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diff --git a/share/doc/gccint/Peephole-Definitions.html b/share/doc/gccint/Peephole-Definitions.html new file mode 100644 index 0000000..e2825b5 --- /dev/null +++ b/share/doc/gccint/Peephole-Definitions.html @@ -0,0 +1,113 @@ +<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> +<html> +<!-- Copyright (C) 1988-2023 Free Software Foundation, Inc. + +Permission is granted to copy, distribute and/or modify this document +under the terms of the GNU Free Documentation License, Version 1.3 or +any later version published by the Free Software Foundation; with the +Invariant Sections being "Funding Free Software", the Front-Cover +Texts being (a) (see below), and with the Back-Cover Texts being (b) +(see below). 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For example, +sometimes two consecutive insns related in purpose can be combined even +though the second one does not appear to use a register computed in the +first one. A machine-specific peephole optimizer can detect such +opportunities. +</p> +<p>There are two forms of peephole definitions that may be used. The +original <code>define_peephole</code> is run at assembly output time to +match insns and substitute assembly text. Use of <code>define_peephole</code> +is deprecated. +</p> +<p>A newer <code>define_peephole2</code> matches insns and substitutes new +insns. The <code>peephole2</code> pass is run after register allocation +but before scheduling, which may result in much better code for +targets that do scheduling. +</p> +<table class="menu" border="0" cellspacing="0"> +<tr><td align="left" valign="top">• <a href="define_005fpeephole.html#define_005fpeephole" accesskey="1">define_peephole</a>:</td><td> </td><td align="left" valign="top">RTL to Text Peephole Optimizers +</td></tr> +<tr><td align="left" valign="top">• <a href="define_005fpeephole2.html#define_005fpeephole2" accesskey="2">define_peephole2</a>:</td><td> </td><td align="left" valign="top">RTL to RTL Peephole Optimizers +</td></tr> +</table> + + + + +</body> +</html> |