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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/Constant-Attributes.html | |
https://developer.arm.com/downloads/-/arm-gnu-toolchain-downloads
Change-Id: I7303388733328cd98ab9aa3c30236db67f2e9e9c
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diff --git a/share/doc/gccint/Constant-Attributes.html b/share/doc/gccint/Constant-Attributes.html new file mode 100644 index 0000000..1aae5bc --- /dev/null +++ b/share/doc/gccint/Constant-Attributes.html @@ -0,0 +1,110 @@ +<!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: Constant Attributes</title> + +<meta name="description" content="GNU Compiler Collection (GCC) Internals: Constant Attributes"> +<meta name="keywords" content="GNU Compiler Collection (GCC) Internals: Constant Attributes"> +<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="Insn-Attributes.html#Insn-Attributes" rel="up" title="Insn Attributes"> +<link href="Mnemonic-Attribute.html#Mnemonic-Attribute" rel="next" title="Mnemonic Attribute"> +<link href="Insn-Lengths.html#Insn-Lengths" rel="previous" title="Insn Lengths"> +<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="Constant-Attributes"></a> +<div class="header"> +<p> +Next: <a href="Mnemonic-Attribute.html#Mnemonic-Attribute" accesskey="n" rel="next">Mnemonic Attribute</a>, Previous: <a href="Insn-Lengths.html#Insn-Lengths" accesskey="p" rel="previous">Insn Lengths</a>, Up: <a href="Insn-Attributes.html#Insn-Attributes" accesskey="u" rel="up">Insn Attributes</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="Constant-Attributes-1"></a> +<h4 class="subsection">17.19.6 Constant Attributes</h4> +<a name="index-constant-attributes"></a> + +<p>A special form of <code>define_attr</code>, where the expression for the +default value is a <code>const</code> expression, indicates an attribute that +is constant for a given run of the compiler. Constant attributes may be +used to specify which variety of processor is used. For example, +</p> +<div class="smallexample"> +<pre class="smallexample">(define_attr "cpu" "m88100,m88110,m88000" + (const + (cond [(symbol_ref "TARGET_88100") (const_string "m88100") + (symbol_ref "TARGET_88110") (const_string "m88110")] + (const_string "m88000")))) + +(define_attr "memory" "fast,slow" + (const + (if_then_else (symbol_ref "TARGET_FAST_MEM") + (const_string "fast") + (const_string "slow")))) +</pre></div> + +<p>The routine generated for constant attributes has no parameters as it +does not depend on any particular insn. RTL expressions used to define +the value of a constant attribute may use the <code>symbol_ref</code> form, +but may not use either the <code>match_operand</code> form or <code>eq_attr</code> +forms involving insn attributes. +</p> + + + +</body> +</html> |