<!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="Source to the Rust file `libcore/../stdsimd/coresimd/x86/cpuid.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>cpuid.rs.html -- source</title><link rel="stylesheet" type="text/css" href="../../../../../../normalize.css"><link rel="stylesheet" type="text/css" href="../../../../../../rustdoc.css" id="mainThemeStyle"><link rel="stylesheet" type="text/css" href="../../../../../../dark.css"><link rel="stylesheet" type="text/css" href="../../../../../../light.css" id="themeStyle"><script src="../../../../../../storage.js"></script><link rel="shortcut icon" href="https://doc.rust-lang.org/favicon.ico"></head><body class="rustdoc source"><!--[if lte IE 8]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"><div class="sidebar-menu">☰</div><a href='../../../../../../core/index.html'><img src='https://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png' alt='logo' width='100'></a></nav><div class="theme-picker"><button id="theme-picker" aria-label="Pick another theme!"><img src="../../../../../../brush.svg" width="18" alt="Pick another theme!"></button><div id="theme-choices"></div></div><script src="../../../../../../theme.js"></script><nav class="sub"><form class="search-form js-only"><div class="search-container"><input class="search-input" name="search" autocomplete="off" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"><a id="settings-menu" href="../../../../../../settings.html"><img src="../../../../../../wheel.svg" width="18" alt="Change settings"></a></div></form></nav><section id="main" class="content"><pre class="line-numbers"><span id="1"> 1</span> <span id="2"> 2</span> <span id="3"> 3</span> <span id="4"> 4</span> <span id="5"> 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<span id="125">125</span> <span id="126">126</span> <span id="127">127</span> <span id="128">128</span> <span id="129">129</span> <span id="130">130</span> <span id="131">131</span> <span id="132">132</span> <span id="133">133</span> <span id="134">134</span> <span id="135">135</span> <span id="136">136</span> <span id="137">137</span> <span id="138">138</span> <span id="139">139</span> <span id="140">140</span> <span id="141">141</span> <span id="142">142</span> <span id="143">143</span> <span id="144">144</span> <span id="145">145</span> <span id="146">146</span> <span id="147">147</span> <span id="148">148</span> <span id="149">149</span> <span id="150">150</span> <span id="151">151</span> <span id="152">152</span> <span id="153">153</span> <span id="154">154</span> </pre><pre class="rust "> <span class="doccomment">//! `cpuid` intrinsics</span> <span class="attribute">#![<span class="ident">cfg_attr</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"cargo-clippy"</span>, <span class="ident">allow</span>(<span class="ident">stutter</span>))]</span> <span class="kw">use</span> <span class="ident">mem</span>; <span class="attribute">#[<span class="ident">cfg</span>(<span class="ident">test</span>)]</span> <span class="kw">use</span> <span class="ident">stdsimd_test</span>::<span class="ident">assert_instr</span>; <span class="doccomment">/// Result of the `cpuid` instruction.</span> <span class="attribute">#[<span class="ident">derive</span>(<span class="ident">Copy</span>, <span class="ident">Clone</span>, <span class="ident">Eq</span>, <span class="ident">Ord</span>, <span class="ident">PartialEq</span>, <span class="ident">PartialOrd</span>)]</span> <span class="attribute">#[<span class="ident">cfg_attr</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"cargo-clippy"</span>, <span class="ident">allow</span>(<span class="ident">stutter</span>))]</span> <span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"simd_x86"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.27.0"</span>)]</span> <span class="kw">pub</span> <span class="kw">struct</span> <span class="ident">CpuidResult</span> { <span class="doccomment">/// EAX register.</span> <span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"simd_x86"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.27.0"</span>)]</span> <span class="kw">pub</span> <span class="ident">eax</span>: <span class="ident">u32</span>, <span class="doccomment">/// EBX register.