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diff --git a/share/doc/gccint/PIC.html b/share/doc/gccint/PIC.html new file mode 100644 index 0000000..f220adb --- /dev/null +++ b/share/doc/gccint/PIC.html @@ -0,0 +1,132 @@ +<!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: PIC</title> + +<meta name="description" content="GNU Compiler Collection (GCC) Internals: PIC"> +<meta name="keywords" content="GNU Compiler Collection (GCC) Internals: PIC"> +<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="Target-Macros.html#Target-Macros" rel="up" title="Target Macros"> +<link href="Assembler-Format.html#Assembler-Format" rel="next" title="Assembler Format"> +<link href="Sections.html#Sections" rel="previous" title="Sections"> +<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="PIC"></a> +<div class="header"> +<p> +Next: <a href="Assembler-Format.html#Assembler-Format" accesskey="n" rel="next">Assembler Format</a>, Previous: <a href="Sections.html#Sections" accesskey="p" rel="previous">Sections</a>, Up: <a href="Target-Macros.html#Target-Macros" accesskey="u" rel="up">Target Macros</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="Position-Independent-Code"></a> +<h3 class="section">18.19 Position Independent Code</h3> +<a name="index-position-independent-code"></a> +<a name="index-PIC"></a> + +<p>This section describes macros that help implement generation of position +independent code. Simply defining these macros is not enough to +generate valid PIC; you must also add support to the hook +<code>TARGET_LEGITIMATE_ADDRESS_P</code> and to the macro +<code>PRINT_OPERAND_ADDRESS</code>, as well as <code>LEGITIMIZE_ADDRESS</code>. You +must modify the definition of ‘<samp>movsi</samp>’ to do something appropriate +when the source operand contains a symbolic address. You may also +need to alter the handling of switch statements so that they use +relative addresses. +</p> +<dl> +<dt><a name="index-PIC_005fOFFSET_005fTABLE_005fREGNUM"></a>Macro: <strong>PIC_OFFSET_TABLE_REGNUM</strong></dt> +<dd><p>The register number of the register used to address a table of static +data addresses in memory. In some cases this register is defined by a +processor’s “application binary interface” (ABI). When this macro +is defined, RTL is generated for this register once, as with the stack +pointer and frame pointer registers. If this macro is not defined, it +is up to the machine-dependent files to allocate such a register (if +necessary). Note that this register must be fixed when in use (e.g. +when <code>flag_pic</code> is true). +</p></dd></dl> + +<dl> +<dt><a name="index-PIC_005fOFFSET_005fTABLE_005fREG_005fCALL_005fCLOBBERED"></a>Macro: <strong>PIC_OFFSET_TABLE_REG_CALL_CLOBBERED</strong></dt> +<dd><p>A C expression that is nonzero if the register defined by +<code>PIC_OFFSET_TABLE_REGNUM</code> is clobbered by calls. If not defined, +the default is zero. Do not define +this macro if <code>PIC_OFFSET_TABLE_REGNUM</code> is not defined. +</p></dd></dl> + +<dl> +<dt><a name="index-LEGITIMATE_005fPIC_005fOPERAND_005fP"></a>Macro: <strong>LEGITIMATE_PIC_OPERAND_P</strong> <em>(<var>x</var>)</em></dt> +<dd><p>A C expression that is nonzero if <var>x</var> is a legitimate immediate +operand on the target machine when generating position independent code. +You can assume that <var>x</var> satisfies <code>CONSTANT_P</code>, so you need not +check this. You can also assume <var>flag_pic</var> is true, so you need not +check it either. You need not define this macro if all constants +(including <code>SYMBOL_REF</code>) can be immediate operands when generating +position independent code. +</p></dd></dl> + +<hr> +<div class="header"> +<p> +Next: <a href="Assembler-Format.html#Assembler-Format" accesskey="n" rel="next">Assembler Format</a>, Previous: <a href="Sections.html#Sections" accesskey="p" rel="previous">Sections</a>, Up: <a href="Target-Macros.html#Target-Macros" accesskey="u" rel="up">Target Macros</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> + + + +</body> +</html> |