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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/Memory-model.html | |
https://developer.arm.com/downloads/-/arm-gnu-toolchain-downloads
Change-Id: I7303388733328cd98ab9aa3c30236db67f2e9e9c
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| -rw-r--r-- | share/doc/gccint/Memory-model.html | 109 |
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diff --git a/share/doc/gccint/Memory-model.html b/share/doc/gccint/Memory-model.html new file mode 100644 index 0000000..6169ef2 --- /dev/null +++ b/share/doc/gccint/Memory-model.html @@ -0,0 +1,109 @@ +<!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: Memory model</title> + +<meta name="description" content="GNU Compiler Collection (GCC) Internals: Memory model"> +<meta name="keywords" content="GNU Compiler Collection (GCC) Internals: Memory model"> +<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="Tree-SSA.html#Tree-SSA" rel="up" title="Tree SSA"> +<link href="RTL.html#RTL" rel="next" title="RTL"> +<link href="Alias-analysis.html#Alias-analysis" rel="previous" title="Alias analysis"> +<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="Memory-model"></a> +<div class="header"> +<p> +Previous: <a href="Alias-analysis.html#Alias-analysis" accesskey="p" rel="previous">Alias analysis</a>, Up: <a href="Tree-SSA.html#Tree-SSA" accesskey="u" rel="up">Tree SSA</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="Memory-model-1"></a> +<h3 class="section">13.5 Memory model</h3> +<a name="index-memory-model"></a> + +<p>The memory model used by the middle-end models that of the C/C++ +languages. The middle-end has the notion of an effective type +of a memory region which is used for type-based alias analysis. +</p> +<p>The following is a refinement of ISO C99 6.5/6, clarifying the block copy case +to follow common sense and extending the concept of a dynamic effective +type to objects with a declared type as required for C++. +</p> +<div class="smallexample"> +<pre class="smallexample">The effective type of an object for an access to its stored value is +the declared type of the object or the effective type determined by +a previous store to it. If a value is stored into an object through +an lvalue having a type that is not a character type, then the +type of the lvalue becomes the effective type of the object for that +access and for subsequent accesses that do not modify the stored value. +If a value is copied into an object using <code>memcpy</code> or <code>memmove</code>, +or is copied as an array of character type, then the effective type +of the modified object for that access and for subsequent accesses that +do not modify the value is undetermined. For all other accesses to an +object, the effective type of the object is simply the type of the +lvalue used for the access. +</pre></div> + + + + + +</body> +</html> |