</span> <span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"simd_x86"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.27.0"</span>)]</span> <span class="kw">pub</span> <span class="ident">ebx</span>: <span class="ident">u32</span>, <span class="doccomment">/// ECX register.</span> <span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"simd_x86"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.27.0"</span>)]</span> <span class="kw">pub</span> <span class="ident">ecx</span>: <span class="ident">u32</span>, <span class="doccomment">/// EDX register.</span> <span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"simd_x86"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.27.0"</span>)]</span> <span class="kw">pub</span> <span class="ident">edx</span>: <span class="ident">u32</span>, } <span class="doccomment">/// Returns the result of the `cpuid` instruction for a given `leaf` (`EAX`)</span> <span class="doccomment">/// and</span> <span class="doccomment">/// `sub_leaf` (`ECX`).</span> <span class="doccomment">///</span> <span class="doccomment">/// The highest-supported leaf value is returned by the first tuple argument of</span> <span class="doccomment">/// [`__get_cpuid_max(0)`](fn.__get_cpuid_max.html). For leaves containung</span> <span class="doccomment">/// sub-leaves, the second tuple argument returns the highest-supported</span> <span class="doccomment">/// sub-leaf</span> <span class="doccomment">/// value.</span> <span class="doccomment">///</span> <span class="doccomment">/// The [CPUID Wikipedia page][wiki_cpuid] contains how to query which</span> <span class="doccomment">/// information using the `EAX` and `ECX` registers, and the interpretation of</span> <span class="doccomment">/// the results returned in `EAX`, `EBX`, `ECX`, and `EDX`.</span> <span class="doccomment">///</span> <span class="doccomment">/// The references are:</span> <span class="doccomment">/// - [Intel 64 and IA-32 Architectures Software Developer's Manual Volume 2:</span> <span class="doccomment">/// Instruction Set Reference, A-Z][intel64_ref].</span> <span class="doccomment">/// - [AMD64 Architecture Programmer's Manual, Volume 3: General-Purpose and</span> <span class="doccomment">/// System Instructions][amd64_ref].</span> <span class="doccomment">///</span> <span class="doccomment">/// [wiki_cpuid]: https://en.wikipedia.org/wiki/CPUID</span> <span class="doccomment">/// [intel64_ref]: http://www.intel.de/content/dam/www/public/us/en/documents/manuals/64-ia-32-architectures-software-developer-instruction-set-reference-manual-325383.pdf</span> <span class="doccomment">/// [amd64_ref]: http://support.amd.com/TechDocs/24594.pdf</span> <span class="attribute">#[<span class="ident">inline</span>]</span> <span class="attribute">#[<span class="ident">cfg_attr</span>(<span class="ident">test</span>, <span class="ident">assert_instr</span>(<span class="ident">cpuid</span>))]</span> <span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"simd_x86"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.27.0"</span>)]</span> <span class="kw">pub</span> <span class="kw">unsafe</span> <span class="kw">fn</span> <span class="ident">__cpuid_count</span>(<span class="ident">leaf</span>: <span class="ident">u32</span>, <span class="ident">sub_leaf</span>: <span class="ident">u32</span>) <span class="op">-></span> <span class="ident">CpuidResult</span> { <span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">r</span> <span class="op">=</span> <span class="ident">mem</span>::<span class="ident">uninitialized</span>::<span class="op"><</span><span class="ident">CpuidResult</span><span class="op">></span>(); <span class="kw">if</span> <span class="macro">cfg</span><span class="macro">!</span>(<span class="ident">target_arch</span> <span class="op">=</span> <span class="string">"x86"</span>) { <span class="macro">asm</span><span class="macro">!</span>(<span class="string">"cpuid"</span> : <span class="string">"={eax}"</span>(<span class="ident">r</span>.<span class="ident">eax</span>), <span class="string">"={ebx}"</span>(<span class="ident">r</span>.<span class="ident">ebx</span>), <span class="string">"={ecx}"</span>(<span class="ident">r</span>.<span class="ident">ecx</span>), <span class="string">"={edx}"</span>(<span class="ident">r</span>.