<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "xhtml1-transitional.dtd">
<!-- saved from url=(0013)about:internet -->
<?xml-stylesheet type="text/xsl" href="mathml.xsl"?><html xmlns="http://www.w3.org/1999/xhtml" xmlns:pref="http://www.w3.org/2002/Math/preference" xmlns:xlink="http://www.w3.org/1999/xlink" pref:renderer="mathplayer-dl">
  <head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
    <style xmlns="" type="text/css">
    /* This style sets a margin around the entire page */
        html, body {
            margin: 10px;
        }

        p {
            font: normal 16px verdana, sans-serif;
            margin: 0;
            padding-bottom:12px;
        }

        h1 {
            font: bold 25px verdana, sans-serif;
            margin-top: 0;
            margin-bottom: 3px;
            padding-top: 0;
            padding-bottom: 0;
        }

        h2 {
            font: bold 19px verdana, sans-serif;
            margin-top: 28px;
            margin-bottom: 3px;
            padding-top: 0; 
            padding-bottom: 0;
        }

        h3 {
            font: bold 19px verdana, sans-serif !important;
            margin-top: 28px;
            margin-bottom: 3px;
            padding-top: 0;
            padding-bottom: 0;
        }

        li {
            font: normal 16px verdana, sans-serif;
            margin-top: 0;
            margin-bottom: 18px;
            padding-top: 0;
            padding-bottom: 0;
        }

        .pdparam {
            font: italic 16px verdana, sans-serif;
        }
		
		.term {
			font: italic 16px verdana, sans-serif;
			font-weight: normal;
		}	
		
		.type {
			font: normal 16px verdana, sans-serif !important;
		}			
		
		.parameter { 
			font-style: italic; 
			}

        a:link, a:visited {
            color: blue;
            text-decoration: none;
            font: normal 16px;
        }

        a:hover {
            background-color: #FFFF99;
            font: normal 16px;
        }

        div.funcsynopsis {
            text-align: left;
            background-color: #e6e6e6;
            font: normal 16px verdana, sans-serif;
			padding-top: 10px;
			padding-bottom: 10px;
        }

        div.funcsynopsis table {
            border-collapse: separate;
            font: normal 16px verdana, sans-serif;
        }

        div.funcsynopsis td {
            background-color: #e6e6e6;
            border: 0 solid #000;
            padding: 1px;
            font: normal 16px verdana, sans-serif;
        }

        div.refsect1 {
            font-family: verdana, sans-serif;
            font-size: 16px;
        }

        code.constant {
            font: normal 16px courier new, monospace !important;
        }
		
		span.errorname {
            font: normal 16px verdana, sans-serif !important;
        }

        code.function {
            font: bold 16px verdana, sans-serif !important;
        }
		
        b.fsfunc {
            font: bold 16px verdana, sans-serif !important;
        }
		
        code.varname {
            font: italic 16px verdana, sans-serif;
        }

        code.replaceable {
            font: italic 16px courier new, monospace;
        }

        code.funcdef {
            font: normal 16px verdana, sans-serif !important;
        }

        .citerefentry {
            font: normal 16px verdana, sans-serif !important;
        }

        .parameter {
            font-style: italic;
        }

        code.fsfunc {
            font: normal 16px verdana, sans-serif !important;
        }

        /* PARAMETER: This style controls spacing between the terms in Parameter section */
        dt {
            margin-top: 15px;
        }

        /* TABLES: These styles apply to all tables OTHER than the Synopsis and Example tables */
        div.refsect1 table {
            width: 100%;
			margin-top: 10px;
            background-color: #FFF;
			border-collapse: collapse;
			border-color: #000;
            border-width: 1px;
			font: normal 16px verdana, sans-serif;
        }
		
        div.refsect1 th {
			border-collapse: collapse;
			border-color: #000;
            border-width: 1px;
            font: bold 16px verdana, sans-serif;
        }
		
        div.refsect1 td {
            background-color: #FFF;
            padding: 5px;
            vertical-align: text-top;
			border-collapse: collapse;
			border-color: #000;
            border-width: 1px;
            font: normal 16px verdana, sans-serif;
        }
		
		  div.refsect1 p{
            font: normal 16px verdana, sans-serif;
            margin-top: 8px;
            margin-bottom: 8px;
            padding-top: 0;
            padding-bottom: 0;
        }
		

        /* EXAMPLE: These styles apply only to the Example section */
        div.refsect2 {
            font: normal 16px courier new, monospace !important;
        }

        div.refsect2 table {
            margin-top: 0;
            background-color: #e6e6e6;
            width: 100%;
            border: 0 solid #000;
            padding: 2px;
            font: normal 16px courier new, monospace !important;
        }

        div.refsect2 td {
            background-color: #e6e6e6;
            font: normal 16px courier new, monospace !important;
			white-space:pre;
        }

        /* COPYRIGHT: This style formats the text of the copyright statement at the bottom of the page */
        div.refsect3 {
            font: normal 11px verdana, sans-serif;
            margin-top: 50px;
            margin-bottom: 20px;
            padding-top: 0;
            padding-bottom: 0;
        }
					
