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| author | alk3pInjection <webmaster@raspii.tech> | 2024-02-04 16:16:35 +0800 |
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| committer | alk3pInjection <webmaster@raspii.tech> | 2024-02-04 16:16:35 +0800 |
| commit | abdaadbcae30fe0c9a66c7516798279fdfd97750 (patch) | |
| tree | 00a54a6e25601e43876d03c1a4a12a749d4a914c /share/doc/gccint/Defining-Mode-Iterators.html | |
https://developer.arm.com/downloads/-/arm-gnu-toolchain-downloads
Change-Id: I7303388733328cd98ab9aa3c30236db67f2e9e9c
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diff --git a/share/doc/gccint/Defining-Mode-Iterators.html b/share/doc/gccint/Defining-Mode-Iterators.html new file mode 100644 index 0000000..e4215c2 --- /dev/null +++ b/share/doc/gccint/Defining-Mode-Iterators.html @@ -0,0 +1,125 @@ +<!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). A copy of the license is included in the section entitled +"GNU Free Documentation License". + +(a) The FSF's Front-Cover Text is: + +A GNU Manual + +(b) The FSF's Back-Cover Text is: + +You have freedom to copy and modify this GNU Manual, like GNU + software. Copies published by the Free Software Foundation raise + funds for GNU development. --> +<!-- Created by GNU Texinfo 5.1, http://www.gnu.org/software/texinfo/ --> +<head> +<title>GNU Compiler Collection (GCC) Internals: Defining Mode Iterators</title> + +<meta name="description" content="GNU Compiler Collection (GCC) Internals: Defining Mode Iterators"> +<meta name="keywords" content="GNU Compiler Collection (GCC) Internals: Defining Mode Iterators"> +<meta name="resource-type" content="document"> +<meta name="distribution" content="global"> +<meta name="Generator" content="makeinfo"> +<meta http-equiv="Content-Type" content="text/html; charset=utf-8"> +<link href="index.html#Top" rel="start" title="Top"> +<link href="Option-Index.html#Option-Index" rel="index" title="Option Index"> +<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents"> +<link href="Mode-Iterators.html#Mode-Iterators" rel="up" title="Mode Iterators"> +<link href="Substitutions.html#Substitutions" rel="next" title="Substitutions"> +<link href="Mode-Iterators.html#Mode-Iterators" rel="previous" title="Mode Iterators"> +<style type="text/css"> +<!-- +a.summary-letter {text-decoration: none} +blockquote.smallquotation {font-size: smaller} +div.display {margin-left: 3.2em} +div.example {margin-left: 3.2em} +div.indentedblock {margin-left: 3.2em} +div.lisp {margin-left: 3.2em} +div.smalldisplay {margin-left: 3.2em} +div.smallexample {margin-left: 3.2em} +div.smallindentedblock {margin-left: 3.2em; font-size: smaller} +div.smalllisp {margin-left: 3.2em} +kbd {font-style:oblique} +pre.display {font-family: inherit} +pre.format {font-family: inherit} +pre.menu-comment {font-family: serif} +pre.menu-preformatted {font-family: serif} +pre.smalldisplay {font-family: inherit; font-size: smaller} +pre.smallexample {font-size: smaller} +pre.smallformat {font-family: inherit; font-size: smaller} +pre.smalllisp {font-size: smaller} +span.nocodebreak {white-space:nowrap} +span.nolinebreak {white-space:nowrap} +span.roman {font-family:serif; font-weight:normal} +span.sansserif {font-family:sans-serif; font-weight:normal} +ul.no-bullet {list-style: none} +--> +</style> + + +</head> + +<body lang="en" bgcolor="#FFFFFF" text="#000000" link="#0000FF" vlink="#800080" alink="#FF0000"> +<a name="Defining-Mode-Iterators"></a> +<div class="header"> +<p> +Next: <a href="Substitutions.html#Substitutions" accesskey="n" rel="next">Substitutions</a>, Up: <a href="Mode-Iterators.html#Mode-Iterators" accesskey="u" rel="up">Mode Iterators</a> [<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> +</div> +<hr> +<a name="Defining-Mode-Iterators-1"></a> +<h4 class="subsubsection">17.23.1.1 Defining Mode Iterators</h4> +<a name="index-define_005fmode_005fiterator"></a> + +<p>The syntax for defining a mode iterator is: +</p> +<div class="smallexample"> +<pre class="smallexample">(define_mode_iterator <var>name</var> [(<var>mode1</var> "<var>cond1</var>") … (<var>moden</var> "<var>condn</var>")]) +</pre></div> + +<p>This allows subsequent <samp>.md</samp> file constructs to use the mode suffix +<code>:<var>name</var></code>. Every construct that does so will be expanded +<var>n</var> times, once with every use of <code>:<var>name</var></code> replaced by +<code>:<var>mode1</var></code>, once with every use replaced by <code>:<var>mode2</var></code>, +and so on. In the expansion for a particular <var>modei</var>, every +C condition will also require that <var>condi</var> be true. +</p> +<p>For example: +</p> +<div class="smallexample"> +<pre class="smallexample">(define_mode_iterator P [(SI "Pmode == SImode") (DI "Pmode == DImode")]) +</pre></div> + +<p>defines a new mode suffix <code>:P</code>. Every construct that uses +<code>:P</code> will be expanded twice, once with every <code>:P</code> replaced +by <code>:SI</code> and once with every <code>:P</code> replaced by <code>:DI</code>. +The <code>:SI</code> version will only apply if <code>Pmode == SImode</code> and +the <code>:DI</code> version will only apply if <code>Pmode == DImode</code>. +</p> +<p>As with other <samp>.md</samp> conditions, an empty string is treated +as “always true”. <code>(<var>mode</var> "")</code> can also be abbreviated +to <code><var>mode</var></code>. For example: +</p> +<div class="smallexample"> +<pre class="smallexample">(define_mode_iterator GPR [SI (DI "TARGET_64BIT")]) +</pre></div> + +<p>means that the <code>:DI</code> expansion only applies if <code>TARGET_64BIT</code> +but that the <code>:SI</code> expansion has no such constraint. +</p> +<p>Iterators are applied in the order they are defined. This can be +significant if two iterators are used in a construct that requires +substitutions. See <a href="Substitutions.html#Substitutions">Substitutions</a>. +</p> + + + +</body> +</html> |