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| author | alk3pInjection <webmaster@raspii.tech> | 2024-02-04 16:16:35 +0800 |
|---|---|---|
| committer | alk3pInjection <webmaster@raspii.tech> | 2024-02-04 16:16:35 +0800 |
| commit | abdaadbcae30fe0c9a66c7516798279fdfd97750 (patch) | |
| tree | 00a54a6e25601e43876d03c1a4a12a749d4a914c /share/doc/gccint/RTL-Classes.html | |
https://developer.arm.com/downloads/-/arm-gnu-toolchain-downloads
Change-Id: I7303388733328cd98ab9aa3c30236db67f2e9e9c
Diffstat (limited to 'share/doc/gccint/RTL-Classes.html')
| -rw-r--r-- | share/doc/gccint/RTL-Classes.html | 302 |
1 files changed, 302 insertions, 0 deletions
diff --git a/share/doc/gccint/RTL-Classes.html b/share/doc/gccint/RTL-Classes.html new file mode 100644 index 0000000..006fc67 --- /dev/null +++ b/share/doc/gccint/RTL-Classes.html @@ -0,0 +1,302 @@ +<!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: RTL Classes</title> + +<meta name="description" content="GNU Compiler Collection (GCC) Internals: RTL Classes"> +<meta name="keywords" content="GNU Compiler Collection (GCC) Internals: RTL Classes"> +<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="RTL.html#RTL" rel="up" title="RTL"> +<link href="Accessors.html#Accessors" rel="next" title="Accessors"> +<link href="RTL-Objects.html#RTL-Objects" rel="previous" title="RTL Objects"> +<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="RTL-Classes"></a> +<div class="header"> +<p> +Next: <a href="Accessors.html#Accessors" accesskey="n" rel="next">Accessors</a>, Previous: <a href="RTL-Objects.html#RTL-Objects" accesskey="p" rel="previous">RTL Objects</a>, Up: <a href="RTL.html#RTL" accesskey="u" rel="up">RTL</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="RTL-Classes-and-Formats"></a> +<h3 class="section">14.2 RTL Classes and Formats</h3> +<a name="index-RTL-classes"></a> +<a name="index-classes-of-RTX-codes"></a> +<a name="index-RTX-codes_002c-classes-of"></a> +<a name="index-GET_005fRTX_005fCLASS"></a> + +<p>The various expression codes are divided into several <em>classes</em>, +which are represented by single characters. You can determine the class +of an RTX code with the macro <code>GET_RTX_CLASS (<var>code</var>)</code>. +Currently, <samp>rtl.def</samp> defines these classes: +</p> +<dl compact="compact"> +<dt><code>RTX_OBJ</code></dt> +<dd><p>An RTX code that represents an actual object, such as a register +(<code>REG</code>) or a memory location (<code>MEM</code>, <code>SYMBOL_REF</code>). +<code>LO_SUM</code> is also included; instead, <code>SUBREG</code> and +<code>STRICT_LOW_PART</code> are not in this class, but in class +<code>RTX_EXTRA</code>. +</p> +</dd> +<dt><code>RTX_CONST_OBJ</code></dt> +<dd><p>An RTX code that represents a constant object. <code>HIGH</code> is also +included in this class. +</p> +</dd> +<dt><code>RTX_COMPARE</code></dt> +<dd><p>An RTX code for a non-symmetric comparison, such as <code>GEU</code> or +<code>LT</code>. +</p> +</dd> +<dt><code>RTX_COMM_COMPARE</code></dt> +<dd><p>An RTX code for a symmetric (commutative) comparison, such as <code>EQ</code> +or <code>ORDERED</code>. +</p> +</dd> +<dt><code>RTX_UNARY</code></dt> +<dd><p>An RTX code for a unary arithmetic operation, such as <code>NEG</code>, +<code>NOT</code>, or <code>ABS</code>. This category also includes