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Previous: <a href="Alternate-complex-function-syntax.html#Alternate-complex-function-syntax" accesskey="p" rel="prev">Alternate complex function syntax</a>, Up: <a href="Extensions-not-implemented-in-GNU-Fortran.html#Extensions-not-implemented-in-GNU-Fortran" accesskey="u" rel="up">Extensions not implemented in GNU Fortran</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Option-Index.html#Option-Index" title="Index" rel="index">Index</a>]</p>
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<a name="Volatile-COMMON-blocks-1"></a>
<h4 class="subsection">6.2.5 Volatile <code>COMMON</code> blocks</h4>
<a name="index-VOLATILE"></a>
<a name="index-COMMON"></a>

<p>Some Fortran compilers, including <code>g77</code>, let the user declare
<code>COMMON</code> with the <code>VOLATILE</code> attribute. This is
invalid standard Fortran syntax and is not supported by
<code>gfortran</code>.  Note that <code>gfortran</code> accepts
<code>VOLATILE</code> variables in <code>COMMON</code> blocks since revision 4.3.
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