142 lines
9.1 KiB
HTML
142 lines
9.1 KiB
HTML
<!DOCTYPE html>
|
|
<html lang="zh" dir="ltr" class="client-nojs" xmlns="http://www.w3.org/1999/xhtml" xml:lang="zh">
|
|
<head><meta http-equiv="x-ua-compatible" content="ie=edge">
|
|
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
|
|
<title>std::experimental::simd_abi::deduce</title>
|
|
<link rel="stylesheet" href="ext.css" />
|
|
<link rel="stylesheet" href="site_modules.css" />
|
|
</head>
|
|
<body class="mediawiki ltr sitedir-ltr ns-0 ns-subject page-cpp_experimental_simd_deduce skin-cppreference2 action-view cpp-navbar">
|
|
<div id="cpp-content-base">
|
|
<div id="content"><a id="top"></a>
|
|
<h1 id="firstHeading" class="firstHeading"><span style="font-size:0.7em; line-height:130%">std::experimental::simd_abi::</span>deduce</h1>
|
|
<div id="bodyContent">
|
|
<div id="contentSub"><span class="subpages">< <a href="cpp.html">cpp</a>‎ | <a href="cpp-experimental.html">experimental</a>‎ | <a href="cpp-experimental-simd.html">simd</a></span></div>
|
|
<div id="mw-content-text" lang="zh" dir="ltr" class="mw-content-ltr" xml:lang="zh">
|
|
<table class="t-dcl-begin">
|
|
<tbody>
|
|
<tr class="t-dsc-header">
|
|
<td>
|
|
<div>定义于头文件 <code><a href="https://zh.cppreference.com/mwiki/index.php?title=cpp/header/experimental/simd&action=edit&redlink=1" class="new" title="cpp/header/experimental/simd（页面不存在）"><experimental/simd></a></code></div>
|
|
</td>
|
|
<td></td>
|
|
<td></td>
|
|
</tr>
|
|
<tr class="t-dcl t-since-parallelism_ts_2">
|
|
<td>
|
|
<div><span class="mw-geshi cpp source-cpp"><span class="kw1">template</span> <span class="sy1"><</span> <span class="kw1">class</span> T, <a href="cpp-types-size_t.html"><span class="kw100">std::<span class="me2">size_t</span></span></a> N, <span class="kw1">class</span> ...<span class="me1">Abis</span> <span class="sy1">></span><br />
|
|
<span class="kw1">struct</span> deduce<span class="sy4">;</span></span></div>
|
|
</td>
|
|
<td class="t-dcl-nopad"></td>
|
|
<td><span class="t-mark-rev t-since-parallelism-ts-2 t-mark-ts">(并行 TS v2)</span></td>
|
|
</tr>
|
|
<tr class="t-dcl-sep">
|
|
<td></td>
|
|
<td></td>
|
|
<td></td>
|
|
</tr>
|
|
</tbody>
|
|
</table>
|
|
<p>类型 <span class="t-c"><span class="mw-geshi cpp source-cpp">deduce<span class="sy1"><</span>T, N, Abis...<span class="sy1">></span><span class="sy4">::</span><span class="me2">type</span></span></span> 当且仅当符合下列条件才存在：</p>
|
|
<ul>
|
|
<li><span class="t-c"><span class="mw-geshi cpp source-cpp">T</span></span> 是可向量化的类型，且</li>
|
|
<li><span class="t-c"><span class="mw-geshi cpp source-cpp">simd_abi<span class="sy4">::</span><span class="me2">fixed_size</span><span class="sy1"><</span>N<span class="sy1">></span></span></span> 得到支持，且</li>
|
|
<li><span class="t-c"><span class="mw-geshi cpp source-cpp">Abis...</span></span> 中的每个元素均为 ABI 标签</li>
|
|
</ul>
|
|
<p>当 <span class="t-c"><span class="mw-geshi cpp source-cpp">deduce<span class="sy1"><</span>T, N, Abis...<span class="sy1">></span><span class="sy4">::</span><span class="me2">type</span></span></span> 存在时以 <code>DA</code> 指代它，则</p>
|
|
<ul>
|
|
<li><span class="t-c"><span class="mw-geshi cpp source-cpp">simd_size_v<span class="sy1"><</span>T, DA<span class="sy1">></span> <span class="sy1">==</span> N</span></span></li>
|
|
<li><span class="t-c"><span class="mw-geshi cpp source-cpp">simd<span class="sy1"><</span>T, DA<span class="sy1">></span></span></span> 可默认构造，即它受支持</li>
|
|
<li>若 <span class="t-c"><span class="mw-geshi cpp source-cpp">N<span class="sy1">==</span><span class="nu0">1</span></span></span> 则 <code>DA</code> 为 <a href="cpp-experimental-simd-scalar.html"><code>simd_abi::scalar</code></a> ，否则它是实现定义的</li>
|
|
</ul>
|
|
<h3><span class="mw-headline" id=".E6.88.90.E5.91.98.E7.B1.BB.E5.9E.8B">成员类型</span></h3>
|
|
<table class="t-dsc-begin">
|
|
<tr class="t-dsc-hitem">
|
|
<td>名字</td>
|
|
<td>定义</td>
|
