ceph/src/boost/libs/math/doc/html/math_toolkit/multiprecision.html

   1 <html>
   2 <head>
   3 <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
   4 <title>Cost of High-Precision Non-built-in Floating-point</title>
   5 <link rel="stylesheet" href="../math.css" type="text/css">
   6 <meta name="generator" content="DocBook XSL Stylesheets V1.77.1">
   7 <link rel="home" href="../index.html" title="Math Toolkit 2.5.1">
   8 <link rel="up" href="../perf.html" title="Chapter&#160;16.&#160;Performance">
   9 <link rel="prev" href="tradoffs.html" title="Trading Accuracy for Performance">
  10 <link rel="next" href="tuning.html" title="Performance Tuning Macros">
  11 </head>
  12 <body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
  13 <table cellpadding="2" width="100%"><tr>
  14 <td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../boost.png"></td>
  15 <td align="center"><a href="../../../../../index.html">Home</a></td>
  16 <td align="center"><a href="../../../../../libs/libraries.htm">Libraries</a></td>
  17 <td align="center"><a href="http://www.boost.org/users/people.html">People</a></td>
  18 <td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td>
  19 <td align="center"><a href="../../../../../more/index.htm">More</a></td>
  20 </tr></table>
  21 <hr>
  22 <div class="spirit-nav">
  23 <a accesskey="p" href="tradoffs.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../perf.html"><img src="../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="tuning.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a>
  24 </div>
  25 <div class="section">
  26 <div class="titlepage"><div><div><h2 class="title" style="clear: both">
  27 <a name="math_toolkit.multiprecision"></a><a class="link" href="multiprecision.html" title="Cost of High-Precision Non-built-in Floating-point">Cost of High-Precision Non-built-in
  28     Floating-point</a>
  29 </h2></div></div></div>
  30 <p>
  31       Using user-defined floating-point like <a href="../../../../../libs/multiprecision/doc/html/index.html" target="_top">Boost.Multiprecision</a>
  32       has a very high run-time cost.
  33     </p>
  34 <p>
  35       To give some flavour of this:
  36     </p>
  37 <div class="table">
  38 <a name="math_toolkit.multiprecision.linpack_time"></a><p class="title"><b>Table&#160;16.2.&#160;Linpack Benchmark</b></p>
  39 <div class="table-contents"><table class="table" summary="Linpack Benchmark">
  40 <colgroup>
  41 <col>
  42 <col>
  43 </colgroup>
  44 <thead><tr>
  45 <th>
  46               <p>
  47                 floating-point type
  48               </p>
  49             </th>
  50 <th>
  51               <p>
  52                 speed Mflops
  53               </p>
  54             </th>
  55 </tr></thead>
  56 <tbody>
  57 <tr>
  58 <td>
  59               <p>
  60                 double
  61               </p>
  62             </td>
  63 <td>
  64               <p>
  65                 2727
  66               </p>
  67             </td>
  68 </tr>
  69 <tr>
  70 <td>
  71               <p>
  72                 __float128
  73               </p>
  74             </td>
  75 <td>
  76               <p>
  77                 35
  78               </p>
  79             </td>
  80 </tr>
  81 <tr>
  82 <td>
  83               <p>
  84                 multiprecision::float128
  85               </p>
  86             </td>
  87 <td>
  88               <p>
  89                 35
  90               </p>
  91             </td>
  92 </tr>
  93 <tr>
  94 <td>
  95               <p>
  96                 multiprecision::cpp_bin_float_quad
  97               </p>
  98             </td>
  99 <td>
 100               <p>
 101                 6
 102               </p>
 103             </td>
 104 </tr>
 105 </tbody>
 106 </table></div>
 107 </div>
 108 <br class="table-break">
 109 </div>
 110 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 111 <td align="left"></td>
 112 <td align="right"><div class="copyright-footer">Copyright &#169; 2006-2010, 2012-2014 Nikhar Agrawal,
 113       Anton Bikineev, Paul A. Bristow, Marco Guazzone, Christopher Kormanyos, Hubert
 114       Holin, Bruno Lalande, John Maddock, Jeremy Murphy, Johan R&#229;de, Gautam Sewani,
 115       Benjamin Sobotta, Thijs van den Berg, Daryle Walker and Xiaogang Zhang<p>
 116         Distributed under the Boost Software License, Version 1.0. (See accompanying
 117         file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
 118       </p>
 119 </div></td>
 120 </tr></table>
 121 <hr>
 122 <div class="spirit-nav">
 123 <a accesskey="p" href="tradoffs.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../perf.html"><img src="../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="tuning.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a>
 124 </div>
 125 </body>
 126 </html>