<span class="ident">edx</span>) : <span class="string">"{eax}"</span>(<span class="ident">leaf</span>), <span class="string">"{ecx}"</span>(<span class="ident">sub_leaf</span>) : :); } <span class="kw">else</span> { <span class="comment">// x86-64 uses %rbx as the base register, so preserve it.</span> <span class="macro">asm</span><span class="macro">!</span>(<span class="string">"cpuid\n"</span> : <span class="string">"={eax}"</span>(<span class="ident">r</span>.<span class="ident">eax</span>), <span class="string">"={ebx}"</span>(<span class="ident">r</span>.<span class="ident">ebx</span>), <span class="string">"={ecx}"</span>(<span class="ident">r</span>.<span class="ident">ecx</span>), <span class="string">"={edx}"</span>(<span class="ident">r</span>.<span class="ident">edx</span>) : <span class="string">"{eax}"</span>(<span class="ident">leaf</span>), <span class="string">"{ecx}"</span>(<span class="ident">sub_leaf</span>) : <span class="string">"rbx"</span> :); } <span class="ident">r</span> } <span class="doccomment">/// See [`__cpuid_count`](fn.__cpuid_count.html).</span> <span class="attribute">#[<span class="ident">inline</span>]</span> <span class="attribute">#[<span class="ident">cfg_attr</span>(<span class="ident">test</span>, <span class="ident">assert_instr</span>(<span class="ident">cpuid</span>))]</span> <span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"simd_x86"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.27.0"</span>)]</span> <span class="kw">pub</span> <span class="kw">unsafe</span> <span class="kw">fn</span> <span class="ident">__cpuid</span>(<span class="ident">leaf</span>: <span class="ident">u32</span>) <span class="op">-></span> <span class="ident">CpuidResult</span> { <span class="ident">__cpuid_count</span>(<span class="ident">leaf</span>, <span class="number">0</span>) } <span class="doccomment">/// Does the host support the `cpuid` instruction?</span> <span class="attribute">#[<span class="ident">inline</span>]</span> <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">has_cpuid</span>() <span class="op">-></span> <span class="ident">bool</span> { <span class="attribute">#[<span class="ident">cfg</span>(<span class="ident">target_arch</span> <span class="op">=</span> <span class="string">"x86_64"</span>)]</span> { <span class="bool-val">true</span> } <span class="attribute">#[<span class="ident">cfg</span>(<span class="ident">target_arch</span> <span class="op">=</span> <span class="string">"x86"</span>)]</span> { <span class="kw">use</span> <span class="ident">coresimd</span>::<span class="ident">x86</span>::{<span class="ident">__readeflags</span>, <span class="ident">__writeeflags</span>}; <span class="comment">// On `x86` the `cpuid` instruction is not always available.</span> <span class="comment">// This follows the approach indicated in:</span> <span class="comment">// http://wiki.osdev.org/CPUID#Checking_CPUID_availability</span> <span class="kw">unsafe</span> { <span class="comment">// Read EFLAGS:</span> <span class="kw">let</span> <span class="ident">eflags</span>: <span class="ident">u32</span> <span class="op">=</span> <span class="ident">__readeflags</span>(); <span class="comment">// Invert the ID bit in EFLAGS:</span> <span class="kw">let</span> <span class="ident">eflags_mod</span>: <span class="ident">u32</span> <span class="op">=</span> <span class="ident">eflags</span> <span class="op">|</span> <span class="number">0x0020_0000</span>; <span class="comment">// Store the modified EFLAGS (ID bit may or may not be inverted)</span> <span class="ident">__writeeflags</span>(<span class="ident">eflags_mod</span>); <span class="comment">// Read EFLAGS again:</span> <span class="kw">let</span> <span class="ident">eflags_after</span>: <span class="ident">u32</span> <span class="op">=</span> <span class="ident">__readeflags</span>(); <span class="comment">// Check if the ID bit changed:</span> <span class="ident">eflags_after</span> <span class="op">!=</span> <span class="ident">eflags</span> } } } <span class="doccomment">/// Returns the highest-supported `leaf` (`EAX`) and sub-leaf (`ECX`) `cpuid`</span> <span class="doccomment">/// values.</span> <span class="doccomment">///</span> <span class="doccomment">/// If `cpuid` is supported, and `leaf` is zero, then the first tuple argument</span> <span class="doccomment">/// contains the highest `leaf` value that `cpuid` supports. For `leaf`s</span> <span class="doccomment">/// containing sub-leafs, the second tuple argument contains the</span> <span class="doccomment">/// highest-supported sub-leaf value.