diff options
Diffstat (limited to 'share/doc/gccint/Caller-Saves.html')
| -rw-r--r-- | share/doc/gccint/Caller-Saves.html | 97 |
1 files changed, 97 insertions, 0 deletions
diff --git a/share/doc/gccint/Caller-Saves.html b/share/doc/gccint/Caller-Saves.html new file mode 100644 index 0000000..7b8c0ec --- /dev/null +++ b/share/doc/gccint/Caller-Saves.html @@ -0,0 +1,97 @@ +<!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: Caller Saves</title> + +<meta name="description" content="GNU Compiler Collection (GCC) Internals: Caller Saves"> +<meta name="keywords" content="GNU Compiler Collection (GCC) Internals: Caller Saves"> +<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="Stack-and-Calling.html#Stack-and-Calling" rel="up" title="Stack and Calling"> +<link href="Function-Entry.html#Function-Entry" rel="next" title="Function Entry"> +<link href="Aggregate-Return.html#Aggregate-Return" rel="previous" title="Aggregate Return"> +<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="Caller-Saves"></a> +<div class="header"> +<p> +Next: <a href="Function-Entry.html#Function-Entry" accesskey="n" rel="next">Function Entry</a>, Previous: <a href="Aggregate-Return.html#Aggregate-Return" accesskey="p" rel="previous">Aggregate Return</a>, Up: <a href="Stack-and-Calling.html#Stack-and-Calling" accesskey="u" rel="up">Stack and Calling</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="Caller_002dSaves-Register-Allocation"></a> +<h4 class="subsection">18.9.10 Caller-Saves Register Allocation</h4> + +<p>If you enable it, GCC can save registers around function calls. This +makes it possible to use call-clobbered registers to hold variables that +must live across calls. +</p> +<dl> +<dt><a name="index-HARD_005fREGNO_005fCALLER_005fSAVE_005fMODE"></a>Macro: <strong>HARD_REGNO_CALLER_SAVE_MODE</strong> <em>(<var>regno</var>, <var>nregs</var>)</em></dt> +<dd><p>A C expression specifying which mode is required for saving <var>nregs</var> +of a pseudo-register in call-clobbered hard register <var>regno</var>. If +<var>regno</var> is unsuitable for caller save, <code>VOIDmode</code> should be +returned. For most machines this macro need not be defined since GCC +will select the smallest suitable mode. +</p></dd></dl> + + + + +</body> +</html> |