|
</tr>
|
|
<tr class="t-dsc">
|
|
<td><code>type</code></td>
|
|
<td>适合给定元素类型 <code>T</code> 和大小 <code>N</code> 的 ABI 标签类型</td>
|
|
</tr>
|
|
</table>
|
|
<h3><span class="mw-headline" id=".E8.BE.85.E5.8A.A9.E7.B1.BB.E5.9E.8B">辅助类型</span></h3>
|
|
<table class="t-dcl-begin">
|
|
<tbody>
|
|
<tr class="t-dcl t-since-parallelism_ts_2">
|
|
<td>
|
|
<div><span class="mw-geshi cpp source-cpp"><span class="kw1">template</span> <span class="sy1"><</span> <span class="kw1">class</span> T, <a href="cpp-types-size_t.html"><span class="kw100">std::<span class="me2">size_t</span></span></a> N, <span class="kw1">class</span> ...<span class="me1">Abis</span> <span class="sy1">></span><br />
|
|
<span class="kw1">using</span> deduce_t <span class="sy1">=</span> <span class="kw1">typename</span> deduce<span class="sy1"><</span>T, N, Abis...<span class="sy1">></span><span class="sy4">::</span><span class="me2">type</span><span class="sy4">;</span></span></div>
|
|
</td>
|
|
<td class="t-dcl-nopad"></td>
|
|
<td><span class="t-mark-rev t-since-parallelism-ts-2 t-mark-ts">(并行 TS v2)</span></td>
|
|
</tr>
|
|
<tr class="t-dcl-sep">
|
|
<td></td>
|
|
<td></td>
|
|
<td></td>
|
|
</tr>
|
|
</tbody>
|
|
</table>
|
|
<h3><span class="mw-headline" id=".E6.B3.A8.E8.A7.A3">注解</span></h3>
|
|
<p><code>simd_abi::deduce</code> 对 SFINAE 友好。</p>
|
|
<p>通过此设施推导的 ABI 标签是实现质量特性。简单的实现可以简单地返回 <span class="t-c"><span class="mw-geshi cpp source-cpp">fixed_size<span class="sy1"><</span>N<span class="sy1">></span></span></span> 。优化的实现可以对大多数输入返回实现定义的扩展 ABI 标签。从而若你需要给定元素数的 ABI 标签，就使用 <a href="cpp-experimental-simd-fixed_size.html"><code>fixed_size</code></a> ，否则更应该用 <code>deduce_t</code> 。</p>
|
|
<h3><span class="mw-headline" id=".E7.A4.BA.E4.BE.8B">示例</span></h3>
|
|
<table class="metadata plainlinks ambox mbox-small-left ambox-notice" style="">
|
|
<tr>
|
|
<td class="mbox-empty-cell"></td>
|
|
<td class="mbox-text" style="">本节未完成<br />
|
|
原因：暂无示例</td>
|
|
</tr>
|
|
</table>
|
|
<h3><span class="mw-headline" id=".E5.8F.82.E9.98.85">参阅</span></h3>
|
|
<table class="t-dsc-begin">
|
|
<tr class="t-dsc">
|
|
<td>
|
|
<div class="t-dsc-member-div">
|
|
<div><a href="cpp-experimental-simd-scalar.html"><span class="t-lines"><span>scalar</span></span></a></div>
|
|
<div><span class="t-lines"><span><span class="t-mark-rev t-since-parallelism-ts-2 t-mark-ts">(并行 TS v2)</span></span></span></div>
|
|
</div>
|
|
</td>
|
|
<td>存储单个元素的标签类型<br />
|
|
<span class="t-mark">(typedef)</span></td>
|
|
</tr>
|
|
<tr class="t-dsc">
|
|
<td>
|
|
<div class="t-dsc-member-div">
|
|
<div><a href="cpp-experimental-simd-fixed_size.html"><span class="t-lines"><span>fixed_size</span></span></a></div>
|
|
<div><span class="t-lines"><span><span class="t-mark-rev t-since-parallelism-ts-2 t-mark-ts">(并行 TS v2)</span></span></span></div>
|
|
</div>
|
|
</td>
|
|
<td>存储指定数量元素的标签类型<br />
|
|
<span class="t-mark">(别名模板)</span></td>
|
|
</tr>
|
|
<tr class="t-dsc">
|
|
<td>
|
|
<div class="t-dsc-member-div">
|
|
<div><a href="cpp-experimental-simd-compatible.html"><span class="t-lines"><span>compatible</span></span></a></div>
|
|
<div><span class="t-lines"><span><span class="t-mark-rev t-since-parallelism-ts-2 t-mark-ts">(并行 TS v2)</span></span></span></div>
|
|
</div>
|
|
</td>
|
|
<td>确保 ABI 兼容性的标签类型<br />
|
|
<span class="t-mark">(别名模板)</span></td>
|
|
</tr>
|
|
<tr class="t-dsc">
|
|
<td>
|
|
<div class="t-dsc-member-div">
|
|
<div><a href="cpp-experimental-simd-native.html"><span class="t-lines"><span>native</span></span></a></div>
|
|
<div><span class="t-lines"><span><span class="t-mark-rev t-since-parallelism-ts-2 t-mark-ts">(并行 TS v2)</span></span></span></div>
|
|
</div>
|
|
</td>
|
|
<td>最有效率的标签类型<br />
|
|
<span class="t-mark">(别名模板)</span></td>
|
|
</tr>
|
|
</table>
|
|
</div>
|
|
<div class="visualClear"></div>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
</body>
|
|
</html>
|