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Next: <a href="Match-and-Simplify.html#Match-and-Simplify" accesskey="n" rel="next">Match and Simplify</a>, Previous: <a href="Plugins.html#Plugins" accesskey="p" rel="prev">Plugins</a>, Up: <a href="index.html#Top" accesskey="u" rel="up">Top</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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<h2 class="chapter">25 Link Time Optimization</h2>
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<p>Link Time Optimization (LTO) gives GCC the capability of
dumping its internal representation (GIMPLE) to disk,
so that all the different compilation units that make up
a single executable can be optimized as a single module.
This expands the scope of inter-procedural optimizations
to encompass the whole program (or, rather, everything
that is visible at link time).
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<tr><td align="left" valign="top">&bull; <a href="LTO-Overview.html#LTO-Overview" accesskey="1">LTO Overview</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Overview of LTO.
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<tr><td align="left" valign="top">&bull; <a href="LTO-object-file-layout.html#LTO-object-file-layout" accesskey="2">LTO object file layout</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">LTO file sections in ELF.
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<tr><td align="left" valign="top">&bull; <a href="IPA.html#IPA" accesskey="3">IPA</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Using summary information in IPA passes.
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<tr><td align="left" valign="top">&bull; <a href="WHOPR.html#WHOPR" accesskey="4">WHOPR</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Whole program assumptions,
                            linker plugin and symbol visibilities.
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<tr><td align="left" valign="top">&bull; <a href="Internal-flags.html#Internal-flags" accesskey="5">Internal flags</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Internal flags controlling <code>lto1</code>.
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