partial_sort</code></p></li><li class="listitem"><p><code class="function">std::partition</code></p></li><li class="listitem"><p><code class="function">std::random_shuffle</code></p></li><li class="listitem"><p><code class="function">std::set_union</code></p></li><li class="listitem"><p><code class="function">std::set_intersection</code></p></li><li class="listitem"><p><code class="function">std::set_symmetric_difference</code></p></li><li class="listitem"><p><code class="function">std::set_difference</code></p></li><li class="listitem"><p><code class="function">std::sort</code></p></li><li class="listitem"><p><code class="function">std::stable_sort</code></p></li><li class="listitem"><p><code class="function">std::unique_copy</code></p></li></ul></div></div><div class="bibliography"><div class="titlepage"><div><div><h2 class="title"><a id="parallel_mode.biblio"></a>Bibliography</h2></div></div></div><div class="biblioentry"><a id="id-1.3.5.5.10.2"></a><p><span class="citetitle"><em class="citetitle">
      Parallelization of Bulk Operations for STL Dictionaries
    </em>. </span><span class="author"><span class="firstname">Johannes</span> <span class="surname">Singler</span>. </span><span class="author"><span class="firstname">Leonor</span> <span class="surname">Frias</span>. </span><span class="copyright">Copyright © 2007 . </span><span class="publisher"><span class="publishername">
	Workshop on Highly Parallel Processing on a Chip (HPPC) 2007. (LNCS)
      . </span></span></p></div><div class="biblioentry"><a id="id-1.3.5.5.10.3"></a><p><span class="citetitle"><em class="citetitle">
      The Multi-Core Standard Template Library
    </em>. </span><span class="author"><span class="firstname">Johannes</span> <span class="surname">Singler</span>. </span><span class="author"><span class="firstname">Peter</span> <span class="surname">Sanders</span>. </span><span class="author"><span class="firstname">Felix</span> <span class="surname">Putze</span>. </span><span class="copyright">Copyright © 2007 . </span><span class="publisher"><span class="publishername">
	 Euro-Par 2007: Parallel Processing. (LNCS 4641)
      . </span></span></p></div></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="debug_mode_design.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="extensions.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="parallel_mode_semantics.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">Design </td><td width="20%" align="center"><a accesskey="h" href="../index.html">Home</a></td><td width="40%" align="right" valign="top"> Semantics</td></tr></table></div></body></html>