</style>
    <title>cl_khr_fp64</title>
    <meta name="generator" content="DocBook XSL Stylesheets V1.79.1" />
    <meta name="keywords" content="                            &#10;                cl_khr_fp64&#10;            " />
  </head>
  <body>
    <div class="refentry">
      <a id="idm1"></a>
      <div class="titlepage"></div>
      <div xmlns="" class="refnamediv">
        <a xmlns="http://www.w3.org/1999/xhtml" id="cl_khr_fp64"></a>
        <h1>cl_khr_fp64</h1>
        <p>
            Support for <span xmlns="http://www.w3.org/1999/xhtml" class="type">double</span> floating-point precision.
        </p>
      </div>
      <div class="refsect2">
        <a id="synopsis"></a>
        <h3>
        </h3>
        <div class="informaltable">
          <table class="informaltable" border="0">
            <colgroup>
              <col align="left" class="col1" />
            </colgroup>
            <tbody>
              <tr>
                <td align="left">
#pragma OPENCL EXTENSION cl_khr_fp64 : enable
                        </td>
              </tr>
            </tbody>
          </table>
        </div>
      </div>
      <div class="refsect1">
        <a id="description"></a>
        <h2>Description</h2>
        <p>
Support for double floating-point precision is a requirement for a class of scientific computing algorithms/applications. This class of applications can be enabled by adding support for double precision floating-point as an optional extension.
        </p>
        <p>
OpenCL 1.0 adds support for double precision floating-point as an optional extension. An application that wants to use <span class="type">double</span> will need to include the <code class="function">#pragma OPENCL EXTENSION cl_khr_fp64 : enable</code> directive before any double precision data type is declared in the kernel code.
        </p>
        <p>
The lists of built-in <a class="citerefentry" href="scalarDataTypes.html"><span class="citerefentry"><span class="refentrytitle">scalar data types</span></span></a> and <a class="citerefentry" href="vectorDataTypes.html"><span class="citerefentry"><span class="refentrytitle">vector data types</span></span></a> are extended to include the following:
            </p>
        <div class="informaltable">
          <table class="informaltable" border="1">
            <colgroup>
              <col align="left" class="col1" />
              <col align="left" class="col2" />
            </colgroup>
            <thead>
              <tr>
                <th align="left">Type in OpenCL Language</th>
                <th align="left">Description</th>
                <th align="left">API type for application</th>
              </tr>
            </thead>
            <tbody>
              <tr>
                <td align="left">double</td>
                <td align="left">A double precision vector</td>
                <td align="left">cl_double</td>
              </tr>
              <tr>
                <td align="left">double2</td>
                <td align="left">2-component double vector</td>
                <td align="left">cl_double2</td>
              </tr>
              <tr>
                <td align="left">double4</td>
                <td align="left">4-component double vector</td>
                <td align="left">cl_double4</td>
              </tr>
              <tr>
                <td align="left">double8</td>
                <td align="left">8-component double vector</td>
                <td align="left">cl_double8</td>
              </tr>
              <tr>
                <td align="left">double16</td>
                <td align="left">16-component double vector</td>
                <td align="left">cl_double16</td>
              </tr>
            </tbody>
          </table>
        </div>
        <p>
        </p>
        <p>
The double data type must confirm to the IEEE-754 double precision storage format.
        </p>
        <p>
       Conversions from <span class="type">double</span> to <span class="type">half</span> are correctly rounded. Conversions from <span class="type">half</span> to <span class="type">double</span> are lossless.
        </p>
      </div>
      <div class="refsect1">
        <a id="specification"></a>
        <h2>Specification</h2>
        <p>
            <img src="pdficon_small1.gif" />
                                                 
            <a href="http://www.khronos.org/registry/cl/specs/opencl-1.0.pdf#page=225" target="OpenCL Spec">OpenCL Specification</a>
        </p>
      </div>
      <div class="refsect1">
        <a id="seealso"></a>
        <h2>Also see</h2>
        <p>
            <a class="citerefentry" href="clGetDeviceInfo.html"><span class="citerefentry"><span class="refentrytitle">clGetDeviceInfo</span>, <a class="citerefentry" href="EXTENSION.html"><span class="citerefentry"><span class="refentrytitle">EXTENSION</span></span></a></span></a>
        </p>
      </div>
      <div xmlns="" class="refsect3" lang="en" xml:lang="en"><a xmlns="http://www.w3.org/1999/xhtml" id="Copyright"></a><h4 xmlns="http://www.w3.org/1999/xhtml"></h4><img xmlns="http://www.w3.org/1999/xhtml" src="KhronosLogo.jpg" /><p xmlns="http://www.w3.org/1999/xhtml"></p>Copyright © 2007-2009 The Khronos Group Inc. 
Permission is hereby granted, free of charge, to any person obtaining a
copy of this software and/or associated documentation files (the
"Materials"), to deal in the Materials without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Materials, and to
permit persons to whom the Materials are furnished to do so, subject to
the condition that this copyright notice and permission notice shall be included
in all copies or substantial portions of the Materials. 
</div>
    </div>
  </body>
</html>