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| author | alk3pInjection <webmaster@raspii.tech> | 2024-02-04 16:16:35 +0800 |
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| committer | alk3pInjection <webmaster@raspii.tech> | 2024-02-04 16:16:35 +0800 |
| commit | abdaadbcae30fe0c9a66c7516798279fdfd97750 (patch) | |
| tree | 00a54a6e25601e43876d03c1a4a12a749d4a914c /share/doc/gccint/Int-Iterators.html | |
https://developer.arm.com/downloads/-/arm-gnu-toolchain-downloads
Change-Id: I7303388733328cd98ab9aa3c30236db67f2e9e9c
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diff --git a/share/doc/gccint/Int-Iterators.html b/share/doc/gccint/Int-Iterators.html new file mode 100644 index 0000000..8585acd --- /dev/null +++ b/share/doc/gccint/Int-Iterators.html @@ -0,0 +1,163 @@ +<!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: Int Iterators</title> + +<meta name="description" content="GNU Compiler Collection (GCC) Internals: Int Iterators"> +<meta name="keywords" content="GNU Compiler Collection (GCC) Internals: Int Iterators"> +<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="Iterators.html#Iterators" rel="up" title="Iterators"> +<link href="Subst-Iterators.html#Subst-Iterators" rel="next" title="Subst Iterators"> +<link href="Code-Iterators.html#Code-Iterators" rel="previous" title="Code Iterators"> +<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="Int-Iterators"></a> +<div class="header"> +<p> +Next: <a href="Subst-Iterators.html#Subst-Iterators" accesskey="n" rel="next">Subst Iterators</a>, Previous: <a href="Code-Iterators.html#Code-Iterators" accesskey="p" rel="previous">Code Iterators</a>, Up: <a href="Iterators.html#Iterators" accesskey="u" rel="up">Iterators</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="Int-Iterators-1"></a> +<h4 class="subsection">17.23.3 Int Iterators</h4> +<a name="index-int-iterators-in-_002emd-files"></a> +<a name="index-define_005fint_005fiterator"></a> +<a name="index-define_005fint_005fattr"></a> + +<p>Int iterators operate in a similar way to code iterators. See <a href="Code-Iterators.html#Code-Iterators">Code Iterators</a>. +</p> +<p>The construct: +</p> +<div class="smallexample"> +<pre class="smallexample">(define_int_iterator <var>name</var> [(<var>int1</var> "<var>cond1</var>") … (<var>intn</var> "<var>condn</var>")]) +</pre></div> + +<p>defines a pseudo integer constant <var>name</var> that can be instantiated as +<var>inti</var> if condition <var>condi</var> is true. Each <var>int</var> must have the +same rtx format. See <a href="RTL-Classes.html#RTL-Classes">RTL Classes</a>. Int iterators can appear in only +those rtx fields that have ’i’, ’n’, ’w’, or ’p’ as the specifier. This +means that each <var>int</var> has to be a constant defined using define_constant +or define_c_enum. +</p> +<p>As with mode and code iterators, each pattern that uses <var>name</var> will be +expanded <var>n</var> times, once with all uses of <var>name</var> replaced by +<var>int1</var>, once with all uses replaced by <var>int2</var>, and so on. +See <a href="Defining-Mode-Iterators.html#Defining-Mode-Iterators">Defining Mode Iterators</a>. +</p> +<p>It is possible to define attributes for ints as well as for codes and modes. +Attributes are defined using: +</p> +<div class="smallexample"> +<pre class="smallexample">(define_int_attr <var>name</var> [(<var>int1</var> "<var>value1</var>") … (<var>intn</var> "<var>valuen</var>")]) +</pre></div> + +<p>Here’s an example of int iterators in action, taken from the ARM port: +</p> +<div class="smallexample"> +<pre class="smallexample">(define_int_iterator QABSNEG [UNSPEC_VQABS UNSPEC_VQNEG]) + +(define_int_attr absneg [(UNSPEC_VQABS "abs") (UNSPEC_VQNEG "neg")]) + +(define_insn "neon_vq<absneg><mode>" + [(set (match_operand:VDQIW 0 "s_register_operand" "=w") + (unspec:VDQIW [(match_operand:VDQIW 1 "s_register_operand" "w") + (match_operand:SI 2 "immediate_operand" "i")] + QABSNEG))] + "TARGET_NEON" + "vq<absneg>.<V_s_elem>\t%<V_reg>0, %<V_reg>1" + [(set_attr "type" "neon_vqneg_vqabs")] +) + +</pre></div> + +<p>This is equivalent to: +</p> +<div class="smallexample"> +<pre class="smallexample">(define_insn "neon_vqabs<mode>" + [(set (match_operand:VDQIW 0 "s_register_operand" "=w") + (unspec:VDQIW [(match_operand:VDQIW 1 "s_register_operand" "w") + (match_operand:SI 2 "immediate_operand" "i")] + UNSPEC_VQABS))] + "TARGET_NEON" + "vqabs.<V_s_elem>\t%<V_reg>0, %<V_reg>1" + [(set_attr "type" "neon_vqneg_vqabs")] +) + +(define_insn "neon_vqneg<mode>" + [(set (match_operand:VDQIW 0 "s_register_operand" "=w") + (unspec:VDQIW [(match_operand:VDQIW 1 "s_register_operand" "w") + (match_operand:SI 2 "immediate_operand" "i")] + UNSPEC_VQNEG))] + "TARGET_NEON" + "vqneg.<V_s_elem>\t%<V_reg>0, %<V_reg>1" + [(set_attr "type" "neon_vqneg_vqabs")] +) + +</pre></div> + +<hr> +<div class="header"> +<p> +Next: <a href="Subst-Iterators.html#Subst-Iterators" accesskey="n" rel="next">Subst Iterators</a>, Previous: <a href="Code-Iterators.html#Code-Iterators" accesskey="p" rel="previous">Code Iterators</a>, Up: <a href="Iterators.html#Iterators" accesskey="u" rel="up">Iterators</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> |