</span> <span class="doccomment">///</span> <span class="doccomment">/// See also [`__cpuid`](fn.__cpuid.html) and</span> <span class="doccomment">/// [`__cpuid_count`](fn.__cpuid_count.html).</span> <span class="attribute">#[<span class="ident">inline</span>]</span> <span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"simd_x86"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.27.0"</span>)]</span> <span class="kw">pub</span> <span class="kw">unsafe</span> <span class="kw">fn</span> <span class="ident">__get_cpuid_max</span>(<span class="ident">leaf</span>: <span class="ident">u32</span>) <span class="op">-></span> (<span class="ident">u32</span>, <span class="ident">u32</span>) { <span class="kw">let</span> <span class="ident">CpuidResult</span> { <span class="ident">eax</span>, <span class="ident">ebx</span>, .. } <span class="op">=</span> <span class="ident">__cpuid</span>(<span class="ident">leaf</span>); (<span class="ident">eax</span>, <span class="ident">ebx</span>) } <span class="attribute">#[<span class="ident">cfg</span>(<span class="ident">test</span>)]</span> <span class="kw">mod</span> <span class="ident">tests</span> { <span class="kw">use</span> <span class="ident">coresimd</span>::<span class="ident">x86</span>::<span class="kw-2">*</span>; <span class="attribute">#[<span class="ident">test</span>]</span> <span class="kw">fn</span> <span class="ident">test_always_has_cpuid</span>() { <span class="comment">// all currently-tested targets have the instruction</span> <span class="comment">// FIXME: add targets without `cpuid` to CI</span> <span class="macro">assert</span><span class="macro">!</span>(<span class="ident">cpuid</span>::<span class="ident">has_cpuid</span>()); } <span class="attribute">#[<span class="ident">cfg</span>(<span class="ident">target_arch</span> <span class="op">=</span> <span class="string">"x86"</span>)]</span> <span class="attribute">#[<span class="ident">test</span>]</span> <span class="kw">fn</span> <span class="ident">test_has_cpuid</span>() { <span class="kw">unsafe</span> { <span class="kw">let</span> <span class="ident">before</span> <span class="op">=</span> <span class="ident">__readeflags</span>(); <span class="kw">if</span> <span class="ident">cpuid</span>::<span class="ident">has_cpuid</span>() { <span class="macro">assert</span><span class="macro">!</span>(<span class="ident">before</span> <span class="op">!=</span> <span class="ident">__readeflags</span>()); } <span class="kw">else</span> { <span class="macro">assert</span><span class="macro">!</span>(<span class="ident">before</span> <span class="op">==</span> <span class="ident">__readeflags</span>()); } } } } </pre> </section><section id="search" class="content hidden"></section><section class="footer"></section><aside id="help" class="hidden"><div><h1 class="hidden">Help</h1><div class="shortcuts"><h2>Keyboard Shortcuts</h2><dl><dt><kbd>?</kbd></dt><dd>Show this help dialog</dd><dt><kbd>S</kbd></dt><dd>Focus the search field</dd><dt><kbd>↑</kbd></dt><dd>Move up in search results</dd><dt><kbd>↓</kbd></dt><dd>Move down in search results</dd><dt><kbd>↹</kbd></dt><dd>Switch tab</dd><dt><kbd>⏎</kbd></dt><dd>Go to active search result</dd><dt><kbd>+</kbd></dt><dd>Expand all sections</dd><dt><kbd>-</kbd></dt><dd>Collapse all sections</dd></dl></div><div class="infos"><h2>Search Tricks</h2><p>Prefix searches with a type followed by a colon (e.g. <code>fn:</code>) to restrict the search to a given type.</p><p>Accepted types are: <code>fn</code>, <code>mod</code>, <code>struct</code>, <code>enum</code>, <code>trait</code>, <code>type</code>, <code>macro</code>, and <code>const</code>.</p><p>Search functions by type signature (e.g. <code>vec -> usize</code> or <code>* -> vec</code>)</p><p>Search multiple things at once by splitting your query with comma (e.g. <code>str,u8</code> or <code>String,struct:Vec,test</code>)</p></div></div></aside><script>window.rootPath = "../../../../../../";window.currentCrate = "core";</script><script src="../../../../../../aliases.js"></script><script src="../../../../../../main.js"></script><script defer src="../../../../../../search-index.js"></script></body></html>