summaryrefslogtreecommitdiff
path: root/share/doc/gcc/Hints-implementation.html
diff options
context:
space:
mode:
Diffstat (limited to 'share/doc/gcc/Hints-implementation.html')
-rw-r--r--share/doc/gcc/Hints-implementation.html118
1 files changed, 118 insertions, 0 deletions
diff --git a/share/doc/gcc/Hints-implementation.html b/share/doc/gcc/Hints-implementation.html
new file mode 100644
index 0000000..ae6fc5a
--- /dev/null
+++ b/share/doc/gcc/Hints-implementation.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): Hints implementation</title>
+
+<meta name="description" content="Using the GNU Compiler Collection (GCC): Hints implementation">
+<meta name="keywords" content="Using the GNU Compiler Collection (GCC): Hints implementation">
+<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-Implementation.html#C-Implementation" rel="up" title="C Implementation">
+<link href="Structures-unions-enumerations-and-bit_002dfields-implementation.html#Structures-unions-enumerations-and-bit_002dfields-implementation" rel="next" title="Structures unions enumerations and bit-fields implementation">
+<link href="Arrays-and-pointers-implementation.html#Arrays-and-pointers-implementation" rel="previous" title="Arrays and pointers implementation">
+<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="Hints-implementation"></a>
+<div class="header">
+<p>
+Next: <a href="Structures-unions-enumerations-and-bit_002dfields-implementation.html#Structures-unions-enumerations-and-bit_002dfields-implementation" accesskey="n" rel="next">Structures unions enumerations and bit-fields implementation</a>, Previous: <a href="Arrays-and-pointers-implementation.html#Arrays-and-pointers-implementation" accesskey="p" rel="previous">Arrays and pointers implementation</a>, Up: <a href="C-Implementation.html#C-Implementation" accesskey="u" rel="up">C Implementation</a> &nbsp; [<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="Hints"></a>
+<h3 class="section">4.8 Hints</h3>
+
+<ul>
+<li> <cite>The extent to which suggestions made by using the <code>register</code>
+storage-class specifier are effective (C90 6.5.1, C99 and C11 6.7.1).</cite>
+
+<p>The <code>register</code> specifier affects code generation only in these ways:
+</p>
+<ul>
+<li> When used as part of the register variable extension, see
+<a href="Explicit-Register-Variables.html#Explicit-Register-Variables">Explicit Register Variables</a>.
+
+</li><li> When <samp>-O0</samp> is in use, the compiler allocates distinct stack
+memory for all variables that do not have the <code>register</code>
+storage-class specifier; if <code>register</code> is specified, the variable
+may have a shorter lifespan than the code would indicate and may never
+be placed in memory.
+
+</li><li> On some rare x86 targets, <code>setjmp</code> doesn&rsquo;t save the registers in
+all circumstances. In those cases, GCC doesn&rsquo;t allocate any variables
+in registers unless they are marked <code>register</code>.
+
+</li></ul>
+
+</li><li> <cite>The extent to which suggestions made by using the inline function
+specifier are effective (C99 and C11 6.7.4).</cite>
+
+<p>GCC will not inline any functions if the <samp>-fno-inline</samp> option is
+used or if <samp>-O0</samp> is used. Otherwise, GCC may still be unable to
+inline a function for many reasons; the <samp>-Winline</samp> option may be
+used to determine if a function has not been inlined and why not.
+</p>
+</li></ul>
+
+
+
+
+</body>
+</html>