diff options
Diffstat (limited to 'share/doc/gcc/Using-Assembly-Language-with-C.html')
| -rw-r--r-- | share/doc/gcc/Using-Assembly-Language-with-C.html | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/share/doc/gcc/Using-Assembly-Language-with-C.html b/share/doc/gcc/Using-Assembly-Language-with-C.html new file mode 100644 index 0000000..ba68099 --- /dev/null +++ b/share/doc/gcc/Using-Assembly-Language-with-C.html @@ -0,0 +1,118 @@ +<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> +<html> +<!-- This file documents the use of the GNU compilers. + +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>Using the GNU Compiler Collection (GCC): Using Assembly Language with C</title> + +<meta name="description" content="Using the GNU Compiler Collection (GCC): Using Assembly Language with C"> +<meta name="keywords" content="Using the GNU Compiler Collection (GCC): Using Assembly Language with C"> +<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="Indices.html#Indices" rel="index" title="Indices"> +<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents"> +<link href="C-Extensions.html#C-Extensions" rel="up" title="C Extensions"> +<link href="Basic-Asm.html#Basic-Asm" rel="next" title="Basic Asm"> +<link href="Volatiles.html#Volatiles" rel="previous" title="Volatiles"> +<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_US" bgcolor="#FFFFFF" text="#000000" link="#0000FF" vlink="#800080" alink="#FF0000"> +<a name="Using-Assembly-Language-with-C"></a> +<div class="header"> +<p> +Next: <a href="Alternate-Keywords.html#Alternate-Keywords" accesskey="n" rel="next">Alternate Keywords</a>, Previous: <a href="Volatiles.html#Volatiles" accesskey="p" rel="previous">Volatiles</a>, Up: <a href="C-Extensions.html#C-Extensions" accesskey="u" rel="up">C Extensions</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Indices.html#Indices" title="Index" rel="index">Index</a>]</p> +</div> +<hr> +<a name="How-to-Use-Inline-Assembly-Language-in-C-Code"></a> +<h3 class="section">6.47 How to Use Inline Assembly Language in C Code</h3> +<a name="index-asm-keyword"></a> +<a name="index-assembly-language-in-C"></a> +<a name="index-inline-assembly-language"></a> +<a name="index-mixing-assembly-language-and-C"></a> + +<p>The <code>asm</code> keyword allows you to embed assembler instructions +within C code. GCC provides two forms of inline <code>asm</code> +statements. A <em>basic <code>asm</code></em> statement is one with no +operands (see <a href="Basic-Asm.html#Basic-Asm">Basic Asm</a>), while an <em>extended <code>asm</code></em> +statement (see <a href="Extended-Asm.html#Extended-Asm">Extended Asm</a>) includes one or more operands. +The extended form is preferred for mixing C and assembly language +within a function, but to include assembly language at +top level you must use basic <code>asm</code>. +</p> +<p>You can also use the <code>asm</code> keyword to override the assembler name +for a C symbol, or to place a C variable in a specific register. +</p> +<table class="menu" border="0" cellspacing="0"> +<tr><td align="left" valign="top">• <a href="Basic-Asm.html#Basic-Asm" accesskey="1">Basic Asm</a>:</td><td> </td><td align="left" valign="top">Inline assembler without operands. +</td></tr> +<tr><td align="left" valign="top">• <a href="Extended-Asm.html#Extended-Asm" accesskey="2">Extended Asm</a>:</td><td> </td><td align="left" valign="top">Inline assembler with operands. +</td></tr> +<tr><td align="left" valign="top">• <a href="Constraints.html#Constraints" accesskey="3">Constraints</a>:</td><td> </td><td align="left" valign="top">Constraints for <code>asm</code> operands +</td></tr> +<tr><td align="left" valign="top">• <a href="Asm-Labels.html#Asm-Labels" accesskey="4">Asm Labels</a>:</td><td> </td><td align="left" valign="top">Specifying the assembler name to use for a C symbol. +</td></tr> +<tr><td align="left" valign="top">• <a href="Explicit-Register-Variables.html#Explicit-Register-Variables" accesskey="5">Explicit Register Variables</a>:</td><td> </td><td align="left" valign="top">Defining variables residing in specified + registers. +</td></tr> +<tr><td align="left" valign="top">• <a href="Size-of-an-asm.html#Size-of-an-asm" accesskey="6">Size of an asm</a>:</td><td> </td><td align="left" valign="top">How GCC calculates the size of an <code>asm</code> block. +</td></tr> +</table> + + + + +</body> +</html> |