value extension +(sign or zero) and conversions between integer and floating point. +</p> +</dd> +<dt><code>RTX_COMM_ARITH</code></dt> +<dd><p>An RTX code for a commutative binary operation, such as <code>PLUS</code> or +<code>AND</code>. <code>NE</code> and <code>EQ</code> are comparisons, so they have class +<code>RTX_COMM_COMPARE</code>. +</p> +</dd> +<dt><code>RTX_BIN_ARITH</code></dt> +<dd><p>An RTX code for a non-commutative binary operation, such as <code>MINUS</code>, +<code>DIV</code>, or <code>ASHIFTRT</code>. +</p> +</dd> +<dt><code>RTX_BITFIELD_OPS</code></dt> +<dd><p>An RTX code for a bit-field operation. Currently only +<code>ZERO_EXTRACT</code> and <code>SIGN_EXTRACT</code>. These have three inputs +and are lvalues (so they can be used for insertion as well). +See <a href="Bit_002dFields.html#Bit_002dFields">Bit-Fields</a>. +</p> +</dd> +<dt><code>RTX_TERNARY</code></dt> +<dd><p>An RTX code for other three input operations. Currently only +<code>IF_THEN_ELSE</code>, <code>VEC_MERGE</code>, <code>SIGN_EXTRACT</code>, +<code>ZERO_EXTRACT</code>, and <code>FMA</code>. +</p> +</dd> +<dt><code>RTX_INSN</code></dt> +<dd><p>An RTX code for an entire instruction: <code>INSN</code>, <code>JUMP_INSN</code>, and +<code>CALL_INSN</code>. See <a href="Insns.html#Insns">Insns</a>. +</p> +</dd> +<dt><code>RTX_MATCH</code></dt> +<dd><p>An RTX code for something that matches in insns, such as +<code>MATCH_DUP</code>. These only occur in machine descriptions. +</p> +</dd> +<dt><code>RTX_AUTOINC</code></dt> +<dd><p>An RTX code for an auto-increment addressing mode, such as +<code>POST_INC</code>. ‘<samp>XEXP (<var>x</var>, 0)</samp>’ gives the auto-modified +register. +</p> +</dd> +<dt><code>RTX_EXTRA</code></dt> +<dd><p>All other RTX codes. This category includes the remaining codes used +only in machine descriptions (<code>DEFINE_*</code>, etc.). It also includes +all the codes describing side effects (<code>SET</code>, <code>USE</code>, +<code>CLOBBER</code>, etc.) and the non-insns that may appear on an insn +chain, such as <code>NOTE</code>, <code>BARRIER</code>, and <code>CODE_LABEL</code>. +<code>SUBREG</code> is also part of this class. +</p></dd> +</dl> + +<a name="index-RTL-format"></a> +<p>For each expression code, <samp>rtl.def</samp> specifies the number of +contained objects and their kinds using a sequence of characters +called the <em>format</em> of the expression code. For example, +the format of <code>subreg</code> is ‘<samp>ep</samp>’. +</p> +<a name="index-RTL-format-characters"></a> +<p>These are the most commonly used format characters: +</p> +<dl compact="compact"> +<dt><code>e</code></dt> +<dd><p>An expression (actually a pointer to an expression). +</p> +</dd> +<dt><code>i</code></dt> +<dd><p>An integer. +</p> +</dd> +<dt><code>w</code></dt> +<dd><p>A wide integer. +</p> +</dd> +<dt><code>s</code></dt> +<dd><p>A string. +</p> +</dd> +<dt><code>E</code></dt> +<dd><p>A vector of expressions. +</p></dd> +</dl> + +<p>A few other format characters are used occasionally: +</p> +<dl compact="compact"> +<dt><code>u</code></dt> +<dd><p>‘<samp>u</samp>’ is equivalent to ‘<samp>e</samp>’ except that it is printed differently +in debugging dumps. It is used for pointers to insns. +</p> +</dd> +<dt><code>n</code></dt> +<dd><p>‘<samp>n</samp>’ is equivalent to ‘<samp>i</samp>’ except that it is printed differently +in debugging dumps. It is used for the line number or code number of a +<code>note</code> insn. +</p> +</dd> +<dt><code>S</code></dt> +<dd><p>‘<samp>S</samp>’ indicates a string which is optional. In the RTL objects in +core, ‘<samp>S</samp>’ is equivalent to ‘<samp>s</samp>’, but when the object is read, +from an ‘<samp>md</samp>’ file, the string value of this operand may be omitted. +An omitted string is taken to be the null string. +</p> +</dd> +<dt><code>V</code></dt> +<dd><p>‘<samp>V</samp>’ indicates a vector which is optional. In the RTL objects in +core, ‘<samp>V</samp>’ is equivalent to ‘<samp>E</samp>’, but when the object is read +from an ‘<samp>md</samp>’ file, the vector value of this operand may be omitted. +An omitted vector is effectively the same as a vector of no elements. +</p> +</dd> +<dt><code>B</code></dt> +<dd><p>‘<samp>B</samp>’ indicates a pointer to basic block structure. +</p> +</dd> +<dt><code>p</code></dt> +<dd><p>A polynomial integer. At present this is used only for <code>SUBREG_BYTE</code>. +</p> +</dd> +<dt><code>0</code></dt> +<dd><p>‘<samp>0</samp>’ means a slot whose contents do not fit any normal category. +‘<samp>0</samp>’ slots are not printed at all in dumps, and are often used in +special ways by small parts of the compiler. +</p></dd> +</dl> + +<p>There are macros to get the number of operands and the format +of an expression code: +</p> +<dl compact="compact"> +<dd><a name="index-GET_005fRTX_005fLENGTH"></a> +</dd> +<dt><code>GET_RTX_LENGTH (<var>code</var>)</code></dt> +<dd><p>Number of operands of an RTX of code <var>code</var>. +</p> +<a name="index-GET_005fRTX_005fFORMAT"></a> +</dd> +<dt><code>GET_RTX_FORMAT (<var>code</var>)</code></dt> +<dd><p>The format of an RTX of code <var>code</var>, as a C string. +</p></dd> +</dl> + +<p>Some classes of RTX codes always have the same format. For example, it +is safe to assume that all comparison operations have format <code>ee</code>. +</p> +<dl compact="compact"> +<dt><code>RTX_UNARY</code></dt> +<dd><p>All codes of this class have format <code>e</code>. +</p> +</dd> +<dt><code>RTX_BIN_ARITH</code></dt> +<dt><code>RTX_COMM_ARITH</code></dt> +<dt><code>RTX_COMM_COMPARE</code></dt> +<dt><code>RTX_COMPARE</code></dt> +<dd><p>All codes of these classes have format <code>ee</code>. +</p> +</dd> +<dt><code>RTX_BITFIELD_OPS</code></dt> +<dt><code>RTX_TERNARY</code></dt> +<dd><p>All codes of these classes have format <code>eee</code>. +</p> +</dd> +<dt><code>RTX_INSN</code></dt> +<dd><p>All codes of this class have formats that begin with <code>iuueiee</code>. +See <a href="Insns.html#Insns">Insns</a>. Note that not all RTL objects linked onto an insn chain +are of class <code>RTX_INSN</code>. +</p> +</dd> +<dt><code>RTX_CONST_OBJ</code></dt> +<dt><code>RTX_OBJ</code></dt> +<dt><code>RTX_MATCH</code></dt> +<dt><code>RTX_EXTRA</code></dt> +<dd><p>You can make no assumptions about the format of these codes. +</p></dd> +</dl> + +<hr> +<div class="header"> +<p> +Next: <a href="Accessors.html#Accessors" accesskey="n" rel="next">Accessors</a>, Previous: <a href="RTL-Objects.html#RTL-Objects" accesskey="p" rel="previous">RTL Objects</a>, Up: <a href="RTL.html#RTL" accesskey="u" rel="up">RTL</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> |