sdk/2.0/docs/man/local.xml

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<refentry>
    <refentryinfo>
        <keywordset>
            <keyword>__local</keyword>
        </keywordset>
    </refentryinfo>

    <refmeta>
        <refentrytitle>__local</refentrytitle>

        <refmiscinfo>
            <copyright>
                <year>2007-2013</year>
                <holder>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.</holder>
            </copyright>
        </refmiscinfo>
        <manvolnum>3</manvolnum>
    </refmeta>

<!-- ================================ SYNOPSIS -->

    <refnamediv id="__local">
        <refname>__local</refname>

        <refpurpose>
            Address Space Qualifier.
        </refpurpose>
    </refnamediv>

    <!-- ALTERNATIVE SYNTAX SYNOPSIS (NON-FUNCTION) -->
    <refsect2 id="synopsis">
        <title>
        </title>

        <informaltable frame="none">
            <tgroup cols="1" align="left" colsep="0" rowsep="0">
                <colspec colname="col1" colnum="1" />
                <tbody>
                    <row>
                        <entry>
__local
local
                        </entry>
                    </row>
                </tbody>
            </tgroup>
        </informaltable>
    </refsect2>

<!-- ================================ DESCRIPTION  -->

    <refsect1 id="description"><title>Description</title>

        <para>
            The <function>__local</function> or <function>local</function> address space name is
            used to describe variables that need to be allocated in local memory and are shared by
            all work-items of a work-group. Pointers to the <function>__local</function> address
            space are allowed as arguments to functions (including kernel
            functions). Variables allocated in the <function>__local</function> address space 
            inside a kernel function must occur at kernel function scope. 
        </para>

    </refsect1>

<!-- ================================ NOTES  -->

    <refsect1 id="notes"><title>Notes</title>

        &qualifierInc;

    </refsect1>

<!-- ================================ EXAMPLE  -->

    <refsect2 id="example1">
        <title>
            Example
        </title>

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                        <entry>
// Examples of variables allocated in the __local address space
// inside a kernel function

kernel void my_func(...)
{
      local float      a;       // A single float allocated
                                // in local address space

      local float      b[10];   // An array of 10 floats
                                // allocated in local address space.
      if (...)
      {
          // example of variable in __local address space but not
          // declared at __kernel function scope.
          local float c;        // not allowed.
      }
}
                        </entry>
                    </row>
                </tbody>
            </tgroup>
        </informaltable>

        <para>
          Variables allocated in the <function>__local</function> address space inside a
          kernel function cannot be initialized.
        </para>

        <informaltable frame="none">
            <tgroup cols="1" align="left" colsep="0" rowsep="0">
                <colspec colname="col1" colnum="1" />
                <tbody>
                    <row>
                        <entry>
    kernel void my_func(...)
    {
       local float a = 1;    // not allowed 

       local float b; 
       b = 1;                // allowed
    }
                        </entry>
                    </row>
                </tbody>
            </tgroup>
        </informaltable>

        <para>
            NOTE: Variables allocated in the <function>__local</function> address
            space inside a kernel function 
            are allocated for each work-group executing
            the kernel and exist only for the lifetime of the work-group 
            executing the kernel.
        </para>

        &qualifierExampleInc;

    </refsect2>

<!-- ================================ SPECIFICATION  -->
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    <refsect1 id="specification"><title>Specification</title>
        <para>
            <imageobject>
                <imagedata fileref="pdficon_small1.gif" format="gif" />
            </imageobject>

            <olink uri="addressSpaceQualifiers">OpenCL Specification</olink>
        </para>
    </refsect1>

<!-- ================================ ALSO SEE  -->

    <refsect1 id="seealso"><title>Also see</title>
        <para>
            <citerefentry href="global"><refentrytitle>__global</refentrytitle></citerefentry>,
            <citerefentry href="constant"><refentrytitle>__constant</refentrytitle></citerefentry>,
            <citerefentry href="private"><refentrytitle>__private</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>qualifiers</refentrytitle></citerefentry>
        </para>
    </refsect1>

<!-- ============================== COPYRIGHT -->
<!-- Content included from copyright.inc.xsl -->

    <refsect3 id="Copyright"><title></title>
        <imageobject>
                <imagedata fileref="KhronosLogo.jpg" format="jpg" />
        </imageobject>
        <para />
    </refsect3>

<!-- 25-Dec-2013, rev. 19 -->
</refentry>